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.
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.
Showing the most recent 10 out of 42 publications
