MOVE Research Institute Amsterdam, Faculty of Human Movement Sciences, VU University Amsterdam, The Netherlands.
Behav Brain Res. 2013 Aug 1;250:334-42. doi: 10.1016/j.bbr.2013.05.005. Epub 2013 May 13.
Sensorimotor biases were examined for intentional (tracking task) and unintentional (distractor task) rhythmic coordination. The tracking task involved unimanual tracking of either an oscillating visual signal or the passive movements of the contralateral hand (proprioceptive signal). In both conditions the required coordination patterns (isodirectional and mirror-symmetric) were defined relative to the body midline and the hands were not visible. For proprioceptive tracking the two patterns did not differ in stability, whereas for visual tracking the isodirectional pattern was performed more stably than the mirror-symmetric pattern. However, when visual feedback about the unimanual hand movements was provided during visual tracking, the isodirectional pattern ceased to be dominant. Together these results indicated that the stability of the coordination patterns did not depend on the modality of the target signal per se, but on the combination of sensory signals that needed to be processed (unimodal vs. cross-modal). The distractor task entailed rhythmic unimanual movements during which a rhythmic visual or proprioceptive distractor signal had to be ignored. The observed biases were similar as for intentional coordination, suggesting that intentionality did not affect the underlying sensorimotor processes qualitatively. Intentional tracking was characterized by active sensory pursuit, through muscle activity in the passively moved arm (proprioceptive tracking task) and rhythmic eye movements (visual tracking task). Presumably this pursuit afforded predictive information serving the coordination process.
研究了有意（跟踪任务）和无意（分心任务）节律协调的运动觉偏差。跟踪任务涉及单侧跟踪摆动视觉信号或对侧手的被动运动（本体感觉信号）。在这两种情况下，所需的协调模式（同方向和镜像对称）相对于身体中线定义，手不可见。对于本体感觉跟踪，两种模式在稳定性上没有差异，而对于视觉跟踪，同方向模式比镜像对称模式更稳定。然而，当在视觉跟踪期间提供有关单手运动的视觉反馈时，同方向模式不再占主导地位。这些结果表明，协调模式的稳定性并不取决于目标信号的模态本身，而是取决于需要处理的感觉信号的组合（单模态与跨模态）。分心任务涉及单侧有节奏的运动，在此期间必须忽略有节奏的视觉或本体感觉分心信号。观察到的偏差与有意协调相似，表明意向性不会从质上影响潜在的运动觉过程。有意跟踪的特点是通过被动移动手臂中的肌肉活动（本体感觉跟踪任务）和有节奏的眼球运动（视觉跟踪任务）进行主动感觉追踪。据推测，这种追踪提供了有助于协调过程的预测信息。
