Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, 16163 Genova, Italy,
Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, 16163 Genova, Italy.
J Neurosci. 2014 Jul 2;34(27):9164-72. doi: 10.1523/JNEUROSCI.2782-13.2014.
Saccades cause compression of visual space around the saccadic target, and also a compression of time, both phenomena thought to be related to the problem of maintaining saccadic stability (Morrone et al., 2005; Burr and Morrone, 2011). Interestingly, similar phenomena occur at the time of hand movements, when tactile stimuli are systematically mislocalized in the direction of the movement (Dassonville, 1995; Watanabe et al., 2009). In this study, we measured whether hand movements also cause an alteration of the perceived timing of tactile signals. Human participants compared the temporal separation between two pairs of tactile taps while moving their right hand in response to an auditory cue. The first pair of tactile taps was presented at variable times with respect to movement with a fixed onset asynchrony of 150 ms. Two seconds after test presentation, when the hand was stationary, the second pair of taps was delivered with a variable temporal separation. Tactile stimuli could be delivered to either the right moving or left stationary hand. When the tactile stimuli were presented to the motor effector just before and during movement, their perceived temporal separation was reduced. The time compression was effector-specific, as perceived time was veridical for the left stationary hand. The results indicate that time intervals are compressed around the time of hand movements. As for vision, the mislocalizations of time and space for touch stimuli may be consequences of a mechanism attempting to achieve perceptual stability during tactile exploration of objects, suggesting common strategies within different sensorimotor systems.
扫视会导致扫视目标周围视觉空间的压缩，以及时间的压缩，这两种现象都被认为与保持扫视稳定性的问题有关（Morrone 等人，2005 年；Burr 和 Morrone，2011 年）。有趣的是，在手运动时也会出现类似的现象，此时触觉刺激会被系统地定位在运动的方向上（Dassonville，1995 年；Watanabe 等人，2009 年）。在这项研究中，我们测量了手部运动是否也会导致触觉信号感知时间的改变。人类参与者在响应听觉提示移动右手时，比较了两对触觉敲击之间的时间间隔。第一对触觉敲击在相对于运动的可变时间处呈现，其起始固定延迟为 150 毫秒。测试呈现后两秒钟，当手静止时，第二对敲击以可变的时间间隔呈现。触觉刺激可以施加到手正在运动的右手或静止的左手。当触觉刺激在运动前和运动期间施加到手的运动效应器时，它们的感知时间间隔会缩短。时间压缩是效应器特异性的，因为左手静止时的感知时间是真实的。结果表明，在手运动期间时间间隔会被压缩。与视觉一样，触觉刺激的时间和空间的错位可能是一种试图在触摸物体时实现知觉稳定性的机制的结果，这表明不同感觉运动系统中存在共同的策略。
