Neurological Examination, clinical cases and neuropsychological ...

23/07/54 

415703 Cognitive Neuropsychology 

Week 8: 

Review and Summary: 

Neurological Examination, clinical cases 

and neuropsychological 

interpretation 

etat Naiphinich Kotchabhakdi, Ph.D. 

Director, Salaya Stem Cell R & D Project, 

Research Center for Neuroscience, 

Institute of Molecular Biosciences, 

Mahidol University Salaya Campus, 

999 Phutthamonthol 4 Road, Salaya, Phutthamonthol, 

Nakornpathom 73170 Thailand 

Email: scnkc@mahidol.ac.th or naiphinich@gmail.com 

Web: www.neuroscience.mahidol.ac.th 

Main Objectives: 

1. The Neurological Examination 

2. The Neuropsychological tests 

3. Clinical cases and neuropsychological interpretation 

4. Review and Summary 

4.1 Organization of the nervous system 

4.2 Functional Brain Imaging 

4.3 Sensory–Motor Systems and Cortical Functions 

4.4 Cerebral cortexes and lobe functions: Occipital, 

Parietal, Temporal and Frontal lobes 

A neurological examination is the 

assessment of sensory neuron and motor responses, 

especially reflexes, to determine whether the 

nervous system is impaired. It can be used both as a 

screening tool and as an investigative tool, the 

former of which when examining the patient when 

there is no expected neurological deficit and the 

latter of which when examining a patient where you 

do expect to find abnormalities. If a problem is found 

either in an investigative or screening process then 

further tests can be carried out to focus on a 

particular aspect of the nervous system (such as 

lumbar punctures and blood tests). 

Generally a neurological examination is focused 

towards finding out if there are lesions in the central 

and peripheral nervous systems or whether there is 

another diffuse process which is troubling the 

patient. Once the patient has been thoroughly 

tested, it is then the role of the physician to 

determine whether or not these findings combine to 

form a recognizable medical syndrome such as 

Parkinson's disease or motor neurone disease. 

Finally, it is the role of the physician to find the 

etiological reasons for why such a problem has 

occurred, for example finding if the problem was due 

to inflammation or congenital. 

Patient’s History 

A patient's history is the most important part of a neurological examination and must be 

performed before any other procedures unless impossible (i.e. the patient is unconscious). 

Certain aspects of a patients history will become more important depending upon the 

complaint issued. Important factors to be taken in the medical history include: 

1. Time of onset, duration and associated symptoms (e.g. is the complaint chronic or 

acute) 

2. Age, gender and occupation of the patient 

3. Handedness (right or left handed) 

4. Past medical history 

5. Drug history 

6. Family and social history 

Handedness is important in establishing the area of the brain important for language (as 

almost all right‐handed people have a left hemisphere which is responsible for language). As 

patients answer questions, it is important to gain an idea of the complaint thoroughly and 

understand its time course. Understanding the patient's neurological state at the time of 

questioning is important, and an idea should be obtained of how competent the patient is 

with various tasks and their level of impairment in carrying out these tasks. The interval of a 

complaint is important as it can help aid the diagnosis. For example, vascular disorders occur 

very frequently over minutes and hours, whereas congenital disorders occur over a matter of 

years. 

Carrying out a 'general' examination is just as important as the neurological exam as it may 

lead to clues to the etiology of the complaint. This is shown by cases of cerebral metastases 

where the initial complaint was of a mass in the breast. 

List of tests 

Specific tests in a neurological examination include: 

1. Mental Status Examination 

2. Cranial Nerves Examination 

3. Motor System Examination 

4. Deep tendon Reflexes 

5. Sensory System Examination 

6. Cerebellum Examination (Motor Coordination 

and Gaits) 

7. Higher Brain Functions 

1

23/07/54 

Interpretation 

The results of the examination are taken together to anatomically identify the lesion. This may 

be diffuse (e.g. neuromuscular diseases, encephalopathy) or highly specific (e.g. abnormal 

sensation in one dermatome due to compression of a specific spinal nerve by a tumor deposit). 

A differential diagnosis may then be constructed that takes into account the patient's 

background (e.g. previous cancer, autoimmune diathesis) and present findings to include the 

most likely causes. Examinations are aimed at ruling out the most clinically significant causes 

(even if relatively rare, e.g. brain tumor in a patient with subtle word finding abnormalities but 

no increased intracranial pressure) and ruling in the most likely causes 

Romberg's test or the Romberg maneuver is a 

test used by doctors in a neurological examination, and also as a test 

for drunken driving. The exam is based on the premise that a person 

requires at least two of the three following senses to maintain 

balanced while standing: 

Proprioception (the ability to know one's body in space); Vestibular 

function (the ability to know one's head position in space); and 

Vision (which can be used to monitor [and adjust for] changes in 

body position). 

A patient who has a problem with proprioception can still maintain 

balance by using vestibular function and vision. In the Romberg test, 

the patient is stood up and asked to close his eyes. A loss of balance 

is interpreted as a positive Romberg sign. 

The Romberg test is a test of the body's sense of positioning 

(proprioception), which requires healthy functioning of the dorsal 

columns of the spinal cord, [1] . 

The Romberg test is used to investigate the cause of loss of motor 

coordination (ataxia). A positive Romberg test suggests that the 

ataxia is sensory in nature, that is, depending on loss of 

proprioception. If a patient is ataxic and Romberg's test is not 

positive, it suggests that ataxia is cerebellar in nature, that is, 

depending on localized cerebellar dysfunction instead. 

It is used as an indicator for possible alcohol or drug impaired 

driving and neurological decompression sickness. [2][3] When used to 

test impaired driving, the test is performed with the subject 

estimating 30 seconds in his head. This is used to gauge the subject's 

internal clock and can be an indicator of stimulant or depressant 

use. The test was named after the German neurologist Moritz 

Heinrich Romberg [1] (1795‐1873), who also gave his name to Parry‐ 

Romberg syndrome and Howship‐Romberg sign. 

Procedure for Romberg's test or the Romberg maneuver 

Ask the subject to stand erect with feet together and eyes closed. Stand close by as a 

precaution in order to stop the person from falling over and hurting himself or herself. 

Watch the movement of the body in relation to a perpendicular object behind the 

subject (corner of the room, door, window etc). A positive sign is noted when a swaying, 

sometimes irregular swaying and even toppling over occurs. The essential feature is that 

the patient becomes more unsteady with eyes closed. 

The essential features of the test are as follows: 

1. the subject stands with feet together, eyes open and hands by the sides. 

2. the subject closes the eyes while the examiner observes for a full minute. 

Because the examiner is trying to elicit whether the patient falls when the eyes are 

closed, it is advisable to stand ready to catch the falling patient. For large subjects, a 

strong assistant is recommended. 

Romberg's test is positive if the patient sways or falls while the patient's eyes are closed. 

Patients with a positive result are said to demonstrate Romberg's sign or Rombergism. 

They can also be described as Romberg's positive. The basis of this test is that balance 

comes from the combination of several neurological systems, namely proprioception, 

vestibular input, and vision. If any two of these systems are working the person should be 

able to demonstrate a fair degree of balance. The key to the test is that vision is taken 

away by asking the patient to close their eyes. This leaves only two of the three systems 

remaining and if there is a vestibular disorder (labyrinthine) or a sensory disorder 

(proprioceptive dysfunction) the patient will become much more imbalanced. 

2

23/07/54 

Maintaining balance while standing in the stationary position relies on intact 

sensory pathways, sensorimotor integration centers and motor pathways. 

The main sensory inputs are: 

1. Joint position sense (proprioception), carried in the dorsal columns 

of the spinal cord; 

2. Vision 

3. Vestibular apparatus 

Crucially, the brain can obtain sufficient information to maintain balance if any 

two of the three systems are intact. 

Sensorimotor integration is carried out by the cerebellum and by the dorsal 

column‐medial lemniscus tract. The motor pathway is the corticospinal 

(pyramidal) tract and the medial and lateral vestibular tracts. 

The first stage of the test (standing with the eyes open), demonstrates that at 

least two of the three sensory pathways is intact, and that sensorimotor 

integration and the motor pathway are functioning. 

In the second stage, the visual pathway is removed by closing the eyes, known as 

a "sharpened Romberg". If the proprioceptive and vestibular pathways are intact, 

balance will be maintained. But if proprioception is defective, two of the sensory 

inputs will be absent and the patient will sway then fall. 

The sharpened Romberg does have an early learning effect that will plateau 

between the third and fourth attempts. 

Positive Romberg 

Romberg's test is positive in conditions causing sensory ataxia such as: 

Conditions affecting the dorsal columns of the spinal cord, such as tabes 

dorsalis (neurosyphilis), in which it was first described. 

Conditions affecting the sensory nerves (sensory peripheral neuropathies), such 

as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). 

Friedreich's Ataxia 

Romberg and cerebellar function 

Romberg's test is not a test of cerebellar function, as it is commonly 

misconstrued. Patients with cerebellar ataxia will, generally, be unable to 

balance even with the eyes open; [5] therefore, the test cannot proceed beyond 

the first step and no patient with cerebellar ataxia can correctly be described as 

Romberg's positive. Rather, Romberg's test is a test of the proprioception 

receptors and pathways function. A positive Romberg's test has been shown to 

be 90% sensitive for lumbar spinal stenosis. [ 

Neurological Examination Videos 

And Neurological case examples 

http://library.med.utah.edu/neurologicexam/cases/html_case01/case01_history.html 

A case begins with a Case 

History in which 

preliminary information 

about the patient and any 

signs and symptoms are 

presented. 

The Neurological 

Examination follows the 

Case History. You can choose 

the order and the parts of 

the neurological 

examination that you would 

like to view by clicking on 

the icon that represents that 

part of the exam. 

After completing the exam, you advance to listing your 

abnormal findings. You use the supplied Checklist of 

Findings and compare your choices with that of an 

expert's. You are now ready to begin the process of 

anatomical localization. 

You start to Localize the Level(s) of the Lesion by 

selecting from the level of the neuroaxis. Your 

choices include: 

1. Supratentorial 

2. Infratentorial 

3. Spinal Cord 

4. Peripheral Nerve System 

5. Multiple Levels 

From a list of the structures, you choose the brain 

structure(s) those you think are damaged for the case. 

Your choices are compared to an expert's, and the 

lesion is highlighted on the image. 

You have now arrived at an anatomical diagnosis, the 

first essential step in making a neurological diagnosis. 

Finally, in the Case Discussion, you review the case and 

the thought processes used to reach the diagnosis. 

Neuroimaging studies, if available, are shown as part of 

the case discussion. 

3

23/07/54 

Case No. 01: The Upset Office Manager 

The patient is a 48‐year‐old woman who was in her usual state of 

good health when she experienced nausea and vomiting after being 

emotionally upset. After 3 hours of nausea and vomiting she had the 

sudden onset of numbness of her left arm which progressed to 

include her left leg and the left side of her face. 

She was taken to the Emergency Room. Upon arrival she complained 

that she had double vision especially when she looked to the right. 

When she covered her right eye, the most peripheral image (the 

ghost image) would disappear. She also noticed that when she looked 

in the mirror the right side of her face didn’t move. 

Over the next 2 months, the double vision resolved, but the rest of 

her complaints have persisted 

http://library.med.utah.edu/neurologicexam/cases/html_case01/case01_history.html 

4

23/07/54 

5

23/07/54 

This 48‐year‐old woman had the sudden onset and rapid progression of her symptoms, 

which is the temporal profile of an acute vascular event or a stroke. Risk factors for stroke 

include hypertension, cardiac disease, diabetes mellitus, smoking as well as coagulation and 

autoimmune disorders. This patient had none of these risk factors. 

One of the first steps in localizing the occluded vessel in a stroke is to decide if the vessel is 

in the anterior or posterior arterial circulation of the brain. Most strokes occur in the 

anterior or carotid circulation because most of the brain’s blood supply is supplied by the 

carotids. Although strokes in the posterior or vertebrobasilar circulation are less common, 

this patient’s cranial nerve findings suggest an infarct in the brainstem and not the carotid 

territory. 

By history and examination there are 3 findings that indicate possible cranial nerve 

involvement. Her history of diplopia indicates a right 6th (abducens) cranial nerve deficit 

(remember the most peripheral image is the false image and covering the right eye 

eliminated this image) and by examination she has a right 7th (facial) cranial nerve deficit. To 

explain these two deficits one has to localize the lesion in the caudal pons in the area of the 

6th and 7th cranial nerve nuclei or the pathway of the nerves at this level. 

To explain the sensory findings on the left side of her face, we could postulate either a left 

spinal trigeminal tract lesion or it could be from a lesion affecting the axons of the 2nd order 

neurons which have crossed over to the right side of the pons and are ascending in the 

ventral trigeminothalamic tract. The left spinal trigeminal tract lesion hypothesis is 

unattractive, because it would mean a second lesion. In the pons, the ascending ventral 

trigeminothalamic tract is near the facial nucleus, so a lesion affecting this tract is the likely 

explanation. 

The last finding that we have to account for anatomically is the sensory deficit on 

the left side of the body. We first have to decide if the deficit is from a lesion in the 

DC‐ML system or the spinothalamic (ALS) system. For this patient, pain and 

temperature are affected while vibratory, position sense, and discriminatory 

sensation are preserved, which indicates that the spinothalamic tract is involved 

but the DC‐ML system is spared. Recall that the axons from the second order 

neurons that form the spinothalamic tract cross immediately in the spinal cord and 

ascend in the anterolateral spinal cord and the lateral part of the brainstem. In the 

pons, the spinothalamic tract, carrying pain and temperature for the left side of the 

body, is adjacent to the facial motor nucleus. 

So we could explain all the clinical findings for this case by a lesion in the 

mediolateral part of the right lower pons most likely caused by occlusion of one of 

the short circumferential branches of the basilar artery. It is not a paramedian 

lesion because the patient has no findings referable to the corticospinal tracts and 

the medial lemniscus. It is also not a far lateral lesion because there are no rightsided 

spinal trigeminal tract, vestibular, or cerebellar findings. 

An MRI scan of the patient done 6 months after her stroke shows a small residual 

lesion in the area of the right abducens nucleus. This imaging finding doesn’t cover 

the entire anatomical area where we know there has to be disease, but it does 

support the hypothesis that there has been a small stroke in the area where we 

localized her lesion based on her clinical findings 

Review and Summary: 

6

23/07/54 


Week 1: 

Introduction to Neuropsychology, 

and the Organization of the 

Nervous System. 

Naiphinich Kotchabhakdi, Ph.D. 










1. What is Neuropsychology (for education)? 

2. What are neuropsychological disorders? 

3. New Approaches and tools in neuropsychological 

disorders. 

4. What are neuropsychological py 

assessment? 

5. What is the Organization of the nervous system? 

6. What are the structure and functions of specific 

human brain areas? 

Neuropsychology (Brain and Mind) 

Neuropsychology studies the structure and function of the 

brain related to specific psychological (mental) processes 

and behaviors. 

The term neuropsychology has been applied to lesion studies in humans and 

animals. It has also been applied to efforts to record electrical activity from 

individual cells (or groups of cells) in higher primates (including some studies 

of human patients). It is scientific in its approach and shares an information 

processing view of the mind with cognitive psychology and cognitive 

neuroscience. 

In practice neuropsychologists tend to work in clinical settings (involved 

in assessing or treating patients with neuropsychological problems – 

see clinical neuropsychology), forensic settings or industry (often as 

consultants where neuropsychological knowledge is applied to product design 

or in the management of pharmaceutical clinical-trials research for drugs that 

might have a potential impact on CNS functioning). 

Posner, M.I.& DiGirolamo,G.J.(2000 

2000) Cognitive Neuroscience:Origins 

and Promise,Psychological 

Psychological Bulletin, 126:6, 873‐889 

889 

From Wikipedia, the free encyclopedia 

Divisions of the Nervous System 

Cellular components of the nervous tissue 

7

23/07/54 

Spinal cord 

The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that 

extends from the brain (the medulla oblongata specifically). The brain and spinal cord 

together make up the central nervous system. The spinal cord begins at the Occipital bone 

and extends down to the space between the first and second lumbar vertebrae; itdoes 

not extend the entire length of the vertebral column.Itisaround45cm(18in)inmenand 

around 43 cm (17 in) long in women. Also, the spinal cord has a varying width, ranging 

from 1/2 inch thick in the cervical and lumbar regions to 1/4 inch thick in the thoracic 

area. The enclosing bony vertebral column protects the relatively shorter spinal cord. 

The spinal cord functions primarily in the transmission of neural signals between the brain 

and the rest of the body but also contains ti neural circuits it thatt can independently d control 

numerous reflexes and central pattern generators. The spinal cord has three major 

functions:1.Serve 

as a conduit for motor information, which travels down the spinal cord. 

2.Serve 

as a conduit for sensory information, which travels up the spinal cord. 3. Serve as 

acenter 

for coordinating certain reflexes. 

The spinal cord is the main pathway for information connecting the brain and peripheral 

nervous system. The length of the spinal cord is much shorter than the length of the bony 

spinal column. The human spinal cord extends from the medulla oblongata and continues 

through the conus medullaris near the first lumbar vertebra, terminating in a fibrous 

extension known as the filum terminale 

Spinal cord 

Somatosensory system 

Dermatome 

8

23/07/54 

Autonomic nervous 

nervous system) 

system 

(ANS 

or 

visceral 

system) is the part of the peripheral nervous system that acts 

as a control system functioning largely below the level of consciousness, and 

controls visceral functions. The ANS affects heart rate, digestion, respiration rate, 

salivation, perspiration, diameter of the pupils, micturition (urination), and sexual 

arousal. Whereas most of its actions are involuntary, some, such as breathing, 

work in tandem with the conscious mind. 

It is classically divided into two subsystems: the parasympathetic nervous system 

(PSNS) and sympathetic nervous system (SNS). Relatively recently, a third 

subsystem of neurons that have been named 'non‐adrenergic 

and non‐cholinergic' 

neurons (because they use nitric oxide as a neurotransmitter) have been 

described and found to be integral in autonomic function, particularly in the gut 

and the lungs. 

With regard to function, the ANS is usually divided into sensory (afferent) and 

motor (efferent) subsystems. Within these systems, however, there are inhibitory 

and excitatory synapses between neurons. 

