Reference frame for reaching movements to somatsensory targets

由体感信息感知的目标定向运动，如触觉或本体感觉，在日常活动中起着重要作用，例如抓住钱包里的钥匙或抓痒的身体部位。为了将体感输入转化为运动计划，目标和效应器（如手）的信息需要在一个共同的空间参照系中表示。虽然有越来越多的证据表明视觉目标是以目光为中心的表征，但用于表征运动体感目标的参考框架却相当不清楚。本研究的目的是确定本体感觉目标的参照系，并进一步研究空间表征如何因目标效应器的运动而变化。本文提出了三个项目，旨在(a)确定以身体、手和眼睛为中心的参照系对本体感觉到达目标的贡献，(b)确定在以身体和/或眼睛为中心的参照系中代表本体感觉到达目标的大脑区域，以及(c)揭示视觉和本体感觉到达目标的多个空间表征如何被组合和整合到一个共同的空间表征中。这些目标将通过结合行为实验、功能神经成像和计算建模的多模式方法来实现。

Goal-directed movements to targets perceived by somatosensory information, such as touch or proprioception, play an important role for everyday activities, e.g. grasping the keys in a purse or scratching an itchy body part. In order to transform the somatosensory input into a movement plan, information about target and effector (e.g. hand) needs to be represented in a common spatial reference frame. While there is converging evidence for a gaze-centered representation of visual targets, the reference frame used to represent somatosensory targets for movements is rather unclear. The goal of the present proposal is to determine the reference frame for proprioceptive targets for reaching and to further examine how the spatial representation changes due to a movement of the target effector. Three projects are proposed which aim to (a) determine the contribution of body-, hand-, and gaze-centered reference frames for proprioceptive reach targets, (b) identify the brain areas representing proprioceptive reach targets in a body- and/or gaze-centered reference frame, and (c) reveal how multiple spatial representations of visual and proprioceptive reach targets are combined and integrated into a common spatial representation. These goals shall be achieved by a multimodal approach combining behavioral experiments, functional neuroimaging and computational modelling.