The electrophysiology of sequential adjustments of dual-task order coordination.

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.

Surprise-minimization as a solution to the structural credit assignment problem.

The structural credit assignment problem arises when the causal structure between actions and subsequent outcomes is hidden from direct observation. To solve this problem and enable goal-directed behavior, an agent has to infer structure and form a representation thereof. In the scope of this study, we investigate a possible solution in the human brain. We recorded behavioral and electrophysiological data from human participants in a novel variant of the bandit task, where multiple actions lead to multiple outcomes. Crucially, the mapping between actions and outcomes was hidden and not instructed to the participants. Human choice behavior revealed clear hallmarks of credit assignment and learning. Moreover, a computational model which formalizes action selection as the competition between multiple representations of the hidden structure was fit to account for participants data. Starting in a state of uncertainty about the correct representation, the central mechanism of this model is the arbitration of action control towards the representation which minimizes surprise about outcomes. Crucially, single-trial latent-variable analysis reveals that the neural patterns clearly support central quantitative predictions of this surprise minimization model. The results suggest that neural activity is not only related to reinforcement learning under correct as well as incorrect task representations but also reflects central mechanisms of credit assignment and behavioral arbitration.

Error-related cardiac deceleration: Functional interplay between error-related brain activity and autonomic nervous system in performance monitoring.

Coordinated interactions between the central and autonomic nervous systems are crucial for survival due to the inherent propensity for human behavior to make errors. In our ever-changing environment, when individuals make mistakes, these errors can have life-threatening consequences. In response to errors, specific reactions occur in both brain activity and heart rate to detect and correct errors. Specifically, there are two brain-related indicators of error detection and awareness known as error-related negativity and error positivity. Conversely, error-related cardiac deceleration denotes a momentary slowing of heart rate following an error, signaling an autonomic response. However, what is the connection between the brain and the heart during error processing? In this review, we discuss the functional and neuroanatomical connections between the brain and heart markers of error processing, exploring the experimental conditions in which they covary. Given the current limitations of available data, future research will continue to investigate the neurobiological factors governing the brain-heart interaction, aiming to utilize them as combined markers for assessing cognitive control in healthy and pathological conditions.

Stimulus-triggered task conflict affects task-selection errors in task switching: A Bayesian multinomial processing tree modeling approach.

In the present study, we used a modeling approach for measuring task conflict in task switching, assessing the probability of selecting the correct task via multinomial processing tree (MPT) modeling. With this method, task conflict and response conflict can be independently assessed as the probability of selecting the correct task and the probability of selecting the correct response within a given task, respectively. These probabilities can be estimated on the basis of response accuracy in the different experimental conditions. In two task-switching experiments, we used bivalent stimuli and manipulated irrelevant-task difficulty by varying the saliency of the stimulus feature belonging to the irrelevant task. The more salient the task-irrelevant stimulus feature, the more salient the irrelevant task, leading to more task conflict. Consistent with this assumption, we observed that task conflict, but not response conflict, was larger when the task-irrelevant stimulus feature was made more salient. Furthermore, both task conflict and response conflict were larger when the task switched than when the task was repeated. On a methodological level, the present results demonstrate that MPT modeling is a useful approach for measuring task conflict in task switching and for dissociating it from within-task response conflict. Furthermore, the present results inform theories of task switching by showing that the task-irrelevant feature tends to activate the irrelevant task set rather than being associated with a specific response option via a direct stimulus-response route. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Neural correlates of adaptive cognitive control in working memory.

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.

Effects of the number of competing responses on neural signatures of pre- and post-response conflict.

The optimization of human performance requires the continuous monitoring of behavioral conflicts. According to conflict monitoring theory, the dorsal anterior cingulate cortex registers response conflict which is reflected by two electrophysiological signatures, the N2 and the Ne/ERN. The theory assumes that, if a stimulus activates an incorrect response that competes with the correct response, pre-response conflict on correct trials (reflected by the N2) is enhanced but post-response conflict on error trials (reflected by the Ne/ERN) is reduced. Here, we asked whether response conflict depends on the number of competing incorrect responses activated by a stimulus, that is, whether the N2 is further enhanced and the Ne/ERN is further reduced if two incorrect responses are activated as compared to one. To this end, we used a modified flanker paradigm, in which the two flankers were associated either with the same incorrect response or with different incorrect responses. Our results indicate an increased N2 on correct trials and a reduced Ne/ERN on error trials in the latter as compared to the former condition. These results confirm central predictions of conflict monitoring theory and demonstrate that response conflict is directly related to the number of competing incorrect responses.

