Attribute processing in patients with graphical copying disability.
This study investigated whether defective copying of multiple-line figures in lesion patients is associated with a deficit in perceptually processing and copying elementary attributes. Lesion and Control patients were assessed on a copying test comprising multi-line figures, and on parallel perceptual and motor forms of single-attribute tasks for Size, Orientation, Angle, Position and Direction. Copying test performance was correlated with perceptual attribute performance for the Lesion but not the Control group. Mean attribute performance of the Lesion patients who showed a copying disability (defined as a copying performance below the minimum performance of the Control group) was inferior to that of the non-disabled and Control subjects. The non-disabled patients did not differ from the Controls on any of these tasks. Performance in the copying test for left- and right-hemisphere patients did not differ, but left-hemisphere patients showed less impairment in the simple attribute tasks. The results are discussed in terms of the role of elementary perceptual deficits in copying disability and hemispheric differences in the nature of this condition.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001072:Apraxias / Q000523:psychology*; D004192:Discrimination, Psychological; D005556:Form Perception; D006801:Humans; D008297:Male; D008875:Middle Aged; D009949:Orientation; D011601:Psychophysics; D012858:Size Perception