Sensory Re-Weighting and Re-Alignment: Cerebellar and Parietal Contributions

描述(申请人提供)：人类依靠多种类型的感觉信息来定位到达的目标，其中视觉和本体感觉使用最多。然而，出现一种模式可能比另一种更有用的情况(例如，在黑暗的房间里视力很差)。据推测，不同模式的有用性不断变化，使神经系统能够动态地切换它最“听”的模式是有利的。我们称这一过程为感官再加权。此外，在大多数情况下，组合来自不同模式的信息来估计目标位置是最佳的。因此，它们彼此一致是至关重要的。可能会出现视觉和本体感觉错位的情况(例如戴带棱镜的眼镜)。当感觉模式变得错位时，对神经系统来说，将两者恢复到正常状态是有利的。我们称这一过程为感觉重新排列。重新加权和重新对齐可能是两个独立的过程，在某些情况下单独使用，在其他情况下结合使用，因此在功能和神经学上是不同的。在这里，我们建议研究人类的这些行为过程。使用心理物理技术，我们将确定两者是否可分离，并确定神经系统控制它们的规则。我们还将通过研究局灶性脑损伤患者，最初专注于小脑和顶叶，来确定重叠或不同的大脑回路对这些过程是否重要。最后，我们将讨论如何操纵这些过程来弥补患者群体的缺陷。大脑以最佳方式组合不同类型感觉信息的能力对于在不同环境(例如光线不佳的房间)下精确控制运动至关重要。对齐不同种类的感觉信息的能力对行为也是至关重要的，这使人们能够从关于其环境中物体位置的多个信息源中受益。失去其中任何一种能力的人都会失去行为灵活性和运动准确性；对感觉整合和适应规则的更好理解应该让我们了解如何训练个人来提高这些能力，并最终实现运动控制。

DESCRIPTION (provided by applicant): Humans rely on multiple types of sensory information to localize targets for reaching, with vision and proprioception most heavily used. However, situations arise where one modality might be more useful than the other (e.g. vision is poor in a dark room). Presumably, the usefulness of different modalities constantly changes, making it advantageous for the nervous system to be able to dynamically switch which modality it "listens to" the most. We call this process sensory re-weighting. Additionally, in most situations it is optimal to combine information from different modalities to estimate a target location. It is therefore critical that they be aligned with one another. Situations can arise when vision and proprioception become misaligned (e.g. wearing glasses with prisms). When sensory modalities become misaligned, it is advantageous for the nervous system to bring the two back into register. We call this process sensory re-alignment. Re-weighting and re-alignment may be two separate processes that are optimally used alone in some situations and in combination in others, and therefore functionally and neurologically distinct. Here we propose to study these behavioral processes in humans. Using psychophysical techniques, we will determine whether the two are separable, and we will ascertain the rules by which the nervous system governs them. We will also determine whether overlapping or distinct brain circuits are important for these processes by studying individuals with focal brain damage, initially focusing on the cerebellum and parietal lobe. Finally, we will discuss how these processes might be manipulated to compensate for deficits in patient populations. The brain's ability to optimally combine different kinds of sensory information is critically important for precise movement control in different contexts (e.g. poorly lit rooms). The ability to align different kinds of sensory information is also critical for behavior, allowing people to benefit from multiple sources of information about the location of objects in their environment. People who lose either of these abilities lose behavioral flexibility and movement accuracy; a better understanding of the rules of sensory integration and adaptation should allow us to understand how to train individuals to improve these abilities, and ultimately movement control.