Inhibitory control in prospective memory: An event related potential comparison of task-switch and dual task processing

This study cross-validates reported changes in behavioural and event-related potential (ERP) correlates of prospective memory (PM) inhibitory control performance applying different PM response selection demands (Bisiacchi et al., 2009). Participants were randomly assigned to a control group condition with no PM requirement, or to either inhibit ongoing task processing to respond to PM task cues (task-switch; TS) or provide an ongoing task response prior to providing a PM button press (dual-task; DT). The behavioural data indicated that ongoing task reaction time (RT) performance was similar in the DT, TS, and control group conditions. PM cue detection mechanisms reflected by the N300 did not differ between PM tasks. However, early occurring (400–700 ms) PM late parietal complex (LPC) amplitudes recorded over anterior electrode sites were larger in the TS compared to the DT-PM condition, and this difference persisted during the 700–1000 ms epoch. Thus, ERP correlates of PM task-set remapping were significantly altered via the induction of different PM response production rules retrieved from retrospective memory (RM). The enhancement of anteriorly distributed TS LPC amplitudes between 400 and 700 ms led to the suggestion that increased inhibition in this group condition was accompanied by heightened frontally mediated neural activations that support prepotent ongoing task response inhibition processing.