Pattern separation deficits following damage to the hippocampus.
Computational models of hippocampal function propose that the hippocampus is capable of rapidly storing distinct representations through a process known as pattern separation. This prediction is supported by electrophysiological data from rodents and neuroimaging data from humans. Here, we test the prediction that damage to the hippocampus would result in pattern separation deficits by having memory-impaired patients with bilateral hippocampal damage study a series of objects or faces and then perform a modified recognition memory test. In the test phase, participants viewed true repetitions, novel foils, and lures that were perceptually and semantically related to the studied stimuli. Patients with hippocampal damage were unimpaired relative to matched controls in their baseline recognition memory. However, patients were less likely to uniquely identify lures as "similar" than matched controls, indicating an impairment in pattern separation processes following damage to the hippocampus.
Department of Psychology, Brigham Young University, 1001 Kimball Tower, Provo, UT 84602-5543, USA. kirwan@byu.edu
C
C
Brock Kirwan
Andrew
A
Hartshorn
Shauna M
SM
Stark
Naomi J
NJ
Goodrich-Hunsaker
Ramona O
RO
Hopkins
Craig E L
CE
Stark
D000328:Adult; D005260:Female; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000473:pathology / Q000503:physiopathology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology*