Contributions of attentional and inhibitory functioning to saccadic decisions

项目摘要 扫视是一种基本的行为，它通过频繁地改变输入接收的信息来实现功能视觉 乳房加工。注视是两次扫视之间的时刻，在此期间新的输入被处理， 下一次扫视的目的地也被编程。因此，产生扫视的决定是 这是一个复杂的过程，依赖于众多系统的相互作用。扫视行为在不同的范围内差异很大 临床状态的差异，在婴儿期就出现了差异。一大篇文献研究了眼跳的动力学 通过计算建模和神经生理学数据进行决策。然而，人们对此知之甚少。 典型人群中的个体差异。这项建议的目标是确定潜在的 解释注视持续时间倾向的个体差异的机制，并调查它们如何影响 下游注意选择。在目标1中，注意和抑制功能的独立测量将 与个体注视持续时间的变异性进行比较。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向外围目标移动。因此，能力上的个体差异 为了检测与任务相关的外围信息，将测量对计划扫视至关重要的信息。抑制功能 将被估计为停止信号反应时间(SSRT)，从跳跃反击任务中获得。抑制 在减缓积聚以防止电机单元快速达到阈值方面起着重要作用。上一首 结果表明，初始注视时间较长的个体会产生更大幅度的眼跳，并可能更接近 一个目标。因此，假设增强的外周检测能力与更长时间的注视同时发生 持续时间趋势。可替换地或附加地，假设个体抑制功能以防止快速 眼跳和延长注视持续时间。目标2将调查个体对短注视持续时间的倾向 影响扫视目的地的选择。该目标使用比目标1更复杂的搜索显示，具有强大的 来自显著干扰因素的竞争。关于个体之间的关系，提出了一个新的假说 SSRT和动眼运动捕捉的差异：SSRT较长的个体将产生更快的眼跳 明显的干扰因素。最后，目标3将使用新的方法来研究注视的个体差异。 已知的持续时间发生在延长观看自然场景的过程中。动态有用视场(UFOV)任务 将在精确的偏心处使用凝视条件下的探头呈现来测量个体对 免费观看期间的外围信息。这种外围处理措施将更直接地反映 在自然视觉过程中出现的情况，以及这些注意力广度的测量被预测与 自然景物自由观赏时注视行为的个体差异。我们的长期目标是在 神经生理学数据的计算模型和人类眼跳行为的理论之间的差距。 了解眼球运动行为的病因学有助于有针对性地治疗疾病并阐明 个体的可变性如何改变视觉信息获取和环境互动。

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.