title: What is still working in working memory in old age: dual tasking and resistance to interference do not explain age-related item loss after a focus switch.
abstract: OBJECTIVE
  In 2 experiments, we examined the oft-replicated finding of age-related differences in accuracy at retrieving items stored in working memory, but outside the focus of attention. Specifically, we investigated whether such differences could be explained by (a) age-related differences in coping with the dual-task nature of swapping items into and out of the focus of attention and/or (b) age-related differences in resistance to interference.
  
  
  METHODS
  We used a modified version of the N-Back task with stimuli of different levels of difficulty, and experimental manipulations aimed at isolating the dual-task and interference effects.
  
  
  RESULTS
  We found both explanations lacking: We obtained a dual-task cost (Experiment 1) and an interference cost (Experiment 2), as well as a large age effect (Cohen's d = 1.6 in Experiment 1 and 0.7 in Experiment 2) but neither the dual task nor the interference effect was sensitive to age.
  
  
  CONCLUSIONS
  These findings, combined with previous failures to find an explanation for the age effects, suggest that item availability after a focus switch might be an important new and fundamental variable-a cognitive primitive-potentially necessary for a full understanding of age effects in higher order cognition.
authors.affiliation: Department of Psychology, Georgia Institute of Technology, 654 Cherry Street, Atlanta, GA 30332-0170, USA. verhaeghen@gatech.edu
authors.forename: Paul
authors.initials: P
authors.lastname: Verhaeghen
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging / Q000523:psychology*; D001288:Attention; D003071:Cognition; D006801:Humans; D008570:Memory, Short-Term; D009483:Neuropsychological Tests; D011930:Reaction Time; D055815:Young Adult