Department of Psychology, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
Exp Brain Res. 2012 Feb;216(4):489-97. doi: 10.1007/s00221-011-2953-z. Epub 2011 Nov 20.
Previous research has shown that tactile-spatial information originating from the front of the body is remapped from an anatomical to an external spatial coordinate system, guided by the availability of visual information early in development. Comparably little is known about regions of space for which visual information is not typically available, such as the space behind the body. This study tests for the first time the electrophysiological correlates of the effects of proprioceptive information on tactile-attentional mechanisms in the space behind the back. Observers were blindfolded and tactually cued to detect infrequent tactile targets on either their left or right hand and to respond to them either vocally or with index finger movements. We measured event-related potentials to tactile probes on the hands in order to explore tactile-spatial attention when the hands were either held close together or far apart behind the observer's back. Results show systematic effects of arm posture on tactile-spatial attention different from those previously found for front space. While attentional selection is typically more effective for hands placed far apart than close together in front space, we found that selection occurred more rapidly for close than far hands behind the back, during both covert attention and movement preparation tasks. This suggests that proprioceptive space may "wrap" around the body, following the hands as they extend horizontally from the front body midline to the center of the back.
先前的研究表明，来自身体前部的触觉-空间信息在发育早期受到视觉信息的引导，从解剖空间坐标重新映射到外部空间坐标系统。相比之下，人们对视觉信息通常不可用的空间区域（例如身体后面的空间）了解甚少。这项研究首次测试了本体感受信息对身体后面的触觉注意机制的电生理相关性。观察者被蒙住眼睛，通过触觉提示来检测左手或右手偶尔出现的触觉目标，并通过口头或食指运动来做出反应。我们测量了手的触觉探针的事件相关电位，以探索当手在观察者的背部紧紧或远远地放在一起时的触觉空间注意力。结果表明，手臂姿势对触觉-空间注意力的影响与以前在前空间中发现的影响不同。虽然在前面的空间中，与手靠近相比，手分开时的注意力选择通常更有效，但我们发现，在隐蔽注意和运动准备任务中，手靠近时的选择速度比手远时更快。这表明本体感受空间可能会“包裹”身体，随着手从身体中线的前部水平伸展到背部的中心。