The enteric nervous system is sometimes considered part of the autonomic 

nervous system, and sometimes considered an independent system. 

Autonomic Nervous 

System (ANS) and autonomic reflexes 

Alongside the other two components of the autonomic nervous system, thesympathetic 

nervous system aids in the control of most of the body's internal organs. Stress—as in the 

flight‐or‐fight response—is thought to counteract the parasympathetic system, which 

generally works to promote maintenance of the body at rest. In truth, the functions of 

both the parasympathetic and sympathetic nervous systems are not so straightforward, 

but this is a useful rule of thumb. 

There are two kinds of neurons involved in the transmission of any signal through the 

sympathetic system; pre‐ and post‐ ganglionic. The shorter preganglionic neurons originate 

from the thoracolumbar region of the spinal cord (levels T1 ‐ L2, specifically) and travel to 

a ganglion, often one of the paravertebral ganglia, where they synapse with a 

postganglionic neuron. From there, the long postganglionic neurons extend across most of 

the body. 

At the synapses within the ganglia, preganglionic neurons release acetylcholine, a 

neurotransmitter that activates nicotinic acetylcholine receptors on postganglionic 

neurons. In response to this stimulus postganglionic neurons ‐ with two important 

exceptions ‐ release norepinephrine, which activates adrenergic receptors on the 

peripheral target tissues. The activation of target tissue receptors causes the effects 

associated with the sympathetic system. 

The two exceptions mentioned above are postganglionic neurons innervating sweat 

glands—which release acetylcholine for the activation of muscarinic receptors ‐ and the 

adrenal medulla. The adrenal medulla develops in tandem with the sympathetic nervous 

system, and acts as a modified sympathetic ganglion: synapses occur between pre‐ and 

post‐ ganglionic neurons within it, but the post ganglionic neurons do not leave the 

medulla; instead they directly release norepinephrine and epinephrine into the blood. 

Sympathetic and parasympathetic systems 

Sympathetic nervous system 

Parasympathetic nervous system 

9

23/07/54 

Control of blood 

vessels 

Control of 

pupil 

Brainstem (or brain stem) is the posterior part of the brain, 

adjoining and structurally continuous with the spinal cord. The brain stem 

providesthemainmotorandsensoryinnervationtothefaceandneckviathe 

cranial nerves. Though small, this is an extremely important part of the brain as 

the nerve connections of the motor and sensory systems from the main part of 

the brain to the rest of the body pass through the brain stem. This includes the 

corticospinal tract (motor), the posterior column‐medial lemniscus pathway (fine 

touch, vibration sensation and proprioception)andthespinothalamic tract (pain, 

temperature, itch and crude touch). The brain stem also plays an important role 

in the regulation of cardiac and respiratory function. It also regulates the central 

nervoussystem,andispivotalinmaintaining consciousness and regulating the 

sleep cycle. 

Brainstem is made up of 1. medulla oblongata (myelencephalon), 2. pons (part of 

metencephalon), 3. midbrain (mesencephalon), and 4. diencephalon 

Mid‐sagittal 

view of the 

adult human brain 

There are three main functions of the brain stem: 

1. The first is its role in conduction. That is, all information relayed from the body 

to the cerebrum and cerebellum and vice versa, must traverse the brain stem. 

The ascending pathways coming from the body to the brain are the sensory 

pathways, and include the spinothalamic tract for pain and temperature 

sensation and the dorsal column, fasciculus gracilis, and cuneatus for touch, 

proprioception, and pressure sensation (both of the body). (The facial sensations 

have simiar pathways, and will travel in the spinothalamic tract and the medial 

lemniscus also). Descending tracts are upper motor neurons destined to synapse 

on lower motor neurons in the ventral horn and intermediate horn of the spinal 

cord. In addition, there are upper motor neurons that originate in the brain 

stem's vestibular, red, tectal, and reticular nuclei, which also descend and synapse 

in the spinal cord. 

2. The cranial nerves 3‐12 emerge from the brain stem. 

3. The brain stem has integrative functions (it is involved in cardiovascular system 

control, respiratory control, pain sensitivity control, alertness, awareness, and 

consciousness). Thus, brain stem damage is a very serious and often lifethreatening 

problem. 

Brainstem and cerebellum 

Ventral 

view 

10

23/07/54 

12 Cranial nerves: 

1. Olfactory 

2. Optic 

3. Oculomotor 

4. Trochlear 

5. Trigeminal 

6. Abducens 

7. Facial 

8. Auditory and 

Vestibular 

9. Glossopharyngeal 

10. Vagus 

11. Spinal Accessory 

12. Hypoglossal 

Control of respiration 

Cardiovascular controls 

Long tracts of Sensory and Motor 

Systems 

1. Pathways in spinal cord and brainstem 

2. Functions 

3. Clinical correlates, signs and symptoms 

11

23/07/54 

Cerebellum 

Vestibular 

and 

Cerebellum 

The cerebellum (Latin for little brain) isaregionofthe 

brain that plays an important role in motor control.Itisalsoinvolved 

in some cognitive functions such as attention and language, and 

probably in some emotional functions such as regulating fear and 

pleasure responses. Its movement‐related functions are the most 

clearly understood, however. The cerebellum does not initiate 

movement, but it contributes to coordination, precision, and 

accurate timing. It receives input from sensory systems and from 

other parts of the brain and spinal cord, and integrates these inputs 

to fine tune motor activity. Because of this fine‐tuning function, 

damage to the cerebellum does not cause paralysis, but instead 

produces disorders in fine movement, equilibrium, posture, and 

motor learning 

In addition to its direct role in motor control and coordination, the 

cerebellum also is necessary for several types of motor learning, the 

most notable one being learning to adjust 

to changes 

in 

sensorimotor relationships. 

The Human Cerebellum: 

Cerebellar Functions (Classical Functions): 

Co‐ordination of Movements 

Stabilizing of Vestibulo‐ocular Reflex (VOR) 

Patterned Skilled Movements 

Coordination of Eye Movements 

Vermis Lobule VI‐‐‐‐Saccadic Eye Movements 

Flocculus‐‐‐‐ Visual Tracking 

Equilibrium, Gait and Postural Controls 

Controls of Autonomic Functions (Cardiovascular) 

Immune Functions (?) 

12

23/07/54 


Clinical Correlates on the Human Cerebellum: 

Flocculo‐Nodular Lobe: 

Disturbed Equilibrium or Balance 

Tendency to fall on the side of the lesion 

Extensor hypotonia 

“Reeling or Drunken” ”Gi Gait or Posture 

Deviation Nystagmus 

1. Eye in mid‐line Position: 

fine nystagmus, quick phase toward lesion side 

2. Eye fixed 10 –30 degree away from the lesion side: 

No nystagmus 

3. Eye fixed beyond 30 degree away from the lesion side 

nystagmus with quick phase away from lesion side 

4. Eye shift beyond midline toward the lesion side 

gross nystagnus, quick phase toward lesion side 


Clinical Correlates on the Human Cerebellum: 

Anterior Lobe & Vermis: 

Hypotonia (Reduced muscle tone) 

Hyporeflexia 

Ataxia (Incoordination of Movements) 

Asynergia, Dysynergia (lack of synergy) 

Intention or Action Tremor (Atelokinesia) 

Asthenia (Weakness of muscular strength) 

Rebounded Phenomenon 

Cerebellar Hemisphere & Dentate Nucleus: 

Dysmetria (Pass pointing) 

Dysdiadochokinesia or Adiadochokinesia 

(can not perform rapid alternating movements) 

Disturbed Voluntary Skilled movements 

Disturbed Speech (Drunken Speech) 

13

23/07/54 

Dysmetria of thought 

The Principles of Motor Controls of Movements: 

1. The central nervous system (CNS) has to choose the right group 

of muscles by selecting specific pathways. 

2. The CNS must give the right amount of excitatory or inhibitory 

inputs (“Command”) to specific motoneuron pools 

3. The excitatory and inhibitory commands must be regulated 

“Spatially” and “Temporally”. 

4. The CNS must regulate the following parameters: 

‐ force 

‐displacement (distance) 

‐ velocity, acceleration or deceleration 

Pyramidal System: 

Cortico‐spinal tracts 

UMN Lesions (Pyramidal Syndrome) 

A. Paralyze movements in hemiplegic, 

quadriplegic, or paraplegic distribution, not 

individual muscles 

B. Atrophy of disuse only (late and slight) 

C. Hyperactive MSRs Clonus 

D. Clasp‐knife spasticity 

E. Absent abdominal and cremasteric reflexes 

F. Extensor toe sign (Babinski sign) 

14

23/07/54 

Plantar Flexion 

Dorsi‐ Flexion 

LMN Lesions 

A. Paralyze individual muscles or sets of muscles 

in root or peripheral nerve distribution 

B. Atrophy of denervation (early and severe 

C. Fasciculations and fibrillations 

D. Hypoactive or absent MSRs Hypotonia 

UMN = upper motoneuron; LMN = lower 

motoneuron; MSRs = muscle stretch reflexes 

Basal ganglion and 

Extrapyramidal 

System 

Disease of the basal ganglion: 

Parkinson’s disease 

Chorea and Huntington’s Chorea 

Athetosis and Athetoid 

Sydenham’s Chorea 

Hemibalism .. Lesion of subthalamic nucleus 

Dystonia, Torticolis, 

Wilson’s disease (Copper) 

Kern icterus (Bilirubin stain) 

Parkinson’s disease: 

Akinesia or Hypokiesia 

cog wheel rigidity 

Resting Tremor 

Degeneration of Dopaminergic neurons in 

Pars Compacta of the Substantia Nigra 

Motor 

control 

system 

Motor 

homonculus 

(Maps) 

15

23/07/54 

Control of 

body 

movements, 

visceral 

organs, 

behavior 


emotion 

Hypothalamus 

The Hypothalamus is a portion of the brain that contains a number of small 

nuclei with a variety of functions. One of the most important functions of the 

hypothalamus is to link the nervous system to the endocrine system via the 

pituitary gland (hypophysis). 

The hypothalamus is located below the thalamus, just above the brain stem. In 

the terminology of neuroanatomy, itformstheventral part of the diencephalon. 

All vertebrate brains contain a hypothalamus. In humans, it is roughly the size of 

an almond. 

The hypothalamus is responsible for certain metabolic processes and other 

activities of the autonomic nervous system. It synthesizes and secretes certain 

neurohormones, often called hypothalamic‐releasing hormones, and these in 

turn stimulate or inhibit the secretion of pituitary hormones. The hypothalamus 

controls body temperature, hunger, thirst,fatigue,sleep,andcircadian cycles. 

Controls of body 

temperature 

Controls of food 

intake and body 

weight 

Endocrine and 

Hormonal controls 

Controls of 

kidney functions 

16

23/07/54 

Limbic 

System 

Controls of 

emotion and 

motivation 

The thalamus is a midline paired symmetrical 

structure within the brains of vertebrates, including 

humans. It is situated between the cerebral cortex and 

midbrain, both in terms of location and neurological 

connections. Its function includes relaying sensation, 

spatial sense, and motor signals to the cerebral cortex, 

along with the regulation of consciousness, sleep, and 

alertness. The thalamus surrounds the third ventricle. It is 

the main product of the embryonic diencephalon 

Thalamus 


Cerebral 

cortex 

The thalamus has multiple functions. It is generally believed to act as a relay between a 

variety of subcortical areas and the cerebral cortex. In particular, every sensory system (with the 

exception of the olfactory system) includes a thalamic nucleus that receives sensory signals and sends 

them to the associated primary cortical area. For the visual system, for example, inputs from the retina 

are sent to the lateral geniculate nucleus ofthethalamus,whichinturnprojectstotheprimary visual 

cortex (area V1) in the occipital lobe. The thalamus is believed to both process sensory information as 

well as relaying it—each of the primary sensory relay areas receives strong "back projections" from 

the cerebral cortex. Similarly the medial geniculate nucleus acts as a key auditory relay between the 

inferior colliculus of the midbrain and the primary auditory cortex,andtheventral posterior nucleus is 

a key somatosensory relay, which sends touch and proprioceptive information to the primary 

somatosensory cortex. 

The thalamus also plays an important role in regulating states of sleep and wakefulness. [4] Thalamic 

nuclei have strong reciprocal connections with the cerebral cortex, forming thalamo‐cortico‐thalamic 

thalamic 

circuits that are believed to be involved with consciousness. The thalamus plays a major role in 

regulating arousal, the level of awareness, and activity. Damage to the thalamus can lead to 

permanent coma. 

Many different functions are linked to various regions of the thalamus. This is the case for many of the 

sensory systems (except for the olfactory system), such as the auditory, somatic, visceral, gustatory 

and visual systems where localized lesions provoke specific sensory deficits. A major role of the 

thalamus is devoted to "motor" systems. This has been and continues to be a subject of interest for 

investigators. VIm, the relay of cerebellar afferences, is the target of stereotactians particularly for the 

improvement of tremor. The role of the thalamus in the more anterior pallidal and nigral territories in 

the basal ganglia system disturbances is recognized but still poorly understood. The contribution of the 

thalamus to vestibular or to tectal functions is almost ignored. The thalamus has been thought of as a 

"relay" that simply forwards signals to the cerebral cortex. Newer research suggests that thalamic 

function is more selective 

Cerebral cortex in different areas 

The cerebral cortex is a sheet of neural tissue that is outermost to the 

cerebrum of the mammalian brain. It plays a key role in memory, attention, 

perceptual awareness, thought, language, andconsciousness. It is constituted of 

up to six horizontal layers, each of which has a different composition in terms of 

neurons and connectivity. The human cerebral cortex is 2–4 mm (0.08– 

0.16 inches) thick. 

In preserved brains, it has a gray color, hence the name "gray matter". In contrast 

to gray matter that is formed from neurons and their unmyelinated fibers, the 

white matter below them is formed predominantly by myelinated axons 

interconnecting neurons in different regions of the cerebral cortex with each 

other and neurons in other parts of the central nervous system. 

The surface of the cerebral cortex is folded in large mammals, such that more 

than two‐thirds of it in the human brain is buried in the grooves, called "sulci". 

The phylogenetically most recent part of the cerebral cortex, the neocortex (also 

called isocortex), is differentiated into six horizontal layers; themoreancientpart 

of the cerebral cortex, the hippocampus (also called archicortex), has at most 

three cellular layers, and is divided into subfields. Neurons in various layers 

connect vertically to form small microcircuits, called columns. Different 

neocortical architectonic fields are distinguished upon variations in the thickness 

of these layers, their predominant cell type and other factors such as 

neurochemical markers. 

17

23/07/54 

Functional brain mapping 

แผนที 

่การทํางานของสมอง (Brain Mapping 

Brain Mapping) 

Broadmann’ s Areas 

Broadmann’s area # 

Brodmann’s area is a region of the cerebral cortex defined based on 

its cytoarchitectonics, or organization of cells 

Brodmann areas were originally defined and numbered by the German neurologist 

Korbinian Brodmann basedonthecytoarchitecture organisation of neurons he 

observed in the cerebral cortex using the Nissl stain. Brodmann published his maps 

of cortical areas in humans, monkeys, and other species in 1909, along with many 

other findings and observations regarding the general cell types and laminar 

organization of the mammalian cortex. (The same Brodmann area number in 

different species does not necessarily indicate homologous areas.) 

A more detailed and verifiable cortical map have since been published by Constantin von 

Economo and Georg N. Koskinas which greatly improves the quality of the cytoarchitectonic 

classifications. 

Many of the areas Brodmann defined based solely on their neuronal organization have since 

been correlated closely to diverse cortical functions. For example, Brodmann areas 1, 2 and 

3aretheprimary somatosensory cortex; area4istheprimary motor cortex; area17isthe 

primary visual cortex; and areas 41 and 42 correspond closely to primary auditory cortex. 

Higher order functions of the association cortical areas are also consistently localized to the 

same Brodmann areas by neurophysiological, functional imaging, and other methods (e.g., 

the consistent localization of Broca's speech and language area to the left Brodmann areas 

44 and 45). However, functional imaging can only identify the approximate localization of 

brain activations in terms of Brodmann areas since their actual boundaries in any individual 

brain requires its histological examination. 

18

่ 

23/07/54 

Brodmann areas for human & non‐human primates 

Brodmann’s areas 3D 

map: Lateral Surface 

map: Medial Surface 


Paul MacLean 

M.D. 

