Intact memory for irrelevant information impairs perception in amnesia.
Memory and perception have long been considered separate cognitive processes, and amnesia resulting from medial temporal lobe (MTL) damage is thought to reflect damage to a dedicated memory system. Recent work has questioned these views, suggesting that amnesia can result from impoverished perceptual representations in the MTL, causing an increased susceptibility to interference. Using a perceptual matching task for which fMRI implicated a specific MTL structure, the perirhinal cortex, we show that amnesics with MTL damage including the perirhinal cortex, but not those with damage limited to the hippocampus, were vulnerable to object-based perceptual interference. Importantly, when we controlled such interference, their performance recovered to normal levels. These findings challenge prevailing conceptions of amnesia, suggesting that effects of damage to specific MTL regions are better understood not in terms of damage to a dedicated declarative memory system, but in terms of impoverished representations of the stimuli those regions maintain.
Department of Psychology University of Toronto, Toronto, ON, Canada. barense@psych.utoronto.ca
Morgan D
MD
Barense
Iris I A
II
Groen
Andy C H
AC
Lee
Lok-Kin
LK
Yeung
Sinead M
SM
Brady
Mariella
M
Gregori
Narinder
N
Kapur
Timothy J
TJ
Bussey
Lisa M
LM
Saksida
Richard N A
RN
Henson
D000293:Adolescent; D000328:Adult; D000647:Amnesia / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008568:Memory / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult