Zampini Massimiliano, Harris Charlotte, Spence Charles
Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford, OX1 3UD, UK.
Exp Brain Res. 2005 Oct;166(3-4):498-508. doi: 10.1007/s00221-005-2390-y. Epub 2005 Jul 21.
We report a series of experiments in which participants had to judge the direction in which a pair of vibrotactile stimuli presented to two adjacent digits of either the same or different hands were stimulated (left-to-right or vice versa in experiments 1 and 2; near-to-far or vice versa in experiment 3, at stimulus onset asynchronies varying between 100 and 600 ms). When the participant's hands were placed side-by-side (anatomical posture), with their fingers either pointing away from them or else pointing toward the midline, directional discrimination performance was generally accurate. By contrast, when the fingers of the two hands were interleaved in either of these postures, performance deteriorated significantly for certain specific combinations of digits, with a more pronounced impairment seen when the fingers pointed away from the participant than when they pointed toward the midline. This decline in tactile direction discrimination performance in the interleaved fingers posture appears to reflect a failure to represent the position of tactile stimuli correctly when the fingers of the two hands are interleaved.
我们报告了一系列实验，在这些实验中，参与者必须判断呈现给同一只手或不同手的两个相邻手指的一对振动触觉刺激的刺激方向（实验1和2中为从左到右或反之；实验3中为从近到远或反之，刺激起始异步时间在100至600毫秒之间变化）。当参与者的手并排摆放（解剖姿势），手指要么远离身体，要么指向身体中线时，方向辨别表现总体上较为准确。相比之下，当两只手的手指以这两种姿势中的任何一种交叉时，对于某些特定手指组合，表现会显著下降，当手指远离参与者时比指向身体中线时出现更明显的损伤。在交叉手指姿势下触觉方向辨别表现的这种下降似乎反映出当两只手的手指交叉时，无法正确表征触觉刺激的位置。
