Descriptive Psychopathology: The Signs and Symptoms of ...

56 Section 1: Present, past, and futurethe first social vocalizations of human infants, emerging between 2 and 6monthsafter birth. Congenitally deaf and blind infants laugh although never havingperceived the laughter of others. 17 Despite substantial individual variability,laughter is a stereotypic, species-specific behavior. Its precursor is the “play-face”and pant-like vocalizations of apes in social play during their “safe times”, and isconsidered an important evolutionary development in small hominid groupcohesion. In humans, laughter and humor has been elaborated to support novelsocial functions, but it remains a brain-derived expression with reproductive(e.g. being emotionally attractive) and resource-gathering advantage (e.g. gettingalong with co-workers and superiors and in leadership strategies). The loss of theability to laugh is always pathological. 18 Among patients with melancholia,regaining the ability to laugh (e.g. at the examiner’s humor) is an important signof the resolution of the depressive illness.Cortical activities such as internal speech and verbal-based thinking are experiencedas a significant part of mental life, but these thoughts are expressions ofneurologic functioning. Internal speech is experienced throughout wakefulness asa running commentary on what has recently happened, what is happening, andwhat may happen. But the elements of internal speech are subserved by the sameneurology as conversational speech. Functional imaging of normal persons tosimple language-based tasks show different left cerebral hemisphere metabolicresponse patterns to each task. Hearing and speaking words as in conversationalspeech, generating words (ideas) as in “mental speech”, and seeing words as inreading are all experienced as mental activity. But these functions and the brainareas subserving them are the same behavior–brain relationships associated withstroke and aphasia. 19The “mental status examination” is thus anachronistic. The behavioral andcognitive assessments incorporated in it do not characterize “the mind”, butrather the brain, and the effort is best described as “the behavioral examinationof the brain”.Brain disease and dysfunction as psychopathologyAlthough brain–behavior relationships are complex, broad relationships areunderstood and these are diagnostically helpful. A movement disorder willinvolve the motor system at some level, and more specific localization is likelywith careful examination (e.g. basal ganglia versus cerebellar disease). A personwith no speech or language disturbances but with misidentification delusions ismore likely to have non-dominant than dominant cerebral hemisphere disease.Intense emotional expression, as in mood disorders, will be associated withamygdala activation.