The effect of cerebrovascular accident on the ability to localize sounds under conditions of the precedence effect.

This study examines the ability of patients with cerebrovascular accident to localize single clicks and assign spatial locations to paired clicks presented from loudspeakers on the left and right of midline. The clicks within each pair were separated by intervals of either 2, 4, 8, or 16 msec. Normal subjects and brain-damaged patients without evidence of discrete lesions in their CT scans were able to localize both single and paired clicks. Patients with discrete right temporo-parietal lobe lesions were able to localize single clicks, but frequently reversed the apparent perceptual locus of paired clicks in the hemifield contralateral to the side of lesion. Patients with lesions in the left hemisphere, in areas outside the temporo-parietal region, did not display deficits under any condition.