Resolution Of Response Conflict Research Articles

Cursor movements to targets labelled “stop”: a kinematic analysis

The label ‘Stop’ potentially generates conflict—signifying important corrective action, or a warning not to touch. To examine potential conflict between an incongruent label (i.e. STOP) and an imperative command (i.e. MOVE!), 18 participants used a computer mouse to move a crosshair cursor to targets with superimposed labels. Trials systematically varied Imperative (blank or MOVE!), Label (+GO + or STOP) and movement Distance. Kinematic analyses examined response latency, movement duration and accuracy. Incongruent labels had little impact upon response latencies, but they affected cursor deceleration and the variability of cursor placement. Although reading is assumed to be obligatory, the impact of written labels is not immediate, instead affecting cursor deceleration. Indeed, responses to controls labelled STOP were less accurate than those labelled + GO+. As labelled interfaces can create error versus command confusions, enhancing the discriminability of controls to afford more obvious visible cues as to method of use is recommended. Practitioner summary: Emergency stop and shutdown controls can cause response conflict as their labels signify both urgent corrective actions and ‘don’t touch’. Response conflict caused by confusing superimposed labels is resolved as cursors near the target control and may result in reduced movement accuracy. Prior warnings may influence resolution of response conflict. Abbreviations: Hz: Hertz; M: Mean; ms: millisecond; mm: millimetre; S: second; SD: Standard Deviation; SE: Standard Error; USB: Universal Serial Bus

Reward and expectancy effects on neural signals of motor preparation and execution

The magnitude and prospect of rewards can have strong modulatory effects on response preparation and execution. Importantly, reward-seeking behavior in real life happens under an environment characterized by uncertainty and dynamic changes. The current study investigated how the brain's motor and cognitive control system adapts to the dynamic changes in the environment in pursuit of rewards. To this end, we tested the effect of reward and expectancy on the hallmark neural signals that reflect activity in motor and prefrontal systems, the lateralized readiness potential (LRP) and the mediofrontal (mPFC) theta oscillations, while participants performed an expected and unexpected actions to retrieve rewards. To better capture the dynamic changes in neural processes represented in the LRP waveform, we decomposed the LRP into the preparation (LRPprep) and execution (LRPexec) components. In the comparison of LRP magnitude across task conditions, we found a greater LRPprep when large rewards were more likely, reflecting a greater motor preparation to obtain larger rewards. We also found a greater LRPexec when large rewards were presented unexpectedly, suggesting a greater motor effort placed for executing a correct movement when presented with large rewards. In the analysis of mPFC theta, we found a greater theta power prior to performing an unexpected than expected response, indicating its contribution in response conflict resolution. Collectively, these results demonstrate an optimized motor and cognitive control to maximize rewards under the dynamic changes of real-life environment.

Revealing the effects of temporal orienting of attention on response conflict using continuous movements

Orienting attention in time enables us to prepare for forthcoming perception and action (e.g., estimating the duration of a yellow traffic light when driving). While temporal orienting can facilitate performance on simple tasks, its influence on complex tasks involving response conflict is unclear. Here, we adapted the flanker paradigm to a choice-reaching task where participants used a computer mouse to reach to the left or right side of the screen, as indicated by the central arrow presented with either the congruent or incongruent flankers. We assessed the effects of temporal orienting by manipulating goal-driven temporal expectation (using probabilistic variations in target timing) and stimulus-driven temporal priming (using sequential repetitions versus switches in target timing). We tested how temporal orienting influenced the dynamics of response conflict resolution. Recent choice-reaching studies have indicated that under response conflict, delayed movement initiation captures the response threshold adjustment process, whereas increased curvature toward the incorrect response captures the degree of coactivation of the response alternatives during the controlled response selection process. Both temporal expectation and priming reduced the initiation latency regardless of response conflict, suggesting that both lowered response thresholds independently of response conflict. Notably, temporal expectation, but not temporal priming, increased the curvature toward the incorrect response on incongruent trials. These results suggest that temporal orienting generally increases motor preparedness, but goal-driven temporal orienting particularly interferes with response conflict resolution, likely through its influence on response thresholds. Overall, our study highlights the interplay between temporal orienting and cognitive control in goal-directed action.

Reward facilitates response conflict resolution via global motor inhibition: Electromyography evidence.

