An ear asymmetry for gap detection following anterior temporal lobectomy.

A threshold elevation in the performance of auditory temporal order judgment in man has been reported in the ear contralateral to the side of an anterior temporal lobectomy. On the basis of temporal order judgments alone it is not possible to determine whether the deficit is attributable to an impairment of recognition, identification, or temporal resolution. The present monaural experiments compared the performance of the two ears in the detection of a gap in a broad-band noise burst in normal and temporal lobectomized subjects. The results revealed a right-left symmetry in gap detection performance by normal subjects but a significant deficit in gap detection in the ear contralateral to the side of an anterior temporal lobectomy--a finding interpreted as revealing the existence of a bonafide deficit in auditory temporal resolution induced by such resection.