Around the clock surveillance: simple graphic disturbance in patients with hemispatial neglect carries implications for the clock drawing task.
BACKGROUND
Drawing, and the clock drawing task in particular, is widely used as a diagnostic tool in the study of hemispatial neglect. It is generally assumed that the errors in graphic production, such as the misplacement of numbers, reflect a visuospatial deficit, and that drawing production itself (for example, producing the circle) is unimpaired.


OBJECTIVE
To test this assumption by examining whether the production of simple circles is affected by neglect.


METHODS
16 right hemisphere stroke patients copied circles of various sizes and their drawings were measured for size accuracy.


RESULTS
Patients with more severe neglect produced greater scaling errors, consistently drawing the circle smaller than the original. Errors were not in the horizontal axis alone--shrinkage occurred equally in both height and width axes.


CONCLUSIONS
Neglect can co-occur with constructional difficulties that serve to exacerbate the symptoms presented. This should be taken into account in the assessment of even apparently simple drawing tasks.
Department of Experimental Psychology, University of Bristol, 8 Woodland Road, Bristol BS8 1TN, UK. alastair.smith@bristol.ac.uk
A D
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Smith
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Gilchrist
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Butler
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Harvey
D000368:Aged; D000369:Aged, 80 and over; D000381:Agraphia / Q000175:diagnosis* / Q000523:psychology; D002544:Cerebral Infarction / Q000150:complications / Q000175:diagnosis; D004292:Dominance, Cerebral; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D010468:Perceptual Disorders / Q000175:diagnosis*; D011597:Psychomotor Performance