Affective tasks elicit material-specific memory effects in temporal lobectomy patients.

Eighteen patients who had undergone a right (9) or left (9) temporal lobectomy (RTL, LTL) including removal of the amygdala and hippocampus were evaluated. Sixteen male and sixteen female undergraduate subjects were evaluated for normative comparison. All subjects were administered Verbal (words) and Visual (faces) paired associates tasks. The present study sought to evaluate material-specific memory after temporal lobectomy, and to compare affective versus neutral memory as well. Thus, there were 4 tasks: Verbal Affective, Verbal Neutral, Visual Affective, and Visual Neutral. The material-specific effects of better Verbal memory performance by the RTL subjects compared to the LTL subjects and better Visual memory performance by the LTL subjects than the RTL subjects were only significant for the Affective tasks, and not the Neutral tasks. Perhaps adding an affective dimension to the material-specific memory tasks engaged the amygdala in addition to the other structures known to be important in memory. A strong interpretaion of the present data is made difficult by task differences and the low average IQ and possible reorganization of function that may have occurred in the patient sample.