Wales Institute of Cognitive Neuroscience, School of Psychology, Bangor University, Bangor, United Kingdom.
Neuropsychologia. 2009 Dec;47(14):3118-24. doi: 10.1016/j.neuropsychologia.2009.07.012. Epub 2009 Jul 28.
To date, several posterior brain regions have been identified that play a role in the visual perception of other people and their movements. The aim of the present study is to understand how these areas may be involved in relating body movements to their visual consequences. We used fMRI to examine the extrastriate body area (EBA), the fusiform body area (FBA), and an area in the posterior superior temporal sulcus (pSTS) that responds to patterns of human biological motion. Each area was localized in individual participants with independent scans. In the main experiment, participants performed and/or viewed simple, intransitive hand actions while in the scanner. An MR-compatible camera with a near-egocentric view of the participant's hand was used to manipulate the relationship between motor output and the visual stimulus. Participants' only view of their hands was via this camera. In the Compatible condition, participants viewed their own live hand movements projected onto the screen. In the Incompatible condition, participants viewed actions that were different from the actions they were executing. In pSTS, the BOLD response in the Incompatible condition was significantly higher than in the Compatible condition. Further, the response in the Compatible condition was below baseline, and no greater than that found in a control condition in which hand actions were performed without any visual input. This indicates a strong suppression in pSTS of the response to the visual stimulus that arises from one's own actions. In contrast, in EBA and FBA, we found a large but equivalent response to the Compatible and Incompatible conditions, and this response was the same as that elicited in a control condition in which hand actions were viewed passively, with no concurrent motor task. These findings indicate that, in contrast to pSTS, EBA and FBA are decoupled from motor systems. Instead we propose that their role is limited to perceptual analysis of body-related visual input.
迄今为止，已经确定了几个大脑后区在他人及其运动的视觉感知中发挥作用。本研究的目的是了解这些区域如何参与将身体运动与视觉后果联系起来。我们使用 fMRI 检查了额下回的额外体区（EBA）、梭状回的额外体区（FBA）以及后上颞沟中的一个区域（pSTS），这些区域对人类生物运动的模式有反应。每个区域都在个体参与者的独立扫描中进行定位。在主要实验中，参与者在扫描仪中执行和/或观看简单的非传递性手部动作。使用具有参与者手部近自心视图的 MR 兼容相机来操纵运动输出和视觉刺激之间的关系。参与者只能通过这个相机看到自己的手。在兼容条件下，参与者看到自己的实时手部动作投射到屏幕上。在不兼容条件下，参与者看到的动作与他们正在执行的动作不同。在 pSTS 中，不兼容条件下的 BOLD 反应明显高于兼容条件。此外，兼容条件下的反应低于基线，并且不比在没有任何视觉输入的情况下执行手部动作的对照条件下的反应大。这表明 pSTS 对自身动作引起的视觉刺激的反应受到强烈抑制。相比之下，在 EBA 和 FBA 中，我们发现对兼容和不兼容条件的反应较大，但与在对照条件下观察手部动作时的反应相同，在对照条件下，没有同时进行运动任务。这些发现表明，与 pSTS 相反，EBA 和 FBA 与运动系统分离。相反，我们认为它们的作用仅限于对与身体相关的视觉输入的感知分析。
