Role of neural variation in smooth pursuit eye movements

University Of California, San Francisco, San Francisco CA

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Linked publications & trials

Abstract

Smooth pursuit eye movements are a well-understood behavior with a known neural substrate. Pursuit is[unreadable] generated when a target moves smoothly. It depends on a traditional cortical-cerebellar circuit with inputs[unreadable] from sensory cortex, processing in parietal sensory-motor areas, and motor commands from a frontal motor[unreadable] area. Outputs from the cerebral cortex interact with cerebro-cerebellar circuits and cerebro-basal ganglia[unreadable] circuits to generate motor commands. Much is known about the mean responses of neurons in these areas[unreadable] and how they contribute to the generation of the average pursuit movement. However, the analysis of[unreadable] variation in neural codes and pursuit behavior opens a new vista. The sensory input for pursuit is highly[unreadable] variable, yet the behavior itself is remarkably precise. The presence and ease of quantifying variation in the[unreadable] neural signals and the behavior offers the opportunity to ask where neural variation falls on the continuum[unreadable] from being a negative, neutral, or positive component of the neural generation of behavior. This project will[unreadable] focus on the frontal pursuit area (FPA), near the saccadic frontal eye fields and will ask 3 questions that are[unreadable] tightly linked to the aims of the Conte Center for Neuroscience Research. First, it will ask how much the[unreadable] neural code in the FPA varies and what fractions of the variance are 1) related to the behavior and 2)[unreadable] "residual", unrelated to the behavior. How do these fractions vary over the different phases of a pursuit[unreadable] movement? Second, it will use differential reward and penalty to modulate the distribution of behavioral[unreadable] variation and explore how that variation is effected by changes in the neural variation in the FPA. Third, it[unreadable] will explore neural variation in the FPA during the instructional period for visually-guided learning in pursuit,[unreadable] and during the subsequent expression of learning. The research in this project will contribute to the overall[unreadable] goals of the CCNR by providing an exemplar behavior where narrowly defined, quantitative questions can be[unreadable] answered about the specific roles of neural variation in a tightly controlled and well-understood behavior. In[unreadable] addition, an understanding of how the frontal cortex controls pursuit may help us to understand why[unreadable] schizophrenics have such profound deficits in smooth pursuit eye movements.