Aging and Perceptual Learning: Behavioral and fMRI Studies

描述（由申请人提供）：文献中有充分记录的发现是视觉感知随年龄增长而下降。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福尔斯摔倒的主要原因，也是老年驾驶员发生事故的风险增加的主要原因。本研究旨在探讨阈下刺激的知觉学习是否可以用于恢复与年龄相关的视知觉下降。拟议的研究将包括行为研究和功能磁共振成像研究。拟议的行为实验将确定老年观察者通过感知学习的改善表现是否是由于早期视觉处理，视觉处理后期或非感官处理的变化。知觉学习的效果和改善的位点将通过检查位置和眼间转移以及通过评估来自与同一处理阶段相关联的知觉任务的训练转移（例如，取向和对比度）以及不同的处理阶段（例如，全局运动和定向）。知觉学习对非感觉处理的影响将通过检查反应标准的变化和注意力分散的改善来评估。功能磁共振成像研究将检查老年观察者感知学习的行为表现改善是否是由于功能可塑性，神经募集或半球激活不对称性的变化。功能磁共振成像研究将检查与行为研究相同的感知学习任务，并将检查视觉皮层和前额叶皮层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，以确定知觉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。这一系列研究的目标是检查使用知觉学习恢复视觉功能是否可以应用于已知对老年人的安全，健康和生活质量具有重要意义的情况。公共卫生相关性：拟议的研究将研究如何使用视觉显示器进行训练，以改善老年人的视觉感知。这些研究将包括行为研究和大脑成像研究，以确定感知如何改善以及这种改善如何与大脑活动的变化相关。

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.