NEURAL MECHANISMS OF VISUAL PERCEPTION

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 我们提出了一些实验来检验有关大脑决策能力的神经机制的假设。我们的实验解决了大脑将视觉皮层神经元代表的感觉信息转换为决定这些信息对计划行为的意义的机制。我们发现，猕猴的联合皮层神经元代表了这种选择和反对另一种选择的证据的积累。今年，我们证明了这些决策神经元的放电率符合扩散数学，为它们在噪声证据积累过程中的作用提供了进一步的支持（Churchland et al，2011）。我们还展示了该机制如何结合关于更可能的替代方案的先验知识影响决策过程（Hanks等人，提交）。我们还发现了人类（Jazayeri & Shadlen，2010）和猴子（Jazayeri & Shadlen，修订版）感知和再现时间间隔的机制。 决策弥合了感觉和行为之间的差距。几乎所有的非反射行为都需要大脑利用其感觉皮层来指导未来的行为。因此，我们所研究的简单决策的神经机制可能有助于深入了解更复杂的认知策略。我们的实验最终为影响感知，计划和推理的精神障碍的原因和治疗提供了新的见解。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We proposed experiments that test hypotheses about the neural mechanisms that underlie the brain's ability to make decisions. Our experiments address the mechanism used by the brain to convert sensory information represented by neurons in the visual cortex to a decision about what this information means for purposes of planning behavior. We showed that neurons in the association cortex of the macaque represent the accumulation of this evidence for one choice and against an alternative. This year, we demonstrated that the firing rate of these decision-making neurons conforms to the mathematics of diffusion, providing further support for their role in the process of noisy evidence accumulation (Churchland et al, 2011). We also showed how the mechanism incorporates prior knowledge about the more likely alternative affects the decision-making process (Hanks et al, submitted). We also discovered a mechanism for sensing and reproducing time intervals in humans (Jazayeri & Shadlen, 2010) and monkeys (Jazayeri & Shadlen, in revision). Decision-making bridges the gap between sensation and behavior. Nearly all non-reflexive behaviors require the brain to draw upon its sensory cortex to guide future behavior. Thus, the neural mechanisms for the simple decisions we study are likely to lend insight into more complex cognitive strategies. Our experiments ultimately furnish new insights into the causes and treatments of mental disorders affecting perception, planning and reasoning.