LEFT TEMPORAL NEOCORTEX MEDIATION OF VERBAL MEMORY - EVIDENCE FROM FUNCTIONAL MAPPING WITH CORTICAL STIMULATION

We examined the contribution of the temporal neocortex to short-term m emory (STM) in 15 patients with left hemisphere language dominance dur ing intraoperative or extraoperative cortical mapping prior to left an terior temporal lobectomy. Recall errors were examined following stimu lation during the acquisition, consolidation, and retrieval stages of a verbal STM task. Ten patients showed stimulation-induced recall erro rs, and five patients showed no significant memory errors. More patien ts showed errors following stimulation during consolidation than durin g acquisition or retrieval, possibly because of disrupted transfer of information from the temporal neocortex to the hippocampus. Patients w ith stimulation-induced recall errors did not differ significantly fro m patients without memory errors in terms of seizure, demographic, or neuropsychological variables. Patients with resection of sites showing stimulation-induced recall errors had greater postoperative decline i n verbal memory than did patients with resection sparing these sites. We suggest that the left, temporal neocortex contributes to verbal mem ory consolidation in patients with chronic epilepsy.