Department of Psychology, University of Trier , Trier , Germany.
Department of Experimental Psychology, University of Oxford , Oxford , United Kingdom.
J Neurophysiol. 2019 Jun 1;121(6):2358-2363. doi: 10.1152/jn.00128.2019. Epub 2019 Apr 10.
Representational momentum (RM) is the term used to describe a systematic mislocalization of dynamic stimuli, a forward shift; that is, an overestimation of the location of a stimulus along its anticipated trajectory. In the present study, we investigate the effect of velocity on tactile RM, because two distinct and contrasting predictions can be made, based on different theoretical accounts. According to classical accounts of RM, based on numerous visual and auditory RM studies, an increase of the forward shift with increasing target velocity is predicted. In contrast, theoretical accounts explaining spatiotemporal tactile illusions such as the tau or cutaneous rabbit effect predict a decrease of the forward shift with increasing target velocity. In three experiments reported here, a tactile experimental setup modeled on existing RM setups was implemented. Participants indicated the last location of a sequence of three tactile stimuli, which either did or did not imply motion in a consistent direction toward the elbow/wrist. Velocity was manipulated by changing the interstimulus interval as well as the duration of the stimuli. The results reveal that increasing target velocity led to a decrease and even a reversal of the forward shift, resulting in a backward shift. This result is consistent with predictions based on the evidence from tactile spatiotemporal illusions. The theoretical implications of these results for RM are discussed. This study tests two distinct predictions concerning the influence of velocity on the localization of dynamic tactile stimuli. We demonstrate for tactile stimuli that with increasing velocity, a misperception in the direction of anticipated motion (termed "representational momentum") turns into a misperception against the direction of motion. This result is in line with predictions based on tactile spatiotemporal illusions but challenges classical theoretical accounts of representational momentum based on evidence from vision and audition.
代表性动量（RM）是用来描述动态刺激的系统定位错误，即向前移位；也就是说，对刺激位置的估计沿其预期轨迹向前偏移。在本研究中，我们研究了速度对触觉 RM 的影响，因为基于不同的理论解释，可以做出两种截然不同的预测。根据基于大量视觉和听觉 RM 研究的 RM 的经典解释，随着目标速度的增加，预测会出现向前的位移增加。相比之下，解释时空触觉错觉的理论解释，如 tau 或皮肤兔子效应，预测随着目标速度的增加，向前的位移会减少。在本文报告的三个实验中，实现了一个基于现有 RM 设置的触觉实验设置。参与者指示三个触觉刺激序列中的最后一个位置，这些刺激序列要么暗示沿向肘部/手腕的一致方向运动，要么没有。通过改变刺激间间隔以及刺激的持续时间来操纵速度。结果表明，目标速度的增加导致向前位移的减少甚至反转，导致向后位移。这一结果与基于触觉时空错觉的证据的预测一致。讨论了这些结果对 RM 的理论意义。 本研究测试了关于速度对动态触觉刺激定位影响的两个不同预测。我们证明，对于触觉刺激，随着速度的增加，对预期运动方向的感知错误（称为“代表性动量”）转变为对运动方向的感知错误。这一结果与基于触觉时空错觉的预测一致，但挑战了基于视觉和听觉证据的基于经典理论解释的代表性动量。
