The role of vision on hand preshaping during reach to grasp.

摘要: During reaching to grasp objects with different shapes hand posture is molded gradually the object's contours. The present study examined extent which temporal evolution of depends on continuous visual feedback. We asked subjects reach and under five vision conditions (VCs). Subjects wore liquid crystal spectacles that occluded at four latencies from onset reach. As a control, full-vision trials (VC5) were interspersed among blocked trials. Object all VCs presented in random order. Hand was measured by 15 sensors embedded glove. Linear regression analysis, discriminant information theory used assess effect removing shape. found duration increased when early This caused primarily slower approach toward object near end However, condition did not have significant covariation patterns joint rotations, indicating gradual occurs similar fashion regardless vision. Discriminant analysis further supported this interpretation, as resembled shape rate discrimination occurred throughout movement across conditions. These results extend previous observations memory-guided reaches showing feedback and/or necessary allow conform