The intertwined roles of vision and sensorimotor adaptation on reach-to-grasp movements

当我们执行日常活动时，比如拿起一杯咖啡，我们的大脑需要弄清楚杯子的位置，形状和重量（这取决于它的满度）。我们倾向于认为，我们对杯子的感知体验决定了我们与它的互动，然而，过去20年的几项研究一再表明，感知任务（如判断物体的大小或重量）与行动任务（如伸手举起物体）是由大脑不同的部分处理的。这个项目采取了另一种观点，大脑处理视觉场景，但这个过程可能会出现错误（比如高估杯子的大小或重量）。当动作展开时，这些错误会立即被检测到，并且随后向对象的移动会被快速纠正。本研究计划将探讨这些复杂校正的性质。它还将检查某些情况下，我们的感知是错误的，而我们的行动是准确的。这些知识可以帮助人们快速学习新的视觉技能，例如在虚拟现实环境中进行交互和远程操作。事实上，对视觉引导行动的更全面理解可以为这些新兴技术的发展提供信息。最后，这项提案的发现可以帮助改善神经系统疾病患者的生活，这些疾病通常会导致运动能力的严重丧失，从而严重损害日常生活活动。该研究项目使用最先进的虚拟现实环境来测试1）人类可以在多大程度上“即时”调整其运动动作以补偿视觉感知的不准确性，以及2）当无法通过运动调整实现平滑运动协调时，视觉感知是否会发生变化。三个机制的假设将进行测试，其中感官预测错误-信号时产生的感官反馈不符合一个人的期望-提高在重复的视觉交互的准确性的行动。每一个假设的核心都是这样一个想法，即当感知偏差导致不准确的运动时，感觉预测错误将推动整个感觉运动系统的适应性变化。将测试适应性变化的三种非相互排斥的机制：（1）运动输出与物理世界的快速重新对齐，（2）视觉感知校准的变化，和/或（3）视觉信息特定方面对动作的贡献的选择性变化。为了验证这些假设，将进行一系列综合的行为实验，同时开发计算模型，以机械地解释感知和行动紧密交织的作用。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

When we perform mundane daily actions like picking up a cup of coffee, our brain needs to figure out the location of the cup, its shape and weight (which changes depending on how full it is). We tend to think that our perceptual experience of the cup is what determines our interaction with it. However, several studies over the past two decades have repeatedly shown that a perceptual task, like judging the size of an object or its weight, is processed by a different part of the brain than an action task, like reaching to lift the object. This project takes an alternate view, in which the brain processes the visual scene, but this process may be subject to errors (like overestimating the size of a cup or its weight). These errors are immediately detected while an action is unfolding and the subsequent movements toward the object are quickly corrected. This research plan will explore the nature of these complex corrections. It will also examine certain circumstances in which our perception is faulty while our actions are accurate. This knowledge could help people rapidly learn new visuomotor skills, such as interacting in virtual-reality environments and teleoperation. Indeed, a more comprehensive understanding of visually guided action could inform the development of these emerging technologies. Finally, discoveries from this proposal could help improve the lives of individuals with neurological disorders, which often lead to a profound loss of motor ability that significantly impairs activities of daily living. This research project uses state-of-the-art virtual reality environments to test 1) to what extent humans can adjust their motor actions "on the fly" to compensate for inaccuracies in visual perception and 2) whether visual perception changes when smooth movement coordination cannot be achieved through motor adjustments. Three mechanistic hypotheses will be tested in which sensory-prediction errors - signals produced when sensory feedback does not match one's expectations - enhance the accuracy of action during repeated visuomotor interactions. At the core of each hypothesis is the idea that when biases in perception lead to inaccurate movements, sensory-prediction errors will drive adaptive changes across the sensorimotor system. Three non-mutually exclusive mechanisms of adaptive change will be tested: (1) Rapid re-alignment of the motor output with the physical world, (2) Changes in calibration of visual perception, and/or (3) Selective changes in the contribution of specific aspects of visual information to action. To test these hypotheses, an integrated set of behavioral experiments will be conducted, in tandem with the development of computational models to mechanistically explain the closely intertwined roles of perception and action.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.