FATIGUE VERSUS DISENGAGEMENT IN UNILATERAL NEGLECT

A letter cancellation task revealed neglect of the lower left quadrant when cancellation began at the top, but of the upper left quadrant wh en it began in the bottom. When the cancellation was done line by line through a ''window'' which covered all but the fine currently worked on, the quadrant effects disappeared, so that fatigue could not explai n these effects. An alternative hypothesis is that as the cancellation progressed, the subject's attention was attracted by progressively mo re stimuli on the right, and that disengagement difficulty and hence n eglect increased proportionately to die number of stimuli.