Quantitative modeling of category learning in amnesic patients.
Category rule learning was examined in two amnesic patients using the perceptual categorization task (e.g., Ashby & Gott, 1988; Filoteo & Maddox, 1999). Traditional accuracy-based analyses as well as quantitative model-based analyses were performed. Unlike accuracy-based analyses, the model-based approach allowed us to examine both categorization rule learning and variability in the trial-by-trial application of the participant's categorization rule. The results indicated that the amnesic patients were as accurate as the controls in learning a complex, nonlinear rule over a large number of trials. The model-based analysis indicated that, in general, the amnesic patients learned the categorization rule as well as controls and applied their rule as consistently as controls. Categorization performance on a second day of testing revealed that amnesic patients can retain the categorization rule over a 24-h period. These results suggest that the brain regions damaged in amnesia are not involved in category learning or memory for the category structures.
Department of Psychiatry, University of California, San Diego 92161, USA. vfiloteo@ucsd.edu
J V
JV
Filoteo
W T
WT
Maddox
J D
JD
Davis
D000328:Adult; D000647:Amnesia / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D012720:Severity of Illness Index; D013702:Temporal Lobe / Q000473:pathology; D014888:Wechsler Scales