Goble Daniel J, Brown Susan H
Division of Kinesiology, University of Michigan, 1402 Washington Heights, Ann Arbor, MI 48109-2013, USA.
J Neurophysiol. 2008 Jun;99(6):3063-74. doi: 10.1152/jn.90259.2008. Epub 2008 Apr 24.
The purpose of the current study was to determine the extent to which "sensory dominance" exists in right-handers with respect to the utilization of proprioceptive versus visual feedback. Thirteen right-handed adults performed two target-matching tasks using instrumented manipulanda. In the proprioceptive matching task, the left or right elbow of blindfolded subjects was passively extended by a torque motor system to a target position and held for 3 s before being returned to the start position. The target angle was then matched with either the ipsilateral or contralateral arm. In the second task, visual matching, circular targets were briefly projected to either side of a visual fixation point located in front of the subject. Subjects then matched the target positions with a laser pointer by moving either the ipsilateral or contralateral arm. Overall, marked arm differences in accuracy were seen based on the type of sensory feedback used for target presentation. For the proprioceptive matching task errors were smaller for the nonpreferred left arm, whereas during the visual matching task smaller errors were found for the preferred right arm. These results suggest a left arm/right hemisphere advantage for proprioceptive feedback processing and a right arm/left hemisphere advantage for visual information processing. Such asymmetries may reflect fundamental differences between the two arm/hemisphere systems during the performance of bimanual tasks where the preferred arm requires visual guidance to manipulate an object, whereas the nonpreferred stabilizes that object on the basis of proprioceptive feedback.
本研究的目的是确定在使用本体感觉反馈与视觉反馈方面，右利手人群中“感觉优势”的存在程度。13名右利手成年人使用仪器化操作器进行了两项目标匹配任务。在本体感觉匹配任务中，蒙眼受试者的左肘或右肘由扭矩电机系统被动伸展至目标位置，并保持3秒，然后返回起始位置。然后将目标角度与同侧或对侧手臂进行匹配。在第二项任务，即视觉匹配任务中，圆形目标短暂投射到位于受试者前方的视觉固定点的两侧。然后受试者通过移动同侧或对侧手臂，用激光笔匹配目标位置。总体而言，根据用于目标呈现的感觉反馈类型，在准确性方面存在明显的手臂差异。对于本体感觉匹配任务，非优势左手的误差较小，而在视觉匹配任务中，优势右手的误差较小。这些结果表明，在处理本体感觉反馈方面左臂/右半球具有优势，在处理视觉信息方面右臂/左半球具有优势。这种不对称可能反映了在双手任务执行过程中，两个手臂/半球系统之间的根本差异，其中优势手臂需要视觉引导来操纵物体，而非优势手臂则根据本体感觉反馈来稳定该物体。
