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

如果我们伸手去拿早晨的一杯咖啡，但我们错过了右边，我们可以很容易地调整我们的下一步向左移动来拿起杯子。尽管这看起来毫不费力，但它需要不同感觉信号的整合和大脑多个区域的协调。在实验室里检验这种运动学习的一种方法是使用棱镜适应。在棱镜适应过程中，一个人戴着护目镜，将他们的视线朝一个方向移动，例如，向右。当佩戴护目镜时，该人被要求向物体伸手。然而，由于护目镜引起的视觉移动，他们的触角将错过对象的右侧。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，向右棱镜适应可以帮助右脑损伤患者更容易地注意到左侧的物体。同样，向左移动的棱镜会导致运动向右调整，也会使健康成年人的注意力向右移动。这表明，运动控制和注意力背后的机制是密切相关的。这项研究计划的长期目标是更好地了解使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式。这里提出的工作将通过三个目标帮助科学家更好地了解运动和注意系统如何相互作用的基本机制：1)我们将探索如何优化整合棱镜适应过程中产生的不同感觉错误信号，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觉误差信号的整合，以增加棱镜对视觉注意的影响。3)我们将通过对小脑损伤患者的研究，确定不同的感觉错误信号在小脑--已知对运动学习至关重要的大脑区域--是如何处理的。此外，我们将研究使用非侵入性脑刺激改变健康成年人小脑神经活动水平如何扰乱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康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控制系统，即机器人，它可以学习利用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.