Aging and Perceptual Learning: Behavioral and fMRI Studies

描述（由申请人提供）：文献中有充分的证据表明，视觉感知能力随着年龄的增长而下降。这些下降包括对目标方向、低对比度刺激、运动、形状和形式的感知。与年龄相关的视觉处理能力下降被认为是老年人跌倒的主要原因，也是老年司机事故风险增加的主要原因。本研究的目的是探讨在阈下刺激下的知觉学习是否可以用于恢复与年龄相关的视觉知觉衰退。拟议的研究将包括行为研究和功能磁共振成像研究。所提出的行为实验将确定老年观察者通过感知学习提高的表现是由于早期视觉处理、后期视觉处理还是非感觉处理的变化。知觉学习和改进轨迹的影响将通过检查位置和眼间转移，以及通过评估在同一加工阶段（例如定向和对比）以及不同加工阶段（例如全局运动和定向）相关的知觉任务的训练转移来评估。知觉学习对非感觉加工的影响将通过检查反应标准的变化和分散注意的改善来评估。fMRI研究将检验老年观察者从感知学习中获得的行为表现的改善是由于功能可塑性、神经补充还是半球不对称激活的变化。fMRI研究将检查与行为研究中检查的相同的感知学习任务，并将检查视觉皮层和前额皮质中几个区域的激活变化。此外，根据行为和功能磁共振成像研究的结果，我们计划进行结构成像研究，以确定感知学习是否会导致神经系统的生理变化。最后，我们还计划进行干预研究，以确定通过感知学习提高老年观察者的表现是否可以提高驾驶相关任务的表现。这条研究路线的目标是检查使用感知学习的视觉功能恢复是否可以应用于已知对老年人的安全，健康和生活质量重要的情况。公共卫生相关性：这项拟议的研究将研究如何使用视觉显示训练来提高老年人的视觉感知能力。这些研究将包括行为研究和脑成像研究，以确定知觉如何改善，以及这种改善与大脑活动的变化之间的关系。

DESCRIPTION (provided by applicant): A well documented finding in the literature is that visual perception declines with age. These declines include the perception of target orientation, low contrast stimuli, motion, shape and form. Age related declines in visual processing have been implicated as a leading cause of falls among the elderly as well as the increased risk of accidents for older drivers. The purpose of this research is to examine whether perceptual learning with sub threshold stimuli can be used to recover age-related declines in visual perception. The proposed research will include behavioral studies and fMRI studies. The proposed behavioral experiments will determine whether the improved performance for older observers via perceptual learning is due to changes in early stage visual processing, later stages of visual processing, or non-sensory processing. The effects of perceptual learning and the locus of improvement will be assessed by examining location and interocular transfer and by assessing transfer of training from perceptual tasks associated at the same stage of processing (e.g., orientation and contrast) as well as different stages of processing (e.g., global motion and orientation). The impact of perceptual learning on non-sensory processing will be assessed by examining changes in response criteria and improvements in divided attention. fMRI studies will examine whether the improved behavioral performance from perceptual learning for older observers is due to functional plasticity, neural recruitment, or changes in hemispheric asymmetry of activation. The fMRI studies will examine the same perceptual learning tasks that will be examined in the behavioral studies and will examine changes in activation in several regions in visual cortex as well as prefrontal cortex. In addition, contingent on the results of the behavioral and fMRI studies we plan on conducting structural imaging studies to determine whether perceptual learning results in physiological changes in neuronal systems. Finally, we also plan on conducting intervention studies to determine whether improved performance for older observers via perceptual learning can improve performance in driving related tasks. The goal of this line of research is to examine whether recovery of visual function using perceptual learning can be applied to situations known to be of importance for the safety, well being and quality of life of older populations. PUBLIC HEALTH RELEVANCE: The proposed research will examine how training with visual displays can be used to improve visual perception for older individuals. The studies will include behavioral research and brain imaging research to determine how perception improves and how the improvement is related to changes in brain activity.