Rao A K, Gordon A M
Department of Biobehavioral Sciences, Teachers College Columbia University, New York, NY 10027, USA.
Exp Brain Res. 2001 Jun;138(4):438-45. doi: 10.1007/s002210100717.
We examined the contribution of tactile cues to accuracy during point-to-point movements. We used a task in which the experimenter guided either the left or right hand of the subject to a spatial location during the reference movement. During the subsequent test movement subjects were asked to point with the right hand to the remembered location without vision. Subjects contacted the target with their fingertip either during the reference movement, both the reference and test movements, or neither movement (i.e., the fingertip was held above the target surface). To differentiate between the contribution of tactile and proximal deep pressure information, the left index finger was anesthetized in a subsequent experiment. When subjects contacted the surface with the fingertip of the reference hand alone, error in movement direction decreased. When subjects made fingertip contact during the reference and test movements, gain error also decreased. Anesthesia of the fingertip degraded accuracy, suggesting that tactile information, independent of information from proximal deep pressure receptors, influenced movement accuracy. Thus, tactile information contributed to accuracy in pointing movements. We suggest that forces at fingertip contact may provide information regarding the orientation of the finger and forearm in space, which is used to replicate final arm posture. In addition, tactile cues at the beginning and end of the movement may be used to scale movement amplitude.
我们研究了触觉线索在点对点运动过程中对准确性的贡献。我们采用了一项任务，即在参考运动期间，实验者将受试者的左手或右手引导至一个空间位置。在随后的测试运动中，要求受试者在无视觉的情况下用右手指向记忆中的位置。受试者在参考运动期间、参考运动和测试运动期间或两者都不接触（即指尖保持在目标表面上方）的情况下用指尖接触目标。为了区分触觉和近端深部压力信息的贡献，在随后的实验中对左手食指进行了麻醉。当受试者仅用参考手的指尖接触表面时，运动方向的误差减小。当受试者在参考运动和测试运动期间进行指尖接触时，增益误差也减小。指尖麻醉会降低准确性，这表明独立于近端深部压力感受器信息的触觉信息会影响运动准确性。因此，触觉信息有助于指向运动的准确性。我们认为，指尖接触时的力可能提供有关手指和前臂在空间中方向的信息，这些信息用于复制最终的手臂姿势。此外，运动开始和结束时的触觉线索可能用于调整运动幅度。
