Effect of characteristics of target cues on task interference from prospective memory

Abstract

Event-related potential technique was used to examine the effect of characteristics of target cues on brain activity related to task interference during event-based prospective memory (PM). Three conditions were tested. In the control condition participants had no PM task and merely performed a shape decision task. In one PM condition the task of PM was to respond to a salient cue, whereas in the other PM condition the task of PM was to respond to a nonsalient cue. The results seemed to support preparatory attentional and memory processes theory and suggested frontal lobe involvement in monitoring, which caused task interference effects, and those characteristics of cues modulated the amount of task interference and the extent to which the frontal lobe was engaged.

Electrophysiological Correlates of Strategic Monitoring in Event-Based and Time-Based Prospective Memory

“…Consistently with the previous electrophysiological studies of event-based PM [34]–[39], also in our event-based condition, the addition of a PM instruction to the ongoing task led to a sustained increased and widespread ERP activity, relative to the ERPs elicited by the ongoing trials in the baseline block. Interestingly, a similar pattern of sustained ERP activity was found when individuals had to accomplish a time-based PM task.…”

“…Indeed, in both the time-based and the event-based PM tasks, the prospective intention has to be maintained active in mind across the ongoing trials, in preparation for executing the intended action. Moreover, the frontal and prefrontal distribution of these ERP modulations is in line with the findings from the other ERP studies [34], [35], [38] and might provide support for the notion that the retrieval mode is mediated by the activity in the frontal cortex [43], [44], [59]–[66]. It might also extend the results of the neuroimaging studies suggesting that prefrontal cortex is implied in maintaining delayed intentions regardless of their nature, being active during the maintenance not only of the event-based PM intentions [24], [25], [30] but also of the time-based ones [31], [67].…”

“…Indeed, a later study considered the long-lasting activity expressed over frontal and posterior regions a likely candidate to be the ERP correlate of retrieval mode [40]. Other works that have investigated the effect of Strategic Monitoring on the ERPs reported similar ERP modulations, mainly expressed over the frontal regions [34], [35]. These findings seem to confirm a recruitment of the frontal lobe in Strategic Monitoring, supporting previous neuroimaging studies [e.g.…”

“…In the second block, which included a total of 350 trials, participants were required to perform a PM task in addition to the ongoing task ( PM block). Similarly to previous studies [34], [35], the baseline block was administered before the PM block, in both the groups, in order to avoid a potential long-lasting interference effect of PM instruction on the baseline block. This consideration is driven by the fact that engagement of Strategic Monitoring has been still shown in tasks even though the PM intentions were no more relevant [16], [39].…”

“…The choice of the electrodes was driven by the previous findings in the ERP literature of PM [34]–[36] and by a visual inspection of the regions where the effects were mainly expressed (Fp1, Fp2, F3, F4, P3, P4, O1, O2). Concerning the time windows investigated (Figure 1), the first (130–180 ms) and the second (180–300 ms) time windows captured respectively the first and the second positive peaks.…”