Stimulus-response Conflict Research Articles

Investigating cognitive-physical task interaction during self-paced cycling: A Granger causality study.

Self-pacing physical exercise is thought to rely on high-order cognitive processing (e.g., attentional control to monitor afferent cardiovascular feedback for exercise goals). Therefore, performing a cognitive task during a self-paced exercise could lead to cognitive-physical interactions. We explored cognitive-physical interactions by applying time-domain Granger Causality (a correlation analysis that uses a temporal series of one variable to improve the prediction of values in a temporal series of another variable given its past values) to data that combined 20min of indoor self-paced high-intensity cycling and a Sustained Attention to Response cognitive task, and to data that combined 30min of indoor self-paced high-intensity cycling and a stimulus-response conflict task. Moreover, we explored whether greater experience in cycling would reduce the need for exerting cognitive attentional control and therefore dual-task effects. The results showed that the experienced cycling group (i.e., at least 4 days of weekly cycling training in the last 3 years) demonstrated better overall physical performance than the non-experienced cycling group (i.e., at least 4 days of weekly training in another endurance sport different to cycling in the last 3 years), while no evidence of differences in cognitive performance was obtained. The results also showed that reaction times and power output interacted bidirectionally in a reduced sample of experienced cyclists and non-experienced cyclists. Hence, cognitive-physical interactions may not be excluded for every single high-fit athlete, irrespective of their particular exercise experience. Our study highlights the value of GC to investigate cognitive-physical interactions during self-paced exercise at the individual level.

Joint attention effect on irrelevant stimuli resistance in high functional autism and neurotypical adults

Background and objectivesClinical practice reveals that individuals with autism characterized by the absence of cognitive impairment (High Functioning Autism-HFA) show difficulty in sharing attention with unfamiliar people. We hypothesized that this difficulty could affect cognitive control by selectively impairing stimulus-encoding or response-selection. MethodsTwenty-one HFA and 23 neurotypical adults were involved in a two-phase study. The first phase was performed at home, through an online link; the second one was held four months later in our laboratory in the presence of two experimenters. A letter-flanker task was administered in both phases. In the Stimulus-Response (SR) conflict condition, the target and flankers were assigned to the same/different response keys. In the Stimulus-Stimulus (SS) conflict condition, the target and flankers were perceptually similar/dissimilar. Two mixed-ANOVAs were conducted on response times and accuracy with Phases (Home vs Lab), Groups (HFA, Neurotypical), SR conditions (congruent, incongruent, neutral) and SS conditions (congruent, incongruent) as factors. ResultsResults show that only HFAs' inhibition ability was negatively affected by the experimenters’ presence compared to when they were alone, by reducing accuracy when dealing with an SS conflict. LimitationsThe differences between the home-phase and lab-phase sessions require further elaboration to understanding the nature of social interaction during the lab session. ConclusionsThese results suggest that, for HFA, the “at home” context, free from social and emotional pressure, allowed them to emphasize their detail-focused cognitive style.

Does the frequency of cultural switching modulate bilinguals’ performance on Executive Functions tasks? A study of highly proficient bicultural-bilinguals

Aims and Objectives: This study investigates how bicultural switching could influence cognitive performance on Executive Functions tasks among bicultural-bilinguals. Methodology: Study 1 ( n = 233) integrates self-report questionnaire data on cultural and language behaviour with a priming experiment, providing empirical evidence of young adult bilinguals’ ability to shift between multiple cultures. Study 2 ( n = 48) explores the effect of cultural switching frequency on young adult bicultural bilinguals’ performance on tests for interference and inhibition control, set-shifting ability, and attention. Data and Analysis: Study 1: A repeated measures ANOVA was conducted to determine the effect of different primes on participant’s ratings. We ran a two-way mixed ANOVA to ascertain the effect of interlocutors (Grandparents/relatives, Parents, Siblings, Peers/co-workers, Social media) on behaviour (Cultural, Language). Study 2: A one-way ANOVA was conducted on Simon, Flanker, and Wisconsin Card Sort tasks (WCST). Each of the three attention network components was analysed using a 2 (trial-type, within-subjects) × 2 (Switching Group, between-groups) mixed-ANOVA for the Attention Network task. Findings: Study 1: Participants who alternate frequently between cultural frames made a clearer distinction between Western primes than those who switched between cultural frames less, suggesting that the frequency of cultural switching could impact cognition. Study 2: Bicultural bilinguals who switched between cultural frames frequently resolved stimulus-response conflict significantly faster in the Flanker task, made fewer mistakes within each sorting block in the WCST, and had a smaller conflict effect compared to infrequent switchers in the Attention Network Task. Significance: This study examines the effects of bicultural switching on Executive Functions of highly proficient bicultural bilinguals, highlighting it as a potential confound in bilingual research. Bicultural switching effects on interference and inhibition-control persist even in participants at the developmental peak of their cognitive processing capabilities after controlling for a plethora of socio-linguistic variables. Our research highlights how this understudied aspect of multiculturalism may have broad implications for bilingual research in Executive Functions.

