Neurobehavioral studies of isolation-reared monkeys

Vocal pathology in socially deprived monkeys

“…Each observation period consisted of 15 min undisturbed observation and 5 min in which manipulations were carried out to ascertain reactions to various novel and stressful stimuli. Results of these tests have been reported elsewhere (Symmes, Eisengart, & Healy, 1971).…”

“…However, the abnormal structure of Isolates' clear calls may have a neurologic basis. Electrophysiological abnormalities in limbic and cerebellar structures have been reported (Heath, 1972;Synimes & Chase, 1972), and motor clumsiness has been described in nonstereotyped movements (Symmes, Eisengart, & Healy, 1971). A peripheral origin of the defects in vocal production seems unlikely as examination of the vocal tracts of individuals from both groups of monkeys did not reveal any abnormalities* (Moses, 1960).…”