Failing to get the gist: reduced false recognition of semantic associates in semantic dementia.
In 2 experiments involving patients with semantic dementia, the authors investigated the impact of semantic memory loss on both true and false recognition. Experiment 1 involved recognition memory for categories of everyday objects that shared a predominantly semantic relationship. The patients showed preserved item-specific recollection for the pictorial stimuli but, compared with control participants, exhibited significantly reduced utilization of gist information regarding the categories of objects. The latter result is consistent with the patients' degraded semantic knowledge. Experiment 2 involved categories of abstract objects that were related to one another perceptually rather than semantically. Patients with semantic dementia obtained item-specific recollection and gist memory scores that were indistinguishable from those of control participants. These results suggest that the reduction in gist memory in semantic dementia is largely specific to semantic representations and cannot be attributed to general difficulty with abstracting and/or utilizing gistlike commonalities between stimuli.
Simons
Jon S
JS
Institute of Cognitive Neuroscience, University College London, London, United Kingdom. jon.simons@ucl.ac.uk
Verfaellie
Mieke
M
Hodges
John R
JR
Lee
Andy C H
AC
Graham
Kim S
KS
Koutstaal
Wilma
W
Schacter
Daniel L
DL
Budson
Andrew E
AE
D000368:Aged; D016022:Case-Control Studies; D003704:Dementia / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000503:physiopathology*; D008570:Memory, Short-Term / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation / Q000379:methods; D021641:Recognition, Psychology / Q000502:physiology*; D012016:Reference Values; D012094:Repression, Psychology; D012660:Semantics; D018709:Statistics, Nonparametric; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*