Stochastic Models of Visual Search

描述（由申请人提供）：我们研究的长期目标是了解视觉任务（如定位和转移视线到视觉阵列目标）的计算模型如何映射到产生该性能的特定神经过程。阐明这种映射为区分相互竞争的模型架构提供了收敛约束，并提供了神经回路功能的功能解释。本提案的目的是测试、扩展、改进和集成我们最近开发的视觉搜索过程中目标选择的两个主要的新计算模型。数据将包括猴子和人类参与者在视觉阵列中寻找目标的表现，其中目标位置可能会发生不可预测的变化，并辅以先前收集的FEF神经生理学数据。该模型提供了视觉搜索中正确和错误扫视行为的详细模式的定量描述，并解释了额叶视野（FEF）神经元的时间调节。与以前的视觉搜索模型不同，我们的模型考虑了有效和无效搜索期间正确和错误的响应概率和响应时间分布的整个范围，即使目标意外改变位置。目标1将开发、完善和扩展一个用于扫视目标选择的INTERACTIVE RACE模型。我们将测试由多个随机累积器（GO单元）组成的竞争模型架构，这些随机累积器（GO单元）控制何时何地进行眼动，其中GO单元之间相互作用的性质以及用于施加认知控制的潜在包含的STOP单元在模型变量中被操纵。成功的模型预测了猴子和人类的反应概率和反应时间分布，以及之前在猴子身上观察到的神经活动。目标2将测试、改进和扩展一个GATED ACCUMULATOR模型，该模型描述了如何将视觉显著性转换为眼跳命令。FEF神经元提供的视觉显著性表示将作为随机GO单元的神经网络的输入，该神经网络具有不同的架构，可以实现关于前馈、横向和门控抑制作用的相互竞争的假设。Aim 3将整合这两个模型。这种整合将由执行视觉搜索任务的人类参与者的新数据来指导，其中关键变量被操纵以获得测试竞争架构的新措施。

DESCRIPTION (provided by applicant): The long-term goal of our research is to understand how computational models of performance of visual tasks like locating and shifting gaze to a target a visual array map onto specific neural processes producing that performance. Elucidating this mapping provides converging constraints for discriminating between competing model architectures and provides functional explanations of neural circuit function. The aims of this proposal test, extend, refine, and integrate two major new computational models of target selection during visual search that we have recently developed. Data will consist of performance of monkeys and human participants searching for a target in a visual array in which target location can change unpredictably supplemented by neurophysiological data from FEF that was collected previously. The models provide quantitative accounts of detailed patterns of correct and error saccade behavior during visual search and also provide explanations for the temporal modulation of neurons in frontal eye field (FEF). Unlike previous models of visual search, ours account for the entire range of correct and error response probabilities and response time distributions during efficient and inefficient search, even when the target changes location unexpectedly. Aim 1 will develop, refine, and extend an INTERACTIVE RACE model of saccade target selection. We will test competing model architectures consisting of multiple stochastic accumulators (GO units) that govern when and where a saccade is made, where the nature of the interactions between GO units and the potential inclusion of a STOP unit for exerting cognitive control is manipulated across model variants. Successful models predict response probabilities and response time distributions in monkeys and humans and neural activity observed previously in monkeys. Aim 2 will test, refine, and extend a GATED ACCUMULATOR model of how visual salience is translated into a saccade command. The visual salience representation provided by FEF neurons will be the input to a neural network of stochastic GO units with alternative architectures that implement competing hypotheses about the role of feed forward, lateral and gating inhibition. Aim 3 will integrate these two models. This integration will be guided by new data from human participants performing visual search tasks in which key variables are manipulated to obtain new measures to test competing architectures. PUBLIC HEALTH RELEVANCE: The models tested and refined through this research plan will provide a firm foundation from which to understand disorders of visual attention, orientation and mobility that are consequences of impaired visual search. Elucidation of the mapping between effective mathematical models of behavior and specific brain processes is necessary for translational research seeking to understand how vision and cognition are impacted by injury, disease, or pharmacological interventions.