The Role of Sensory Function in Processing Speed and Working Memory Aging

Abstract

ABSTRACTBackground: Sensory function, processing speed, and working memory are considered to be mechanisms that play important explanatory roles in age-related decline of cognitive abilities. As individuals age, sensory function declines along with other cognitive abilities, including processing speed and working memory. Moreover, the relationship between sensory function, processing speed, and working memory, which represent the most basic mechanism, is one of the important issues in the field of cognitive aging.Methods: To explore the role of sensory function, especially visual function, in processing speed and working memory aging, the present study adopted a 2 (age: young and old) × 4 (visual perceptual stress: high, medium, low, and non-stress) mixed design and explored age differences in tasks testing processing speed and working memory. To generate different levels of visual perceptual stress, test materials were masked with Gaussian noise according to each individual‘s visual function.Results: The results indicated that age differences in processing speed were not influenced by different levels of visual perceptual stress, while age differences in working memory performance decreased gradually with the increase of visual perceptual stress.Conclusion: Visual function affected age differences in working memory rather than in processing speed. The common-cause hypothesis and information-degradation hypothesis were applied to interpret the relationships between visual function and processing speed and between visual function and working memory, respectively. Moreover, sensory function may not directly affect working memory function, which was also consistent with a resource decrement model of aging.