Automatic imitation in children: Age-related change and comparison to adults.

Automatic imitation, in which one person's movement is affected by the observation of another person's movements, has been widely reported. However, it remains unclear how automatic imitation changes over a wide age range, particularly during childhood. In this study, we examined the differences in the tendency for automatic imitation between adults and children and the cross-sectional age-related changes in children aged 5-12 years, using a stimulus-response conflict paradigm. In this task, participants perform a choice-reactive finger movement corresponding to a given response stimulus while observing another participant's compatible or incompatible movement stimuli. The tendency for automatic imitation was assessed based on the reaction time, correct rate, and inverse efficiency score. The results showed that the degree of automatic imitation was weak until the children were 7 years old. Interestingly, our results show that the tendency for automatic imitation during childhood changed to an inverted U-shape, indicating nonlinear changes in automatic imitation during childhood. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Action-rule-based cognitive control enables efficient execution of stimulus-response conflict tasks: a model validation of Simon task performance.

The human brain can flexibly modify behavioral rules to optimize task performance (speed and accuracy) by minimizing cognitive load. To show this flexibility, we propose an action-rule-based cognitive control (ARC) model. The ARC model was based on a stochastic framework consistent with an active inference of the free energy principle, combined with schematic brain network systems regulated by the dorsal anterior cingulate cortex (dACC), to develop several hypotheses for demonstrating the validity of the ARC model. A step-motion Simon task was developed involving congruence or incongruence between important symbolic information (illustration of a foot labeled "L" or "R," where "L" requests left and "R" requests right foot movement) and irrelevant spatial information (whether the illustration is actually of a left or right foot). We made predictions for behavioral and brain responses to testify to the theoretical predictions. Task responses combined with event-related deep-brain activity (ER-DBA) measures demonstrated a key contribution of the dACC in this process and provided evidence for the main prediction that the dACC could reduce the Shannon surprise term in the free energy formula by internally reversing the irrelevant rapid anticipatory postural adaptation. We also found sequential effects with modulated dip depths of ER-DBA waveforms that support the prediction that repeated stimuli with the same congruency can promote remodeling of the internal model through the information gain term while counterbalancing the surprise term. Overall, our results were consistent with experimental predictions, which may support the validity of the ARC model. The sequential effect accompanied by dip modulation of ER-DBA waveforms suggests that cognitive cost is saved while maintaining cognitive performance in accordance with the framework of the ARC based on 1-bit congruency-dependent selective control.

Exploring the impact of stimulus-stimulus and stimulus-response conflicts on computer mouse trajectories: continuous flow of information from stimulus encoding to response preparation to motor action.

In recent years, mouse tracking (designing experiments in which participants provide responses via dynamic computer mouse movements) has enjoyed increasing experience in experimental psychology. Mouse-tracking studies typically involve some form of stimulus-response (S-R) conflict, and S-R effects emerge in movement trajectories (as well as in latencies). By contrast, it is currently unclear how stimulus-stimulus (S-S) compatibility affects movements. Here, we used a spatial arrow task which allowed us to generate S-R and S-S effects within the same experiment. Experiment 1 clarified in a key press experiment that this manipulation generates clear S-S and S-R effects in latencies. More critically, Experiment 2 demonstrated that both types of conflict impact mouse trajectories with incompatibility emerging as increased 'curvature' of responses when compared to congruent responses. We argue that these results are best explained via the assumption of 'continuous flow' of information, from stimulus encoding to response preparation and finally into motor action. By contrast, the S-S effect on trajectories contradicts the notion that processing is 'thresholded' between stimulus encoding and response preparation.