Paul MacLean’s 

Triune Brain 

The Reptilian Brain : Core brainstem 

The Paleomammalian Brain : the limbic system 

The Neomammalian Brain : neocortex and neocerebellum 

สมองส่วนแรก คือ สมองของสัตว์เลื้อยคลาน (Reptilian Brain) 

เป็นสมองที่มนุษย์เราได้รับมรดกตกทอดมาจากสัตว์เลื้อยคลานยุคดึกดําบรรพ์ อยู ่ภายใต้ 

อิทธิพลของพันธุกรรม 90 – 95 % และเจริญเติบโตในระหว่างที่อยู ่ในครรภ์มารดาเป็น 

ส่วนใหญ่ เมื่อเกิดมาแล้วสิ่งแวดล้อมมีอิทธิพลต่อสมองส่วนนี้น้อยมาก มันจะถูกปัจจัย 

ทางพันธุกรรมกําหนดมาเลยว่าเป็นสมองคน หรือสมองสัตว์และมีโครงสร้างและการ 

ทํางานอย่างไร สมองส่วนนี้ควบคุมการทํางานของอวัยวะต่างในร่างกายโดยอัตโนมัติ 

และพฤติกรรมที่เป็นสัญชาติญาณของสิ่งมีชีวิตที่มีมาโดยกําเนิดโดยการกําหนดของ 

พันธุกรรม ได้มรดกโดยตรงมาจากพ่อแม่ พ่อแม่เป็นอย่างไรลูกจะได้มรดกตกทอดมาเป็น 

อย่างนั้นเลย อยางนนเลย Reptilian Brain มีลักษณะเป็นแกนอย่ตอนในสดของสมองเป็นส่วนของ 

มลกษณะเปนแกนอยูตอนในสุดของสมองเปนสวนของ 

ก้านสมองและสมองตอนกลาง สมองส่วนที่หนึ่งนี้ เป็นสมองส่วนที่ทําให้มนุษย์มีสัญชาติ 

ญาณของการอยู ่รอด การกิน การขับถ่าย การสืบพันธ์ เริ่มสร้างขึ้นตั้งแต่ขณะที่ทารกอยู ่ใน 

ครรภ์มารดา ในวันที่คลอดนั้นสมองส่วนนี้สามารถทํางานได้ราว 99 % และเติบโตสมบูรณ์ 

พร้อมทํางานเต็มที่ในช่วงขวบปีแรก ถ้าสมองส่วนแรกนี้ไม่สามารถทํางานได้ดีทารกก็ไม่ 

อาจมีชีวิตอยู ่รอดได้ เพราะมันไปควบคุมการเต้นของหัวใจ การหายใจ ระบบขับถ่าย การ 

กินการอยู ่ การตื่น การนอนหลับทุกอย่างหมดเลย ในช่วงสองขวบปีแรก พ่อแม่ และผู ้เลี้ยง 

ดูเด็กจะสอนเด็กให้สามารถควบคุมร่างกาย ควบคุมการกินอยู ่ ควบคุมการขับถ่าย และ 

สร้างนิสัยต่างๆที่เหมาะสมกับการอยู ่รอดในสังคม 

สมองส่วนที ่สอง คือ สมองสัตว์เลี้ยงลูกด้วยนมยุคโบราณ 

(Paleomammalian Brain หรือ Limbic System) เป็นสมองส่วนที่ 

มนุษย์เราได้รับมรดกตกทอดมาจากสัตว์เลี้ยงลูกด้วยนมยุคโบราณ สมองส่วนนี้จะเริ่ม 

สร้างและเจริญเติบโตเมื่อทารกอยู ่ในครรภ์มารดาได้ราว ๆ หกเดือน Limbic 

Systemจะมีลักษณะคล้ายวงแหวนที่หุ ้มรอบๆสมองส่วนแรกซึ่งมีลักษณะเป็นแกน 

เอาไว้ หน้าที่ของสมองส่วนนี้ก็คือ ทําให้ทารกเกิดความจําเกี่ยวกับเหตุการณ์และสถานที่ 

(Episodic or Spatiotemporal Memory) โดยเฉพาะความจําที่เกี่ยวกับ 

ใบหน้าแม่ จํากลิ่นแม่ได้ ทําให้มนุษย์รู ้จักตัวเอง (“Self”) และพัฒนาให้มีความรู ้สึก 

(Feeling)และการแสดงออกทางอารมณ์ต่าง ๆ มันจะเป็นตัวที่ทําให้ทารกร้องไห้โยเย 

เรียกร้องความสนใจ แสดงอารมณ์ความรู ้สึกเวลา ดีใจ-เสียใจ ชอบ-ไม่ชอบ พอใจ-ไม่ 

พอใจ สมองส่วนที่สองนี้ทําให้มนุษย์เราแตกต่างจากสัตว์เลื้อยคลาน เช่น จิ้งจก กิ้งก่า 

เต่า ซึ่งมีเพียงแค่สัญชาติญาณแต่ปราศจากความรู ้สึก และอารมณ์ อย่างไรก็ตามตอนที่ 

ทารกคลอดออกมาสมองส่วนนี้ เพิ่งสร้างเสร็จไปเพียง 50 % เท่านั้น มันจะเจริญเติบโต 

ต่อไปโดยเฉพาะในช่วงสี่ขวบปีแรกของชีวิต 

19

้ 

23/07/54 

สมองส่วนที 

่สองจะได้รับอิทธิพลจากพันธุกรรมประมาณ 50 % ส่วนอีก 50 % ที่ 

เหลือนั้นพัฒนาตามสภาพแวดล้อม ประสบการณ์และการเรียนรู ้โดยเฉพาะช่วงตั้งแต่ 

แรกเกิด ขวบปีแรกจนถึงปฐมวัย (0 – 8 ปี ) สมองส่วนนี้สําคัญมากตรงที่ เป็น 

ตัวกําหนด พื้นอารมณ์ (Temperament) ควบคุมการแสดงออกของอารมณ์ให้ 

เหมาะกับเหตุการณ์ และสถานการณ์ ซึ่งเป็นรากฐานของบุคลิกภาพของปัจเจกคน 

(Individual Personality)ที่ทําให้เราทุกคนแตกต่างกัน การที่เด็กจะเติบโตเป็นคน 

ที่ฉลาดทางอารมณ์ ทฉลาดทางอารมณ (Emotional Intelligence) มีมนษยสัมพันธ์ดีหรือไม่ขึ้นอย่ 

มมนุษยสมพนธดหรอไมขนอยู 

กับการเลี้ยงดูในช่วงปฐมวัย และการพัฒนาของสมองส่วนนี้ เป็นสําคัญ 

สมองส่วนที ่สาม คือ สมองของสัตว์เลี้ยงลูกด้วยนมยุคใหม่ และเปลือกหุ ้ม 

สมองใหม่ (Neo‐Mammalianหรือ Neo‐Cortex Brain) คือ สมองที่พบได้ 

เฉพาะในสัตว์ชั้นสูงที่มีเปลือกหุ ้มสมองใหญ่เท่านั้น เช่น มนุษย์ ปลาโลมาและสัตว์ 

ประเภทวานร ลิง (Primates)เป็นต้น สมองส่วนที่สามนี้จะมีลักษณะคล้ายเปลือกหุ ้ม 

สมอง หุ ้มสมองส่วนที่หนึ่งและส่วนที่สองเอาไว้ ตอนที่ทารกคลอดออกมาใหม่ ๆ สมอง 

ส่วนนี้ยังไม่พัฒนามากเลย มันจะเริ่มก่อร่างสร้างตัวและเจริญเติบโตอย่างรวดเร็วมาก 

ในช่วงสามปีแรกของชีวิต จนกระทั่งเมื่อเด็กอายุได้หกขวบจึงเจริญเติบโตราว 80 % 

ตอนเกาขวบจะเตบโตราว ้ ิ 90 % และจะเจรญเตบโตเรอยตอไปกระทงอายุ ิ ิ ื่ ่ ั่ 25 ปี สมอง 

ส่วนที่สามจะได้รับอิทธิพลจากพันธุกรรมน้อยมาก แทบจะเรียกได้ว่าพันธุกรรมควบคุม 

มัน 10-20 % เท่านั้น เพราะมันมาเจริญเติบโตหลังคลอด พัฒนาการของสมองส่วนนี้ 

จึงได้รับอิทธิพลมาจากสิ ่งแวดล้อมเป็ นส่วนใหญ่ และต้องการการกระตุ ้นจาก 

สิ ่งแวดล้อมให้สามารถพัฒนาได้เต็มที ่ตามศักยภาพที ่มีมากับตัวของเด็ก 

สมองส่วนที ่สาม มีความยืดหยุ ่นค่อนข้างมาก มีบทบาทเปรียบได้กับหน้าต่าง 

ของโอกาส (Windows of opportunities)ที่จะส่งเสริมให้เด็กฉลาดโดยการ 

กระตุ ้นการรับรู ้ และกิจกรรมต่างๆจากประสบการณ์การเรียนรู ้ต่างๆ การได้รับอาหารที่ 

มีครบทุกหมู ่อาหารในปริมาณที่เหมาะสม และคุณภาพที่ดีจําเป็นมากต่อการ 

เจริญเติบโตของสมองส่วนนี้ การสัมผัสและการกระตุ ้นประสาทสัมผัสต่างๆอย่าง 

เหมาะสมเป็นความจําเป็นอย่างยิ่งที่จะทําให้สมองส่วนนี้พัฒนาก้าวหน้า และสามารถ 

เรียนร้ประสบการณ์ต่างๆ เรยนรูประสบการณตางๆ ททาใหอยางเตมท ที่ทําให้อย่างเต็มที่ เพราะฉะนน เพราะฉะนั้น เรองการเลยงดูเดกในชวง 

เรื่องการเลี้ยงดเด็กในช่วง 

สามขวบปีแรกจึงเป็นเรื่องสําคัญมาก เพราะในช่วงนี้สมองส่วนนี้จะเจริญเติบโตจากที่ 

ไม่มีอะไรมากเลย คือ ประมาณ 25% ของผู ้ใหญ่ตอนแรกเกิด จนกระทั่งเติบโตได้ถึง 80 

% ตอนอายุ 3 ขวบปีแรก สมองส่วนนี้ทําให้เด็กสามารถเรียนรู ้ สร้างโลกทัศน์ของการ 

รับรู ้ และความเข้าใจเกี่ยวกับจักรวาลรอบตัว มีทักษะต่างๆในการเคลื่อนไหว เรียนรู 

ภาษาที่ใช้ในการสื่อสาร ทั้งภาษาพูด ภาษาเขียน การคํานวณ การคิดหาเหตุผล 

คณิตศาสตร์ และตรรกวิทยา (Logic thinking) รวมทั้งการเรียนรู ้วิชาการต่างๆ และ 

จินตนาการทางศิลปะ 

ในสมองส่วนที ่สําคัญที ่สุด ในด้านการพัฒนาสมอง คือ สมอง 

ส่วนหน้า (Frontal lobe) ที่อยู ่ด้านหลังหน้าผากของมนุษย์ หรือ สมองส่วนปรี 

ฟรอนตัล (Prefrontal Cortex) เป็นสมองส่วนที่อยู ่ในสมองส่วนที่สาม สาเหตุที่ทํา 

ให้สมองส่วนนี้มีความสําคัญมาก เพราะมันมีหน้าที่ความสําคัญเปรียบได้กับเป็น “นาย 

ของสมอง” (Chief Executive Officer หรือCEO ของสมองทั้งหมด) เพราะเป็น 

สมองส่วนที่เกิดทีหลังสุด ในช่วงสองขวบปีแรกเพิ่งเริ่มสร้างเท่านั้นเอง ทําหน้าที่เชื่อมโยง 

กับสมองทีทีสร้างก่อนมาทังหมด ี่ ี่ ่ ั้ สมองส่วนนีจะได้รับเส้นประสาทมาจากสมองส่วนต่างๆ 

ี้ ้ ั ้ ่ ่ 

เมื่อเจริญเติบโตเต็มที่ในช่วงที่ย่างเข้าสู ่วัยรุ ่น จะเป็นส่วนที่ควบคุมร่างกายและจิตใจ 

ทั้งหมด ทําให้เราเหมือนมีจิตใจเป็นหนึ่งเดียว มีเจ้านายคนเดียวสั่งงาน สังเกตดูจะเห็นว่า 

ช่วงวัยเด็กเล็ก เด็ก ๆ จะวิ่งเล่นตามประสา สะเปะสะปะไปตามสิ่งเร้า สิ่งกระตุ ้น เหมือน 

ไม่มีการควบคุมการสั่งงาน แต่พอเราโตขึ้นชีวิตเริ่มมีการวางแผน สมองส่วนนี้นี่เองที่จะ 

คอยควบคุมกําหนดให้มนุษย์มีการวางแผนงานล่วงหน้า มีความรับผิดชอบ มีสมาธิ 

ปรีฟรอนตัล 

Prefrontal 

ภาพสมองคนแสดง สมองสามระบบ (Triune brain) สมองระบบแรก Reptilian brain ควบคุมสมดุลของการมีชีวิต 

และการอยู ่รอด (Homeostasis and survival) อยู ่ในบริเวณก้านของสมอง และสมองส่วนลึกที่อยู ่ใจกลางภายใน 

ของสมอง ระบบที่สอง ส่วนของสมองลิมบิค (Limbic brain structures) หุ ้มห่อสมองระบบแรกที่อยู ่ภายใน ซึ่งทํา 

หน้าที่เกี่ยวกับพัฒนาการของอารมณ์ ความสัมพันธ์และสังคมกับคนอื่นๆ และกับจิตใจกับความประพฤติของตัวเราเอง ระบบ 

ที่สาม นีโอคอร์เท็กซ์ (Neocortex) เป็นส่วนเปลือกที่หุ ้มห่อภายนอกของสมองใหญ่ ทั้ง Cerebrum and 

cerebellum ควบคุมการรับรู ้ การเรียนรู ้ และทักษะความชํานาญ และความเฉลียวฉลาด รวมทั้งบริเวณ ปรีฟรอนตัล 

(Prefrontal) ที่เป็น นายหรือ CEO ของสมอง 

20

23/07/54 

ทีมงานวิจัยของมหาวิทยาลัยไอโอวานําโดยประสาทแพทย์ชื่อ ดร.อันโตนิ 

โอ ดามาสซิโอ (Dr. Antonio Damassio) และภรรยา ดร.ฮันนา ดามาสซิโอ (Dr. 

Hanna Damassio) ได้ทําการวิจัยติดตามเด็กเล็กที่เมื่ออายุประมาณขวบหรือขวบ 

ครึ่งเคยได้รับบาดเจ็บจากอุบัติเหตุ เช่น หกล้มไปข้างหน้า แล้วศีรษะส่วนหน้าผาก 

ฟาดพื้น ทําให้สมองบริเวณนั้นเกิดอาการชํ้า ทีมงานวิจัยติดตามเด็กกลุ ่มนี้ไป 

จนกระทั่งวัยรุ่นแล้วพบว่า เด็กกลุ ่มนี้จะมีอาการทางประสาท ที่จิตแพทย์เรียกว่า 

สมองส่วนหน้าพิการ (Frontal lobe syndrome) คือ เด็กที่สมองส่วนหน้าทํางาน 

ไม่สมบูรณ์ ทําให้ประสบปัญหาเรื่องการเรียน และพฤติกรรมแม้ว่าบางคนจะมีไอ 

คิว (IQ) สูงก็ตาม เนืองจากมีสมาธิสัน ื่ ิ ้ (Attention Deficit หรือ AD)) ไม่สามารถ 

ควบคุมตัวเองให้สงบนิ่ง ที่จะทําอะไรนิ่งๆ อยู ่กับที่นาน ๆ ได้พอ ไม่มีการวางแผนที่ 

ดี ขาดความรับผิดชอบ และมีปัญหาในการเรียน และการเข้าสมาคมกับคนอื่นๆ 

เด็กวัยรุ่นที่มาจากครอบครัวที่ดีแต่ตัวเด็กกลับมีพฤติกรรมไม่เหมาะสม และเป็น 

อันธพาลชอบต่อต้านกฎระเบียบต่างๆ ต่อต้านสังคม และบางครั้งชอบใช้ความ 

ก้าวร้าวและพฤติกรรมรุนแรง นั้น เมื่อศึกษาลึกลงไป จะพบว่ามีสาเหตุเกี่ยวกับ 

ความพิการของสมองส่วนนี้เข้ามาเกี่ยวข้องได้เสมอ ดังนั้น จึงควรดูแลป้ องกัน 

ระมัดระวังไม่ให้ศีรษะส่วนนี้ของเด็กทารกได้รับบาดเจ็บ 

Prefrontal lobe syndrome 

• Personality changes 

• Deficits in strategic planning 

• Perseveration 

• Release of primitive reflexes 

• Abulia = general slowing of the intellectual 

faculties i.e. apathetic, slow speech etc. 

Corpus 

callosum 


Week 2: 

How neurons communicate, effects of 

drugs on the brain, and functional brain 

imaging 











1. How neurons communicate? 

2. Concepts of chemical neurotransmissions and various 

neurotransmitters and neuromodulators? 

3. Effects of various chemicals and drugs on the brain 

(Nervous System). 

4. Concepts of functional localization in the brain and 

brain mapping. 

5. Brain Imaging and Functional Brain Imaging. 

21

23/07/54 

22

23/07/54 

Axon terminal 

Synaptic cleft 

Excitation: 

EPSP 

Inhibition: 

IPSP 

สารสื 

่อประสาท (Neurotransmitters ) ที 

่สําคัญในสมอง 

Biogenic amines Amino acids Neuropeptides 

‐Acetyl Choline ‐Glutamic acid ‐Enkephalins 

‐Norepinephrine ‐Aspartic acid ‐Endorphins 

‐Dopamine ‐Glycine ‐Dynorphins 

‐Serotonin ‐GABA ‐Substance P 

‐Histamine Polyamines ‐VIP 

‐Epinephrine ‐Taurine ‐Somatostatin 

‐CCK 

Diagram of cholinergic nerve terminal 

with prototype drugs and chemicals 

23

23/07/54 

Neurotransmitters in Somatic and 

Autonomic nervous system 

Cholinergic pathways in human brain 

Ach: Acetyl choline 

NE: Norepinephrine 

E: Epinephrine 

Glutamate 

GABA: Gamma amino 

butyric acid 

Dopamine 

VTA: 

Ventral 

tegment 

al area 

Dopamine pathway in 

the human brain 

24

23/07/54 

Central Noradrenergic 

nerve terminal 

Locus coeruleus 

Cocaine and 

other local 

anesthetics 

25

23/07/54 

ลักษณะของยาและสารเสพติด 

‐Psychotomimetics, and some are Psychedelics 

‐Euphoria, Ecstasy etc. 

‐Reward and Reinforcement 

‐Tolerance 

‐Withdrawal syndromes and Dysphoria yp 

‐Physical, psychological and 

behavioural dependence 

‐Craving 

‐Compulsive drug seeking behaviour 

‐Relapse 

Brain Reward System 

Serotonin 

5‐hydroxy tryptamine 

Raphe nucleus 

26

23/07/54 


Week 3: 

Sensory ‐motor and cortical 

organization 











1. Sensory ‐ motor and cortical organization? 

2. The sensory systems? 

3. The Reticular formation, Sensory‐Motor Integration 

for states of Consciousness, Waking, Sleep and 

Dream. 

4. The Motor System, Movements and Motor Controls 

5. The Cerebral Cortex, and Cortical Columnar 

Organization, Concepts of functional localization and 

representation in the brain and brain mapping. 

6. Brain Imaging and Functional Brain Imaging. 

sensory system is a part of the nervous system 

responsible for processing sensory information. 

A sensory system consists of sensory receptors, neural pathways, 

and parts of the brain involved in sensory perception. Commonly 

recognized sensory systems are those for vision, hearing, somatic 

sensation (touch), taste and olfaction (smell). In short, senses are 

transducers from the physical world to the realm of the mind. 

The receptive field is the specific part of the world to which a 

receptor organ and receptor cells respond. For instance, the part 

of the world an eye can see, is its receptive field; the light that 

each rod or cone can see, is its receptive field. Receptive fields 

have been identified for the visual system, auditory system and 

somatosensory system, so far. 


