Vision Performance Institute, College of Optometry, Pacific University, Forest Grove, Oregon; and Smith-Kettlewell Eye Research Institute, San Francisco, California
Smith-Kettlewell Eye Research Institute, San Francisco, California.
J Neurophysiol. 2014 Jun 15;111(12):2644-55. doi: 10.1152/jn.00543.2013. Epub 2014 Mar 26.
Single-unit recording in monkeys and functional imaging of the human frontal lobe indicate that the supplementary eye field (SEF) and the frontal eye field (FEF) are involved in ocular decision making. To test whether these structures have distinct roles in decision making, single-neuron activity was recorded from each structure while monkeys executed an ocular go/nogo task. The task rule is to pursue a moving target if it intersects a visible square or "go zone." We found that most SEF neurons showed differential go/nogo activity during the delay period, before the target intersected the go zone (delay period), whereas most FEF neurons did so after target intersection, during the period in which the movement was executed (movement period). Choice probability (CP) for SEF neurons was high in the delay period but decreased in the movement period, whereas for FEF neurons it was low in the delay period and increased in the movement period. Directional selectivity of SEF neurons was low throughout the trial, whereas that of FEF neurons was highest in the delay period, decreasing later in the trial. Increasing task difficulty led to later discrimination between go and nogo in both structures and lower CP in the SEF, but it did not affect CP in the FEF. The results suggest that the SEF interprets the task rule early but is less involved in executing the motor decision than is the FEF and that these two areas collaborate dynamically to execute ocular decisions.
在猴子中进行的单细胞记录和人类额叶的功能成像表明，补充眼区（SEF）和额眼区（FEF）参与眼球决策。为了测试这些结构在决策中是否具有不同的作用，当猴子执行眼球 Go/NoGo 任务时，记录了每个结构中的单个神经元活动。任务规则是，如果目标与可见的正方形或“Go 区”相交，则追踪移动的目标。我们发现，大多数 SEF 神经元在目标与 Go 区相交之前的延迟期（延迟期）表现出不同的 Go/NoGo 活动，而大多数 FEF 神经元则在目标相交后、在执行运动期间（运动期）表现出这种活动。SEF 神经元的选择概率（CP）在延迟期较高，但在运动期降低，而 FEF 神经元的 CP 在延迟期较低，在运动期增加。SEF 神经元的方向选择性在整个试验中较低，而 FEF 神经元的方向选择性在延迟期最高，随后在试验中降低。增加任务难度会导致这两个结构中的 Go 和 NoGo 之间的区分延迟，并且在 SEF 中的 CP 降低，但不会影响 FEF 中的 CP。结果表明，SEF 早期解释任务规则，但与 FEF 相比，它较少参与执行运动决策，并且这两个区域动态协作以执行眼球决策。
