Representation of action space and multi-limb actions

为了让人类执行功能性动作，大脑必须解决至少两个问题。首先，它必须形成一个特定的“被行动”对象在空间中的位置的表示。该信息可以用多种方式表示。例如，我们面前桌子上的咖啡杯的位置可以用我们的手、眼睛、头或躯干的当前位置来表示。除了这些“自我中心”表征之外，杯子的位置也可以相对于环境中的其他物体来表征，比如桌子上的电脑鼠标（称为“非中心”表征）。大脑必须解决的第二个问题是如何整合来自自我中心和非中心来源的相关信息，并向我们的四肢发送适当的神经命令，以实现协调行动。我研究的一个目的是了解大脑如何整合各种来源（自我中心和非中心）的信息，以产生目标位置的可靠表示。我将通过系统地操纵环境中的信息，并在指向中确定对空间定位性能的影响来解决这个问题。我的研究还旨在了解使人类在对环境中的物体进行动作时能够顺利协调四肢动作的过程。我将通过要求参与者做出双手动作来研究这个问题，在这个动作中，双手的运动关系是根据所涉及的肌肉和运动的空间方向来操纵的。我还将操纵指导动作的线索，以确定促进或损害双手表演的线索特征。这两种相关的研究方向都非常重要，因为在现实世界中，行动通常是双手操作的，而行动目标很少是孤立存在的。除了推进关于大脑的基础知识外，我的研究还对人机界面的设计、康复制度以及熟练人员的培训（包括外科医生、牙医、飞行员、计算机/机器操作员和运动员）产生了影响。我的研究也会引起机器人、人工智能和人体工程学研究人员的兴趣。

In order for humans to perform functional actions, the brain must solve at least two problems. First, it must form a representation of where a particular 'to-be-acted-upon' object is located in space. This information can be represented in many ways. For example, the position of a coffee cup on the table in front of us can be represented with respect to the current position of our hands, eyes, head or torso. In addition to these 'egocentric' representations, the position of the cup can also be represented with respect to other objects in the environment, such as the computer mouse on our table (termed 'allocentric' representations).  The second problem that the brain must solve is how to integrate relevant information from both egocentric and allocentric sources, and send appropriate neural commands to our limbs to enable coordinated actions. One aim of my research is to understand how the brain integrates various sources of (egocentric and allocentric) information to produce a reliable representation of a target's location. I will address this issue by systematically manipulating information in the environment, and determining the effects on spatial localization performance, in pointing. My research also aims to understand the processes that enable humans to smoothly coordinate the actions of two limbs when acting on objects in the environment. I will study this issue by requiring participants to make bimanual actions in which the relationship between the movements of the two hands is manipulated in terms of the muscles involved and the spatial direction of movements. I will also manipulate the cues that instruct the movements to determine the cue features that facilitate or impair bimanual performance. Both these related lines of enquiry are extremely important because, in the real-world, actions are often bimanual, and targets for action are rarely present in isolation. As well as advancing fundamental knowledge about the brain, my research has implications for the design of human/machine interfaces, rehabilitation regimes, and the training of skilled personnel including, surgeons, dentists, pilots, computer/machine operators, and athletes. My research will also be of interest to researchers in robotics, artificial intelligence and ergonomics.