Visual and auditory modality and suffix effects in young and elderly adults.

Research has shown that elderly as compared with young adults show relative deficits both in processing visually as compared with auditorily presented stimuli and in tasks having attentional components. In this study, visual and auditory presentation was compared in young and elderly adults using the suffix paradigm in which the control condition involves immediate serial recall and the experimental condition, a suffix, a not-to-be-remembered final item. The standard finding in this paradigm is called the modality effect, superior auditory as compared with visual performance in the control condition which is localized at the end of the sequence. Generally, auditory suffixes following auditory sequences reduce the modality effect while visual suffixes following visual sequences do not. The results showed generally standard modality and suffix effects for both age groups. Relatively inferior performance was present in the elderly in the visual as compared with the auditory control conditions suggesting recoding deficits in this group. Auditory suffixes following auditory sequences had a relatively greater performance effect on the elderly than the young, while visual suffixes following visual sequences did not impair the performance of either group. This suggests a modality specific attentional deficit in the elderly. Rank order correlations suggest that individuals within both age groups showing large differences in performance between auditory and visual control conditions may have relative recoding difficulties for their age. Additionally, increased susceptibility to auditory interference for elderly as compared with young subjects may be a marker of aging, while relative within-group susceptibility to auditory interference may be a deficit on the part of young subjects.