Search

Studies of switching between tasks and studies of error commission have both provided solid behavioral measures of executive control. Nonetheless, a gap remains between these strands of research. In three experiments we sought to reduce this gap by assessing the impact of task errors on N-2 repetition costs, an effect supposedly related to task-set inhibition. Based on previous literature reporting a task-switch benefit following task errors, due to incidental learning of the erroneously executed task-set, we predicted N-2 repetition costs to be decreased after task errors in Trial N-2, relative to correct responses. Furthermore, we predicted this effect to be present only when corrective control mechanisms would not have the time to build up on the post-error trial (i.e., following fast post-error trial only). This hypothesis was tested in a three-tasks paradigm using incongruent stimuli, under the assumption that errors on such trials are partly due to task confusions. Consistent with our predictions, N-2 repetition costs following N-2 errors were found to be reduced when responses in Trial N-1 were fast but were present when the N-1 response was slow. Taken together, our results suggest that task execution leads to associative strengthening of the corresponding task-set, irrespective of response accuracy, and that such automatic strengthening can be counteracted by slowly acting control mechanisms.

Performing two tasks simultaneously involves the coordination of their processing. This task coordination is particularly required in dual‐task situations with varying task orders. When task order switches between subsequent trials, task order coordination leads to task order switch costs in comparison with order repetitions. However, it is open, whether task order coordination is exclusively controlled by the relation of the task orders of the current and the previous trials, or whether additional conditions such as task order before the previous trial leads to a behavioral and neural adjustment of task order coordination. To answer this question, we reanalyzed the data of two previously published experiments with order‐cued dual‐task paradigms. We did so with regard to whether task order switch costs and the EEG component order‐switch positivity in the current dual‐task trial would be modulated by order switches vs. repetitions in the previous trial (Trial N‐1). In Experiment 1, we found a modulation of the task order switch costs in RTs and response reversals; these costs were reduced after an order switch compared with order repetitions in Trial N‐1. In Experiment 2, there were no effects on the task order switch costs in the behavioral data. Nonetheless, we found the order‐switch positivity to be strongly modulated by the order transition of the previous trial in both experiments. The order‐switch positivity was substantially reduced if the previous trial was an order switch (compared to an order repetition) by itself. This implies that order coordination of dual tasks is adjusted in a gradual way depending on trial's history. The present study investigates the neurophysiological effects of task‐order coordination and its meta‐control adjustment in dual‐task situations. The EEG component order‐switch positivity was modulated by task‐order coordination and by coordination adjustment. This implies that order coordination of dual tasks is adjusted in a gradual way depending on the trial's history. [ABSTRACT FROM AUTHOR]

Posterror slowing (PES) refers to an increased response time following errors. While PES has traditionally been attributed to control adjustments, recent evidence suggested that PES reflects interference. The present study investigated the hypothesis that control and interference represent 2 components of PES that differ with respect to their time course and task-specificity. To this end, we investigated PES in a dual-task paradigm in which participants had to classify colors and tones that were separated by a variable stimulus onset asynchrony (SOA). Errors in the color task caused PES both in the tone task of the same trial and the color task of the subsequent trial. However, while the former effect disappeared with an increasing SOA, the latter effect was independent of SOA and lasted for several trials. This suggests that errors simultaneously induce task-unspecific, transient PES reflecting interference and task-specific, more long-lasting PES reflecting control adjustments.

Conflicts in working memory (WM) can occur when retrieval cues activate competing items, which impairs the efficiency of retrieval. It has recently been shown that WM retrieval adapts similarly to these conflicts as predicted by conflict monitoring theory for selective attention tasks. Here, we utilized event‐related potentials (ERPs) to investigate whether conflict and adaptive control in WM are reflected by the same neural markers that have previously been described for selective attention tasks. In our task, participants encoded two differently colored memory lists that contained four digits each (i.e., 2 5 7 1 and 4 5 9 1), and had to recognize whether a probe item from a specific list and position was correct or incorrect. Conflict during retrieval emerged when digits at corresponding positions (e.g., 2 and 5 at the first position) were different (incongruent), but not when these digits were the same (congruent). In behavioral data, we found a congruency sequence effect, that is, responses to incongruent probe items were slower, and this effect was reduced following trials with incongruent probe items. In ERPs, this behavioral marker of adaptive control was accompanied by two effects. First, congruency affected the amplitude of an N450, and this conflict effect was reduced after incongruent trials. Second, the posterior P3 amplitude varied with the congruency of the current and the previous trial. Both results resemble those found for the Stroop task and thus highlight the similarity between conflict and adaptive control in WM and selective attention tasks. Our study links theoretical ideas from two research fields—working memory (WM) and adaptive cognitive control. Utilizing event‐related potentials, our findings show that adaptive cognitive control in WM is reflected by the same neural markers as adaptive cognitive control of selective attention. Furthermore, our results suggest that adaptive cognitive control plays a critical role in optimizing the use of limited WM storage. [ABSTRACT FROM AUTHOR]