INTEREST in organic components of psychiatric disease was given a great impetus by the discovery that a distinct relationship exists between the fetal and perinatal complications known to be associated with brain damage and childhood behavior disorders.^1-3 The search for organic correlates of behavior, in addition to producing data of immediate clinical relevance, also resulted in refinements of the techniques used in the neurological assessment of patients. With the availability of tests capable of eliciting perceptual impairment, movement disorders, and other deviations in neurological organization, attention turned to the so-called functional psychiatric patients. Reports that a very high percentage of psychiatric patients and especially those with the diagnosis of psychosis show minor (nonlocalizing neurologic findings—"soft signs") led several investigators to postulate that such minor deviations represent the organic substrate of impairments in adaptive behavior.^4-11

According to this hypothesis