High-Level Influences on Low-Level Learning

描述(由申请者提供)：人类的能力对实践的影响非常敏感。在实验室和自然环境中对练习效果的研究记录了人类在从运动到认知的各种任务中能够获得异常高水平的表现的程度。在过去的二十年里，一本关于知觉学习的快速增长的文献记录了一系列任务，在这些任务中，对基本知觉判断的练习可以显著提高成绩。这些研究表明，即使是人类信息处理的基本方面也可以进行实质性的修改，进而推而广之，早期的感觉水平可能是高度可塑性的。这项建议的具体重点是视觉任务，涉及在观察者检测阈值或附近水平上操纵刺激特征。虽然特定的任务可能需要分类、识别或辨别判断，但需要准确区分特征的存在和不存在是感兴趣的感知能力的一个基本方面；例如，熟练的放射科医生能够在多大程度上检测和识别X射线图像中的肿瘤。关于这类技能的现有证据提出了三个假设：(A)知觉专业知识的获得和表达依赖于多个级别的编码信息，(B)所有这些代码都是同时可用的，(C)学习的时间进程涉及视觉系统越来越低级别的代码的递增强化。这些假设的测试将涉及行为和神经生理(EEG)数据的收集，以及能够将这两种类型的数据联系起来的计算建模方法的开发。相关性：对感知能力的明确关注需要检测和识别，这在观察者必须掌握可靠地区分某些视觉属性的存在和不存在的领域中具有翻译应用的潜力，并且在观察者可获得的信息可能极其有限的情况下，基于该属性可靠地对对象进行分类或命名。例如，对视力障碍(例如弱视)的行为干预、对警察神枪手的培训或对安检员的培训。

DESCRIPTION (provided by applicant): Human abilities are remarkably responsive to the effects of practice. Studies of the effects of practice, in both laboratory and natural settings, have documented the extent to which humans can obtain exceptionally high levels of performance in tasks ranging from motor to cognitive. Within the past two decades, a rapidly-expanding literature on perceptual learning has documented the range of tasks in which practice on basic perceptual judgments can produce dramatic improvements in performance. These studies suggest that even elementary aspects of human information processing can be substantially modified and, by extension, that early sensory levels may be highly plastic. The specific focus of this proposal is on visual tasks that involve stimulus characteristics manipulated at levels at or near observers' detection thresholds. While specific tasks may require categorization, identification, or discrimination judgments, the need to accurately distinguish between the presence and absence of a characteristic is a fundamental aspect of the perceptual abilities that are of interest; an example would be the extent to which a skilled radiologist is able to both detect and identify a tumor in an X-ray image. The available evidence on these types of skills suggests three hypotheses: (a) The acquisition and expression of perceptual expertise relies on multiple levels of encoded information, (b) All of these codes are available simultaneously, (c) The time-course of learning involves an incremental strengthening of codes at increasingly lower levels of the visual system. Tests of these hypotheses will involve the collection of both behavioral and neurophysiological (EEG) data, and the development of a computational modeling approach capable of linking these two types of data. Relevance: The explicit concern with perceptual abilities that require both detection and identification holds the potential for translational application in domains in which observers must acquire the ability to reliably distinguish between the presence and absence of some visual attribute, and to reliably categorize or name an object based on that attribute when the information available to observers may be extremely limited. Examples include behavioral interventions for visual impairments (e.g., amblyopia), the training of police sharp-shooters, or the training of security screeners.