The Japanese journal of neuropsychology

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ArticleTitle	Size dependent visuo-cognitive disorder: a case study
Language	J
AuthorList	Eriko Matsumoto^/, Yoshitaka Ohigashi, Tokiji Hanihara, Misato Fujimori, Etsuro Mori**
Affiliation	Graduated school of Human and Environmental Studies, Kyoto University *Division of Clinical Neurosciences, Hyogo Institute for Aging Brain Cognitive Disorders
Publication	Japanese Journal of Neuropsychology: 16 (1), 56-65, 2000
Received	Apr 9, 1999
Accepted	Dec 14, 1999
Abstract	We described a 56-year-old, right-handed patient with probable Alzheimer's disease (AD) who showed a peculiar type of progressive visual disturbance. The patients had started experiencing difficulties "seeing" a year previous to her referral to the clinic. The disturbance in identifying visually-presented objects was more evident when seeing large objects than when seeing small ones. To examine the effect of size on the visual attention, digits with varied size were displayed on a screen in various exposure duration. The performance of the patient was better on the small size condition than on the large size condition, and was improved with longer exposure duration especially on the large size condition. This result indicated that the patient could not sufficiently extend attentional visual area under short exposure condition. An impairment in the automatic/reflective attentional system that acts in the initial stage of attentional process would restrict the attended area ("spotlight").
Keywords	Alzheimer's disease, visuo-cognitive disorder, visual attention