Collaborative Research: Sensory Integration and Sensorimotor Transformations for Dexterous Manipulation

抓握和操纵物体的能力是一种极其复杂的运动行为。当握住杯子等物体时，人们通常会改变手指的位置和手指施加的力，以确保达到目标（在这种情况下，举起杯子而不溢出其内容物）。人类是如何做到这一点的尚不清楚，部分原因是以前的研究限制受试者将手指放在物体上预先指定的位置。这导致我们对这些复杂的运动行为是如何学习，计划和执行的理解存在重大差距。为了解决这一差距，拟议的研究将调查受试者如何抓住和操纵物体的任务，让他们选择他们的手指位置和施加的力量，重要的是，调整两者之间的相互作用。抓握的另一个功能是发展物体重量和物体内重量分布的表示。受试者如何发展这种表征和完善他们的行动将通过研究抓取提取的信息和过去的操作对象的记忆之间的相互作用进行检查。通过操纵指尖放置的视觉反馈，改变视觉形状和密度线索，通过物体旋转任务，在视觉线索和先前操作的同一物体的记忆之间产生差异。拟议的研究代表了抓握研究的重大范式转变，开辟了新的和基本的问题大脑是如何学会控制手的因此，这项工作的结果可能会通知设计更灵巧的机器人操纵器，脑机接口，神经假肢手。

The ability to grasp and manipulate objects is an extremely complex motor behavior. When grasping an object such as a cup, people often vary their finger placements and the forces exerted by the fingers in order to ensure that the goal is attained (in this case, lifting the cup without spilling its contents). How humans do this so efficiently is not known, in part because previous research constrained subjects to place their fingers at pre-specified locations on the objects. This has led to a major gap in our understanding of how these complex motor behaviors are learned, planned, and executed. To address this gap, the proposed studies will investigate how subjects grasp and manipulate objects in tasks that allow them to choose their finger placements and applied forces and, importantly, to adjust the interaction between the two. Another function of grasping is to develop a representation of an object's weight and the distribution of weight within the object. How subjects develop this representation and refine their actions will be examined by studying the interaction between information extracted by grasping and memories of past manipulations of the object. The hypothesis that fingertip placement and forces are learned independently from each other will be tested by manipulating visual feedback of fingertip placement, varying visual shape and density cues, and through object rotation tasks that create a discrepancy between visual cues and memories of the same object from prior manipulations.The proposed studies represent a major paradigm shift in the research on grasping by opening new and fundamental questions about how the brain learns to control the hand. Thus, the results of this work may inform the design of more dexterous robotic manipulators, brain-machine interfaces, and neuroprosthetic hands.