Effects of Presentation Modality on Language Processing in Young and Older Adults

Abstract

The segment of the population that is 65 years and older is undergoing rapid growth. With this growth, there is an increased need for speech-language pathologists (SLPs) to treat cognitive-communicative disorders, most of which are age-related disorders secondary to neurologic disease. To do this effectively, SLPs require an understanding of how healthy aging affects cognition, memory and sensory processing. Although the interactions between sensory and cognitive processing are increasingly being investigated, little attention has been paid to the relationship between modality of information presentation and language comprehension in aging. Language comprehension is affected by component processes such as memory span and processing abilities, but to date there has been no systematic investigation of the effect of presentation modality on the processing of linguistic information across a number of tasks ranging in complexity.The primary purpose of this study was to investigate the effects of presentation modality on language processing. The secondary purposes of the study were to determine whether age affected performance on language processing measures, and whether adults can accurately predict if their performance was better in either the auditory or visual presentation condition. The effects of presentation modality were evaluated on four dependent measures: a digit span task, a word span task, a complex span task and a procedural instruction processing task. The participants were 37 older adults and 41 younger adults, matched for years of education and estimated verbal IQ.Three notable findings emerged from the study. First, both young and older adults recalled more information when it was presented in the auditory modality, regardless of the task. Second, age effects were present on all measures. Third, individuals were generally inaccurate in predicting which modality would result in better processing. Implications for the evaluation and treatment of older adults are discussed.