Dermatome 

Reticular 

Formation 

Ascending 

Reticular 

Activating 

System (ARAS) 

Regulation of 

States of 

Consciousness, 

e.g. waking, Sleep, 

Dream; 

attention; 

sensory‐motor 

integration 

Reticular formation is a part of the brain that is involved in actions such as 

awaking/sleeping cycle, and filtering incoming stimuli to discriminate irrelevant background stimuli. It is 

essential for governing some of the basic functions of higher organisms, and is one of the 

phylogenetically oldest portions of the brain. The reticular formation consists of more than 100 small 

neural networks, with varied functions including the following: 

1. Somatic motor control ‐ Some motor neurons send their axons to the reticular formation nuclei, 

giving rise to the reticulospinal tracts of the spinal cord. These tracts function in maintaining tone, 

balance, and posture‐‐especially during body movements. The reticular formation also relays eye and 

ear signals to the cerebellum so that the cerebellum can integrate visual, auditory, and vestibular stimuli 

in motor coordination. Other motor nuclei include gaze centers, which enable the eyes to track and 

fixate objects, and central pattern generators, which produce rhythmic signals to the muscles of 

breathing and swallowing. 

2. Cardiovascular control ‐ The reticular formation includes the cardiac and vasomotor centers of the 

medulla oblongata. 

3. Pain modulation ‐ The reticular formation is one means by which pain signals from the lower body 

reach the cerebral cortex. It is also the origin of the descending analgesic pathways. Thenervefibersin 

these pathways act in the spinal cord to block the transmission of some pain signals to the brain. 

4. Sleep and consciousness ‐ The reticular formation has projections to the thalamus and cerebral 

cortex that allow it to exert some control over which sensory signals reach the cerebrum and come to 

our conscious attention. It plays a central role in states of consciousness like alertness and sleep. Injury 

to the reticular formation can result in irreversible coma. 

5. Habituation ‐ This is a process in which the brain learns to ignore repetitive, meaningless stimuli while 

remaining sensitive to others. A good example of this is when a person can sleep through loud traffic in 

a large city, but is awakened promptly due to the sound of an alarm or crying baby. Reticular formation 

nuclei that modulate activity of the cerebral cortex are called the reticular activating system or 

extrathalamic control modulatory system. 

27

23/07/54 

The Human Reticular Formation: 

Reticular Functions: 

‐ Integration of Sensory and motor functions 

‐ Control of states of consciousness 

Waking, Sleep, Dream, Altered States 

‐ Control of behavioural states 

‐ Arousal, Attention, Orienting, Habituation 

‐ Sensory filtering 

(“The Cocktail Party Effect”) 

‐ Motor functions: 

Postural Controls 

Eye movements: Gaze, Saccade, REM 

‐ Autonomic controls: 

respiration, heart rates, blood pressure 

ARAS: 

Ascending 

Reticular 

Activating 

System 


Week 4: 

The occipital lobes 











1. The occipital lobes and their functions 

2. The Visual System 

3. Visual Perception and Visual Cortical 

Organization 

4. The two Stream Hypothesis: The Dorsal stream, 

“Where or How” and The Ventral Stream, 

“What” 

5. Neuropsychology of the Occipital lobes. 

28

23/07/54 

Occipital lobe 

Vision processing 

The occipital lobe is the visual processing center of the 

mammalian brain containing most of the anatomical region of the 

visual cortex. 

The primary visual cortex is Brodmann area 17, commonly called V1 

(visual one). Human V1 is located on the medial side of the occipital 

lobe within the calcarine sulcus; the full extent of V1 often 

continues onto the posterior pole of the occipital lobe. V1 is often 

also called striate cortex because it can be identified by a large 

stripe ti of myelin, the Striaof Gennari. Visually driven di regions 

outside V1 are called extrastriate cortex. There are many 

extrastriate regions, and these are specialized for different visual 

tasks, such as visuospatial processing, color discrimination and 

motion perception. The name derives from the overlying occipital 

bone, which is named from the Latin oc‐ + caput, "back of the 

head". 

Functions of the Occipital lobes: 

Significant functional aspects of the occipital lobe is that it contains the primary 

visual cortex and is the part of the brain where dreams come from. 

Retinal sensors convey stimuli through the optic tracts to the lateral geniculate 

bodies, where optic radiations continue to the visual cortex. Each visual cortex 

receives raw sensory information from the outside half of the retina on the same 

side of the head and from the inside half of the retina on the other side of the 

head. The cuneus (Brodmann's area 17) receives visual information from the 

contralateral superior retina representing the inferior visual field. The lingula 

receives information from the contralateral inferior retina representing the 

superior visual field. The retinal inputs pass through a "way station" in the lateral 

geniculate nucleus of the thalamus before projecting to the cortex. Cells on the 

posterior aspect of the occipital lobes' gray matter are arranged as a spatial map 

of the retinal field. Functional neuroimaging reveals similar patterns of response 

in cortical tissue of the lobes when the retinal fields are exposed to a strong 

pattern. 

If one occipital lobe is damaged, the result can be homonomous vision loss from 

similarly positioned "field cuts" in each eye. Occipital lesions can cause visual 

hallucinations. Lesions in the parietal‐temporal‐occipital association area are 

associated with color agnosia, movement agnosia, and agraphia. 

The occipital lobe is divided into several functional visual 

areas. Each visual area contains a full map of the visual 

world. Although there are no anatomical markers 

distinguishing these areas (except for the prominent 

striations in the striate cortex), physiologists have used 

electrode recordings to divide the cortex into different 

functional regions. 

The first functional area is the primary visual cortex. It 

contains a low‐level description of the local orientation, 

spatial‐frequency and color properties within small 

receptive fields. Primary visual cortex projects to the 

occipital areas of the ventral stream (visual area V2 and 

visual area V4), and the occipital areas of the dorsal 

stream—visual area V3, visual area MT (V5), and the 

dorsomedial area (DM). 

29

23/07/54 

The visual system is the part of the central nervous 

system which enables organisms to process visual detail, as well as 

enabling several non‐image forming photoresponse functions. It 

interprets information from visible light to build a representation 

of the surrounding world. The visual system accomplishes a 

number of complex tasks, including the reception of light and the 

formation of monocular representations; the construction of a 

binocular perception from a pair of two dimensional projections; 

the identification and categorization of visual objects; assessing 

distances to and between objects; and guiding body movements in 

relation to visual objects. The psychological manifestation of visual 

information is known as visual perception, a lack of which is called 

blindness. Non‐image forming visual functions, independent of 

visual perception, include the pupillary light reflex (PLR) and 

circadian photoentrainment. 

The visual system includes 

the eyes, the connecting 

pathways through to the 

visual cortex and other parts 

of the brain. The illustration 

shows the mammalian 

system. 

Controls of eye 

movements 

Oculomotor (CN3) 

Trochlear (CN4) 

Abducens (CN6) 

PPRF 

PRF 

Frontal eye field 

(Area #8) 

NEUROPSYCHIATRY 177 

30

23/07/54 

Primary visual cortex (V1) 

The primary visual cortex is the best studied visual area in the brain. In all 

mammals studied, it is located in the posterior pole of the occipital cortex (the 

occipital cortex is responsible for processing visual stimuli). It is the simplest, 

earliest cortical visual area. It is highly specialized for processing information 

about static and moving objects and is excellent in pattern recognition. 

The functionally defined primary visual cortex is approximately equivalent to the 

anatomically defined striate cortex. The name "striate cortex" is derived from the 

stria of Gennari, a distinctive stripe visible to the naked eye that represents 

myelinated aonsfrom axons the lateral geniculate body terminating in layer 4 of the 

gray matter. 

The primary visual cortex is divided into six functionally distinct layers, labeled 1 

through 6. Layer 4, which receives most visual input from the lateral geniculate 

nucleus (LGN), is further divided into 4 layers, labelled 4A, 4B, 4Cα, and 4Cβ. 

Sublamina 4Cα receives most magnocellular input from the LGN, while layer 4Cβ 

receives input from parvocellular pathways. 

The average number of neurons in the adult human primary visual cortex, in each 

hemisphere, has been estimated at around 140 million (Leuba & Kraftsik, 

Anatomy and Embryology, 1994). 

V1 has a very well‐defined map of the spatial information in vision. For example, in humans 

the upper bank of the calcarine sulcus responds strongly to the lower half of visual field (below the center), and the lower bank of the 

calcarine to the upper half of visual field. Conceptually, this retinotopic mapping is a transformation of the visual image from retina to 

V1. The correspondence between a given location in V1 and in the subjective visual field is very precise: even the blind spots are 

mapped into V1. Evolutionarily, this correspondence is very basic and found in most animals that possess a V1. In human and animals 

with a fovea in the retina, a large portion of V1 is mapped to the small, central portion of visual field, a phenomenon known as cortical 

magnification. Perhaps for the purpose of accurate spatial encoding, neurons in V1 have the smallest receptive field size of any visual 

cortex microscopic regions. 

The tuning properties of V1 neurons (what the neurons respond to) differ greatly over time. Early in 

time (40 

ms and further) individual V1 neurons have strong tuning to a small set of stimuli. That is, the 

neuronal responses can discriminate small changes in visual orientations, spatial frequencies and colors. Furthermore, individual V1 

neurons in human and animals with binocular vision have ocular dominance, namely tuning to one of the two eyes. In V1, and primary 

sensory cortex in general, neurons with similar tuning properties tend to cluster together as cortical columns. David Hubel and Torsten 

Wiesel proposed the classic ice‐cube cube organization model of cortical columns for two tuning properties: ocular dominance and 

orientation. However, this model cannot accommodate the color, spatial frequency and many other features to which neurons are 

tuned. The exact organization of all these cortical columns within V1 remains a hot topic of current research. 

Current consensus seems to be that early responses of V1 neurons consists of tiled sets of selective spatiotemporal filters. In the spatial 

domain, the functioning of V1 can be thought of as similar to many spatially local, complex Fourier transforms, or more accurately, 

Gabor transforms. Theoretically, these filters together can carry out neuronal processing of spatial frequency, orientation, motion, 

direction, speed (thus temporal frequency), and many other spatiotemporal features. Experiments of neurons substantiate these 

theories, but also raise new questions. 

Later in time (after 100 ms) neurons in V1 are also sensitive to the more global organisation of the scene (Lamme 

& Roelfsema, 2000). 

These response properties probably stem from recurrent processing (the influence of higher‐tier cortical areas on lower‐tier cortical 

areas) and lateral connections from pyramidal neurons (Hupe 

et al. 1998). While feedforward connections are mainly driving, feedback 

connections are mostly modulatory in their effects (Angelucci 

et al., 2003; Hupe et al., 2001). Evidence shows that feedback originating 

in higher level areas such as V4, IT or MT, with bigger and more complex receptive fields, can modify and shape V1 responses, 

accounting for contextual or extra‐classical receptive field effects (Guo 

et al., 2007; Harrison et al., 2007; Huang et al., 2007; Sillito et al., 

2006). 

The visual information relayed to V1 is not coded in terms of spatial (or optical) imagery, but rather as 

the local contrast. As an example, for an image comprising half side black and half side white, the divide line between black and 

white has strongest local contrast and is encoded, while few neurons code the brightness information (black or white per se). As 

information is further relayed to subsequent visual areas, it is coded as increasingly non‐local frequency/phase signals. Importantly, at 

these early stages of cortical visual processing, spatial location of visual information is well preserved amid the local contra 

trast encoding. 

Visual area V2, also called 

, also called prestriate cortex, is the second major area in the visual 

cortex, and the first region within the visual association area. It receives strong feedforward connections 

from V1 (direct and via the pulvinar) and sends strong connections to V3, V4, and V5. It also sends 

strong feedback connections to V1. 

Anatomically, V2 is split into four quadrants, a dorsal and ventral representation in the left and the 

right hemispheres. Together these four regions provide a complete map of the visual world. 

Functionally, V2 has many properties in common with V1. Cells are tuned to simple properties such as 

orientation, spatial frequency, and color. The responses of many V2 neurons are also modulated by 

more complex properties, such as the orientation of illusory contours and whether the stimulus is 

part of the figure or the ground (Qiu and von der Heydt, 2005). 

Recent research has shown that V2 cells show a small amount of attentional modulation (more than V1, 

less than V4), are tuned for moderately complex patterns, and may be driven by multiple orientations at 

different subregions within a single receptive field. 

It is argued that the entire ventral visual‐to‐hippocampal stream is important for visual memory. This 

theory, unlike the dominant one, predicts that object‐recognition memory (ORM) alterations could 

result from the manipulation in V2, an area that is highly interconnected within the ventral stream of 

visual cortices. In the monkey brain, this area receives strong feedforward connections from the primary 

visual cortex (V1) and sends strong projections to other secondary visual cortices (V3, V4, and V5) . 

Most of the neurons of this area are tuned to simple visual characteristics such as orientation, spatial 

frequency, size, color, and shape and V2 cells also respond to various complex shape characteristics, 

such as the orientation of illusory contours and whether the stimulus is part of the figure or the 

ground . Anatomical studies implicate layer 3 of area V2 in visual‐information processing. In contrast to 

layer 3, layer 6 of the visual cortex is composed of many types of neurons, and their response to visual 

stimuli is more complex. 

In a recent study, the Layer 6 cells of the V2 cortex were found to play a very important role in the 

storage of Object Recognition Memory as well as the conversion of short‐term object memories into 

long‐term memories. 

Third visual complex, including area V3 

The term third visual complex refers to the region of cortex located immediately in front of V2, which 

includes the region named visual area V3 in humans. The "complex" nomenclature is justified by the 

fact that some controversy still exists regarding the exact extent of area V3, with some researchers 

proposing that the cortex located in front of V2 may include two or three functional subdivisions. For 

example, David Van Essen and others (1986) have proposed that the existence of a "dorsal V3" in the 

upper part of the cerebral hemisphere, which is distinct from the "ventral V3" (or ventral posterior 

area, VP) located in the lower part of the brain. Dorsal and ventral V3 have distinct connections with 

other parts of the brain, appear different in sections stained with a variety of methods, and contain 

neurons that respond to different combinations of visual stimulus (for example, colour‐selective 

neurons are more common in the ventral V3). Additional subdivisions, including V3A and V3B have 

also been reported in humans. These subdivisions are located near dorsal V3, but do not adjoin V2. 

Dorsal V3 is normally considered to be part of the dorsal stream, receiving inputs from V2 and from 

the primary visual area and projecting to the posterior parietal cortex. It may be anatomically located 

in Brodmann area 19. Recent work with fMRI has suggested that area V3/V3A may play a role in the 

processing of global motion Other studies prefer to consider dorsal V3 as part of a larger area, named 

the dorsomedial area (DM), which contains a representation of the entire visual field. Neurons in area 

DM respond to coherent motion of large patterns covering extensive portions of the visual field (Lui 

and collaborators, 2006). 

Ventral V3 (VP), has much weaker connections from the primary visual area, and stronger connections 

with the inferior temporal cortex. While earlier studies proposed that VP only contained a 

representation of the upper part of the visual field (above the point of fixation), more recent work 

indicates that this area is more extensive than previously appreciated, and like other visual areas it 

may contain a complete visual representation. The revised, more extensive VP is referred to as the 

ventrolateral posterior area (VLP) by Rosa and Tweedale. 

Visual area V4 is one of the visual areas in the extrastriate visual cortex. It is located anterior to 

V2 and posterior to posterior inferotemporal area (PIT). It comprises at least four regions (left and right 

V4d, left and right V4v), and some groups report that it contains rostral and caudal subdivisions as well. 

It is unknown what the human homologue of V4 is, and this issue is currently the subject of much 

scrutiny. 

V4 is the third cortical area in the ventral stream, receiving strong feedforward input from V2 and 

sending strong connections to the PIT. It also receives direct inputs from V1, especially for central 

space. In addition, it has weaker connections to V5 and dorsal prelunate gyrus (DP). 

V4 is the first area in the ventral stream to show strong attentional modulation. Most studies indicate 

that selective attention can change firing rates in V4 by about 20%. A seminal paper by Moran and 

Desimone characterizing these effects was the first paper to find attention effects anywhere in the 

visual cortex. 

Like V1, V4 is tuned for orientation, spatial frequency, and color. Unlike V1, V4 is tuned for object 

features of intermediate complexity, like simple geometric shapes, although no one has developed a 

full parametric description of the tuning space for V4. Visual area V4 is not tuned for complex objects 

such as faces, as areas in the inferotemporal cortex are. 

The firing properties of V4 were first described by Semir Zeki in the late 1970s, who also named the 

area. Before that, V4 was known by its anatomical description, the prelunate gyrus. Originally, Zeki 

argued that the purpose of V4 was to process color information. Work in the early 1980s proved 

that V4 was as directly involved in form recognition as earlier cortical areas. This research supported 

the Two Streams hypothesis, first presented by Ungerleider and Mishkin in 1982. 

Recent work has shown that V4 exhibits long‐term plasticity, encodes stimulus salience, is gated by 

signals coming from the frontal eye fields and shows changes in the spatial profile of its receptive fields 

with attention. 

31

23/07/54 

V5/MT Visual area V5, V also known as visual area MT (middle 

temporal), is a region of extrastriate visual cortex that is thought to play a major 

role in the perception of motion, the integration of local motion signals into 

global percepts and the guidance of some eye movements 

MT is connected to a wide array of cortical and subcortical brain areas. Its inputs 

include the visual cortical areas V1, V2, and dorsal V3 (dorsomedial area), the 

koniocellular regions of the LGN, and the inferior pulvinar. The pattern of 

projections to MT changes somewhat between the representations of the foveal 

and peripheral visual fields, with the latter receiving inputs from areas located in 

the midline ecortex and retrosplenial ospe region 

A standard view is that V1 provides the "most important" input to MT. 

Nonetheless, several studies have demonstrated that neurons in MT are capable 

of responding to visual information, often in a direction‐selective manner, even 

after V1 has been destroyed or inactivated. Moreover, research by Semir Zeki 

and collaborators has suggested that certain types of visual information may 

reach MT before it even reaches V1. 

MT sends its major outputs to areas located in the cortex immediately 

surrounding it, including areas FST, MST and V4t (middle temporal crescent). 

Other projections of MT target the eye movement‐related areas of the frontal 

and parietal lobes (frontal eye field and lateral intraparietal area). 