Two modes of midfrontal theta suggest a role in conflict and error processing

Midfrontal theta increases during scenarios when conflicts are successfully resolved. Often considered a generic signal of cognitive control, its temporal nature has hardly been investigated. Using advanced spatiotemporal techniques, we uncover that midfrontal theta occurs as a transient oscillation or “event” at single trials with their timing reflecting computationally distinct modes. Single-trial analyses of electrophysiological data from participants performing the Flanker (N = 24) and Simon task (N = 15) were used to probe the relationship between theta and metrics of stimulus-response conflict. We specifically investigated “partial errors”, in which a small burst of muscle activity in the incorrect response effector occurred, quickly followed by a correction. We found that transient theta events in single trials could be categorized into two distinct theta modes based on their relative timing to different task events. Theta events from the first mode occurred briefly after the task stimulus and might reflect conflict-related processing of the stimulus. In contrast, theta events from the second mode were more likely to occur around the time partial errors were committed, suggesting they were elicited by a potential upcoming error. Importantly, in trials in which a full error was committed, this “error-related theta” occurred too late with respect to the onset of the erroneous muscle response, supporting the role of theta also in error correction. We conclude that different modes of transient midfrontal theta can be adopted in single trials not only to process stimulus-response conflict, but also to correct erroneous responses.

A process-specific approach in the study of normal aging deficits in cognitive control: What deteriorates with age?

Bearing in mind that cognitive control is a complex function that includes several processes, it is not clear exactly which ones deteriorate with age. In fact, controversial results have been found. For example, some studies indicate that age-related deficits are observed in proactive and not in reactive control, others show that it is reactive control that is impaired and not proactive control, and some studies find no deficits at all (e.g., Kopp, Lange, Howe, & Wessel, 2014; Xiang et al., 2016). One possible reason is that the contribution of different processes to the deterioration of cognitive control was investigated separately, i.e., without testing all processes within the same paradigm. Therefore, the main goal of the present experiment was to study the impact of normal aging on several processes related to cognitive control within the same task, which included both Simon and Spatial Stroop trials. The study focused on the following processes: generation of conflict measured by automatic response capture (i.e., stronger task-irrelevant information processing compared to task-relevant information processing); conflict detection; and control implementation (which can be reactive control, both within trials and across trials, and proactive control, as a task-set strategy). The results showed larger automatic response capture for older adults when facing a stimulus-response conflict (Simon) but not a stimulus-stimulus conflict (Spatial Stroop). Similarly, older adults also showed larger detection effects for both conflicts. However, regarding control implementation, they only showed difficulties in inhibiting the early automatic response capture (within-trial reactive control) but not reactive control across trials or proactive control. In conclusion, it seems that older adults are more affected by the presence of task-irrelevant information, especially when it comes to resolving stimulus-response conflict. However, they showed no impairments in their ability to implement cognitive control both across trials and as a task-set strategy.

Stimulus-Response Conflict Tasks and Their Use in Clinical Psychology.

This article reviews the historical usage of the concept of ‘conflict’ in psychology and delineates the design and development of three basic conflict tasks (Stroop, Flanker, Stop Signal). Afterwards, important theoretical concepts to account for conflict processing are introduced. In the second part, the usage of these tasks in clinical psychology is considered. The article closes with some reflections regarding factors that may have been hitherto largely neglected in this respect.