It is crucial for humans to coordinate between behavioural tendencies that can lead to reward but are in conflict with each other. This response conflict can be measured in a reward-modulated Simon task, in which a discriminative response to the identity of a lateral target is required and the target is associated with either high- or low-reward. Critically, the lateral target is presented either congruent or incongruent with the location of the responding hand. It has been shown that relative to the low-reward target, the high-reward target induced a larger response conflict when the target was incongruent with the position of the task-required, reward-obtaining hand. Here we investigated how this response conflict is resolved by acquiring 24 healthy participants' electromyography (EMG) signals from both the task-required responding hand (i.e., goal-directed effector) and the alternative hand (i.e., inappropriate effector). During the coping with the response conflict, motor inhibition (indexed by reduction in EMG signals between conditions) was observed not only at the inappropriate effector but also at the goal-directed effector. Individuals who showed stronger inhibition on the inappropriate effector suffered less from the inhibition on the goal-directed effector, and had more efficient implementation of the reward-obtaining response. Our findings suggest a global motor inhibition that may function to increase the signal-noise ratio in the motor system so as to implement reward-guided behavior.

Revealing the effects of temporal orienting of attention on response conflict using continuous movements.

Orienting attention in time enables us to prepare for forthcoming perception and action (e.g., estimating the duration of a yellow traffic light when driving). While temporal orienting can facilitate performance on simple tasks, its influence on complex tasks involving response conflict is unclear. Here, we adapted the flanker paradigm to a choice-reaching task where participants used a computer mouse to reach to the left or right side of the screen, as indicated by the central arrow presented with either the congruent or incongruent flankers. We assessed the effects of temporal orienting by manipulating goal-driven temporal expectation (using probabilistic variations in target timing) and stimulus-driven temporal priming (using sequential repetitions versus switches in target timing). We tested how temporal orienting influenced the dynamics of response conflict resolution. Recent choice-reaching studies have indicated that under response conflict, delayed movement initiation captures the response threshold adjustment process, whereas increased curvature toward the incorrect response captures the degree of coactivation of the response alternatives during the controlled response selection process. Both temporal expectation and priming reduced the initiation latency regardless of response conflict, suggesting that both lowered response thresholds independently of response conflict. Notably, temporal expectation, but not temporal priming, increased the curvature toward the incorrect response on incongruent trials. These results suggest that temporal orienting generally increases motor preparedness, but goal-driven temporal orienting particularly interferes with response conflict resolution, likely through its influence on response thresholds. Overall, our study highlights the interplay between temporal orienting and cognitive control in goal-directed action.

Practice makes perfect: Repeatedly dealing with response conflict facilitates its identification and speed of resolution

People repeatedly encounter response conflicts (i.e., self-control dilemmas between long-term and short-term goals). A longitudinal study was conducted to investigate how resolution of response conflict develops over time. Participants pursued a long-term goal. The design entailed pre- and post-measurements, as well as daily/weekly measures using a mobile application over a range of 10–110 days. Of the 180 people participating in the pre-measurement, 90 also completed the post-measurement. Over time, people became faster at successfully resolving response conflicts. The same response conflicts became bigger over time. Repeatedly being confronted with response conflicts facilitates resolution of these conflicts, by improving the identification of these conflicts, resulting in faster resolution.

Reduced hippocampal recruitment during response conflict resolution in mesial temporal lobe epilepsy

Recent evidence suggests that the human hippocampus (HC) is not only involved in the processing of motivationally relevant approach-avoidance conflicts but is also engaged in the resolution of more general response conflicts as measured in the Stroop paradigm. Here we investigated whether neural activity in the HC is necessary for successful response conflict resolution. We compared hippocampal recruitment during an auditory Stroop paradigm in 20 patients with mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis and 20 age-matched healthy controls using functional magnetic resonance imaging (fMRI). We analyzed hippocampal activation and behavioral performance in conflict trials relative to non-conflict trials. Moreover, functional connectivity (FC) analyses with left and right HCs as seeds were performed. Subjects’ regional gray matter volumes were analyzed based on high-resolution T2-weighted MRI scans. The current study replicated previous results showing increased activation in left HC during the processing of conflict trials in healthy subjects. By contrast, MTLE patients showed higher behavioral costs of response conflict resolution and reduced conflict-related HC activation. In patients with left MTLE, left HC activation was predictive of faster conflict-related response times (RTs). By contrast, right HC activation was related to RT slowing, suggestive of a maladaptive compensation attempt in MTLE patients. Our results provide evidence that left hippocampal activation is required for the successful resolution of response conflicts.