Function of V5/MT 

The first studies of the electrophysiological properties of neurons in MT showed that a 

large portion of the cells were tuned to the speed and direction of moving visual stimuli 

These results suggested that MT played a significant role in the processing of 

visual motion. 

Lesion studies have also supported the role of MT in motion perception and eye 

movements and neuropsychological studies of a patient who could not see motion, seeing 

the world in a series of static "frames" instead, suggested that MT in the primate is 

homologous to V5 in the human. 

However, since neurons in V1 are also tuned to the direction and speed of motion, these 

early results left open the question of precisely what MT could do that V1 could not. Much 

work has been carried out on this region as it appears to integrate local visual motion 

signals into the global motion of complex objects ] For example, lesion to the V5 lead to 

deficits in perceiving motion and processing of complex stimuli. It contains many neurons 

selective for the motion of complex visual features (line ends, corners). Microstimulation of 

a neuron located in the V5 affects the perception of motion. For example, if one finds a 

neuron with preference for upward motion, and then we use an electrode to stimulate it, 

the monkey becomes more likely to report 'upward' motion. 

There is still much controversy over the exact form of the computations carried out in area 

MT and some research suggests that feature motion is in fact already available at lower 

levels of the visual system such as V1 

MT was shown to be organized in direction columns. 


Organization of V1 and V2. 

A. Subregions in V1 (area 17) 

and V2 (area 18). This section 

from the occipital lobe of a 

squirrel 

monkey at the border of areas 

17 and 18 was reacted with 

cytochrome oxidase. The 

cytochrome 

oxidase stains the blobs in V1 

and the thick and thin stripes 

in V2. (Courtesy of M. 

Livingstone.) 

B. Connections between V1 

and V2. The blobs in V1 

connect primarily to the thin 

stripes in V2, while 

the interblobs in V1 connect to 

interstripes in V2. Layer 4B 

projects to the thick stripes in 

V2 and to 

the middle temporal area 

(MT). Both thin and 

interstripes project to V4. 

Thick stripes in V2 also 

project to MT. 

Callosal Disconnection 

Syndromes 


32

23/07/54 


Week 5: 

The Parietal lobes 












1. The Parietal lobes and their functions 

2. The Somatosensory System 

3. Somatosensory Perception and Somatosensory 

Cortical Organization 



“What” 

5. Neuropsychology of the Parietal lobes. 

The parietal lobe is a part of the Brain positioned 

above (superior to) the occipital lobe and behind 

(posterior to) the frontal lobe. 

The parietal lobe integrates sensory information from 

different modalities, particularly determining spatial 

sense and navigation. For example, it comprises 

somatosensory cortex and the dorsal stream of the visual 

system. This enables regions of the parietal cortex to map 

objects perceived visually into body coordinate positions. 

The name derives from the overlying parietal bone, 

which is named from the Latin pariet‐, wall. 

33

23/07/54 

The parietal lobe is defined by four anatomical boundaries: the central 

sulcus separates the parietal lobe from the frontal lobe; the parieto‐occipital 

sulcus separates the parietal and occipital lobes; the lateral sulcus (sylvian 

fissure) is the most lateral boundary separating it from the temporal lobe; 

and the medial longitudinal fissure divides the two hemispheres. 

Immediately posterior to the central sulcus, and the most anterior part of 

the parietal lobe, is the postcentral gyrus (Brodmann area 3), the secondary 

somatosensory cortical area. Dividing this and the posterior parietal cortex 

is the postcentral sulcus. 

The posterior parietal cortex can be subdivided into the superior parietal 

lobule (Brodmann areas 5 + 7) and the inferior parietal lobule (39 + 40), 

separated by the intraparietal sulcus (IPS). The intraparietal sulcus and 

adjacent gyri are essential in guidance of limb and eye movement, and 

based on cytoarchitectural and functional differences is further divided into 

medial (MIP), lateral (LIP), ventral (VIP), and anterior (AIP) areas 

Parietal lobe Function 

The parietal lobe plays important roles in integrating sensory information from various 

parts of the body, knowledge of numbers and their relations, and in the manipulation of 

objects. Portions of the parietal lobe are involved with visuospatial processing. Although 

multisensory in nature, the posterior parietal cortex is often referred to by vision scientists 

as the dorsal stream of vision (as opposed to the ventral stream in the temporal lobe). This 

dorsal stream has been called both the 'where' stream (as in spatial vision) and the 'how' 

stream (as in vision for action). 

Various studies in the 1990s found that different regions of the posterior parietal cortex in 

Macaques represent different parts of space. 

► The lateral intraparietal (LIP) contains a map of neurons (retinotopically‐coded when 

the eyes are fixed) representing the saliency of spatial locations, and attention to these 

spatial locations. It can be used by the oculomotor system for targeting eye movements, 

when appropriate. 

►The ventral intraparietal (VIP) area receives input from a number of senses (visual, 

somatosensory, auditory, and vestibular). Neurons with tactile receptive fields represented 

space in a head‐centered reference frame. The cells with visual receptive fields also fire 

with head‐centered reference frames but possibly also with eye‐centered coordinates 

► The medial intraparietal (MIP) area neurons encode the location of a reach target in 

nose‐centered coordinates. 

► The anterior intraparietal (AIP) area contains neurons responsive to shape, size, and 

orientation of objects to be grasped as well as for manipulation of hands themselves, both 

to viewed and remembered stimuli. 

The somatosensory system is a diverse sensory system comprising the 

receptors and processing centres to produce the sensory modalities such as touch, 

temperature, proprioception (body position), and nociception (pain). The sensory 

receptors cover the skin and epithelia, skeletal muscles, bones and joints, internal organs, 

and the cardiovascular system. 

While touch (also, more formally, tactition; adjectival form: "tactile" or "somatosensory") 

is considered one of the five traditional senses, the impression of touch is formed from 

several modalities. In medicine, the colloquial term touch is usually replaced with somatic 

senses to better reflect the variety of mechanisms involved. 

The system reacts to diverse stimuli using different receptors: thermoreceptors, 

nociceptors, mechanoreceptors and chemoreceptors. Transmission of information from 

the receptors passes via sensory nerves through htracts in the spinal cord and into the 

brain. Processing primarily occurs in the primary somatosensory area in the parietal lobe 

of the cerebral cortex. 

The cortical homunculus was devised by Wilder Penfield. 

At its simplest, the system works when activity in a sensory neuron is triggered by a 

specific stimulus such as heat; this signal eventually passes to an area in the brain 

uniquely attributed to that area on the body—this allows the processed stimulus to be felt 

at the correct location. The point‐to‐point mapping of the body surfaces in the brain is 

called a homunculus and is essential in the creation of a body image. This brain‐surface 

("cortical") map is not immutable, however. Dramatic shifts can occur in response to 

stroke or injury. 


Dermatome 

Somatic sensory 

areas of the cortex. 

34

23/07/54 

The neural architecture of 

the somatosensory system. 

Postcentral gyrus 

The lateral postcentral gyrus is bounded 

by: 

medial longitudinal fissure medially (to the 

middle) 

central sulcus rostrally (in front) 

postcentral sulcus caudally (in back) 

lateral sulcus inferiorly (underneath) 

It is the location of primary 

somatosensory cortex, the main 

sensory receptive area for the sense of 

touch. Like other sensory areas, there is 

a map of sensory space called a 

homunculus in this location. For the 

primary somatosensory cortex, this is 

called the sensory homunculus. 

A somatotopic map of 

the body surface onto 

primary somatosensory 

cortex. 

Somatosensory 

homunculus 

Brodmann areas 3, 1 and 2 comprise the primary somatosensory cortex of the human brain 

(or S1). Because Brodmann sliced the brain somewhat obliquely, he encountered area 1 first; however, from rostral to 

caudal the Brodmann designations are 3, 1 and 2, respectively. 

Brodmann area 3 is subdivided into area 3a and 3b. Where BA 1 occupies the apex of the postcentral gyrus, the rostral 

border of BA 3a is in the nadir of the Central sulcus, and is caudally followed by BA 3b, then BA 1, with BA 2 following 

and ending in the nadir of the postcentral sulcus. BA 3b is now conceived as the primary somatosensory cortex because 

1) it receives dense inputs from the NP nucleus of the thalamus; 2) its neurons are highly responsive to somatosensory 

stimuli, but not other stimuli; 3) lesions here impair somatic sensation; and 4) electrical stimulation evokes somatic 

sensory experience. BA 3a also receives dense input from the thalamus; however, this area is concerned with 

proprioception. 

Areas 1 and 2 receive dense inputs from BA 3b. The projection from 3b to 1 primarily relays texture information; the 

projection to area 2 emphasizes size and shape. Lesions confined to these areas produce predictable dysfunction in 

texture, size, and shape discrimination. 

Somatosensory cortex, like other neocortex, is layered. Like other sensory cortex (i.e. visual and auditory) the thalamic 

inputs project into layer IV, which in turn project into other layers. Also like other sensory cortices, S1 neurons are 

grouped together with similar inputs and responses into vertical columns that extend across cortical layers (e.g. As 

shown by Vernon Mountcastle, into alternating layers of slowly adapting and rapidly adapting neurons; or spatial 

segmentation of the vibrissae on mouse/rat cerebral cortex). 

This area of cortex, as shown by Wilder Penfield and others, is organized somatotopically, having the pattern of a 

homunculus. That is, the legs and trunk fold over the midline; the arms and hands are along the middle of the area 

shown here; and the face is near the bottom of the figure. While it is not well‐shown here, the lips and hands are 

enlarged on a proper homunculus, since a larger number of neurons in the cerebral cortex are devoted to processing 

information from these areas. 

The positions of Brodmann area's 3, 1 and 2 are ‐ from the nadir of the central sulcus towards the apex of the 

postcentral gyrus ‐ 3a, 3b, 1 and 2 respectfully. 

These areas contain cells that project to the secondary somatosensory cortex. 

The human secondary somatosensory cortex (S2) is a region 

of cerebral cortex lying mostly on the parietal operculum. 

Region S2 was first described by Adrian in 1940, who found that feeling in cats' feet was not only 

represented in the previously described primary somatosensory cortex (S1) but also in a second 

region adjacent to S1. In 1954, Penfield and Jasper evoked somatosensory sensations in human 

patients during neurosurgery using electrical stimulation in the lateral sulcus, which lies adjacent to 

S1, and their findings were confirmed in 1979 by Woolsey et al. using evoked potentials and electrical 

stimulation. 

Functional neuroimaging studies have found S2 activation in response to light touch, pain, visceral 

sensation, and tactile attention. 

In monkeys, apes and hominids region S2 is divided into several "areas". The area adjoining the 

primary somatosensory cortex is called the parietal ventral area (PV). Adjacent to PV, but towards the 

posterior of the parietal operculum, is area S2 ‐ which must not be confused with region S2 (which 

designates the entire secondary somatosensory cortex, of which area S2 is a part). Deeper in the 

lateral sulcus, bordering areas PV and S2, lies the ventral somatosensory area (VS). In humans, the 

secondary somatosensory cortex includes parts of Brodmann areas 40 and 43. 

Areas PV and S2 both map the body surface. Functional neuroimaging in humans has revealed that in 

areas PV and S2 the face is represented nearest the entrance to the lateral sulcus, and the hands and 

feet deeper in the fissure, nearer the border with VS. Individual neurons in PV and S2 receive input 

from wide areas of the body surface (they have large "receptive fields"), and respond readily to 

stimuli such as wiping a sponge over a large area of skin. 

Areas S2 in the left and right hemispheres are densely interconnected, and stimulation on one side of 

the body will activate area S2 in both hemispheres. Area S2 is interconnected with Brodmann area 

(BA) 1 and densely so with BA 3b, and projects to PV, BA 7b, insular cortex, amygdala and 

hippocampus. PV connects densely with BA 5 and the premotor cortex. 

S2 is colored green and the insular cortex brown in the top right image 

(coronal section) of the human brain. S1 is green in the top left, and the 

supplementary somatosensory area is green in the bottom left. 

35

23/07/54 

• Brodmann area 5 is one of 

Brodmann's cytologically 

defined regions of the 

brain. It is involved in 

somatosensory processing 

and association. 

• Brodmann area 5 is part of 

the parietal cortex in the 

human brain. It is situated 

immediately posterior to 

the primary somatosensory 

areas (Brodmann areas 3, 1, 

and 2), and anterior to 

Brodmann area 7. 

• Brodmann area 7 is one of Brodmann's 

cytologically defined regions of the brain. It is 

involved in locating objects in space. It serves 

as a point of convergence between vision 

and proprioception to determine where 

objects are in relation to parts of the body. 

• Brodmann area 7 is part of the parietal 

cortex in the human brain. Situated posterior 

to the primary somatosensory cortex 

(Brodmann areas 3, 1 and 2), and superior to 

visual cortices (Brodmann areas 17, 18 and 

19), this region is believed to play a role in 

visuo‐motor coordination (e.g., in reaching to 

grasp an object). 

Astereognosis is the inability to identify an object 

by touch without visual input. It is a form of tactile 

agnosia in which an individual is unable to identify 

objects by handling them, despite intact sensation . 

With the absence of vision (i.e. eyes closed), an 

individual with astereognosis is unable to identify what 

is placed din their hand . As opposed to agnosia, when 

the object is observed visually, one should be able to 

successfully identify the object. 

Astereognosis is associated with lesions of the parietal 

lobe or dorsal column or parieto‐temporo‐occipital lobe 

(posterior association areas) of either the right or left 

hemisphere of the cerebral cortex 

Brodmann area 39, or BA39, is part of the 

parietal cortex in the human brain. BA39 encompasses 

the angular gyrus, lying near to the junction of 

temporal, occipital and parietal lobes. 

This area is also known as angular area 39 (H). It 

corresponds to the angular gyrus surrounding the 

caudal tip of the superior temporal sulcus. Dorsally it is 

bounded approximately by the intraparietal sulcus. 

Cytoarchitecturally it is bounded rostrally by the 

supramarginal area 40 (H), dorsally and caudally by the 

peristriate area 19, and ventrally by the 

occipitotemporal area 37 (H) (Brodmann‐1909). 

Damage to Brodmann area 39 plays a role in semantic 

aphasia. It was regarded by Alexander Luria as a part of 

the temporo‐parieto‐occipital area, which includes 

Brodmann area 40, Brodmann area 19, and Brodmann 

area 37. 

Brodmann area 40, or BA40, is part of the parietal 

cortex in the human brain. The inferior part of BA40 is 

in the area of the supramarginal gyrus, which lies at the 

posterior end of the lateral fissure, in the inferior 

lateral part of the parietal lobe. 

It is bounded approximately by the intraparietal sulcus, 

the inferior postcentral sulcus, the posterior subcentral 

sulcus and the lateral sulcus. Cytoarchitecturally it is 

bounded caudally by the angular area 39 (H), rostrally 

and dorsally by the caudal postcentral area 2, and 

ventrally by the subcentral area 43 and the superior 

temporal area 22 (Brodmann‐1909). 

Cytoarchitectonically defined subregions of rostral 

BA40/the supramarginal gyrus are PF, PFcm, PFm, 

PFop, and PFt. Area PF is the homologue to macaque 

area PF, part of the mirror neuron system, and active in 

humans during imitation. 

The supramarginal gyrus part of Brodmann area 40 is 

the region in the inferior parietal lobe that is involved 

in reading both in regards to meaning and phonology. 

More recent fMRI studies have shown that humans have similar functional regions in and 

around the intraparietal sulcus and parietal‐occipital junction. The human 'parietal eye 

fields' and 'parietal reach region', equivalent to LIP and MIP in the monkey, also appear to 

be organized in gaze‐centered coordinates so that their goal‐related activity is 'remapped' 

when the eyes move. Both the left and right parietal systems play a determining role in self 

transcendence, the personality trait measuring predisposition to spirituality 

This lobe is divided into two hemispheres‐ left and right. 

The left hemisphere plays a more prominent role for right handers and is involved in 

symbolic functions in language and mathematics. 

Meanwhile, the right hemisphere plays a more prominent role for left handers and is 

specialised to carry out images and understanding of maps i.e. spatial relationships. 

Damage to the right hemisphere of this lobe results in the loss of imagery, 

visualization of spatial relationships and neglect of left side space and left side of 

the body. Even drawing may be neglected from the left side. 

Damage to the left hemisphere of this lobe will result in problems in 

mathematics, long reading, writing and understanding symbols. 

The parietal association cortex enables individuals to read, write, and solve 

mathematical problems. The sensory inputs from the right side go to the left 

side and vice‐versa. 

36

23/07/54 

Clinical significance 

Lesions affecting the primary somatosensory cortex 

produce characteristic symptoms including: 

agraphesthesia, astereognosia, loss of vibration, 

proprioception and fine touch (because the third‐order 

neuron of the medial‐lemniscal pathway cannot 

synapse in the cortex). It can also produce hemineglect, 

if it affects the non‐dominant hemisphere. 

It could also reduce nociception, thermoception and 

crude touch, but since information from the 

spinothalamic tract is interpreted mainly by other areas 

of the brain (insular cortex and cingulate gyrus), it is not 

as relevant as the other symptoms. 

Analgesia, this is the difficulty perceiving and processing 

pain; thought to underpin some forms of self injury. [ 

Tactile agnosia Impaired ability to recognize or identify 

objects by touch alone. 

Agraphesthesia is a disorder of directional cutaneous 

kinesthesia or a disorientation in cutaneous space. It is a 

difficulty recognizing a written number or letter traced on 

the palm of one's hand after parietal damage 

Astereognosis or Somatosensory agnosia is connected 

to tactile sense ‐ that is, touch. Patient finds it difficult to 

recognize objects by touch based on its texture, size and 

weight. However, they may be able to describe it 

verbally or recognize same kind of objects from pictures 

or draw pictures of them. Thought to be connected to 

lesions or damage in somatosensory cortex. 

Hemispatial neglect 

neglect, also called 

hemiagnosia, hemineglect, unilateral 

neglect, spatial neglect, unilateral visual 

inattention, hemi‐inattention or neglect 

syndrome is a neuropsychological 

condition in which, after damage to one 

hemisphere of the brain, a deficit in 

attention to and awareness of one side 

of space is observed. It is defined by the 

inability for a person to process and 

perceive stimuli on one side of the body 

or environment that is not due to a lack 

of sensation. Hemispatial neglect is very 

commonly contralateral to the damaged 

hemisphere, but instances of ipsilesional 

neglect (on the same side as the lesion) 

have been reported 

Hemispatial neglect is most 

frequently associated with a 

lesion of the right parietal 

lobe 

An example of a 

neglect syndrome. 

