Neuronal evidence that inferomedial temporal cortex is more important than hippocampus in certain processes underlying recognition memory.

Amnesia has been reported to result from combined damage to the amygdala, hippocampus and inferomedial temporal cortex in man and monkey. Evidence is presented that neuronal activity in the monkey inferomedial temporal cortex reflects memory for the previous occurrence of visual stimuli: 26 (15%) of 173 single units responded more strongly to first than to subsequent presentations of unfamiliar stimuli. No such responses were found for neurones recorded in the hippocampus and subicular cortex. The findings suggest that the inferomedial temporal cortex plays a central role in processes necessary for recognition memory.