“…The costs of adding a PM task to an ongoing task were calculated by subtracting each participant's mean response time in the ongoing-task-only block from the mean response time of the ongoing task trials in each PM block. Following previous research, response times of incorrect ongoing task trials, of PM trials, and of the two trials following each target cue, were omitted from analyses (for similar procedure, see Boywitt & Rummel, 2012;Brewer, 2011;Cohen et al, 2016;Horn, Bayen, & Smith, 2013). A mixed-factorial ANOVA indicated significant main effects of maintenance load, F(1, 163) = 26.95, p < .001, η p 2 = .14, focality, F(1, 163) = 5.82, p = .02, η p 2 = .03, and age, F(1, 163) = 10.24, p < .01, η p 2 = .06, reflecting higher ongoing task response time costs in the highcompared to the low-maintenance load condition, nonfocal tasks compared to focal tasks and higher costs for older adults as compared with younger adults.…”