title: Are Alzheimer's disease patients able to learn visual prototypes?
abstract: Recently, controversial results emerged regarding visual prototype learning in Alzheimer's disease (AD). The aim of this study was to elucidate this issue in a larger population of AD patients. The AD patients (N=72) and age-matched healthy control subjects (N=25) learned to recognize and to categorize visual dot patterns. In comparison with the control subjects, the AD patients as a group showed dysfunctions in the recognition task, whereas categorization was relatively spared in their case. Recognition was impaired in patients with mild AD (Mini-Mental score: 18-23) and moderate AD (Mini-Mental score<18), whereas categorization was impaired only in patients with moderate AD. These results suggest that while the medio-temporal/diencephalic explicit memory system is markedly affected even in early AD, the sensory neocortical areas mediating implicit category learning display a sufficient degree of functional capacity until later stages of the disease.
authors.affiliation: Department of Psychiatry, University of Szeged, Semmelweis u. 6, 6725, Szeged, Hungary. szkeri@phys.szote.u-szeged.hu
authors.forename: S
authors.initials: S
authors.lastname: Kéri
authors.forename: J
authors.initials: J
authors.lastname: Kálmán
authors.forename: O
authors.initials: O
authors.lastname: Kelemen
authors.forename: G
authors.initials: G
authors.lastname: Benedek
authors.forename: Z
authors.initials: Z
authors.lastname: Janka
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology*; D008569:Memory Disorders / Q000175:diagnosis / Q000503:physiopathology; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000175:diagnosis* / Q000503:physiopathology*; D021641:Recognition, Psychology; D014796:Visual Perception / Q000502:physiology*