Exploring the cognitive and neural mechanisms underlying visuomotor adaptation and its relationship with attention.

如果我们早上拿起一杯咖啡，但没拿到右边，我们可以很容易地向左调整下一个动作来拿起杯子。虽然这看起来毫不费力，但它需要不同感觉信号的整合和多个大脑区域的协调。在实验室中检验这类运动学习的一种方法是使用棱镜适应。在棱镜适应过程中，一个人戴着目镜，将他们的视线向一个方向移动，例如向右移动。戴着护目镜的人被要求伸手去拿一个物体。然而，由于护目镜引起的视觉偏移，他们的视线会偏离物体的右侧。为了弥补他们向右的错误，这个人必须学会向左调整他们的动作（类似于喝咖啡的人）。我们实验室之前的研究表明，右棱镜适应可以帮助右脑损伤的患者更容易地关注左侧的物体。同样，向左移动的棱镜导致运动向右调整，可以将健康成年人的注意力向右转移。这表明运动控制和注意力的机制是密切相关的。这个研究项目的长期目标是更好地理解让注意力和运动系统相互作用的认知和神经机制。因此，棱镜适应是研究这种相互作用的理想范例。本文提出的工作将帮助科学家更好地理解运动和注意系统如何相互作用的基本机制，重点关注三个目标：1)我们将探索如何将棱镜适应过程中产生的不同感觉错误信号优化整合，以更好地调整未来的运动。2)我们将研究如何优化这些不同的感官误差信号的整合，以增加棱镜对视觉注意的影响。我们将通过研究小脑损伤患者来确定不同的感觉错误信号是如何在小脑中处理的——小脑是一个已知对运动学习至关重要的大脑区域。此外，我们将研究如何使用非侵入性脑刺激来改变健康成人小脑中的神经活动水平，从而破坏这些感觉错误信号的整合。这项研究有许多重要的应用，因此，将在几个方面使加拿大人受益。首先，从这些研究中获得的知识将帮助科学家更好地理解运动学习的基本机制，以及它如何影响注意力。其次，这项工作可以应用于设计更有效的方法来恢复脑损伤患者的注意力问题。最后，这项工作也可以应用于设计更有效的假肢或机器人控制系统，它可以学习利用来自运动错误的感觉反馈信号来优化未来的运动。

If we reach for our morning cup of coffee, but we miss to the right, we can easily adjust our next movement leftward to pickup the cup. Although this seems effortless, it requires the integration of different sensory signals and the coordination of multiple brain regions. One way to examine this type of motor learning in the laboratory is to use prism adaptation. During prism adaptation, a person wears goggles that shift their vision in one direction, for example, to the right. While wearing the goggles the person is asked to reach towards an object. However, their reach will miss to the right of the object because of the visual shift induced by the goggles. To compensate for their rightward error, the person must learn to adjust their movements leftward (similar to the coffee drinker). Previous research in our lab has shown that rightward prism adaptation can be used to help patients with right brain damage attend to objects on their left side more easily. Similarly, leftward shifting prisms, which result in a rightward adjustment in movements, can shift attention rightwards in healthy adults. This suggests that the mechanisms underlying motor control and attention are closely linked. The long-term objective of this research program is to better understand the cognitive and neural mechanisms that allow the attention and motor systems to interact. Thus, prism adaptation represents an ideal paradigm to investigate this interaction. The work proposed here will help scientists better understand the basic mechanisms underlying how the motor and attention systems interact by focusing on three objectives: 1) We will explore how different sensory error signals that are generated during prism adaptation can be optimally integrated to better adjust future movements. 2) We will examine how optimizing the integration of these different sensory error signals can increase the effects of prisms on visual attention. 3) We will determine how different sensory error signals are processed in the cerebellum - a brain region known to be critical for motor learning - by studying patients with cerebellar brain damage. In addition, we will examine how altering levels of neural activity in the cerebellum in healthy adults using non-invasive brain stimulation, can disrupt the integration of these sensory error signals. This research has many important applications and thus, will benefit Canadians in several ways. First, the knowledge obtained from these studies will help scientists better understand the basic mechanisms underlying motor learning, and how it can influence attention. Second, this work can be applied to designing more efficient methods to rehabilitate attention problems in patients with brain damage. Finally, this work can also be applied to engineering more efficient control systems for prosthetic limbs, or robots, which can learn to utilize sensory feedback signals from movement errors in order to optimize future movements.