Matsumoto Eriko, Misaki Masaya, Miyauchi Satoru
Brain Information Group, Communications Research Laboratory, Kansai Advanced Research Center, 588-2 Iwaoka, Iwaoka-cho, Nishi-ku, Hyogo 651-2429, Kobe, Japan.
Exp Brain Res. 2004 Sep;158(1):9-17. doi: 10.1007/s00221-004-1872-7. Epub 2004 Mar 17.
Previous psychological experiments have indicated the existence of a visual-proprioceptive interaction in spatial stimulus-response compatibility (SSRC) tasks, but there is little specific information on the neural basis of such interaction in humans. Using functional magnetic resonance imaging (fMRI), we compared the neural activity associated with two different aspects of spatial coding: the coding of the "internal" spatial position of motor-response effectors (i.e., the position of body parts) as obtained through proprioception, and the coding of "external" positions, i.e., the positions of visual stimuli. A 2 x 2 factorial design was used to investigate the spatial compatibility (incompatible versus compatible) between a visual stimulus and hand position (crossed versus uncrossed). The subjects were instructed to respond to stimuli presented to the right or left visual field with either the ipsilateral (compatible condition) or the contralateral hand (incompatible condition). The incompatible condition produced stronger activation in the bilateral superior parietal lobule, inferior parietal lobule, and bilateral superior frontal gyrus than the compatible condition. The crossed-hand condition produced stronger activation in the bilateral precentral gyrus, superior frontal gyrus, superior parietal lobule, and superior temporal gyrus than the uncrossed-hand condition. These results suggest that activity in the frontal-parietal regions is related to two functions: (1) representation of the visual stimulus-motor response spatial configuration in an SSRC task, and (2) integration between external visual and internal proprioceptive sensory information. The activation in the superior temporal gyrus was not affected by the visual stimulus-motor response spatial configuration in an SSRC task; rather, it was affected by the crossed-hand posture. Thus, it seems to be related to representing internal proprioceptive sensory information necessary to carry out motor actions.
先前的心理学实验已表明，在空间刺激-反应相容性（SSRC）任务中存在视觉-本体感觉交互作用，但关于人类这种交互作用的神经基础的具体信息却很少。我们使用功能磁共振成像（fMRI），比较了与空间编码的两个不同方面相关的神经活动：通过本体感觉获得的运动反应效应器“内部”空间位置（即身体部位的位置）的编码，以及“外部”位置（即视觉刺激的位置）的编码。采用2×2析因设计来研究视觉刺激与手部位置（交叉与不交叉）之间的空间相容性（不相容与相容）。受试者被要求用同侧手（相容条件）或对侧手（不相容条件）对呈现于右侧或左侧视野的刺激做出反应。与相容条件相比，不相容条件在双侧顶上小叶、顶下小叶和双侧额上回产生更强的激活。与不交叉手条件相比，交叉手条件在双侧中央前回、额上回、顶上小叶和颞上回产生更强的激活。这些结果表明，额顶叶区域的活动与两种功能有关：（1）在SSRC任务中视觉刺激-运动反应空间配置的表征，以及（2）外部视觉和内部本体感觉信息之间的整合。在SSRC任务中，颞上回的激活不受视觉刺激-运动反应空间配置的影响；相反，它受交叉手姿势的影响。因此，它似乎与执行运动动作所需的内部本体感觉信息的表征有关。