Self-portraits by an 

artist after damage to 

his right posterior 

parietal cortex. 

Gerstmann's syndrome is associated with lesion to the 

dominant (usually left) parietal lobe. 

Balint's syndrome is associated with bilateral lesions. 

The syndrome of hemispatial neglect is usually 

associated with large deficits of attention of the non‐ 

dominant hemisphere. 

Optic ataxia is associated with difficulties reaching 

toward objects in the visual field opposite to the side of 

the parietal damage. Some aspects of optic ataxia have 

been explained in terms of the functional organization. 

37

23/07/54 

Gerstmann syndrome is a neurological disorder that is characterized by 

a constellation of symptoms that suggests the presence of a lesion in a particular area of 

the brain. 

Gerstmann syndrome is characterized by four primary symptoms: 

►Dysgraphia/agraphia: deficiency in the ability to write 

► Dyscalculia/acalculia: difficulty in learning or comprehending mathematics 

► Finger agnosia: inability to distinguish the fingers on the hand 

► Left‐right disorientation 

Causes 

This disorder is often associated with brain lesions in the dominant (usually left) 

hemisphere including the angular and supramarginal gyri near the temporal and parietal 

lobe junction. There is significant debate in the scientific literature as to whether 

Gerstmann Syndrome truly represents a unified, theoretically motivated syndrome. Thus 

its diagnostic utility has been questioned by neurologists and neuropsychologists alike. 

The angular gyrus is generally involved in translating visual patterns of letter and words 

into meaningful information, such as is done while reading. 

In adults 

In adults, the syndrome may occur after a stroke or in association with damage to the 

parietal lobe. In addition to exhibiting the above symptoms, many adults also experience 

aphasia, which is a difficulty in expressing oneself when speaking, in understanding 

speech, or in reading and writing. 

In children 

There are few reports of the syndrome, sometimes called 

Developmental Gerstmann syndrome, in children. The 

cause is not known. Most cases are identified when children reach 

school age, a time when they are challenged with writing and math 

exercises. Generally, children with the disorder exhibit poor 

handwriting and spelling skills, and difficulty with math functions, 

including adding, subtracting, ti multiplying, l i and dividing. idi An inability 

to differentiate right from left and to discriminate among individual 

fingers may also be apparent. 

In addition to the four primary symptoms, many children also suffer 

from constructional apraxia, an inability to copy simple drawings. 

Frequently, there is also an impairment in reading. Children with a 

high level of intellectual functioning as well as those with brain 

damage may be affected with the disorder. 

Bálint's syndrome is an uncommon and incompletely understood triad 

of severe neuropsychological impairments involving space representation 

(visuospatial processing). Its three major components are 

1) Simultanagnosia, i.e., the inability to perceive the visual field as a whole, 

2) Ocular apraxia, a deficit of visual scanning, and Apraxia—inability to carry out 

familiar movements when asked to do so 

3) Optic ataxia, an impairment of pointing and reaching under visual guidance. 

The syndrome was named in 1909 for the Austro‐Hungarian neurologist Rezső Bálint who 

had been the first to identify it. Since it represents impairment of both visual and 

language functions, it is a significant disability that can affect the patient's safety even in 

one's own home environment, and can render the person incapable of maintaining 

employment. Lack of awareness of this syndrome may lead to a misdiagnosis and 

resulting inappropriate or inadequate treatment. Therefore, clinicians should be familiar 

with Bálint's syndrome and its various etiologies. 

Balint's syndrome occurs most often with an acute onset as a consequence of 

multiple bilateral strokes. The most frequent cause of complete Balint's syndrome is 

said by some to be sudden and severe hypotension, resulting in bilateral 

borderzone infarction in the occipito‐parietal region. More rarely, cases of 

progressive Balint's syndrome have been found in degenerative disorders such as 

Alzheimer's disease or certain other traumatic brain injuries at the border of the 

parietal and the occipital lobes of the brain. 

Acalculia 

7/23/2011 NEUROPSYCHIATRY 226 

Body Schema Disturbance 


Week 6: 

The Temporal lobes 












38

23/07/54 


1. The temporal lobes and their functions 

2. The Auditory System 

3. Auditory Perception and Auditory Cortical 

Organization 



“What” 

5. Deep brain structures in Temporal lobe, e.g., 

Limbic brain structures and their functions 

6. Neuropsychology of the Temporal lobes. 

The temporal lobe is a region of the cerebral cortex that is located beneath 

the Sylvian fissure on both cerebral hemispheres of the mammalian brain. 

The temporal lobe is involved in auditory perception and is home to the primary auditory 

cortex. It is also important for the processing of semantics in both speech and vision. The 

temporal lobe contains the hippocampus and plays a key role in the formation of long‐term 

memory. 

The superior temporal gyrus includes an area (within the Sylvian fissure) where auditory signals from 

the cochlea (relayed via several subcortical nuclei) first reach the cerebral cortex. This part of the cortex 

(primary auditory cortex) is involved in hearing. Adjacent areas in the superior, posterior and lateral 

parts of the temporal lobes are involved in high‐level auditory processing. In humans this includes 

speech, for which the left temporal lobe in particular seems to be specialized. Wernicke's area, which 

spans the region between temporal and parietal lobes, plays a key role (in tandem with Broca's area, 

which is in the frontal lobe). The functions of the left temporal lobe are not limited to low‐level 

perception but extend to comprehension, naming, verbal memory and other language functions. 

The underside (ventral) part of the temporal cortices appear to be involved in high‐level visual 

processing of complex stimuli such as faces (fusiform gyrus) and scenes (parahippocampal gyrus). 

Anterior parts of this ventral stream for visual processing are involved in object perception and 

recognition. 

The medial temporal lobes (near the Sagittal plane that divides left and right cerebral hemispheres) are 

thought to be involved in episodic/declarative memory. Deep inside the medial temporal lobes lie the 

hippocampi, which are essential for memory function ‐ particularly the transference from short to long 

term memory and control of spatial memory and behavior. Damage to this area typically results in 

anterograde amnesia. 

The superior temporal gyrus is one 

of three (sometimes two) gyri in the temporal 

lobe of the human brain, which is located 

laterally to the head, situated somewhat above 

the external ear. 

The superior temporal gyrus is bounded by: 

the lateral sulcus above; 

the superior temporal sulcus below; 

an imaginary line drawn from the preoccipital 

notch to the lateral sulcus posteriorly. 

The superior temporal gyrus contains several 

important structures of the brain, including: 

Brodmann areas 41 and 42, marking the 

location of the primary auditory cortex, the 

cortical region responsible for the sensation of 

sound 

Wernicke's area, Brodmann 22p, an important 

region for the processing of speech so that it 

can be understood as language. 

Brain mechanisms 

for auditory 

functions 

(Hearing) 


Auditory Perception or Hearing 

(or audition; "auditory" or "aural") is the ability 

to perceive sound by detecting vibrations 

through an organ such as the ear. It is one of 

the traditional five senses. The inability to hear 

is called deafness. 

In humans and other vertebrates, hearing is 

performed primarily by the auditory system: 

vibrations are detected by the ear and 

transduced into nerve impulses that are 

perceived by the brain (primarily in the 

temporal lobe). Like touch, audition requires 

sensitivity to the movement of molecules in 

the world outside the organism. Both hearing 

and touch are types of mechanosensation. 

The primary auditory 

cortex 

cortex is the region of the brain 

that is responsible for the 

processing of auditory (sound) 

information. Corresponding 

roughly with Brodmann areas 41 

and 42, it is located on the 

temporal lobe, and performs the 

basics of hearing—pitch and 

volume. Besides receiving input 

from the ear and lower centers of 

the brain, the primary auditory 

cortex also transmits signals back 

to these areas. 

39

23/07/54 

Function of Primary auditory cortex 

As with other primary sensory cortical areas, auditory sensations reach perception only if 

received and processed by a cortical area. Evidence for this comes from lesion studies in 

human patients who have sustained damage to cortical areas through tumors or strokes, or 

from animal experiments in which cortical areas were deactivated by cooling or locally 

applied drug treatment. Damage to the Primary Auditory Cortex in humans leads to a loss of 

any awareness of sound, but an ability to react reflexively to sounds remains as there is a 

great deal of subcortical processing in the auditory brainstem and midbrain. 

Neurons in the auditory cortex are organized according to the frequency of sound to which 

they respond best. Neurons at one end of the auditory cortex respond best to low 

frequencies; neurons at the other respond best to high frequencies. 

There are multiple auditory areas (much like the multiple areas in the visual cortex), which 

can be distinguished anatomically and on the basis that they contain a complete "frequency 

map." The purpose of this frequency map (known as a tonotopic map) is unknown, and 

is likely to reflect the fact that the cochlea is arranged according to sound frequency. The 

auditory cortex is involved in tasks such as identifying and segregating auditory "objects" and 

identifying the location of a sound in space. 

Human brain scans have indicated that a peripheral bit of this brain region is active when 

trying to identify musical pitch. Individual cells consistently get excited by sounds at 

specific frequencies, or multiples of that frequency. 

The auditory cortex is an important yet ambiguous part of the hearing process. When the 

sound pulses pass into the cortex the specifics of what exactly takes place are unclear. 

Distinguished scientist and musician James Beament puts it into perspective when he 

writes, “The cortex is so complex that the most we may ever hope for is to understand it 

in principle, since the evidence we already have suggests that no two cortices work in 

precisely the same way." 

In hearing process, multiple sounds are being absorbed simultaneously. The role of the 

auditory system is to decide which components form the sound link. Many have surmised 

that this linking is based on location of sounds; however, there are numerous distortions 

i 

of sound when reflected off different mediums, which makes this thinking unlikely. 

Instead, the auditory cortex forms groupings based on other more of the reliable, 

fundamentals. In music for example, this would include harmony, timing, and pitch. 

The primary auditory cortex lies in the posterior half of the superior temporal gyrus and 

also dives into the lateral sulcus as the transverse temporal gyri (also called 

Heschl's gyri). 

The primary auditory cortex is located in the temporal lobe. There are additional areas of 

the human cerebral cortex that are involved in processing sound, in the frontal and 

parietal lobes. 

Brodmann area 41 is also known as the anterior transverse temporal area 41 (H). 

It is a subdivision of the cytoarchitecturally‐defined temporal region of cerebral cortex, 

occupying the anterior transverse temporal gyrus (H) in the bank of the lateral sulcus on 

the dorsal surface of the temporal lobe. Brodmann area 41 is bounded medially by the 

parainsular area 52 (H) and laterally by the posterior transverse temporal area 42 (H). 

Brodmann area 42 is also known as the posterior transverse temporal area 42 (H). It is a 

subdivision of the cytoarchitecturally‐defined temporal region of cerebral cortex, located in 

the bank of the lateral sulcus on the dorsal surface of the temporal lobe. Brodmann area 

42 is bounded medially by the anterior transverse temporal area 41 (H) and laterally by the 

superior temporal area 22. 

The primary auditory cortex is tonotopically organized, which means that 

neighboring cells in the cortex respond to neighboring frequencies. This is a 

fascinating function which has been preserved throughout most of the audition 

circuit. This area of the brain is thought to identify the fundamental elements of 

music, such as pitch and loudness. This makes sense, as this is the area which 

receives direct input from the medial geniculate nucleus of the thalamus. The 

secondary auditory cortex has been indicated in the processing of 

“harmonic, melodic and rhythmic patterns.” The tertiary auditory cortex 

supposedly integrates everything into the overall experience of music 


Broca's area is a region of the hominid brain 

with functions linked to speech production. 

The production of language has been linked to the 

Broca’s area since Pierre Paul Broca reported 

impairments in two patients. They had lost the 

ability to speak after injury to the posterior inferior 

frontal gyrus of the brain. Since then, the 

approximate region he identified has become 

known as Broca’s area, and the deficit in language 

production as Broca’s aphasia. Broca’s area is now 

typically defined in terms of the pars opercularis 

and pars triangularis of the inferior frontal gyrus, 

represented in Brodmann’s 

cytoarchitectonic map 

as areas 44 and 45. Studies of chronic aphasia have 

implicated an essential role of Broca’s area in 

various speech and language functions. Further, 

functional MRI studies have also identified 

activation patterns in Broca’s area associated with 

various language tasks. However, slow destruction 

of the Broca's area by brain tumors can leave 

speech relatively intact suggesting its functions can 

shift to nearby areas in the brain. 


40

23/07/54 

Two Streams hypothesis: 

As visual information passes forward through the visual hierarchy, the complexity 

of the neural representations increase. Whereas a V1 neuron may respond 

selectively to a line segment of a particular orientation in a particular retinotopic 

location, neurons in the lateral occipital complex respond selectively to complete 

object (e.g., a figure drawing), and neurons in visual association cortex may 

respond selectively to human faces, or to a particular object. 

Along with this increasing complexity of neural representation may come a level 

of specialization of processing into two distinct pathways: the dorsal stream and 

the ventral stream (the Two Streams hypothesis, first proposed by Ungerleider 

and Mishkin in 1982). 

The dorsal stream, , commonly referred to as the "where" stream, is involved in 

spatial attention (covert and overt), and communicates with regions that control 

eye movements and hand movements. More recently, this area has been called 

the "how" stream to emphasize its role in guiding behaviors to spatial locations. 

The ventral stream, commonly referred as the "what" stream, is involved in the 

recognition, identification and categorization of visual stimuli. 

However, there is still much debate about the degree of specialization within 

these two pathways, since they are in fact heavily interconnected 

The dorsal 

stream (Parietal 

lobe) for 

“Where” 

NEUROPSYCHIATRY 243 NEUROPSYCHIATRY 244 

The ventral stream is associated with object recognition and form 

representation. It has strong connections to the medial temporal lobe (which stores longterm 

memories), the limbic system (which controls emotions), and the dorsal stream 

(which deals with object locations and motion). 

The ventral stream gets its main input from the parvocellular (as opposed to 

magnocellular) layer of the lateral geniculate nucleus of the thalamus. These neurons 

project to V1 sublayers 4Cβ, 4A, 3B and 2/3a successively. From there, the ventral 

pathway goes through V2 and V4 to areas of the inferior temporal lobe: PIT (posterior 

inferotemporal), CIT (central inferotemporal), and AIT (anterior inferotemporal). Each 

visual area contains a full representation of visual space. That is, it contains neurons 

whose receptive fields together represent the entire visual field. Visual information 

enters the ventral stream through hthe primary visual cortex and travels through hthe rest 

of the areas in sequence. 

Moving along the stream from V1 to AIT, receptive fields increase their size, latency, and 

the complexity of their tuning. 

All the areas in the ventral stream are influenced by extraretinal factors in addition to the 

nature of the stimulus in their receptive field. These factors include attention, working 

memory, and stimulus salience. Thus the ventral stream does not merely provide a 

description of the elements in the visual world—it also plays a crucial role in judging the 

significance of these elements. 


41

23/07/54 

Brain mechanisms 

for olfaction 

(Smell), the nose 

brain or 

“Rhinencephalon” 

and associated 

limbic structures 


The limbic system (or Paleomammalian brain) is a set of brain structures 

including the hippocampus, amygdala, anterior thalamic nuclei, septum, limbic 

cortex and fornix, which seemingly support a variety of functions including 

emotion, behavior, long term memory, and olfaction. 

The limbic system operates by influencing the endocrine system and the 

autonomic nervous system. It is highly interconnected with the nucleus 

accumbens, the brain's pleasure center, which plays a role in sexual arousal and 

the "high" derived from certain recreational drugs. These responses are heavily 

modulated by dopaminergic projections from the limbic system. In 1954, Olds 

and Milner found dthat t rats with metal tlelectrodes implanted dinto their nucleus 

accumbens as well as their septal nuclei repeatedly pressed a lever activating 

this region, and did so in preference to eating and drinking, eventually dying of 

exhaustion. 

The limbic system is also tightly connected to the prefrontal cortex. Some 

scientists contend that this connection is related to the pleasure obtained from 

solving problems. To cure severe emotional disorders, this connection was 

sometimes surgically severed, a procedure of psychosurgery, called a prefrontal 

lobotomy (this is actually a misnomer). Patients who underwent this procedure 

often became passive and lacked all motivation. 

The limbic system is the set of brain structures that forms the inner border of the cortex. The cortical 

components generally have fewer layers than the classical 6‐layered neocortex, and are usually classified as allocortex 

or archicortex. 

The limbic system includes many structures in the cerebral pre‐cortex and sub‐cortex of the brain. The term has been 

used within psychiatry and neurology, although its exact role and definition have been revised considerably since the 

term was introduced. 

The following structures are, or have been considered to be, part of the limbic system: 

Hippocampus and associated structures: 

Hippocampus: Required for the formation of long‐term memories and implicated in maintenance of 

cognitive maps for navigation. 

Amygdala:Involved in signaling the cortex of motivationally significant stimuli such as those related 

to reward and fear in addition to social functions such as mating. 

Fornix: carries signals from the hippocampus to the mammillary bodies and septal nuclei. 

Mammillary body:Important for the formation of memory; 

Septal nuclei: Located anterior to the interventricular septum, the septal nuclei provide critical 

interconnections 

Limbic lobe 

Parahippocampal gyrus: Plays a role in the formation of spatial memory 

Cingulate gyrus: Autonomic functions regulating heart rate, blood pressure and cognitive and 

attentional processing 

Dentate gyrus: thought to contribute to new memories and to regulate happiness. 

In addition, these structures are sometimes also considered to be part of the limbic system: 

Entorhinal cortex: Important memory and associative components. 

Piriform cortex: The function of which relates to the olfactory system. 

Fornicate gyrus: Region encompassing the cingulate, hippocampus, and parahippocampal gyrus 

Nucleus accumbens: Involved in reward, pleasure, and addiction 

Orbitofrontal cortex: Required for decision making. 

