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Distortion of size perception in visuospatial neglect
1Psychological Laboratory, University of St Andrews, Fife, UK.
Current Biology : CB
|January 1, 1995
Summary
Patients with left-sided visuospatial neglect underestimate the size of objects on their left. This perceptual distortion may stem from damage to brain regions involved in spatial representation.
Area of Science:
- Neuroscience
- Cognitive Psychology
- Perception
Background:
- Unilateral neglect, often left-sided, is associated with rightward errors in line bisection.
- A potential cause is the underestimation of the left side of stimuli by neglect patients.
Purpose of the Study:
- To directly investigate perceptual distortions in size perception in patients with visuospatial neglect.
- To determine if neglect patients underestimate the horizontal extent of stimuli presented on their left.
Main Methods:
- Three patients with neglect symptoms performed matching tasks on computer-presented shapes (horizontal rectangles, vertical rectangles, nonsense shapes) of varying relative sizes.
- Judgements focused on the horizontal and vertical extent and overall area of the stimuli.
Main Results:
- All tested patients significantly underestimated the horizontal extent and area of stimuli presented on their left side.
- No such misperception of vertical extent was observed.
Conclusions:
- Size perception may be influenced by a representational system located in the parieto-temporal brain regions.
- Damage to this system in neglect patients could explain the observed perceptual distortions.