Interference suppression in bilingualism: Stimulus-Stimulus vs. Stimulus-Response conflict

AbstractStudies examining the potential effects of bilingualism on interference suppression show inconsistent results. Our study approaches this topic by distinguishing two potential subcomponents within interference suppression (i.e., Stimulus-Stimulus and Stimulus-Response conflict). We investigated the two subcomponents through their operationalisation in different tasks and examined the role of language proficiency in modulating it. A sample of 111 young adult participants performed four non-linguistic cognitive tasks measuring both visual and auditory domains of cognitive control. Bilinguals outperformed monolinguals in tasks involving Stimulus-Stimulus conflict, but showed comparable performance in tasks involving Stimulus-Response conflict. Specific effects of language proficiency on cognitive control were observed: group differences in auditory inhibition and visual orienting were only observed between high-proficient bilinguals and monolinguals. Taken together, types of conflicts involved in interference tasks and language proficiency could differentially affect performance in monolinguals and bilinguals.

Parsing the Neural Mechanisms of Short-Term and Long-Term Associations in the Flanker Tasks: An ERP Analysis.

The neural mechanisms of cognitive conflicts within various flanker tasks are still unclear, which may be mixed with different effects of short-term associations and long-term associations. We applied a perceptual (color) flanker task and a symbolic (arrow) flanker task to 25 healthy young adults, while the event-related potentials (ERP) and behavioral performance were recorded. The former contains stimulus-stimulus conflict (SSC) of short-term memory (STM) associations, and the latter contains stimulus-response conflict (SRC) of long-term memory (LTM) associations. Both flanker tasks included congruent and incongruent conditions. The reaction time demonstrated the stimulus-response conflict effect in the arrow flanker task without the stimulus-stimulus conflict effect in the color flanker task. The ERP results showed SSC enhanced the frontocentral N2b without behavioral effects. SRC increased the frontocentral P2 but decreased the centroparietal P3b with prolonged reaction time. In the comparison between both tasks, the color flanker task elicited both the centroparietal N2b/N300 and the frontocentral N400, and the arrow flanker task increased the occipital N1. Our findings provide new evidence that different neural mechanisms underlie conflict effects based on different types of memory associations.

Auditory spatial attention gradients and cognitive control as a function of vigilance.

Selection and effort are central to attention, yet it is unclear whether they draw on a common pool of cognitive resources, and if so, whether there are differences for early versus later stages of cognitive processing. This study assessed effort by quantifying the vigilance decrement, and spatial processing at early and later stages as a function of time-on-task. Participants performed an auditory spatial attention task, with occasional "catch" trials requiring no response. Psychophysiological measures included bilateral cerebral blood flow (transcranial Doppler), pupil dilation, and blink rate. The shape of attention gradients using reaction time indexed early processing, and did not significantly vary over time. Later stimulus-response conflict was comparable over time, except for a reduction to left hemispace stimuli. Target and catch trial accuracy decreased with time, with a more abrupt decrease for catch versus target trials. Diffusion decision modeling found progressive decreases in information accumulation rate and non-decision time, and the adoption of more liberal response criteria. Cerebral blood flow increased from baseline and then decreased over time, particularly in the left hemisphere. Blink rate steadily increased over time, while pupil dilation increased only at the beginning and then returned towards baseline. The findings suggest dissociations between resources for selectivity and effort. Measures of high subjective effort and temporal declines in catch trial accuracy and cerebral blood flow velocity suggest a standard vigilance decrement was evident in parallel with preserved selection. Different attentional systems and classes of computations that may account for dissociations between selectivity versus effort are discussed.

Stimulus and response conflict from a second language: Stroop interference in weakly-bilingual and recently-trained languages

The aim of the present manuscript was to investigate the source of congruency effects in weak bilinguals (Experiment 1) and in early language learning (Experiment 2). In both studies, participants performed a bilingual version of a colour-word Stroop task. The standard finding is slower and less accurate responding when the word and colour are incongruent (e.g., “red” in blue) relative to congruent (e.g., “red” in red). This congruency effect occurs for the distracting colour words from both the first and second language. Both stimulus conflict (i.e., conflict between the meaning of the word and ink colour) and response conflict (i.e., conflict between possible response options) contribute to first-language congruency effects. According to some models of early language learning, only one of these two types of conflict should emerge for non-fluent languages. To separate stimulus and response conflict, we used a 2-to-1 keypress assignment manipulation. Interestingly, in one study both stimulus and response conflict were evidenced for the weakly spoken second language (English in native French speakers). In a second study, participants performed a short Croatian colour word learning phase before the Stroop procedure. Stimulus conflict was observed in response times and response conflict in errors for this recently-trained language. These findings suggest that the relatively low-proficient second language words are potent enough to affect semantic identification and response selection.

