Attention and Perceptual Learning

描述（由申请人提供）：注意力和感知学习（PL）是已知的两种改善视觉感知的机制，尽管在大多数情况下，它们已经被单独研究。我建议彻底调查操纵内隐注意对PL的影响。PL涉及生物体感知系统相对持久（数周或数月）的变化。这种变化提高了对环境中事件的反应能力，被认为是成人大脑神经可塑性的表现。PL已被证明在心理上的许多刺激在各种感官形式，往往是高度具体的刺激和任务。例如，如果观察者（在最初的训练阶段）学习如何在视野中的特定位置执行任务，他们随后（在测试阶段）在未经训练的位置没有表现出任何好处。注意力的作用时间比PL短得多，是选择性和动态地提高感知性能的最重要机制。内隐注意-在给定位置选择性地处理信息而没有眼球运动到该位置-提高了早期视觉中许多检测，辨别和定位任务的感知性能。我感兴趣的外源性（非自愿）和内源性（自愿）内隐注意如何影响PL的标志性特异性，以及注意是否可以与学习相互作用，以克服这种限制，以提高性能PL产生。我将使用PL特异性和注意力调节的视觉维度;例如，位置、方向和空间频率。研究与注意力对PL的影响相关的心理物理变化将增加对视觉系统可塑性的理解。不同形式的注意力是否以及如何增强成年人大脑皮层的可塑性，这一问题在理论上很重要，也有实际意义。PL可能是我们在职业和个人生活中所做的大部分视觉工作的基础，因此具有巨大的基本兴趣和实际重要性。这个问题对于理解和评估视觉系统受损后的康复潜力也至关重要。我们自己的研究注意力对早期视力的影响，在目前的补助金期间进行的地方，我们在一个独特的位置进行拟议的研究。初步研究表明，注意在PL中起着关键的和意想不到的作用。 我将描述每种类型的注意力的影响，内源性和外源性，为以下目的：（1）PL在整个视野的视觉搜索;（2）PL的基本维度（例如，对比灵敏度、方向和空间分辨率），考虑视网膜距离、皮层距离和注意窗口的大小;（3）PL，关于特征（例如，对比敏感度、定向）学习和迁移特异性;（4）在无意识状态下的PL。拟议的研究将利用不同的心理物理程序，以促进我们了解大脑可塑性如何改变PL所指示的视觉，以及视觉处理如何与其他认知相关的大脑系统相互作用，特别是注意力。研究结果将具有理论相关性，并将有助于我们理解和评估视觉系统受损后的康复潜力。 公共卫生相关性：我建议彻底调查操纵内隐注意对PL的影响。PL是我们视觉能力的基础，因此不同形式的注意力是否以及如何增强普通人群成人皮质的可塑性的问题在理论上很重要，并具有实际后果。我将为研究注意力如何影响健康人类观察者的知觉学习而开发的实验方案将很容易适用于患者群体。更好地理解健康观察者的视觉注意力和知觉学习将导致更好地理解限制周边视觉的因素，这在黄斑变性和相关视觉缺陷导致中央视觉受损时至关重要。视觉注意力的基本知识对我们理解几种神经心理障碍和告知其诊断测试的发展有影响，包括单侧忽视，精神分裂症和ADHD。注意力如何影响知觉学习的基本知识对弱视、黄斑变性和皮质盲患者的康复以及对创伤和肿瘤或梗死（“中风”）后视觉康复潜力的评估具有重要意义。

DESCRIPTION (provided by applicant): Attention and perceptual learning (PL) are two mechanisms known to improve visual perception, though, for the most part, they have been studied separately. I propose to thoroughly investigate the effects of manipulating covert attention on PL. PL involves relatively long-lasting (weeks or months) changes to an organism's perceptual system. Such changes improve the ability to respond to events in the environment and are considered a manifestation of neural plasticity in the adult brain. PL has been demonstrated psychophysically for many stimuli in various sensory modalities, and is often highly specific to stimulus and task. For instance, if observers learn (in the initial training phase) how to perform a task at a particular location in the visual field, they later (in the testing phase) show no benefit at untrained locations. Attention operates on a much shorter timescale than PL and is the most important mechanism that selectively and dynamically improves perceptual performance. Covert attention - the selective processing of information at a given location without eye movements to that location - improves perceptual performance on many detection, discrimination and localization tasks in early vision. I am interested in how exogenous (involuntary) and endogenous (voluntary) covert attention affect the hallmark specificity of PL, and whether attention can interact with learning to overcome this limitation to the improvement in performance PL engenders. I will use visual dimensions for which both PL specificity and modulation by attention have been shown; e.g., location, orientation and spatial frequency. Investigating the psychophysical changes associated with the effects of attention on PL will lead to increased understanding of plasticity in the visual system. The question of whether and how different forms of attention enhance plasticity in the adult cortex is important theoretically and has practical consequences. PL probably underlies most of what we do well visually in our professional and personal lives and is thus of enormous basic interest and practical importance. This question is also crucial for understanding and evaluating the potential of rehabilitation following damage to the visual system. Our own studies on the effects of attention on early vision conducted during the period of the current grant place us in a unique position to conduct the proposed research. Pilot studies indicate that attention plays a pivotal and unanticipated role in PL. I will characterize the effects of each type of attention, endogenous and exogenous, for the following aims: (1) PL in visual search across the visual field; (2) PL of basic dimensions (e.g., contrast sensitivity, orientation and spatial resolution) with regard to location specificity, taking into account retinal distance, cortical distance and the size of the attentional window; (3) PL with regard to feature (e.g., contrast sensitivity, orientation) learning and transfer specificity; (4) PL in the absence of awareness. The proposed research will utilize different psychophysical procedures to contribute to our understanding of how brain plasticity alters vision as indicated by PL, and how visual processing interacts with other brain systems underlying cognition, in particular, attention. The findings will have theoretical relevance and will contribute to our understanding and evaluation of potential of rehabilitation following damage to the visual system. PUBLIC HEALTH RELEVANCE: I propose to thoroughly investigate the effects of manipulating covert attention on PL. PL is the foundation of our visual competence, so the question of whether and how different forms of attention may enhance plasticity in the adult cortex in the general population is important theoretically and has practical consequences. The experimental protocols that I will develop for studying how attention affects perceptual learning in healthy human observers will be readily applicable to patient populations. A better understanding of visual attention and perceptual learning with healthy observers will lead to a better understanding of factors limiting peripheral vision, which are critical when central vision is compromised due to macular degeneration and related visual deficits. Basic knowledge of visual attention has implications for our understanding of several neuropsychological disorders and for informing the development of their diagnostic testing, including unilateral neglect, schizophrenia and ADHD. Basic knowledge of how attention affects perceptual learning has implications for rehabilitation of patients with amblyopia, macular degeneration, and cortical blindness as well as for the evaluation of the potential of visual rehabilitation after trauma and tumors or infarcts ('stroke').