AGING AND WORKLOAD CAPACITY: DO OLDER ADULTS INTEGRATE VISUAL STIMULI DIFFERENTLY THAN YOUNGER ADULTS?
The effect of aging on response times and on the processing capacity of redundant-visual signals is a neglected theme in the study of aging. In the redundant target design (RTD), an observer detects the presence of a target. A trial can include two (redundant), single, or no-targets. Do older-adults integrate visual stimuli differently than younger-adults? A new approach to capacity (Townsend & Nozawa, 1995) compares the processing of single- and redundant-target trials to compute an index of workload capacity. We discuss the implication of various theories of aging on Townsendâ€™s capacity coefficient: Generalized cognitive slowing models with a single age-related slowing equation for all trials; Information degradation models linking sensory loss with cognitive tasks; and Models assuming a decrease in the efficiency of inhibiting distractors. Experimentally, we compare target- detection latencies and Townsendâ€™s capacity for younger- and older-adults in RTD, examining the effects of distractor presence and absence for both groups.