Probing the Neural Systems Underlying Flexible Dimensional Attention.

Flexibly shifting attention between stimulus dimensions (e.g., shape and color) is a central component of regulating cognition for goal-based behavior. In the present report, we examine the functional roles of different cortical regions by manipulating two demands on task switching that have been confounded in previous studies-shifting attention between visual dimensions and resolving conflict between stimulus-response representations. Dimensional shifting was manipulated by having participants shift attention between dimensions (either shape or color; dimension shift) or keeping the task-relevant dimension the same (dimension same). Conflict between stimulus-response representations was manipulated by creating conflict between response-driven associations from the previous set of trials and the stimulus-response mappings on the current set of trials (e.g., making a leftward response to a red stimulus during the previous task, but being required to make a rightward response to a red stimulus in the current task; stimulus-response conflict), or eliminating conflict by altering the features of the dimension relevant to the sorting rule (stimulus-response no-conflict). These manipulations revealed activation along a network of frontal, temporal, parietal, and occipital cortices. Specifically, dimensional shifting selectively activated frontal and parietal regions. Stimulus-response conflict, on the other hand, produced decreased activation in temporal and occipital cortices. Occipital regions demonstrated a complex pattern of activation that was sensitive to both stimulus-response conflict and dimensional attention switching. These results provide novel information regarding the distinct role that frontal cortex plays in shifting dimensional attention and posterior cortices play in resolving conflict at the stimulus level.

Processing of Task-Irrelevant Race Information is Associated with Diminished Cognitive Control in Black and White Individuals

The race of an individual is a salient physical feature that is rapidly processed by the brain and can bias our perceptions of others. How the race of others explicitly impacts our actions toward them during intergroup contexts is not well understood. In the current study, we examined how task-irrelevant race information influences cognitive control in a go/no-go task in a community sample of Black (n = 54) and White (n = 51) participants. We examined the neural correlates of behavioral effects using functional magnetic resonance imaging and explored the influence of implicit racial attitudes on brain-behavior associations. Both Black and White participants showed more cognitive control failures, as indexed by dprime, to Black versus White faces, despite the irrelevance of race to the task demands. This behavioral pattern was paralleled by greater activity to Black faces in the fusiform face area, implicated in processing face and in-group information, and lateral orbitofrontal cortex, associated with resolving stimulus-response conflict. Exploratory brain-behavior associations suggest different patterns in Black and White individuals. Black participants exhibited a negative association between fusiform activity and response time during impulsive errors to Black faces, whereas White participants showed a positive association between lateral OFC activity and cognitive control performance to Black faces when accounting for implicit racial associations. Together our findings propose that attention to race information is associated with diminished cognitive control that may be driven by different mechanisms for Black and White individuals.

Stroop N450 reflects both stimulus conflict and response conflict.

N450 is described as a valid event-related potential indicator of Stroop interference, but the true specific psychological meaning of the Stroop N450 remains obscure. In the present research, we first used a Chinese character incongruent-eligible task and manipulated different types of conflict to investigate whether Stroop N450 reflects stimulus conflict, response conflict or both. The results showed that, only the N450 in the incongruent-eligible condition was more negative than that of the incongruent-ineligible and neutral conditions in the frontal-central area; simultaneously, there was a left parietal-occipital N450 that successively weakened in the incongruent-eligible, incongruent-ineligible and neutral conditions. These results indicate that Stroop N450 reflects both stimulus conflict and response conflict.

Intact Stimulus-Response Conflict Processing in ADHD-Multilevel Evidence and Theoretical Implications.

