NEURAL RECORDINGS AND REACTION TIME MODELS

这项拟议的研究有两个目标：第一个目的是使用清醒行为的恒河猴的神经元记录来测试从人类受试者的数据中得出的快速二选决策模型。这些模型已经被应用于简单的知觉任务，在这些任务中，人们被要求决定显示了两个刺激中的哪一个，并且它们很好地描述了数据的速度和准确性特征。猴子可以被训练成相对容易地执行相同的感知任务，通过对两个目标中的一个进行眼动来指示它们的决定，而不是人类使用的按键。我们的目的是调查认知模型确定的加工成分是否反映在神经活动中。这项研究的第二个目的是调查决定眼球运动方向、距离和时间的神经元群的小亚群的联合行为。我们计划使用最多六个神经元的同步记录来检查不同类型和位置的神经元活动的相关性。中心问题是，假设执行相同功能的神经元是否表现出相同的放电模式，动眼神经系统不同部分的神经元是否显示出同步活动，负责移动到一个可能选择的神经元是否与负责移动到另一个选择的神经元相互作用，以及在单一试验过程中刺激信息的变化如何影响神经元的放电速率。这项研究的两个目的紧密地交织在一起，因为假设和来自一个领域的结果将决定另一个领域的假设选择。初级眼球运动系统是检查眼球运动发生之前的神经决策过程的理想选择。我们建议研究前额眼场和上丘中的神经元在眼球运动之前显示准备和眼跳相关的爆发活动的可能性映射到扩散模型的组件上。说得天真些，如果这种神经活动可以用扩散模型中信息积累达到阈值的特征来很好地描述，那不是很令人惊讶吗？考虑到这种可能性，拟议研究的开始阶段将使用扩散模型来指导猴子实验的设计，通过对行为数据的模型拟合来提供对组成过程的估计，并指导神经数据的分析。这些实验将对人类和猴子的决策系统进行直接比较。由于猕猴和人类眼动系统之间已知和预期的相似之处，这些实验也将为人类自主运动的神经控制的功能组织提供一个模型。

The proposed research has two aims: The first is to use neuronal recordings in awake behaving rhesus monkeys to test models of rapid two-choice decision making that have been derived from data from human subjects. The models have been applied to simple perceptual tasks in which humans are asked to decide which of two stimuli was displayed, and they provide a good description of the speed and accuracy characteristics of the data. Monkeys can be trained to perform the same perceptual tasks with relative ease, using eye movements to one of two targets to indicate their decisions instead of the key presses used by humans. Our aim is to investigate whether the components of processing identified by cognitive models are reflected in neural activities. The second aim of the research is to investigate the joint behavior of small subsets of the neuronal populations that decide the direction, distance, and timing of eye movements. We plan to use simultaneous recordings from up to six neurons to examine correlations in the activities of neurons of different types and locations. Central questions are whether neurons hypothesized to perform the same function exhibit the same patterns of firing, whether neurons in the different parts of the oculomotor system show synchronous activities, whether the neurons responsible for movement to one of the possible choices interact with the neurons responsible for movement to the other choice, and how changes in stimulus information in the course of a single trial affect neuronal firing rates. The two aims of the research are tightly intertwined in that hypotheses and results from one of the domains will inform choices of hypotheses in the other. The primary oculomotor system is ideal for examining the neural decision processes that precede the generation of eye movements. We propose to investigate the possibility that neurons in the frontal eye field and superior colliculus that show preparatory and saccade-related burst activities prior to eye movements map onto the components of the diffusion model. To put it naively, wouldn't it be amazing if this neural activity was well-described by the characteristics of the accumulation of information reaching a threshold in the diffusion model? With this possibility in mind, the beginning phases of the proposed research will use the diffusion model to guide the designs of experiments with monkeys, to provide estimates of component processes through model fits to the behavioral data, and to guide the analysis of neural data. These experiments will make direct comparisons between human and monkey decision-making systems. Because of known and expected similarities between rhesus monkey and human oculomotor systems, these experiments will also provide a model for the functional organization of the neural control of voluntary movement in humans.