title: Backward compatibility effects in younger and older adults.
abstract: In many dual-task situations, responses to the second of two tasks are slowed when the time between tasks is short. The response-selection bottleneck model of dual-task performance accounts for this phenomenon by assuming that central processing of the second task is blocked by a bottleneck until central processing of Task 1 is complete. This assumption could be called into question if it could be demonstrated that the response to Task 2 affected the central processing of Task 1, a backward response compatibility effect. Such effects are well-established in younger adults. Backward compatibility effects in older (as well as younger) adults were explored in two experiments. The first experiment found clear backward response compatibility effects for younger adults but no evidence of them for older adults. The second experiment explored backward stimulus compatibility and found similar effects in both younger and older adults. Evidence possibly consistent with some pre-bottleneck processing of Task 2 central stages also was found in the second experiment in both age groups. For younger adults, the results provide further evidence falsifying the claim of an immutable response selection bottleneck. For older adults, the evidence suggested that Task 2 affects Task 1 when there is stimulus compatibility but not when there is response compatibility.
authors.affiliation: Department of Psychology, Scripps College, Claremont, CA, 91711, USA. ahartley@scrippscollege.edu.
authors.forename: Alan A
authors.initials: AA
authors.lastname: Hartley
authors.affiliation: Laboratoire de Psychologie & MSHE-Ledoux, Université Bourgogne Franche-Comté, Besançon, France.
authors.forename: François
authors.initials: F
authors.lastname: Maquestiaux
authors.affiliation: Department of Psychology, Scripps College, Claremont, CA, 91711, USA.|School of Behavioral and Brain Sciences, Center for Vital Longevity, University of Texas-Dallas, Dallas, TX, USA.
authors.forename: Sara B
authors.initials: SB
authors.lastname: Festini
authors.affiliation: Department of Psychology, Scripps College, Claremont, CA, 91711, USA.|Department of Psychology, Clark University, Worcester, MA, USA.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Frazier
authors.affiliation: Department of Psychology, Scripps College, Claremont, CA, 91711, USA.
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Krimmer
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D011597:Psychomotor Performance; D012033:Refractory Period, Psychological; D013647:Task Performance and Analysis; D055815:Young Adult
keywords: Aging; Backward compatibility effect; Dual task; Parallel processing; Psychological refractory period; Response selection; Response-selection bottleneck model