摘要

Background: Auditory distraction is known to affect serial recall (irrelevant sound effect), but there has been limited study about the effect of distraction on performance of more complex metalinguistic tasks, particularly as cognitive performance declines with normal ageing. The inhibitory deficit theory offers an explanation for this decline in performance with ageing, suggesting that older adults have difficulty limiting access of irrelevant information to attentional resources. Recent imaging data provide physiological evidence for changes that are seen with normal ageing. Aims: This study compared the effect of three levels of auditory distraction on judgement of well-formedness for grammatical and ungrammatical passive sentences varied by length (padding) and semantic reversibility, in younger and older normal adults. Methods Procedures: Younger (n = 20; mean age 22.23) and older (n = 10; mean age 67.11) adults silently read sentences varied as above, presented in their entirety on a computer screen, in quiet, cafeteria noise, and narrative distraction. Participants made immediate grammaticality judgements (GJ) by pressing a keypad. Reaction time data (RTs) were evaluated using an analysis of variance. Outcomes Results: Significant main effects were noted for age (young = faster RTs), distraction (narrative = fastest RTs), grammaticality (bad = faster RTs), and reversibility (non-reversible = faster RTs) for both base and padded sentences. There was a significant Age x Distraction interaction; older adults showed no difference in RTs across the three distraction conditions for the longer padded sentences, while younger adults maintained faster RTs in the narrative distraction for both sentence lengths. In addition, there was an Age x Reversibility effect for older participants in the longer sentences only. Conclusions: Older adults responded differently from younger adults in the GJ task in distraction, consistent with the inhibitory deficit theory. Their response pattern was also affected by reversibility and memory variables, apart from distraction, suggesting that multiple cognitive and linguistic components contribute to the decline in processing speed with normal ageing.

  • 出版日期2010