Disentangling task-selection failures from task-execution failures in task switching: an assessment of different paradigms.

Differentiating errors on the basis of the distinct cognitive mechanisms that may have generated them has provided neuropsychologists with useful diagnostic tools. For example, perseverative errors arising from the inability of the patient to set a new criterion for responding are considered one of the hallmarks of cognitive inflexibility. Similarly, in the task-switching paradigm it is possible to distinguish between task-confusion errors, produced by a failure in task selection, and response-confusion errors, arising when the correct task is selected, but the wrong response is given. Nonetheless, only a few studies so far have exploited the existence of different kinds of errors in multitasking situations to inform theories of cognitive flexibility. In the present study, we set out to use a variety of methodologies employed so far in the literature for disentangling errors due to task-selection failure from errors due to task-execution failure. In three experiments, we assessed the capacity of each method to produce error categories that can be mapped as clearly as possible to the cognitive mechanism(s) underlying them using multinomial processing tree modelling. Subsequently, the distinction between task- and response-confusion errors was used to test their differential impact on inhibitory mechanisms in task switching as measured by N-2 repetition costs. Our results are encouraging regarding the possibility of correctly detecting response- and task-selection failures, thus allowing us to assess their differential impact on N-2 repetition costs.

The role of action inhibition for behavioral control in joint action.

When two individuals share a task with a common goal, coordinating one's own and the other's actions is pivotal. Inhibition of one's own actions when it is the other's turn to act is assumed to play a crucial role in this process. For instance, in the joint Simon task, two individuals share a two-choice task such that one of them responds to one stimulus type and ignores the stimulus type to which the other responds. Because stimuli can either appear on one's own or on the other's side, stimulus location can conflict with stimulus identity, thus slowing response time. It has previously been shown that such conflict leads to a reduction of the detrimental effects of conflict on immediately upcoming trials both following own responses and even more so following the other's responses. This amplified trial-to-trial adjustment following the other's responses has been assumed to reflect the inhibition of own responses on the other's trials. The present study tested this hypothesis by comparing sequential trial-to-trial adjustments following correct responses and commission errors on which the inhibition of own responses has failed. As expected, adjustments were stronger following the other's correct responses than following own correct responses. Crucially, such amplification of sequential adjustment was not observed following own commission errors on the other's trials. This shows that amplification of sequential adjustments following the other's trials depend on successful inhibition of own responses on these trials and points to a crucial role of response inhibition for behavioral control in joint action.

To switch or to repeat? Commonalities and differences in the electrophysiological correlates of preparation for voluntary and forced task choices.

When switching tasks in the laboratory, either the experimenter or the participant can decide which task comes next. So far, this kind of forced and voluntary task switching is usually investigated in isolation. However, in our everyday life, switching between different tasks and goals often depends both on current situational demands and on our intentions. While research has mainly focused on differences between forced and voluntary switching, it is still unclear whether, and if so, which neural processes are shared between both switch types. To identify these, we compared electrophysiological preparatory activity in blocks of randomly intermixed voluntary and forced task-switching trials. We further manipulated the forced switch rate (20% vs. 80%) between blocks to de-confound voluntariness with switch frequency and to investigate how switch frequency effects influence preparatory potentials. ERP analysis revealed an enhanced early parietal activity pattern in the P3b time window on voluntary trials, possibly reflecting early traces of a decision process. A later pre-target negativity was enhanced on forced as compared to voluntary trials. Multivariate pattern analyses revealed that a common preparatory activity on both forced and voluntary switch trials can be found in the switch positivity time window, which we interpreted as an index of a common endogenous task preparation process.

Error cancellation.

The human cognitive system houses efficient mechanisms to monitor ongoing actions. Upon detecting an erroneous course of action, these mechanisms are commonly assumed to adjust cognitive processing to mitigate the error's consequences and to prevent future action slips. Here, we demonstrate that error detection has far earlier consequences by feeding back directly onto ongoing motor activity, thus cancelling erroneous movements immediately. We tested this prediction of immediate auto-correction by analysing how the force of correct and erroneous keypress actions evolves over time while controlling for cognitive and biomechanical constraints relating to response time and the peak force of a movement. We conclude that the force profiles are indicative of active cancellation by showing indications of shorter response durations for errors already within the first 100 ms, i.e. between the onset and the peak of the response, a timescale that has previously been related solely to error detection. This effect increased in a late phase of responding, i.e. after response force peaked until its offset, further corroborating that it indeed reflects cancellation efforts instead of consequences of planning or initiating the error.

Adaptive control of working memory.

