HUMAN TEMPORAL-LOBE POTENTIALS IN VERBAL-LEARNING AND MEMORY PROCESSES

Animal experiments and lesion studies have shown the importance of tem poral lobe structures for language and memory. We recorded intracrania l cognitive potentials from the human lateral and medial temporal lobe in 26 patients with temporal lobe epilepsy undergoing presurgical eva luation, using a word- and a picture-recognition paradigm. Neuropsycho logical testing included word fluency, verbal reasoning, sustained att ention and a verbal learning memory test (VLMT), which was an adapted version of the Rey auditory verbal learning test. Word-specific N400-p otentials elicited in the middle temporal gyrus of the dominant left h emisphere (LTL-N400) predicted immediate recall performance after lear ning, whereas N400s, elicited by words but not pictures in the left an terior medial temporal Lobe (AMTL-N400), predicted delayed recall. The number of words that were learned but forgotten after a 30-min delay correlated only with N400s elicited by words in the left anterior medi al temporal lobe. Thus, intracranial recordings indicated that differe nt electrophysiological responses in different temporal lobe structure s were linked to memory scores from specific neuropsychological tests. (C) 1997 Elsevier Science Ltd.