Tracking the Within-Trial, Cross-Trial, and Developmental Dynamics of Cognitive Control: Evidence From the Simon Task

How flexible is cognitive control? (Mouse) tracking conflict adaptation across context similarities

Exerting cognitive control to remain on-task and reach our goals is a crucial skill, as is the ability to flexibly adapt our responding in rapidly changing environments. The dynamics of cognitive control are typically studied by examining how participants process stimuli that contain competing relevant and irrelevant information in so-called conflict tasks. Adjustments in performance following the experience of conflict, also termed conflict adaptation, suggests a certain degree of flexibility in the deployment of cognitive control. The present study investigated to what extent conflict adaptation effects transfer across trials of the same and different tasks in three online mouse-tracking experiments. Adaptations of the Simon and Stroop tasks were combined to create different levels of context similarity between the paired tasks. Based on a previous review (Braem et al., Frontiers in Psychology 5:1-13, 2014), across-task conflict adaptation was expected only in the most and least similar contexts. In contrast to our hypothesis, conflict adaptation effects were observed in at least one measure in all three experiments. To our surprise, task order also seemed to impact the size of across-task conflict adaptation effects. The heterogeneity in the current results highlight the importance of using sensitive measurement tools to evaluate conflict adaptation and suggest that the occurrence of across-task conflict adaptation may be conditional on more than just shared relevant and irrelevant dimensions.

Attentional adjustment in priming tasks: control strategies depend on context

Goal-directed behavior is assumed to require processes of attentional biasing to counter unwanted action tendencies elicited by distracting stimulus information. This is particularly so if stimulus categories that define the target and the distractor frequently reverse, requiring participants to respond to previously ignored stimulus categories and vice versa. In the current study, we investigated control strategies under such conditions. Specifically, we assessed trial-to-trial modulation of distractor-interference (i.e., congruency sequence effect, CSE) in a temporal flanker task associated with repetition versus alternation of the assignment of stimulus category (i.e., digits, letters) to targets and distractors (i.e., the character presented second or first, respectively) under conditions of a long SOA of 1000 ms (Experiment 1A) and 1200 ms (Experiment 1B). Whereas previous research, using a shorter SOA, suggested temporal-order control (i.e., the occurrence of a CSE in both repetition and-albeit less pronounced-alternation trials), lengthening the distractor-target SOA resulted in a CSE confined to repetition trials, suggesting strong or exclusive reliance on stimulus categories for attentional control (Experiment 1A and B). Adding a redundant stimulus feature (i.e., color), discriminating targets and distractors, eliminated the difference of CSE patterns in repetition and alternation trials (Experiment 2). Together, our results suggest that the strength of concurrently applied control strategies or the choice of a particular control strategy depend on contextual factors.

Effects of conflict in cognitive control: Evidence from mouse tracking

It has long been debated whether the "congruency sequence effect (CSE)" in conflict tasks such as Flanker could reflect adaptive control. The current study used "mouse tracking" to tackle the issue in a combination of three conflict tasks (i.e., Flanker, Simon, and Spatial Stroop tasks). Congruency effects from previous and current trials emerged in latencies as well as curvature of movement trajectories in all three tasks. Critically, movement initiation times were affected only by congruency on previous but not on current trials. A further analysis showed that even when initiation time on the previous trials was taken into account, a subtle but highly significant effect of conflict arising from trial N-1 on initiation times remained. Although not necessarily implying "conflict adaptation," i.e., a dynamic up- and downregulation of cognitive control in response to a recent conflict, our finding indicates a specific sensitivity to the presence or absence of recent "conflict" in the cognitive environment.

A diffusion model for the congruency sequence effect

Two-choice reaction tasks for which stimuli differ on irrelevant and relevant dimensions (e.g., Simon, flanker, and Stroop tasks) show congruency effects. The diffusion model for conflict tasks (DMC) has provided a quantitative account of the mechanisms underlying decisions in such conflict tasks, but it has not been applied to the congruency sequence effect (CSE) for which the congruency on the prior trial influences performance on the current trial. The present study expands analysis of the reaction time (RT) distributions reflected by delta plots to the CSE, and then extends the DMC to simulate the results. With increasing RT: (1) the spatial Simon effect was almost unchanged following congruent trials but initially became smaller and finally reversed following incongruent trials; (2) the arrow-based Simon effects increased following both congruent and incongruent trials, but more so for the former than the latter; (3) the flanker congruency effect varied quadratically following congruent trials but increased linearly following incongruent trials. These results were modeled by the CSE-DMC, extended from the DMC with two additional assumptions: (1) feature integration influences only the controlled processes; (2) following incongruent trials, the automatic process is weakened. The results fit better with the CSE-DMC than with two variants that separately had only one of the two additional assumptions. These findings indicate that the CSEs for different conflict tasks have disparate RT distributions and that these disparities are likely due to the controlled and automatic processes being influenced differently for each trial sequence.

