Home
HOME ARCHIVE SEARCH TABLE OF CONTENTS

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Services
Right arrow Download to citation manager
PubMed
Right arrow PubMed Citation
The Journals of Gerontology Series B: Psychological Sciences and Social Sciences 63:P57-P66 (2008)
© 2008 The Gerontological Society of America


RESEARCH ARTICLE

Neurophysiological Measures of Task-Set Switching: Effects of Working Memory and Aging

Philippe Goffaux, Natalie A. Phillips, Marco Sinai and Dolores Pushkar

1 Department of Psychology, Concordia University, Montreal, Québec, Canada.
2 Centre for Research in Human Development, Concordia University, Montreal, Québec, Canada.
3 Lady Davis Institute for Medical Research/Jewish General Hospital, Montreal, Québec, Canada.

Address correspondence to Natalie A. Phillips, PhD, Department of Psychology, Concordia University, Centre for Research in Human Development, 7141 Sherbrooke Street West, Montréal, Québec, Canada, H4B 1R6. E-mail: Natalie.Phillips{at}concordia.ca

We investigated age-related differences in task-switching performance by using behavioral measures and event-related brain potentials. We tested younger and older adults, and we separated older adults into groups with high and low working memory (WM); that is, we separated them into old–high-WM and old–low-WM groups. On average, all participants responded more slowly in mixed-task than in single-task blocks (i.e., reaction time or RT mixing cost). Younger adults and old–high-WM participants had equivalent RT mixing costs and showed larger posterior negative slow-wave activity when preparing for mixed trials than for single-task trials, suggesting that mixed-task trials required trial-to-trial preparation. Old–high-WM participants also showed frontally distributed activity on mixed-task trials, suggesting their use of executive control to offset age-related differences in mixed-task preparation. In contrast, old-low-WM participants had large RT mixing costs and large posterior event-related brain potential negativities during single-task trials, suggesting that they prepare during single- and mixed-task blocks. High WM, therefore, may help older adults offset the age-related difficulties often observed when they are task switching.

Key Words: Task switching • Mixing cost • Working memory • Event-related brain potentials • Negative slow wave







HOME ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2008 by The Gerontological Society of America.