The role of the cross-sensory error signal in visuomotor adaptation
The role of the cross-sensory error signal in visuomotor adaptation
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DOI：
10.1007/s00221-013-3564-7
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发表时间：
2013-07-01
影响因子：
2
通讯作者：
Henriques, Denise Y. P.
中科院分区：
文献类型：
--
作者：
Salomonczyk, Danielle;Cressman, Erin K.;Henriques, Denise Y. P.
到达目标与错位的视觉反馈的手导致的手的位置和达到后效的本体感受估计的变化。在这样的任务中，受试者能够利用两个错误信号：期望和实际运动之间的差异，称为感觉运动错误信号，以及视觉和本体感觉估计手的位置之间的差异，我们称之为跨感觉错误信号。我们最近已经表明，仅仅暴露于感官差异，在没有目标导向的运动（即没有感觉运动错误信号）是足以产生类似的变化，感觉手的位置，并达到后效。在这里，我们试图确定的程度，这种跨感官的错误信号可以有助于本体感受重新校准和运动后的影响，通过操纵这个信号的幅度在没有意志瞄准运动。受试者沿着机器人生成的线性路径沿着伸出手，该路径相对于光标的路径逐渐顺时针旋转。在所有的试验中，受试者都看到一个光标直接指向一个记忆中的目标，而他们的手同步移动。在暴露于30A度旋转的手光标失真后，受试者重新校准了他们的感觉手的位置，并调整了他们的范围。然而，在交叉感觉误差信号进一步增加（例如高达70 A度）后，没有观察到重新校准或后效的额外增加。这是在对比我们以前的研究中，受试者自由地达到目标与错位的视觉手的位置反馈，因此经历了感觉运动和跨感官的错误，和失真幅度系统地预测增加本体感受重新校准和达到后效。鉴于这些研究结果，我们认为，跨感觉错误信号的结果，感觉手的位置，驱动部分达到后效的变化，而更大的后效，视觉适应后产生的（并随失真的大小而变化）与感觉运动错误信号。
Reaching to targets with misaligned visual feedback of the hand leads to changes in proprioceptive estimates of hand position and reach aftereffects. In such tasks, subjects are able to make use of two error signals: the discrepancy between the desired and actual movement, known as the sensorimotor error signal, and the discrepancy between visual and proprioceptive estimates of hand position, which we refer to as the cross-sensory error signal. We have recently shown that mere exposure to a sensory discrepancy in the absence of goal-directed movement (i.e. no sensorimotor error signal) is sufficient to produce similar changes in felt hand position and reach aftereffects. Here, we sought to determine the extent that this cross-sensory error signal can contribute to proprioceptive recalibration and movement aftereffects by manipulating the magnitude of this signal in the absence of volitional aiming movements. Subjects pushed their hand out along a robot-generated linear path that was gradually rotated clockwise relative to the path of a cursor. On all trials, subjects viewed a cursor that headed directly towards a remembered target while their hand moved out synchronously. After exposure to a 30A degrees rotated hand-cursor distortion, subjects recalibrated their sense of felt hand position and adapted their reaches. However, no additional increases in recalibration or aftereffects were observed following further increases in the cross-sensory error signal (e.g. up to 70A degrees). This is in contrast to our previous study where subjects freely reached to targets with misaligned visual hand position feedback, hence experiencing both sensorimotor and cross-sensory errors, and the distortion magnitude systematically predicted increases in proprioceptive recalibration and reach aftereffects. Given these findings, we suggest that the cross-sensory error signal results in changes to felt hand position which drive partial reach aftereffects, while larger aftereffects that are produced after visuomotor adaptation (and that vary with the size of distortion) are related to the sensorimotor error signal.