Predictive Representation of Motion in Visual Cortex

描述(申请人提供)：大量证据表明，视觉感知受到我们对视觉世界的预测的影响。预测使我们能够开发和适应我们视觉环境的因果、非随机结构，对于快速和准确地控制视觉引导行为是必不可少的。我们之前在猴子的外侧顶叶区域(LIP)中发现了神经元信号，这些信号提供了视觉运动方向的预测性表征。这一新提议中的首要问题是预测信号与行为的关系，以及预测信号形成的机制。嘴唇中的预测运动信号似乎非常适合于行为的前馈控制，但对预测神经元信号与行为之间的关系知之甚少。我们将通过寻找预测性神经元信号和反应时间之间的逐个试验的相关性来解决这个问题。我们将研究1手动反应和眼动，以测试单个神经元的活动是否特定于特定行为，或者更确切地说，提供对多种行为有用的一般预测信号。我们还将基于最近的视觉刺激试验历史，研究是否由于学习而产生预测性神经元信号和行为优势。我们特别假设预测神经元信号是基于预测误差，即预测的视觉刺激和实际的视觉刺激之间的差异而更新的。此外，我们假设预测性行为和预测性神经元放电将受到最近试验历史的类似影响。最后，另一种“视网膜外”过程，选择性注意，已被证明可以增强感觉运动行为和调节神经元反应。一个关键的问题是，神经元调制的动力学是否能够解释行为优势。我们将同时研究神经元调制的时间进程和当动物内源性地在两个视觉刺激之间切换注意力以响应认知线索时获得的性能优势的时间进程。神经元反应的注意调节的时间进程应该反映神经元在内源性注意力转移中所起的作用。我们的实验将提供一个关于大脑如何使用关于感觉世界的先前信息来促进感知和行动的机械论观点。获得知觉机制的基本信息是理解正常和异常大脑处理的必要步骤。

DESCRIPTION (provided by applicant): A great deal of evidence suggests that visual perception is affected by our predictions about the visual world. Prediction allows us to exploit and adapt to the causal, non-random structure of our visual environment, and is essential for rapid and accurate control of visually guided behavior. We previously identified neuronal signals in the monkey lateral intraparietal area (LIP) that provide a predictive representation of the direction of visual motion. The overarching issues in this new proposal are the relationship of predictive signals to behavior and the mechanisms by which predictive signals develop. Predictive motion signals in LIP seem ideally suited for feedforward control of behavior, but little is known about the relationship between predictive neuronal signals and behavior. We will address this issue by looking for trial-by-trial correlation between predictive neuronal signals and reaction time. We will examine 1 both manual reactions and eye movements to test whether the activity of single neurons is specific for particular behaviors, or rather provides a general predictive signal that is useful for multiple behaviors. We will also examine whether predictive neuronal signals and behavioral advantages arise as a result of learning based on the recent trial history of visual stimulation. We specifically hypothesize that predictive neuronal signals are updated based on prediction errors, the difference between the predicted visual stimulus and the actual visual stimulus. Moreover, we hypothesize that predictive behaviors and predictive neuronal firing will be similarly affected by recent trial history. Finally, another "extraretinal" process, selective attention, has been shown to enhance sensorimotor behaviors and to modulate neuronal responses. A key question is whether the dynamics of the neuronal modulation can account for the behavioral advantage. We will simultaneously examine the time course of neuronal modulation and the time course of the performance advantage that is gained when an animal endogenously switches attention between two visual stimuli in response to a cognitive cue. The time course of attentional modulation of a neuronal response should reflect the role that a neuron plays in endogenous shifts of attention. Our experiments will provide a mechanistic perspective on how the brain uses prior information about the sensory world to facilitate perception and action. Gaining basic information on perceptual mechanisms is an essential step for understanding normal and abnormal brain processing.