Examination of a Response–Effect Compatibility Task With Continuous Mouse Movements: Free- Versus Forced-Choice Tasks and Sequential Modulations

According to ideomotor theory, we select actions by recalling and anticipating their sensory consequences, that is, their action effects. Compelling evidence for this theory comes from response–effect compatibility (REC) experiments, in which a response produces an effect with which it is either compatible or incompatible. For example, pressing a left/right response key is faster if it is predictably followed by an action effect on the same, compatible side compared with the other, incompatible side, even though the effect itself appears only after response time is measured. Recent studies investigated this effect with continuous responses (i.e., computer mouse movements) and reported an REC effect in a forced-choice but not in a free-choice task. From the keypressing literature, the opposite result pattern or no differences would have been expected. To clarify this issue, we report 3 experiments with mouse movement responses. Experiment 1 used a simpler scenario than in prior studies and found a similar result: The REC effect was evident in a forced- but not in a free-choice task. Also, sequential modulations of the REC effect were exploratorily analyzed and replicated with higher power in Experiment 2. However, Experiment 3 demonstrated that at least part of the REC effect with mouse movements can be attributed to stimulus–response compatibility (SRC), with a much smaller compatibility effect evident with a procedure for which SRC was reduced. We conclude that a sequentially modulated compatibility effect can be observed with mouse movements, but previous studies may have underestimated the contribution from SRC. The results are also discussed in terms of why the compatibility effect was observed in forced- but not free-choice tasks with mouse movement responses.

Midfrontal theta oscillations and conflict monitoring in children and adults

Conflict monitoring is central in cognitive control, as detection of conflict serves as a signal for the need to engage control. This study examined whether (1) midfrontal theta oscillations similarly support conflict monitoring in children and adults, and (2) performance monitoring difficulty influences conflict monitoring and resolution. Children (n = 25) and adults (n = 24) completed a flanker task with fair or rigged response feedback. Relative to adults, children showed a smaller congruency effect on midfrontal theta power, overall lower midfrontal theta power and coherence, and (unlike adults) no correlation between midfrontal theta power and N2 amplitude, suggesting that reduced neural communication efficiency contributes to less efficient conflict monitoring in children than adults. In both age groups, response feedback fairness affected response times and the P3, but neither midfrontal theta oscillations nor the N2, indicating that performance monitoring difficulty influenced conflict resolution but not conflict monitoring.

Attentional capture in goal-directed action during childhood, adolescence, and early adulthood

Attentional capture occurs when salient but task-irrelevant information disrupts our ability to respond to task-relevant information. Although attentional capture costs have been found to decrease between childhood and adulthood, it is currently unclear the extent to which such age-related changes reflect an improved ability to recover from attentional capture or to avoid attentional capture. In addition, recent research using hand-tracking techniques with adults indicates that attentional capture by a distractor can generate response activations corresponding to the distractor's location, consistent with action-centered models of attention. However, it is unknown whether attentional capture can also result in the capture of action in children and adolescents. Therefore, we presented 5-year-olds, 9-year-olds, 13- and 14-year-olds, and adults (N = 96) with a singleton search task in which participants responded by reaching to touch targets on a digital display. Consistent with action-centered models of attention, distractor effects were evident in each age group's movement trajectories. In contrast to movement trajectories, movement times revealed significant age-related reductions in the costs of attentional capture, suggesting that age-related improvements in attentional control may be driven in part by an enhanced ability to recover from-as opposed to avoid-attentional capture. Children's performance was also significantly affected by response repetition effects, indicating that children may be more susceptible to interference from a wider range of task-irrelevant factors than adults. In addition to presenting novel insights into the development of attention and action, these results highlight the benefits of incorporating hand-tracking techniques into developmental research.

Different temporal dynamics after conflicts and errors in children and adults

After perceiving cognitive conflicts or errors, children as well as adults adjust their performance in terms of reaction time slowing on subsequent actions, resulting in the so called post-conflict slowing and post-error slowing, respectively. The development of these phenomena has been studied separately and with different methods yielding inconsistent findings. We aimed to assess the temporal dynamics of these two slowing phenomena within a single behavioral task. To do so, 9-13-year-old children and young adults performed a Simon task in which every fifth trial was incongruent and thus induced cognitive conflict and, frequently, also errors. We compared the reaction times on four trials following a conflict or an error. Both age groups slowed down after conflicts and did so even more strongly after errors. Disproportionally high reaction times on the first post-error trial were followed by a steady flattening of the slowing. Generally, children slowed down more than adults. In addition to highlighting the phenomenal and developmental robustness of post-conflict and post-error slowing these findings strongly suggest increasingly efficient performance adjustment through fine-tuning of cognitive control in the course of development.

Layers of latent effects in cognitive control: An EEG investigation

Recent research demonstrates that two components of reaching behavior - initiation time (the time elapsed from stimulus presentation to movement initiation) and reach curvature (the degree to which a reach movement deviates from a direct path to the selected response) - exhibit distinct cross-trial dynamics in cognitive control tasks, indicating that these components of behavior reflect two dissociable processes underlying cognitive control: a threshold adjustment process involving the inhibition of motor output and a controlled selection process involving the recruitment of top-down resources to support goal-relevant behavior. The current study investigates the extent to which the cross-trial dynamics previously observed in reaching behavior in the Eriksen flanker task are reflected in event-related potentials during standard button-press responses. Candidate EEG measures of the threshold adjustment process (N2 and Pre-LRP amplitudes) failed to reveal the cross-trial dynamics previously observed in initiation times. Slow wave amplitudes exhibited a close correspondence to the cross-trial dynamics observed in reach curvatures, indicating that the measure is sensitive to some functions of the controlled selection process. Further, LRP slopes presented a close correspondence to the cross-trial dynamics observed in response times, indicating that this measure reflects the combined output of the threshold adjustment process and controlled selection process. The implications of these findings for future research examining the links among behavioral and neural dynamics are discussed.