Clinical Correlates of Limbic System: 

Amygdala ,,,,,, Fear, Anxiety, Aggressive, Violence, Rage 

Hippocampus… Episodic Memories 

Cingulate Gyrus …. Instinctive Behaviours, Parenting, 

Social bonding, Moral reasoning, 

Delayed alternating tasks 

Septal Nucleus … Docility, 

Hypothalamus ……ANS, Endocrine, Drive, Motivation 

Mammillary Body….. Memory retrieval, recall 


42

23/07/54 

Clinical Correlates of Limbic System: 

Kluver-Bucy Syndrome: 

Fearlessness. Hyperphagia, Hypersexuality, 

Psychic Blindness 

Korsakoff’s Psychosis: Confabulation 

Amnesia: (Retrograde & Anterograde Amnesia) 

Temporal Lobe Epilepsy: 

Stress, Post-traumatic Stress Disorders 

Anxiety, Fear & Phobia 

Panic Attacks, Emotional Depression 

Obsessive- Compulsive Disorders 

Abnormal Aggressive & Violence Behaviours 

Paranoid, Delusion, Schizophrenia 


What is Klüver-Bucy Syndrome? 

Klüver‐Bucy syndrome is a rare behavioral impairment 

that is associated with damage to both of the anterior 

temporal lobes of the brain. It causes individuals to put 

objects in their mouths and engage in inappropriate 

sexual behavior. Other symptoms may include visual 

agnosia (inability to visually recognize objects), loss of 

normal fear and anger responses, memory loss, 

distractibility, seizures, and dementia. The disorder may 

be associated with herpes encephalitis and trauma, 

which can result in brain damage 

Klüver-Bucy syndrome is a behavioral disorder that occurs 

when both the right and left medial temporal lobes of the brain 

malfunction. The amygdala has been a particularly implicated brain 

region in the pathogenesis of this syndrome 

The syndrome is named for Heinrich Klüver and Paul Bucy, who removed the 

temporal lobe bilaterally in rhesus monkeys in an attempt to determine its function. 

This caused the monkeys to develop visual agnosia, emotional changes, altered 

sexual behavior, and oral tendencies. 

Though the monkeys could see, they were unable to recognize even previously 

familiar objects, or their use. They would examine their world with their mouths 

instead of their eyes ("oral tendencies") and developed a desire to explore 

everything ("hypermetamorphosis"). 

Their overt sexual behavior increased dramatically ("hypersexualism"), and the 

monkeys indulged in indiscriminate sexual behavior including masturbation, 

heterosexual acts and homosexual acts. 

Emotionally, the monkeys became dulled, and their facial expressions and 

vocalizations became far less expressive. They were also less fearful of things that 

would have instinctively panicked them in their natural state, such as humans or 

snakes. Even after being attacked by a snake, they would willingly approach it again. 

This aspect of change was termed “Placidity”. 

In humans: (Klüver-Bucy( 

syndrome) 

People with lesions in their temporal lobes (a bilateral 

lesion) show similar behaviors. They may display oral or 

tactile exploratory behavior (socially inappropriate licking 

or touching); hypersexuality; bulimia; memory disorders; 

flattened emotions; and an inability to recognize objects or 

inability to recognize faces. 

The full syndrome rarely, if ever, develops in humans. 

However, parts of it are often noted in patients with 

extensive bilateral temporal damage caused by herpes or 

other encephalitis, dementias of degenerative (Alzheimer's 

disease, Pick's Disease) or post‐traumatic etiologies or 

cerebrovascular disease. 

The fusiform gyrus is part of the temporal 

lobe in Brodmann Area 37. It is also known as the 

(discontinuous) occipitotemporal gyrus. [1] Other sources have 

the fusiform gyrus above the occipitotemporal gyrus and 

underneath the parahippocampal gyrus. [2] 

Function 

There is still some dispute over the functionalities of this area, 

but there is relative consensus on the following: 

►Processing of color information 

► Face and body recognition ( Fusiform face area) 

► Word recognition 

► Number recognition 

► Within‐category identification 

Some researchers think that the fusiform gyrus may be related 

to the disorder known as prosopagnosia, or face blindness. 

Research has also shown that the fusiform face area, the area 

within the fusiform gyrus, is heavily involved in face perception 

but only to any generic within‐category identification which is 

shown to be one of the functions of the fusiform gyrus. 

Fusiform gyrus has also been involved in the perception of 

emotions in facial stimuli. 

Recent research has seen activation of the fusiform gyrus 

during subjective grapheme‐color perception in people with 

synaesthesia 

Medial surface of left cerebral hemisphere. 

(Fusiform gyrus visible near bottom) 

43

23/07/54 

The fusiform face area (FFA) is a part of the human visual system which might be specialized for facial 

recognition, although there is some evidence that it also processes categorical information about other objects, 

particularly familiar ones. 

Localization 

The FFA is located in the ventral stream on the ventral surface of the temporal lobe on the fusiform gyrus. It is 

adjacent to the parahippocampal place area and near the putative extrastriate body area. It is in a slightly different 

place for each human and displays some lateralization, usually being larger in the right hemisphere. 

The FFA was discovered and continues to be investigated in humans using positron emission tomography (PET) and 

functional magnetic resonance imaging (fMRI) studies. Usually, a participant views images of faces, objects, places, 

bodies, scrambled faces, scrambled objects, scrambled places and scrambled bodies. This is called a functional 

localizer. Comparing the neural response between faces and scrambled faces will reveal areas that are faceresponsive, 

while comparing cortical activation between faces and objects will reveal areas that are face‐selective. 

Functional role 

The human FFA was first described by Justine Sergent in 1992 and more recently by Nancy Kanwisher in 1997 who 

proposed that the existence of the FFA is evidence for domain specificity in the visual system. More recently, it has 

been suggested that the FFA processes more than just faces. Some groups, including Isabel Gauthier and others, 

maintain that the FFA is an area for recognizing fine distinctions between well‐known objects. Gauthier et al. tested 

both car and bird experts, and found some activation in the FFA when car experts were identifying cars and when bird 

experts were identifying birds. A recent paper by Kalanit Grill‐Spector et al. also suggests that processing in the FFA is 

not exclusive to faces, although an erratum was later published which brought to light some errors.The debate about 

the functional role of the FFA is ongoing. 

A 2009 magnetoencephalography study found that objects incidentally perceived as faces, an example of pareidolia, 

evoke an early (165 ms) activation in the FFA, at a time and location similar to that evoked by faces, whereas other 

common objects do not evoke such activation. This activation is similar to a slightly earlier peak at 130 ms seen for 

images of real faces. The authors suggest that face perception evoked by face‐like objects is a relatively early process, 

and not a late cognitive reinterpretation phenomenon. 

Fusiform Face Area (FFA) 

N & NJ Kotchabhakdi 2008 260 

Prosopagnosia (Greek: "prosopon" = "face", "agnosia" = "inabilty to 

recognise/identify familiar people or objects") is a disorder of face perception 

where the ability to recognize faces is impaired, while the ability to recognize 

other objects may be relatively intact. The term originally referred to a condition 

following acute brain damage, but a congenital form of the disorder has been 

proposed, which may be inherited by about 2.5% of the population. The specific 

brain area usually associated with prosopagnosia is the fusiform gyrus. 

Few successful therapies have so far been developed for affected people, 

although individuals often learn to use 'piecemeal' or 'feature by feature' 

recognition strategies. This may involve secondary clues such as clothing, gait, 

hair color, body shape, and voice. Because the face seems to function as an 

important identifying feature in memory, it can also be difficult for people with 

this condition to keep track of information about people, and socialize normally 

with others. 

Some also use the term prosophenosia, which refers to the inability to 

recognize faces following extensive damage of both occipital and temporal lobes 


Week 6: 

The Frontal lobes 











1. The Frontal lobes and their functions 

2. The Motor System 

3. Motor Cortical Organization in the Frontal Lobe 

4. The Prefrontal cortex 

5. The Frontal lobes and higher or executive brain 

functions 

6. Deep brain structures in Frontal lobe, e.g., 

Limbic brain structures and their functions 

7. Neuropsychology of the Frontal lobes and 

executive brain function disorders. 

44

23/07/54 

The Frontal lobe is an area in the brain of humans and other 

mammals, located at the front of each cerebral hemisphere and positioned 

anterior to (in front of) the parietal lobes and superior and anterior to the 

temporal lobes (i.e. directly behind the forehead or "temple"). It is 

separated from the parietal lobe by the post‐central gyrus primary motor 

cortex, which controls voluntary movements of specific body parts 

associated with the precentral gyrus posteriorly, inferiorly by lateral 

sulcus[slyvian] which separates it from the temporal lobe, superiorly by the 

superior margin of the hemisphere and anteriorly by the frontal pole. 

The frontal lobe contains most of the dopamine‐sensitive neurons in the 

cerebral cortex. The dopamine system is associated with reward, attention, 

short‐term term memory tasks, planning, and drive. Dopamine tends to limit and 

select sensory information arriving from the thalamus to the fore‐brain. A 

report from the National Institute of Mental Health says a gene variant that 

reduces dopamine activity in the prefrontal cortex is related to poorer 

performance and inefficient functioning of that brain region during working 

memory tasks, and to slightly increased risk for schizophrenia. 

Frontal lobe Anatomy 

On the lateral surface of the human brain, the central sulcus separates the frontal lobe from 

the parietal lobe. The lateral sulcus separates the frontal lobe from the temporal lobe. 

The frontal lobe can be divided into a lateral, polar, orbital (above the orbit; also called basal 

or ventral), and medial part. Each of these parts consists of particular gyri: 

∆ Lateral part: Precentral gyrus, lateral part of the superior frontal gyrus, middle frontal 

gyrus, inferior frontal gyrus. 

∆ Polar part: Transverse frontopolar gyri, frontomarginal gyrus. 

∆ Orbital part: Lateral orbital gyrus, anterior orbital gyrus, posterior orbital gyrus, medial 

orbital gyrus, gyrus rectus. 

∆ Medial part: Medial part of the superior frontal gyrus, cingulate gyrus. 

The gyri are separated by sulci. E.g., the precentral gyrus is in front of the central sulcus, and 

behind the precentral sulcus. The superior and middle frontal gyri are divided by the 

superior frontal sulcus. The middle and inferior frontal gyri are divided by the inferior frontal 

sulcus. 

In humans, the frontal lobe reaches full maturity around only after the 20s, marking the 

cognitive maturity associated with adulthood. 

Dr. Arthur Toga, a UCLA professor of neurology, found increased myelin in the frontal lobe 

white matter of young adults compared to that of teens. A typical onset of schizophrenia in 

early adult years correlates with poorly myelinated and thus inefficient connections 

between cells in the fore‐brain 

Pyramidal motor system: 

Corticospinal tracts 

tracts is a collection of 

axons that travel between the cerebral cortex 

of the brain and the spinal cord. 

The corticospinal tract mostly contains motor axons. 

It actually consists of two separate tracts in the 

spinal cord: the lateral corticospinal tract and the 

anterior corticospinal tract. 

An understanding of these tracts leads to an 

understanding of why for the most part, one side of 

the body is controlled by the opposite side of the 

brain. 

The corticobulbar tract is also considered to be a 

pyramidal tract, though it carries signals to motor 

neurons of the cranial nerve nuclei, rather than the 

spinal cord. 

The neurons of the corticospinal tracts are referred 

to as pyramidal neurons. The name comes from the 

shape of the corticospinal tracts, which somewhat 

resemble pyramids as they pass through the 

medulla. 

The corticospinal tract is concerned specifically with 

discrete voluntary skilled movements, especially of 

the distal parts of the limbs. (Sometimes called 

"fractionated" movements) 

The motor pathway 

The corticospinal tract originates from pyramidal cells in layer V of the 

cerebral cortex. 

About half of its fibres arise from the primary motor cortex. Other 

contributions come from the supplementary motor area, premotor 

cortex, somatosensory cortex, parietal lobe, and cingulate gyrus. The 

average fiber diameter is in the region of 10μm; around 3% of fibres are 

extra‐large (20μm) and arise from Betz cells, mostly in the leg area of the 

primary motor cortex. 

Upper motor neurons 

The neuronal cell bodies in the motor cortex, together with their axons 

that travel down through the brain stem and spinal cord are commonly 

referred to as upper motor neurons. It should be noted however, that 

they do not project to muscles, and thus the term 'motor neuron' is 

somewhat misleading. 

Anatomy of the motor cortex 

The motor cortex can be divided into four main parts: 

∆ the primary motor cortex (or M1, Broadman area #4), 

responsible for generating the neural impulses controlling 

execution of movement 

and the secondary motor cortices, including 

∆ the posterior parietal cortex, responsible for transforming 

visual information into motor commands 

∆ the premotor cortex, (Broadman areas #6, 8, 9,10) 

responsible for motor guidance of movement and control of 

proximal and trunk muscles of the body 

∆ and the supplementary motor area (or SMA), responsible 

for planning and coordination of complex movements such 

as those requiring two hands. 

Other brain regions outside the cortex are also of great 

importance to motor function, most notably the cerebellum and 

subcortical motor nuclei. 

45

23/07/54 

The extrapyramidal system is a neural network located in the 

brain that is part of the motor system involved in the coordination of movement. 

The system is called "extrapyramidal" to distinguish it from the tracts of the motor 

cortex that reach their targets by traveling through the "pyramids" of the medulla. 

The pyramidal pathways (corticospinal and some corticobulbar tracts) may directly 

innervate motor neurons of the spinal cord or brainstem (anterior (ventral) horn 

cells or certain cranial nerve nuclei), whereas the extrapyramidal system centers 

around the modulation and regulation (indirect control) of anterior (ventral) horn 

cells. 

Extrapyramidal tracts are chiefly found in the reticular formation of the pons and 

medulla, and target neurons in the spinal cord involved in reflexes, locomotion, 

complex movements, and postural control. These tracts are in turn modulated by 

various parts of the central nervous system, including the nigrostriatal pathway, 

the basal ganglia, the cerebellum, the vestibular nuclei, and different sensory 

areas of the cerebral cortex. All of these regulatory components can be considered 

part of the extrapyramidal system, in that they modulate motor activity without 

directly innervating motor neurons. 

Corticospinal tract damage 

Damage to the descending motor pathways anywhere 

along the trajectory from the cerebral cortex to the lower 

end of the spinal cord gives rise to a set of symptoms 

called the "upper motor neuron syndrome". A few days 

after the injury to the upper motor neurons a pattern of 

motor signs and symptoms appears, including spasticity, 

the decreased vigor (and increased threshold) of 

superficial reflexes, a loss of the ability to perform fine 

movements, and an extensor plantar response known as 

the Babinski sign. [ 

The frontal eye fields (FEF) is a region located in the premotor cortex, 

which is part of the frontal cortex of the primate brain. 

Function 

The cortical area called frontal eye fields (FEF) plays an important role in the control of 

visual attention and eye movements. Electrical stimulation in the FEF elicits saccadic eye 

movements. The FEF have a topographic structure and represents saccade targets in 

retinotopic coordinates. 

The frontal eye field is reported to be activated during the initiation of eye movements, 

such as voluntary saccades and pursuit eye movements. There is also evidence that it 

plays a role in purely sensory processing and that it belongs to a “fast brain” system 

through a superior colliculus – medial dorsal nucleus –FEF ascending pathway.In 

humans, its earliest activations in regard to visual stimuli occur at 45 ms with activations 

related to changes in visual stimuli within 45–60 ms (these are comparable with 

response times in the primary visual cortex). This fast brain pathway also provides 

auditory input at even shorter times starting at 24 ms and being affected by auditory 

characteristics at 30–60 ms. The FEF constitutes together with the supplementary eye 

fields (SEF), the intraparietal sulcus (IPS) and the superior colliculus (SC) one of the most 

important brain areas involved in the generation and control of eye movements, 

particularly in the direction contralateral to the frontal eye fields' location. 

46

23/07/54 

Brodmann area 8, or BA8, is part of the 

frontal cortex in the human brain. Situated just 

anterior to the premotor cortex (BA6), it includes the 

frontal eye fields (so‐named because they are 

believed to play an important role in the control of 

eye movements). Damage to this area, by stroke, 

trauma or infection, causes tonic deviation of the 

eyes towards the side of the injury. This finding 

occurs during the first few hours of an acute event 

such as cerebrovascular infarct (stroke) or 

hemorrhage (bleeding). 

Distinctive features (Brodmann‐1905): compared to Brodmann area 6‐ 

1909, area 8 has a diffuse but clearly present internal granular layer (IV); 

sublayer 3b of the external pyramidal layer (III) has densely distributed 

medium sized pyramidal cells; the internal pyramidal layer (V) has larger 

ganglion cells densely distributed with some granule cells interspersed; the 

external granular layer (II) is denser and broader; cell layers are more 

distinct; the abundance of cells is somewhat greater. 

Other Functions 

The area is involved in the management of uncertainty. A functional 

magnetic resonance imaging study demonstrated that brodmann area 8 

activation occurs when test subjects experience uncertainty, and that with 

increasing uncertainty there is increasing activation. 

An alternative interpretation is that this activation in frontal cortex encodes 

hope, a higher‐order expectation positively correlated with uncertainty. 

Brain: Brodmann area 8 

The limbic system is also tightly connected to the 

prefrontal cortex. 

Some scientists contend that this connection is 

related to the pleasure obtained from solving problems. To 

cure severe emotional disorders, this connection was 

sometimes surgically severed, a procedure of 

psychosurgery, called a prefrontal lobotomy. Patients who 

underwent this procedure often became passive and 

lacked all motivation. 

There is circumstantial evidence that the limbic 

system also provides a custodial function for the 

maintenance of a healthy conscious state of mind. 

Brodmann’s areas 3D 

map: Lateral Surface 

map: Medial Surface 


47

23/07/54 

Brodmann area 44, , or BA44 

44, is part of the frontal 

cortex in the human brain. Situated just anterior to premotor 

cortex (BA6) and on the lateral surface, inferior to BA9. 

This area is also known as pars opercularis (of the inferior 

frontal gyrus), and it refers to a subdivision of the 

cytoarchitecturally defined frontal region of cerebral cortex. In 

the human it corresponds approximately to the opercular part 

of inferior frontal gyrus (H). Thus, it is bounded caudally by the 

inferior precentral sulcus (H) and rostrally by the anterior 

ascending limb of lateral sulcus (H). It surrounds the diagonal 

sulcus (H). In the depth of the lateral sulcus it borders on the 

insula. Cytoarchitectonically it is bounded caudally and dorsally 

by the agranular frontal area 6, dorsally by the granular frontal 

area 9 and rostrally by the triangular area 45 (Brodmann‐1909). 

