Contributions of attentional and inhibitory functioning to saccadic decisions

项目摘要 扫视是一种基本的行为，通过频繁地改变接收到的输入来实现功能性视觉 中央凹加工注视是处理新输入的扫视之间的时刻， 并且下一个扫视的目的地也被编程。因此，产生扫视的决定是 它是复杂的，取决于许多系统的相互作用。扫视行为在一定范围内差异很大 临床状态的差异，在婴儿期出现差异。大量文献已经研究了扫视的动力学 通过计算建模和神经生理学数据做出决策。然而，相对而言， 典型人群中的个体差异。本提案的目的是确定 机制，解释个体差异的固定持续时间的倾向，并调查他们如何影响 下游注意力选择在目标1中，注意力和抑制功能的独立测量将 与个体注视持续时间变异性进行比较。心理物理阈值将决定敏感性 在保持固定的同时，以一定范围的偏心率照射到周边目标。因此，能力的个体差异 以检测任务相关的外围信息，这对于计划扫视是关键的。抑制功能 将被估计为停止信号反应时间（SSRT）从扫视撤销任务获得。抑制 在减缓积聚以防止运动单位快速达到阈值方面起重要作用。先前 结果表明，具有较长初始注视的个体产生较大幅度的扫视，并且可能落在更靠近 一个目标因此，假设增强的周边检测能力与更长的注视同时发生 持续趋势。或者或另外，假设个体抑制功能阻止快速生长。 扫视和延长注视持续时间。目标2将研究个体如何倾向于短注视时间 影响扫视目标的选择。此aim使用比Aim 1更复杂的搜索显示， 来自显著干扰物的竞争。提出了一个新的假设，关于个人之间的关系， SSRT和眼动捕捉的差异：SSRT较长的个体将产生更多的快速扫视， 突出的干扰物。最后，目标3将使用新的方法来研究注视的个体差异 已知在自然场景的延长观看期间发生的持续时间。动态有用视场（UFOV）任务 将在精确的偏心率下使用凝视视情况而定的探针呈现来测量个体对 自由观看期间的外围信息。这种对外围处理的测量将更直接地反映 在自然视觉期间存在的条件，并且这些注意广度的测量被预测与以下因素有关： 在自由观看自然场景的过程中固定行为的个体差异。长期目标是 神经生理学数据的计算模型和人类扫视行为的理论之间的差距。 了解眼科行为的病因可以帮助针对疾病的治疗，并阐明 个体差异如何改变视觉信息获取和环境相互作用。

Project Summary Saccades are a fundamental behavior that enables functional vision by frequently changing which input receives foveal processing. Fixations are the moments in time between saccades during which new input is processed, and the destination of the next saccade is also programmed. Therefore, the decision to produce a saccade is complex and depends on the interaction of numerous systems. Saccadic behavior differs widely across a range of clinical states, and differences emerge in infancy. A large literature has investigated the dynamics of saccadic decisions through computational modeling and neurophysiological data. However, relatively less is known about individual differences within the typical population. The objective of this proposal is to identify underlying mechanisms that explain individual differences in fixation duration tendency, and to investigate how they affect downstream attentional selection. In Aim 1, independent measures of attentional and inhibitory functioning will be compared against individual fixation duration variability. Psychophysical thresholding will determine sensitivity to peripheral targets at a range of eccentricities while fixation is maintained. Thus, individual differences in ability to detect task-relevant peripheral information, critical for planning a saccade, will be measured. Inhibitory function will be estimated as stop-signal reaction time (SSRT) obtained from a saccadic countermanding task. Inhibition plays an important role in slowing accumulation to prevent motor units from reaching threshold quickly. Previous results show that individuals with longer initial fixations make larger amplitude saccades and may land closer to a target. Therefore, enhanced peripheral detection abilities are hypothesized to cooccur with longer fixation duration tendencies. Alternatively or in addition, individual inhibitory function is hypothesized to prevent fast saccades and extend fixation durations. Aim 2 will investigate how individual tendency for short fixation durations affects the choice of saccade destination. This aim uses more complex search displays than Aim 1, with strong competition from salient distractors. A novel hypothesis is proposed about the relationship between individual differences in SSRT and oculomotor capture: individuals with longer SSRT will produce more fast saccades to salient distractors. Finally, Aim 3 will use novel methodology to investigate individual differences in fixation duration known to occur during extended viewing of natural scenes. A dynamic useful field of view (UFOV) task will use gaze-contingent probe presentation at precise eccentricities to measure individual sensitivity to peripheral information during free-viewing. This measure of peripheral processing will more directly mirror conditions present during natural vision, and these measures of attentional breadth are predicted to relate to individual differences in fixation behavior during free-viewing of natural scenes. The long-term goal is to bridge a gap between theories from computational models of neurophysiological data and human saccadic behavior. Understanding the etiology of oculomotor behavior can help target treatments for disorders and shed light on how individual variability might alter visual information acquisition and environmental interactions.