The present study investigated mechanisms of adaptive cognitive control in working memory (WM). WM is conceived as a system for short-term maintenance, updating and manipulation of representations required for goal-directed action. Adaptive control refers to the finding of flexible adjustments of control processes based on conflict. For instance, a higher frequency of incongruent stimuli, that is, stimuli evoking conflicting response tendencies, leads to a higher level of cognitive control as reflected by smaller congruency effects (i.e., the difference between congruent and incongruent items). Likewise, conflict on the previous trial leads to a higher level of cognitive control on the current trial. To investigate adaptive control in WM, we used a modified Sternberg paradigm. Participants memorized two differently colored lists of four digits (i.e., 2 5 7 1), in which corresponding positions in both lists contained the same digits (congruent items) or different digits (incongruent items). Participants were required to make a match/mismatch judgement (Experiment 1 and 2) or to recollect the correct digit at a probed position in one of the two lists (Experiment 3). In all experiments, we could replicate both hallmark effects of adaptive control, the proportion congruency effect, and the congruency sequence effect. Our results strongly support the assumption that WM representations can be dynamically adapted based on the amount of conflict, and that adaptive control of WM follows the same principles that have previously been shown for selective attention.

Early correlates of error-related brain activity predict subjective timing of error awareness.

Humans are remarkably reliable in detecting errors in their behavior. Whereas error awareness has been assumed to emerge not until 200-400 ms after an error, the so-called early error sensations refer to the subjective feeling of having detected an error even before the erroneous response was executed. Here, we collected electroencephalogram (EEG) to track how early error sensations are reflected in neural correlates of performance monitoring. Participants first had to perform a task, and then had to indicate whether an error has occurred and whether this error was detected before or after response execution. EEG results showed that early error sensations were associated with an earlier peak of the error-related negativity (Ne/ERN), a component of error-related brain activity that occurs briefly after the error response. This demonstrates that early error-related activity influences metacognitive judgments on the time course of error awareness, and thus contributes to error awareness.

Task Learnability Modulates Surprise but Not Valence Processing for Reinforcement Learning in Probabilistic Choice Tasks.

The goal of temporal difference (TD) reinforcement learning is to maximize outcomes and improve future decision-making. It does so by utilizing a prediction error (PE), which quantifies the difference between the expected and the obtained outcome. In gambling tasks, however, decision-making cannot be improved because of the lack of learnability. On the basis of the idea that TD utilizes two independent bits of information from the PE (valence and surprise), we asked which of these aspects is affected when a task is not learnable. We contrasted behavioral data and ERPs in a learning variant and a gambling variant of a simple two-armed bandit task, in which outcome sequences were matched across tasks. Participants were explicitly informed that feedback could be used to improve performance in the learning task but not in the gambling task, and we predicted a corresponding modulation of the aspects of the PE. We used a model-based analysis of ERP data to extract the neural footprints of the valence and surprise information in the two tasks. Our results revealed that task learnability modulates reinforcement learning via the suppression of surprise processing but leaves the processing of valence unaffected. On the basis of our model and the data, we propose that task learnability can selectively suppress TD learning as well as alter behavioral adaptation based on a flexible cost-benefit arbitration.

Errors in task switching: Investigating error aftereffects in a N-2 repetition cost paradigm.

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. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The influence of experienced severe road traffic accidents on take-over reactions and non-driving-related tasks in an automated driving simulator study.

Road traffic accidents (RTAs) are an ever-existing threat to all road users. Automated vehicles (AVs; SAE Level 3-5) are developed in many countries. They are promoted with numerous benefits such as increased safety yielding less RTAs, less congestion, less greenhouse gas emissions, and the possibility of enabling non-driving related tasks (NDRTs). However, there has been no study which has investigated different NDRT conditions, while comparing participants who experienced a severe RTA in the past with those who experienced no RTA. Therefore, we conducted a driving simulator study (N = 53) and compared two NDRT conditions (i.e., auditory-speech (ASD) vs. heads-up display (HUD)) and an accident (26 participants) with a non-accident group (27; between-subjects design). Although our results did not reveal any interaction effect, and no group difference between the accident and the non-accident group on NDRT, take-over request (TOR), and driving performance, we uncovered for both groups better performances for the HUD condition, whereas a lower cognitive workload was reported for the ASD condition. Nevertheless, there was no difference for technology trust between the two conditions. Albeit we observed higher self-ratings of PTSD symptoms for the accident than for the non-accident group, there were no group differences on depression and psychological resilience self-ratings. We conclude that severe RTA experiences do not undermine NDRT, TOR, and driving performance in a SAE Level 3 driving simulator study, although PTSD symptoms after an RTA may affect the psychological wellbeing.

