The human entorhinal cortex participates in associative memory

Abstract
Animal studies have shown that lesions of the parahippocampal cortex impair learning of visual stimulus-stimulus associations. We tested the hypothesis that recall of paired associates, in contrast to recall of non-associated items, activates the parahippocampal cortex in humans. Ten volunteers had their regional cerebral blood flow measured with positron emission tomography during non-associative recall, and during two conditions with associative recall of visual stimuli. Compared with non-associative recall, associative recall specifically increased the blood flow in a field located in the entorhinal cortex, extending into the presubiculum. Our results demonstrate functional differences between the human hippocampal and parahippocampal cortex, and show that the entorhinal cortex is engaged in associative memory.