ABSTRACT: The importance of the perirhinal cortex for visual recognition
memory performance is undisputed. However, it has not been clear
whether its contribution to performance is mainly perceptual, or mainly
mnemonic, or whether the perirhinal cortex contributes to both perception
and memory. We determined the effects of medial temporal lobe
damage that includes complete damage to the perirhinal cortex in two
amnesic patients by assessing recognition memory for complex visual
stimuli across delays from 0 to 40 s. These patients, as well as six other
amnesic patients with damage limited to the hippocampal formation or
diencephalic structures, exhibited intact recognition memory at delays of
0–2 s and a delay-dependent memory impairment at delays of 6 s and
longer. Additionally, the patients with damage to the perirhinal cortex
performed worse than the other amnesic patients at delays of 25 s and
longer. The findings suggest that the perirhinal cortex is not important for
visual perception or immediate memory. In this respect, the findings for
perirhinal cortex resemble the findings for other medial temporal lobe
structures, including the hippocampus. Hippocampus 1998;8:330–339.
r 1998 Wiley-Liss, Inc.†