Executive control deficits correlate with reduced frontal white matter volume in multiple sclerosis

ABSTRACTIntroduction: Executive control deficits are frequently reported in patients with multiple sclerosis (MS). We have previously proposed that in the context of competing automatic and volitional processes, such deficits may in part reflect poor resolution of response conflict. This study aimed to investigate the neuropathological underpinnings of executive control deficits in MS, focusing on the frontostriatal system proposed to mediate executive control.Method: Forty-one MS patients and 25 healthy controls completed measures of executive control that have previously been used to characterize deficit in MS: antisaccade and endogenously cued saccade paradigms, and the Stroop color and word test. Relationships between task performance and volumetric measures of frontal white matter, frontal gray matter, striatum, and pallidum were investigated.Results: MS participants performed significantly more poorly on the Stroop and antisaccade tasks than controls. For MS patients, higher erroneous responding on the antisaccade task was related to reduced frontal white matter volume.Conclusion: These findings suggest that loss of frontal white matter may underlie executive control deficits in MS, and provides information that may inform the development of targeted cognitive training strategies in MS.

Subthalamic nucleus local field potentials recordings reveal subtle effects of promised reward during conflict resolution in Parkinson's disease

Cognitive action control depends on cortical-subcortical circuits, involving notably the subthalamic nucleus (STN), as evidenced by local field potentials recordings (LFPs) studies. The STN consistently shows an increase in theta oscillations power during conflict resolution. Some studies have shown that cognitive action control in Parkinson's disease (PD) could be influenced by the occurrence of monetary reward. In this study, we investigated whether incentive motivation could modulate STN activity, and notably STN theta activity, during response conflict resolution. To achieve this objective, we recorded STN LFPs during a motivated Simon task in PD patients who had undergone deep brain stimulation surgery. Behavioral results revealed that promised rewards increased the difficulty in resolving conflict situations, thus replicating previous findings. Signal analyses locked on the imperative stimulus onset revealed the typical pattern of increased theta power in a conflict situation. However, this conflict-related modulation of theta power was not influenced by the size of the reward cued. We nonetheless identified a significant effect of the reward size on local functional organization (indexed by inter-trial phase clustering) of theta oscillations, with higher organization associated with high rewards while resolving conflict. When focusing on the period following the onset of the reward cue, we unveiled a stronger beta power decrease in higher reward conditions. However, these LFPs results were not correlated to behavioral results. Our study suggests that the STN is involved in how reward information can influence computations during conflict resolution. However, considering recent studies as well as the present results, we suspect that these effects are subtle.

Improved Cognitive Control in Presence of Anthropomorphized Robots

There is evidence that attentional control mechanisms in humans can be boosted in performance contexts involving the presence of other human agents, compared with isolation. This phenomenon was investigated here with the presence of artificial agents, that is, humanoid robots in the context of the well-known Stroop task requiring attentional control for successful performance. We expected and found beneficial effects of robotic presence (compared with isolation) on standard Stroop performance and response conflict resolution (a specific component of Stroop performance) exclusively when robotic presence triggered anthropomorphic inferences based on prior verbal interactions with the robot (a social robot condition contrasted with the presence of the same robot without any prior interactions). Participants’ anthropomorphic inferences about the social robot actually mediated its influence on attentional control, indicating the social nature of this influence. These findings provide further reasons to pay special attention to human–robot interactions and open new avenues of research in social robotics.

Oscillatory Mechanisms of Response Conflict Elicited by Color and Motion Direction: An Individual Differences Approach.

Goal-directed behavior requires control over automatic behavior, for example, when goal-irrelevant information from the environment captures an inappropriate response and conflicts with the correct, goal-relevant action. Neural oscillations in the theta band (∼6 Hz) measured at midfrontal electrodes are thought to form an important substrate of the detection and subsequent resolution of response conflict. Here, we examined the extent to which response conflict and associated theta-band activity depend on the visual stimulus feature dimension that triggers the conflict. We used a feature-based Simon task to manipulate conflict by motion direction and stimulus color. Analyses were focused on individual differences in behavioral response conflict elicited across different stimulus dimensions and their relationship to conflict-related midfrontal theta. We first confirmed the presence of response conflict elicited by task-irrelevant motion and stimulus color, demonstrating the usefulness of our modified version of the Simon task to assess different sensory origins of response conflict. Despite titrating overall task performance, we observed large individual differences in the behavioral manifestations of response conflict elicited by the different visual dimensions. These behavioral conflict effects were mirrored in a dimension-specific relationship with conflict-related midfrontal theta power, such that, for each dimension, individual midfrontal theta power was generally higher when experienced response conflict was high. Finally, exploratory analyses of interregional functional connectivity suggested a role for phase synchronization between frontal and parietal scalp sites in modulating experienced conflict when color was the task-relevant visual dimension. Highlighting the importance of an individual differences approach in cognitive neuroscience, these results reveal large individual differences in experienced response conflict depending on the source of visual interference, which are predicted by conflict-related midfrontal theta power.