Together with left‐hemisphere BA 45, the left hemisphere . BA 

44 comprises Broca's area a region involved in semantic tasks. 

Some data suggest that BA44 is more involved in phonological 

and syntactic processing. Some recent findings also suggest the 

implication of this region in music perception. In 95.5% of righthanders 

and 61.4% of left‐handers, therefore about 90% of the 

clinical population, speech is lateralised in the left hemisphere. 


Brodmann area 45 (BA45), 

is part of the frontal 

cortex in the human brain. Situated on the lateral surface, 

inferior to BA9 and adjacent to BA46. This area is also known as 

pars triangular (of the inferior frontal gyrus). In the human, it 

occupies the triangular part of inferior frontal gyrus (H) and, surrounding 

the anterior horizontal limb of lateral sulcus (H), a portion of the orbital 

part of inferior frontal gyrus (H). Bounded caudally by the anterior 

ascending limb of lateral sulcus (H), it borders on the insula in the depth 

of the lateral sulcus. Cytoarchitectonically it is bounded caudally by the 

opercular area 44 (BA44), rostrodorsally by the middle frontal area 46 

(BA46) and ventrally by the orbital area 47 (BA47) (Brodmann‐1909). 

Together with BA 44 it comprises Broca's area, a region which is active in 

semantic tasks, such as semantic decision tasks (determining whether a 

word represents an abstract or a concrete entity) and generation tasks 

(generating a verb associated with a noun). 

The precise role of BA45 in semantic tasks remains controversial. For 

some researchers, its role would be to subserve semantic retrieval or 

semantic working memory processes. Under this view, BA44 and BA45 

would together guide recovery of semantic information and evaluate the 

recovered information with regards to the criterion appropriate to a 

given context. A slightly modified account of this view is that activation 

of BA45 is needed only under controlled semantic retrieval, when strong 

stimulus‐stimulus associations are absent. For other researchers, BA45's 

role is not restricted to semantics per se, but to all activities which 

require task‐relevant representations from among competing 

representations. 


Brodmann area 47, , or BA47 

47, is part of 

the frontal cortex in the human brain. Curving from the 

lateral surface of the frontal lobe into the ventral 

(orbital) frontal cortex. It is below areas BA10 and BA45, 

and beside BA11. 

This area is also known as orbital area 47. In the human, 

on the orbital surface it surrounds the caudal portion of 

the orbital sulcus (H) from which it extends laterally into 

the orbital part of inferior frontal gyrus (H). 

Cytoarchitectonically yoac eco cayit is bounded caudally by the 

triangular area 45, medially by the prefrontal area 11 of 

Brodmann‐1909, and rostrally by the frontopolar area 10 

(Brodmann‐1909). 

It incorporates the region that Brodmann identified as 

"Area 12" in the monkey, and therefore, following the 

suggestion of Michael Petrides, some contemporary 

neuroscientists refer to the region as "BA47/12." 

BA47 has been implicated in the processing of syntax 

in spoken and signed languages, and more recently in 

musical syntax. 


Prefrontal 

cortex 

Brodmann area 9, , or BA9, is part of the 

frontal cortex in the human brain. It 

contributes to the dorsolateral prefrontal 

cortex. 

Brodmann area 9 refers to a cytoarchitecturally defined 

portion of the frontal lobe of the guenon (Old world 

monkeys). Brodmann‐1909 regarded it on the whole as 

topographically and cytoarchitecturally homologous to the 

granular frontal area 9 and frontopolar area 10 in the 

human. Distinctive features (Brodmann‐1905): unlike 

Brodmann area 6‐1909, area 9 has a distinct internal 

granular layer (IV); unlike Brodmann area 6 or Brodmann 

area 8‐1909 its internal pyramdal layer (V) is divisible into 

two sublayers, an outer layer 5a of densely distributed 

medium sized ganglion cells that partially merges with 

layer IV, and an inner, clearer, cell‐poor layer 5b; the 

pyramidal cells of sublayer 3b of the external pyramidal 

layer (III) are smaller and sparser in distribution; the 

external granular layer (II) is narrow, with small numbers 

of sparsely distributed granule cells. 


The dorsolateral prefrontal cortex (DL‐PFC or DLPFC), 

according to a more restricted definition, is roughly equivalent to Brodmann areas 9 and 46. 

According to a broader definition DL‐PFC consists of the lateral portions of Brodmann areas 

9 – 12, of areas 45, 46, and the superior part of area 47.These regions mainly receive their 

blood supply from the middle cerebral artery. With respect to neurotransmitter systems, 

there is evidence that dopamine plays a particularly important role in DL‐PFC. 

DL‐PFC is connected to the orbitofrontal cortex, and to a variety of brain areas, which 

include the thalamus, parts of the basal ganglia (the dorsal caudate nucleus), the 

hippocampus, and primary and secondary association areas of neocortex, including 

posterior temporal, parietal, and occipital areas. 

DL‐PFC is the last area, 45th, to develop myelinate in the human cerebrum 

DL‐PFC serves as the highest h cortical area responsible for motor planning, organization, i and 

regulation. It plays an important role in the integration of sensory and mnemonic 

information and the regulation of intellectual function and action. It is also involved in 

working memory. However, DL‐PFC is not exclusively responsible for the executive 

functions. All complex mental activity requires the additional cortical and subcortical 

circuits with which the DL‐PFC is connected. 

Damage to the DL‐PFC can result in the dysexecutive syndrome, [4] which leads to problems 

with affect, social judgement, executive memory, abstract thinking and intentionality. [ 

Lucid dream states 

More recent research has found a connection between the DL‐PFC and lucid dream states 

in which executive function is retained 

48

23/07/54 

Brodmann area 10, or BA10 

is the 

frontopolar part of the frontal cortex in the human brain. 

BA10 was originally defined in terms of microscopic 

cytoarchitecturic traits in autopsy brains; modern functional 

imaging research cannot directly identify these boundaries 

and the terms anterior prefrontal, rostral prefrontal cortex 

and frontopolar prefrontal cortex are used to refer to the 

area in the most anterior part of the frontal cortex that 

approximates to or principally covers BA10. 

BA10 is the largest cytoarchitectonic area in the human 

brain. It has been described as "one of the least well 

understood dregions of the human brain". Present research 

suggests that it is involved in strategic processes in memory 

retrieval and executive function. During human evolution, 

the functions in this area resulted in its expansion relative to 

the rest of the brain. 

Although this region is extensive in humans, its function is poorly understood. 

Koechlin & Hyafil have proposed that processing of 'cognitive branching' is the 

core function of the frontopolar cortex. Cognitive branching enables a 

previously running task to be maintained in a pending state for subsequent 

retrieval and execution upon completion of the ongoing one. Many of our 

complex behaviors and mental activities require simultaneous engagement of 

multiple tasks, and they suggest the anterior prefrontal cortex may perform a 

domain‐general function in these scheduling operations. However, other 

hypotheses have also been proffered, such as those by Burgess et al. 


Brodmann area 11 is one of Brodmann's 

cytologically defined regions of the brain. It is 

involved in planning, reasoning, and decision 

making. 

Brodmann area 11, or BA11, is part of the frontal cortex in the 

human brain. BA11 covers the medial part of the ventral surface of 

the frontal lobe. 

Prefrontal area 11 of Brodmann‐1909 is a subdivision of the frontal 

lobe in the human defined on the basis of cytoarchitecture. Defined 

and illustrated in Brodmann‐1909, it included the areas 

subsequently illustrated in Brodmann‐10 as prefrontal area 11 and 

rostral area 12. 

prefrontal area 11 is a subdivision of the cytoarchitecturally defined 

frontal region of cerebral cortex of the human. As illustrated in 

Brodmann‐10, It constitutes most of the orbital gyri, gyrus rectus 

and the most rostral portion of the superior frontal gyrus. It is 

bounded medially by the inferior rostral sulcus (H) and laterally 

approximately by the frontomarginal sulcus (H). Cytoarchitecturally 

it is bounded on the rostral and lateral aspects of the hemisphere 

by the frontopolar area 10, the orbital area 47, and the triangular 

area 45; on the medial surface it is bounded dorsally by the rostral 

area 12 and caudally by the subgenual area 25. In an earlier map, 

the area labeled 11, i.e., prefrontal area 11 of Brodmann‐1909, was 

larger; it included the area now designated rostral area 12. 


Brodmann area 46, or BA46 

46, is part of the frontal cortex 

in the human brain. It is between BA10 and BA45. 

BA46 is known as middle frontal area 46. In the human brain it 

occupies approximately the middle third of the middle frontal 

gyrus and the most rostral portion of the inferior frontal gyrus. 

Brodmann area 46 roughly corresponds with the dorsolateral 

prefrontal cortex (DLPFC), although the borders of area 46 are 

based on cytoarchitecture rather than function. The DLPFC also 

encompasses part of granular frontal area 9, directly adjacent on 

the dorsal surface of the cortex. 

Cytoarchitecturally, BA46 is bounded dorsally by the granular frontal area 

9, rostroventrally by the frontopolar area 10 and caudally by the 

triangular area 45 (Brodmann‐1909). There is some discrepancy between 

the extent of BA8 (Brodmann‐1905) and the same area as described by 

Walker (1940) 

The DLPFC plays a role in sustaining attention and working 

memory. Lesions to the DLPFC impair short‐term memory and 

cause difficulty inhibiting responses. Lesions may also eliminate 

much of the ability to make judgements about what's relevant 

and what's not as well as causing problems in organization. 

The DLPFC has recently been found to be involved in exhibiting 

self‐control. The dorsolateral prefrontal cortex, which is one of the few 

areas deactivated during REM sleep. Neuroscientist J. Allan Hobson has 

hypothesized that activation of the dorsolateral prefrontal cortex produce 

lucid dreams. 


The Brodmann area 32 

32, also known in the 

human brain as the dorsal anterior cingulate area 

32, refers to a subdivision of the cytoarchitecturally 

defined cingulate region of cerebral cortex. In the 

human it forms an outer arc around the anterior 

cingulate gyrus. The cingulate sulcus defines 

approximately its inner boundary and the superior 

rostral sulcus (H) its ventral boundary; rostrally it 

extends almost to the margin of the frontal lobe. 

Cytoarchitecturally it is bounded internally by the 

ventral anterior cingulate area 24, externally by 

medial margins of the agranular frontal area 6, 

intermediate frontal area 8, granular frontal area 9, 

frontopolar area 10, and prefrontal area 11‐1909. 

(Brodmann19‐09). 

Dorsal region of anterior cingulate gyrus is 

associated with rational thought processes, most 

notably active during the Stroop task. 


Stroop effect is a 

demonstration of the reaction time of a 

task. When the name of a color (e.g., 

"blue," "green," or "red") is printed in a 

color not denoted by the name (e.g., the 

word "red" printed in blue ink instead of 

red ink), naming the color of the word 

takes longer and is more prone to errors 

than when the color of the ink matches the 

name of the color. The effect is named 

after John Ridley Stroop who first 

published the effect in English in 1935. The 

effect had previously been published in 

Germany in 1929. The original paper has 

been one of the most cited papers in the 

history of experimental psychology, leading 

to more than 700 replications. The effect 

has been used to create a psychological 

test (Stroop 

Test) that is widely used in 

clinical practice and investigation. 

This test is considered to measure selective 

attention, cognitive flexibility and processing 

speed, and it is used as a tool in the 

evaluation of executive functions. An 

increased interference effect is found in 

disorders such as brain damage, dementias 

and other neurodegenerative diseases, 

attention‐deficit hyperactivity disorder, or a 

variety of mental disorders such as 

schizophrenia, addictions, and depression 

The anterior cingulate cortex has been related 

to the processing of the Stroop effect 

49

23/07/54 

Brodmann area 24 is part of the anterior 

cingulate in the human brain. 

In the human this area is known as ventral anterior 

cingulate area 24, and it refers to a subdivision of the 

cytoarchitecturally defined cingulate cortex region of 

cerebral cortex (area cingularis anterior ventralis). It 

occupies most of the anterior cingulate gyrus in an arc 

around the genu of corpus callosum. Its outer border 

corresponds approximately to the cingulate sulcus. 

Cytoarchitecturally it is bounded internally by the 

pregenual area 33, externally by the dorsal anterior 

cingulate area 32, and caudally by the ventral 

posterior cingulate area 23 and the dorsal posterior 

cingulate area 31. 

Francis Crick, one of the discoverers of DNA, listed 

area 24 as the seat of free will because of its 

centrality in abulia and amotivational syndromes. 


Figure 1 from Experiment 2 of the original description of the Stroop 

Effect (1935). 1 is the time that it takes to name the color of the dots 

while 2 is the time that it takes to say the color when there is a conflict 

with the written word 

Aboulia or Abulia (from the Greek "αβουλία", meaning 

"non‐will"), in neurology, refers to a lack of will or initiative 

and is one of the Disorders of Diminished Motivation or 

DDM. Aboulia falls in the middle of the spectrum of 

diminished motivation, with apathy being less extreme and 

akinetic mutism being more extreme than aboulia. A 

patient with aboulia is unable to act or make decisions 

independently. d It may range in severity from subtle bl to 

overwhelming. It is also known as Blocq's disease (which 

also refers to abasia and astasia‐abasia). Abulia was 

originally considered to be a disorder of the will. [ 

Aboulia has been known to clinicians since 1838. However, in the time since its 

inception, the definition of aboulia has been subjected to many different forms, some 

even contradictory with previous ones. Aboulia has been described as a loss of drive, 

expression, loss of behavior and speech output, slowing and prolonged speech latency, 

and reduction of spontaneous thought content and initiative. The clinical features most 

commonly associated with aboulia are: 

1. Difficulty in initiating and sustaining purposeful movements 

2. Lack of spontaneous movement 

3. Reduced spontaneous movement 

4. Increased response‐time to queries 

5. Passivity 

6. Reduced emotional responsiveness and spontaneity 

7. Reduced social interactions 

8. Reduced interest in usual pastimes 

Especially in patients with progressive dementia, it may affect feeding. Patients may 

continue to chew or hold food in their mouths for hours without swallowing it. The 

behavior may be most evident after these patients have eaten part of their meals 

and no longer have strong appetites. 

Amotivational syndrome is a psychological condition associated 

with diminished inspiration to participate in social situations and activities, 

with lapses in apathy caused by an external event, situation, substance (or 

lack of), relationship, or other cause. 

While some have claimed that chronic use of cannabis causes amotivational 

syndrome in some users, empirical studies suggest that there is no such thing 

as "amotivational syndrome", per se, but that chronic cannabis intoxication 

can lead to apathy and amotivation. From a World Health Organization report: 

The evidence for an "amotivational syndrome" among adults consists largely 

of case histories i and observational reports (e.g. Kl Kolanskyand Moore, 1971; 

Millman and Sbriglio, 1986). The small number of controlled field and 

laboratory studies have not found compelling evidence for such a syndrome 

(Dornbush, 1974; Negrete, 1983; Hollister, 1986)... (I)t is doubtful that 

cannabis use produces a well defined amotivational syndrome. It may be more 

parsimonious to regard the symptoms of impaired motivation as symptoms of 

chronic cannabis intoxication rather than inventing a new psychiatric 

syndrome. 

Apathy (also called impassivity or 

perfunctoriness) is a state of 

indifference, or the suppression of emotions 

such as concern, excitement, motivation and 

passion. An apathetic individual has an 

absence of interest in or concern about 

emotional, social, spiritual, philosophical or 

physical life. 

They may lack a sense of purpose or 

meaning in their life. He or she may also 

exhibit hb insensibility bl or sluggishness. The 

opposite of apathy is flow. In positive 

psychology, apathy is described as a result of 

the individual feeling they have much more 

than the level of skill required to confront a 

challenge. It may also be a result of 

perceiving no challenge at all (e.g. the 

challenge is irrelevant to them, or conversely, 

they have learned helplessness). 

50

23/07/54 

Brodmann area 25 (BA25) is an area in the 

cerebral cortex of the brain and delineated based on 

its cytoarchitectonic characteristics, also called the 

subgenual area, area subgenualis or subgenual 

cingulate. It is the 25th "Brodmann area" defined by 

Korbinian Brodmann (thus its name). BA25 is located in the 

cingulate region as a narrow band in the caudal portion of 

the subcallosal area adjacent to the paraterminal gyrus. The 

posterior parolfactory sulcus separates the paraterminal 

gyrus from BA25. Rostrally it is bound by the prefrontal area 

11 of Brodmann. This region is extremely rich in serotonin 

transporters and is considered as a governor for a vast 

network involving areas like hypothalamus and brain stem, 

which influences changes in appetite and sleep; the 

amygdala and insula, which affect the mood and anxiety; the 

hippocampus, which plays an important role in memory 

formation; and some parts of the frontal cortex responsible 

for self‐esteem. 

One study has noted that BA25 is metabolically overactive in treatmentresistant 

depression and has found that chronic deep brain stimulation in the 

white matter adjacent to the area is a successful treatment for some patients. 

A different study found that metabolic hyperactivity in this area is associated 

with poor therapeutic response of persons with Major Depressive Disorder to 

cognitive‐behavioral therapy and venlafaxine 


Brodmann area 33, , also known as 

pregenual area 33, is a subdivision 

of the cytoarchitecturally defined 

cingulate region of cerebral cortex. It 

is a narrow band located in the 

anterior cingulate gyrus adjacent to 

the supracallosal gyrus in the depth 

of the callosal sulcus. 

Cytoarchitecturally it is bounded by 

the ventral anterior cingulate area 

24 and the supracallosal gyrus 

(Brodmann‐1909). 


Blood supply 

Branches of the middle cerebral artery provide most of 

the arterial blood supply for the primary motor cortex. 

The medial aspect (leg areas) is supplied by branches of 

the anterior cerebral artery. 

Neural input from the thalamus 

The primary motor cortex receive thalamic input from 

the Ventral lateral nucleus of the Thalamus. 

Pathology 

Lesions of the precentral gyrus result in paralysis of the 

contralateral side of the body (facial palsy, arm‐/leg 

monoparesis, hemiparesis) ‐ see upper motor neuron. 

51

23/07/54 

52

Neurological Examination, clinical cases and neuropsychological ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?