The Brain: Structure and Function

The Brain: Structure and Function
• The brain grows to 3 pounds across 20 years
• “Ontology recapitulates phylogeny”
– structures arise in the course of development and mirror evolution
• hindbrain: Medulla, pons, cerebellum
• midbrain: superior colliculi, reticular, etc.
• forebrain: higher cognitive functions

Cortical Orientation
• Directions: Lateral/medial, dorsal/ventral, anterior/posterior
• Lobes: Frontal, Occipital, Parietal, Temporal

Localization of Function
• Franz Gall and
phrenology
– “faculty psychology”
– assumed
• different parts do
different things (yes!)
• size matters (no!)
• different faculties are
independent (no!)

Neuropsychology
• Broca’s aphasia: Failure to produce speech
• Wernicke’s aphasia: Fluent, nonsensical speech

Motor and Somatosensory Cortex

Lateralization
• Left goes to right and vice versa
• Language on the left (usually)
– larger left hemisphere and handedness
– lateralized and bilateralized
• Integration of visual and auditory on right
– larger right temporal areas
– geometric puzzles, navigation, faces, sports
• Analytic/Synthetic, Left/Right brained
– but these are simplifications
– each hemisphere can do most things
• split brain patients and the corpus callosum

Static Imaging Techniques
(CAT, MRI, and PET)

Functional Imaging Techniques
• Hemodynamic:
– Positron Emission
Topography (PET)
– functional Magnetic
Resonance Imaging
(fMRI)
• Electrophysiology:
– EEG/ERP
– MEG

Subtraction Technique

Electroencephalography (EEG) and Event-
Related Potential (ERP)

Presentation
Sequence
Word Priming
doctor
NURSE
Prime: 10 - 2000 ms
Target: ~ 50 ms
What word did
you see?
Mask: ~ 500 ms

Cognitive Neuroscience of Language