Around the clock surveillance: simple graphic disturbance in patients with hemispatial neglect carries implications for the clock drawing task.

摘要

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. OBJECTIVES: 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.