Subjective contour illusion: sex-related effect of unilateral brain damage

The aim of the study was to investigate the effect of unilateral brain lesi ons on the perception of subjective contours. Brain damage resulted in a re duced ability to perceive the illusion. The effect, however, was hemisphere and sex dependent. In women an illusion decrement due to either the left o r right hemisphere damage was observed, while in men only right hemisphere damage caused a decrement. No specific effect of intrahemispheric localisat ion of lesion was found. We conclude that mechanisms contributing to subjec tive contour perception are right. hemisphere dependent in males whereas in females they are bilaterally represented. NeuroReport 12:2289-2292 (C) 200 1 Lippincott Williams & Wilkins.