Aging and Working Memory Inside and Outside the Focus of Attention: Dissociations of Availability and Accessibility

ABSTRACT

Two experiments used the N-Back task to test for age differences in working memory inside and outside the focus of attention. Manipulations of the difficulty of item-context binding (Experiment 1) and of stimulus feature binding (Experiment 2) were used to create conditions that varied in their demand on working memory, with the expectation that greater demand might increase age differences in focus-switching costs and the search rate outside the focus of attention. Results showed, however, that although age differences were evident in measures of overall speed and accuracy, and the manipulations significantly affected response times and accuracy in the expected direction, the experimental manipulations had no impact on age differences. Findings instead pointed to age-related reductions in accuracy but not speed of focus-switching and search outside the focus of attention. Thus, age-related deficits appear to involve the availability of representations in working memory, but not their accessibility.

Keywords:

• Working memory
• Focus of attention
• Focus-switching
• Age differences
• Context memory

ACKNOWLEDGEMENTS

The authors gratefully acknowledge Korena Onyper and Nicole Pukay-Martin for their assistance with programming, data collection, and scoring. This research was supported in part by the National Institute on Aging Grant (AG10593) awarded to Marilyn Hartman and the National Institute on Aging Grant (AG16201) awarded to Paul Verhaeghen. Parts of these data were presented at the 45th Annual Meeting of the Psychonomic Society (Minneapolis, 2004) and the 47th Annual Meeting of the Psychonomic Society (Houston, TX, 2006).