P136 Investigating inhibitory processes within the motor cortex during conflict resolution using paired-pulse transcranial magnetic stimulation

Introduction In daily life, we often need to deal with situations in which multiple actions are possible, situations of so-called ‘response conflict’. Several brain regions have been identified as key nodes of a network involved in resolving response conflict. However, how and by which physiological mechanism those nodes finally affect the ‘output station’ of the brain, the primary motor cortex, is unknown. A potential mechanism is the involvement of inhibitory interneurons, which can be directly tested using paired-pulse transcranial magnetic stimulation (TMS). Question Here we test how inhibitory processes within the primary motor cortex change over time during the resolution of response conflict. Methods Participants performed an arrow version of the Flanker task. The arrows were arranged such that they either elicit one response with no conflict (e.g., all arrows point to the same direction) or two competing responses (e.g., the target arrow points towards the opposite direction as the flankers). To track the involvement of inhibitory processes over time short intra-cortical inhibition (SICI) was measured as the change in the amplitude of the motor-evoked potential over the left motor cortex elicited by a single supra-threshold pulse and by a supra-threshold pulse preceded by a sub-threshold pulse. This enabled the identification of time-specific physiological patterns of inhibitory processes at the level of primary motor cortex. Results Preliminary analyses show increased MEP amplitudes towards the response and specific changes in SICI over time dependent on the level of response conflict. Conclusion These results suggest involvement of primary motor cortex inhibitory interneurons when resolving situations of response conflict.

Performance monitoring and response conflict resolution associated with choice stepping reaction tasks

Choice reaction requires response conflict resolution, and the resolution processes that occur during a choice stepping reaction task undertaken in a standing position, which requires maintenance of balance, may be different to those processes occurring during a choice reaction task performed in a seated position. The study purpose was to investigate the resolution processes during a choice stepping reaction task at the cortical level using electroencephalography and compare the results with a control task involving ankle dorsiflexion responses. Twelve young adults either stepped forward or dorsiflexed the ankle in response to a visual imperative stimulus presented on a computer screen. We used the Simon task and examined the error-related negativity (ERN) that follows an incorrect response and the correct-response negativity (CRN) that follows a correct response. Error was defined as an incorrect initial weight transfer for the stepping task and as an incorrect initial tibialis anterior activation for the control task. Results revealed that ERN and CRN amplitudes were similar in size for the stepping task, whereas the amplitude of ERN was larger than that of CRN for the control task. The ERN amplitude was also larger in the stepping task than the control task. These observations suggest that a choice stepping reaction task involves a strategy emphasizing post-response conflict and general performance monitoring of actual and required responses and also requires greater cognitive load than a choice dorsiflexion reaction. The response conflict resolution processes appear to be different for stepping tasks and reaction tasks performed in a seated position.

Switch hands! Mapping temporal dynamics of proactive manual control with anticues

This study uses a novel behavioral paradigm—the anticue task—to investigate the temporal dynamics of proactive control aimed at the resolution of response conflict in the manual motor system. The anticue task is a 4-choice reaction time (RT) task, with left and right anticues indicating mirror-symmetrical response hands. In particular, anticues require participants to prepare fingers on the hand opposite to the side of the cue (counter-corresponding mapping), which contrasts with the more standard procues that prompt participants to prepare fingers on the hand spatially in line with the cue (corresponding mapping). In Experiment 1, we examined the effects of anticues and procues as a function of cue–target interval (range: 100–850ms). Results showed that procues produced RT benefits (relative to neutral cues), which increased with longer cue–target intervals. Anticues, however, produced RT costs with short cue–target intervals and RT benefits with longer cue–target intervals. These findings support the view that anticues are mediated by a time-consuming, proactive control process that, using inhibition and activation, redirects the initial but wrong activation of the ipsilateral hand to the correct contralateral hand. In Experiment 2, we used a simple detection response to test, and reject, an alternative (attentional) account of these findings. Theoretical and practical implications are discussed in the context of dual-route models of response selection, the activation-suppression model, and related experimental protocols such as antisaccade, Simon, Stroop, Eriksen flanker, and task switching paradigms.

