DISCRIMINATION OF FACIAL IDENTITY AND FACIAL AFFECT BY TEMPORAL AND FRONTAL LOBECTOMY PATIENTS

The purpose of this study was to determine the extent to which lobecto my affects ability to discriminate facial identity or facial expressio n. Fifteen right temporal, 15 left temporal, 5 right frontal, and 4 le ft frontal lobectomy patients, pair-matched for age, sex, and educatio n to normal control subjects, participated in this study. Tasks includ ed a Facial Identity Matching Task and a Facial Affect Matching task. The lobectomized patients as a whole were significantly impaired on bo th tasks (22% decrement in performance). The patients made twice as ma ny errors resulting from perseveration of response-set of the first co ndition (identity or emotion matching) into the second condition. The site of lobectomy did not influence general performance on any one tas k or selective performance on any subset of affective categories. It w as concluded that all four brain regions play a significant and equal role in face processing, and that circuits more specifically dedicated to visual face processing, which are responsible for hemispheric domi nance affects and affect/identity dissociations, are probably located more posteriorly in the brain. Finally, it was concluded that persever ation of acquired habit may, under specific conditions, characterize t emporal lobe dysfunction just as much as frontal lobe dysfunction. (C) 1994 Academic Press, Inc.