Attention-deficit-hyperactivity disorder (ADHD) is closely associated with deficits in cognitive control. It seems, however, that the degree of deficits strongly depends on the examined subprocess, with the resolution of stimulus–stimulus conflicts being particularly difficult for patients with ADHD. The picture is far less clear regarding stimulus–response conflicts. The current study provides multi-level behavioural and neurophysiological data on this type of conflict monitoring in children with ADHD compared to healthy controls. To account for the potentially strong effects of intra-individual variability, electroencephalogram (EEG) signal decomposition methods were used to analyze the data. Crucially, none of the analyses (behavioural, event-related potentials, or decomposed EEG data) show any differences between the ADHD group and the control group. Bayes statistical analysis confirmed the high likelihood of the null hypothesis being true in all cases. Thus, the data provide multi-level evidence showing that conflict monitoring processes are indeed partly intact in ADHD, even when eliminating possible biasing factors such as intra-individual variability. While stimulus–stimulus conflict processing has been shown to be consistently dysfunctional in ADHD, the resolution of stimulus–response conflicts is not deficient in this patient group. In comparison to other studies, the results provide novel theoretical insights into the nature of conflict control deficits in childhood ADHD.

Parsing the Flanker task to reveal behavioral and oscillatory correlates of unattended conflict interference

Stimulus-Response conflict is generated by an overlap between stimulus and response dimensions, but the intrinsic nature of this interaction is not yet deeply clarified. In this study, using a modified Eriksen flanker task, we have investigated how flankers have to be incongruent to target in order to produce an interference and whether and how this interference interacts with the one produced by Stimulus features overlap. To these aims, an Eriksen-like task employing oriented hands\\arrows has been designed to distinguish between two types of Stimulus-Response (S-R) interferences: one derived by a short-term association and one based on automatic processes. Stimulus-Stimulus (S-S) conflict has been also included in the same factorial design. Behavioral, Event Related Potential (ERP) and oscillatory activity data have been measured. Results revealed distinct S-S and automatic S-R effects on behavioral performance. ERP and Theta band power modulation results suggested an early frontal S-S conflict processing followed by a posterior simultaneous S-S and automatic S-R conflict processing. These findings provide evidence that, in presence of different conflicts, the sequence of stimulus identification and response selection could not move forward in a linear serial direction, but it may involve further effort, mirrored in posterior late components and response time prolongation.

On the encapsulation of bilingual language control

Abstract One purpose of this study was to test the hypothesis that prevalent patterns of bilingual language control lead to greater enhancement of the ability to resolve Stimulus-Stimulus conflict compared to Stimulus-Response conflict. To that end 104 bilinguals and 62 monolinguals completed four commonly used nonverbal interference tasks with varied S-S and S-R incompatibilities. No bilingual advantages were observed in any of the tasks. A second purpose was to further investigate whether a general inhibitory-control ability exists by examining inter-task correlations in the current and previous studies. We conclude that there may be a shared mechanism for interference control across spatial Stroop tasks and Simon tasks, but that this mechanism is apparently not recruited during bilingual language control to the extent that such practice would enhance a general ability. Rather, inhibition in language processing may be encapsulated within a lexical-identification system as assumed by Dijkstra and van Heuven’s bilingual-interactive-activation plus model and its update Multilink.

Midfrontal theta transcranial alternating current stimulation modulates behavioural adjustment after error execution

Cognitive control during conflict monitoring, error processing, and post-error adjustment appear to be associated with the occurrence of midfrontal theta (MFϴ). While this association is supported by correlational EEG studies, much less is known about the possible causal link between MFϴ and error and conflict processing. In the present study, we aimed to explore the role of band-specific effects in modulating the error system during a conflict resolution. In turn, we delivered transcranial alternating current stimulation (tACS) at different frequency bands (delta δ, theta θ, alpha α, beta β, gamma γ) and sham stimulation over the medial frontal cortex (MFC) in 36 healthy participants performing a modified version of the Flanker task. Task performance and reports about the sensations (e.g. visual flickering, cutaneous burning) induced by the different frequency bands, were also recorded. We found that online θ-tACS increased the response speed to congruent stimuli after error execution with respect to sham stimulation. Importantly, the accuracy following the errors did not decrease because of speed-accuracy trade off. Moreover, tACS evoked visual and somatosensory sensations were significantly stronger at α-tACS and β-tACS compared to other frequencies. Our findings suggest that theta activity plays a causative role in modulating behavioural adjustments during perceptual choices in a stimulus-response conflict task.