Neural Correlates of Task-order Preparation in Dual Tasks: An EEG Study.

Dual-task scenarios require a coordinated regulation of the processing order of component tasks in light of capacity limitations during response selection. A number of behavioral and neuroimaging findings suggest a distinct set of control processes involved in preparing this task order. In this study, we investigated electrophysiological correlates of task-order preparation in a variant of the overlapping dual-task paradigm with cue-determined task order that resulted in trials with blockwise fixed task order as well as trials with repeated and switched task order in blocks with variable task order. During the cue-stimulus interval, we found an earlier centroparietal order-mixing positivity and a later parietal order-switch positivity. A decoding approach based on multivariate pattern analysis showed that the order-mixing positivity is a necessary prerequisite for successful order selection, whereas the order-switch positivity appears to facilitate the implementation of a new task order after its selection. These correlates of order preparation share striking similarities to commonly found potentials involved in the preparation of individual tasks in the (single-)task-switching paradigm, which is strong empirical support for the account that the underlying preparatory processes are to be considered as higher-level control signals that are implemented independently of specific task representations.

Multiplicative priming of the correct response can explain the interaction between Simon and flanker congruency.

In the Simon task, participants perform a decision on non-spatial features (e.g., stimulus color) by responding with a left or right key-press to a stimulus presented on the left or right side of the screen. In the flanker task, they classify the central character while ignoring the flanking characters. In each task, there is a conflict between the response-relevant features and the response-irrelevant features (i.e., the location on the screen for the Simon task, and the flankers for the flanker task). Thus, in both tasks, resolving conflict requires to inhibit irrelevant features and to focus on relevant features. When both tasks were combined within the same trial (e.g., when the row of characters was presented on the left or right side of the screen), most previous research has shown an interaction. In the present study, we investigated whether this interaction is affected by a multiplicative priming of the correct response occurring when both Simon and flanker irrelevant features co-activate the correct response (Exp. 1), a spatial overlap between Simon and flanker features (Exp. 2), and the learning of stimulus-response pairings (Exp. 3). The results only show an impact of multiplicative priming.

Adaptive rescheduling of error monitoring in multitasking.

The concurrent execution of temporally overlapping tasks leads to considerable interference between the subtasks. This also impairs control processes associated with the detection of performance errors. In the present study, we investigated how the human brain adapts to this interference between task representations in such multitasking scenarios. In Experiment 1, participants worked on a dual-tasking paradigm with partially overlapping execution of two tasks (T1 and T2), while we recorded error-related scalp potentials. The error positivity (Pe), a correlate of higher-level error evaluation, was reduced after T1 errors but occurred after a correct T2-response instead. MVPA-based and regression-based single-trial analysis revealed that the immediate Pe and deferred Pe are negatively correlated, suggesting a trial-wise trade-off between immediate and postponed error processing. Experiment 2 confirmed this finding and additionally showed that this result is not due to credit-assignment errors in which a T1 error is falsely attributed to T2. For the first time reporting a Pe that is temporally detached from its eliciting error event by a considerable amount of time, this study illustrates how reliable error detection in dual-tasking is maintained by a mechanism that adaptively schedules error processing, thus demonstrating a remarkable flexibility of the human brain when adapting to multitasking situations.

Adverse Behavioral Adaptation to Adaptive Forward Collision Warning Systems: An Investigation of Primary and Secondary Task Performance.

Advanced driver assistance systems can effectively support drivers but can also induce unwanted effects in behavior. The present study investigates this adverse behavioral adaptation in adaptive Forward Collision Warning (FCW) systems. Other than conventional FCW systems that provide warnings based on static Time-To-Collision (TTC) thresholds, adaptive FCW systems consider the driver's need for support by adjusting warning thresholds according to distraction. A neglected question is how drivers adapt their behavior when they use adaptive FCW systems under realistic conditions, i.e., when warnings occur infrequently but system functionality is anticipated. Forty-eight participants drove with two different FCW systems (adaptive vs. non-adaptive) while working on a secondary in-vehicle task in a driving simulator. During the main part of the experiment, no brake events occurred and hence FCW functioning was largely anticipated. Additionally, visual system feedback about the driver's distraction state was manipulated between groups. Participants had significantly shorter minimal time-headways and TTCs when driving with the adaptive relative to the non-adaptive system. Participants with system feedback about distraction state spent generally more time with engaging in the secondary task. These results indicate behavioral adaptation which, however, is restricted to the task that is specifically supported by the system, namely longitudinal control.