Effects of covert attention on early vision

描述（由申请人提供）：注意如何影响感知？本研究的长期目标是通过研究隐性注意对早期视觉的影响，借鉴知觉、认知和神经生理学的理论工作，并利用视觉心理物理学的方法，促进对视觉注意的理解。隐蔽注意有两种系统：“瞬时”（外源性或刺激驱动）和“持续”（内源性或概念驱动）。最近的研究表明，短暂注意力通过增强对比敏感度、增加空间分辨率和加速信息积累来影响早期视力。迄今为止，关于持续注意力的研究主要集中在高级认知过程上，而对其对早期视力的影响知之甚少。该研究将系统地调查两种注意力系统对早期视力的影响。研究表明，短暂的注意力是自动的，可能会导致我们的表现受损或偏离真实的感知。当前建议的一个主要目的是测试持续注意比短暂注意更灵活，因此可能更好地适应任务要求的假设。本研究的主要目的是：(1)通过对视场中被注意和未被注意位置的信号质量进行评价，研究短暂注意和持续注意对对比敏感性的影响，考察注意效应对对比敏感性的时间过程，并探讨注意的获得机制和选择性适应对刺激加工的影响；(2)瞬态和持续注意力对有人值守和无人值守位置空间分辨率的影响，以及注意力是否通过增加对更高频率的敏感性来影响通道的空间频率调谐；(3)瞬态和持续注意力对一阶和二阶空间频率通道的增益和调谐是否有差异影响；(4)通过对双眼竞争的研究，发现瞬时注意和持续注意对对比灵敏度和空间分辨率的影响水平；(5)隐蔽注意对标准双眼观看和双目竞争时视对比度和空间分辨率的影响。结果将在线性和非线性系统中操作的空间滤波器集合的理论框架内解释。这些发现对人为因素以及我们对许多神经心理疾病的理解都有影响，例如单侧忽视、精神分裂症和多动症。

DESCRIPTION (provided by applicant): How does attention affect perception? The long-term objective of the research is to contribute to the understanding of visual attention by studying the effects of covert attention on early vision, drawing on theoretical work in perception, cognition, and neurophysiology, and using methods from visual psychophysics. There are two systems of covert attention: 'transient' (exogenous or stimulus-driven) and 'sustained' (endogenous or conceptually-driven). Recent research has shown that transient attention affects early vision by enhancing contrast sensitivity, increasing spatial resolution, and accelerating information accrual. To date, studies on sustained attention have focused on higher cognitive processes, whereas relatively little is known about its effects on early vision. The proposed research will systematically investigate the effects of both attentional systems on early vision. Research has shown that transient attention, being automatic, may result in impaired performance or deviate us from veridical perception. A main objective of the current proposal is to test the hypothesis that sustained attention is more flexible and hence may adapt to task demands better than transient attention. The specific aims are to investigate: (1) the effects of transient and sustained attention on contrast sensitivity by evaluating the quality of the signal at both the attended and unattended locations across the visual field, examining the time course of attentional effects on contrast sensitivity, and exploring how the gain mechanisms of attention and selective adaptation affect stimulus processing; (2) the effects of transient and sustained attention on spatial resolution at the attended and unattended locations and whether attention affects the channels' spatial frequency tuning by increasing sensitivity to higher frequencies; (3) whether transient and sustained attention differentially affect the gain and tuning of 1st and 2nd order spatial frequency channels; (4) the levels at which transient and sustained attention exert their effects on contrast sensitivity and spatial resolution by studying binocular rivalry; (5) the effects of covert attention on apparent contrast and spatial resolution during standard binocular viewing and binocular rivalry. Results will be interpreted within the theoretical framework of an ensemble of spatial filters operating in linear and nonlinear regimes. The findings have implications for human factors, as well as for our understanding of many neuropsychological conditions, e.g. unilateral neglect, schizophrenia, and ADHD.