Egocentric body-centered coordinates modulate visuomotor performance

Abstract

Parietal damage has been hypothesized to distort the body-centered coordinate frame and produce the ipsilesional spatial bias characteristic of unilateral neglect. The present studies investigated the role of the egocentric frame in normal visuomotor performance by manipulating the alignment of the body midline in neurologically-intact adults. The results from two experiments indicate that: (1) rightward rotation causes a right visual field advantage in detection times for lateralized targets; (2) rightward rotation evokes an increase in visual sensitivity to right visual field targets and a decrease in sensitivity to left visual field targets; and (3) leftward rotation does not affect response latency or sensitivity, however, response criterion is mildly affected. By demonstrating that the alignment of the body-centered frame can induce neglect-like asymmetries in visuomotor performance in neurologically-intact subjects, the results support a role for an altered body-centered representation in clinical neglect.