Effects of Trait Self‐Control on Response Conflict About Healthy and Unhealthy Food

Self-control leads to positive life outcomes, but it is poorly understood. While previous research has focused on self-control failure, self-control success remains unexplored. The current studies aim to shed more light on the mechanisms of self-control by focusing on the resolution of response conflict as a key component in self-control success. Trait self-control was measured, and participants reported on the magnitude of response conflict they experienced about healthy and unhealthy foods in Study 1 (N = 146; Mage = 33.03; 59 females, 83 males, 4 unknown). The response conflict process was assessed in Study 2 (N = 118; Mage = 21.45; 68 females, 41 males, 9 unknown). Outcomes showed that self-reported evaluative response conflict about food items was smaller for people high in trait self-control. Study 2 revealed that higher trait self-control predicted faster resolution of self-control conflict, and an earlier peak of the response conflict. Taken together, these results provide insight into what makes people with high trait self-control successful, namely, how they handle response conflict. Implications for self-control theories and future directions are discussed.

The effect of positive affect on conflict resolution: Modulated by approach-motivational intensity

ABSTRACTThe motivational dimensional model of affect proposes that the influence of positive affect on cognitive processing is modulated by approach-motivational intensity. The present research extended this model by examining the influence of positive affect varying in approach-motivational intensity on conflict resolution—the ability to resolve interference from task-irrelevant distractors in order to focus on the target. The global–local task (Experiment 1) and letter-Flanker task (Experiment 2) were used to measure conflict resolution. Additionally, the 4:2 mapping design that assigns two kinds of task-relevant stimuli to one response key and two more to another response key was used in these two tasks to dissociate stimulus and response conflict. Results showed that positive affect varying in approach motivation had opposite influences on conflict resolution. The opposite influences are primarily reflected in low approach-motivated positive affect impairing, while high approach-motivated positive affect facilitating the resolution of response conflict. Conversely, the stimulus conflict was slightly influenced. These findings highlight the utility of distinguishing stimulus and response conflict in future research.

Human Hippocampal Dynamics during Response Conflict

Besides its relevance for declarative memory functions, hippocampal activation has been observed during disambiguation of uncertainty and conflict. Uncertainty and conflict may arise on various levels. On the perceptual level, the hippocampus has been associated with signaling of contextual deviance and disambiguation of similar items (i.e., pattern separation). Furthermore, conflicts can occur on the response level. Animal experiments showed a role of the hippocampus for inhibition of prevailing response tendencies and suppression of automatic stimulus-response mappings, potentially related to increased theta oscillations (3-8 Hz). In humans, a recent fMRI study demonstrated hippocampal involvement in approach-avoidance conflicts. However, the more general significance of hippocampal activity for dealing with response conflicts also on a cognitive level is still unknown. Here, we investigated the role of the hippocampus for response conflict in the Stroop task by combining intracranial electroencephalography (iEEG) recordings from the hippocampus of epilepsy patients with region of interest-based fMRI in healthy participants. Both methods revealed converging evidence that the hippocampus is recruited in a regionally specific manner during response conflict. Moreover, our iEEG data show that this activation depends on theta oscillations and is relevant for successful response conflict resolution.

The prelimbic cortex uses higher-order cues to modulate both the acquisition and expression of conditioned fear.

The prelimbic (PL) cortex allows rodents to adapt their responding under changing experimental circumstances. In line with this, the PL cortex has been implicated in strategy set shifting, attentional set shifting, the resolution of response conflict, and the modulation of attention towards predictive stimuli. One interpretation of this research is that the PL cortex is involved in using information garnered from higher-order cues in the environment to modulate how an animal responds to environmental stimuli. However, data supporting this view of PL function in the aversive domain are lacking. In the following experiments, we attempted to answer two questions. Firstly, we wanted to investigate whether the role of the PL cortex in using higher-order cues to influence responding generalizes across appetitive and aversive domains. Secondly, as much of the research has focused on a role for the PL cortex in performance, we wanted to assess whether this region is also involved in the acquisition of hierarchal associations which facilitate an ability to use higher-order cues to modulate responding. In order to answer these questions, we assessed the impact of PL inactivation during both the acquisition and expression of a contextual bi-conditional discrimination. A contextual bi-conditional discrimination involves presenting two stimuli. In one context, one stimulus is paired with shock while the other is presented without shock. In another context, these contingencies are reversed. Thus, animals have to use the present contextual cues to disambiguate the significance of the stimulus and respond appropriately. We found that PL inactivation disrupted both the encoding and expression of these context-dependent associations. This supports a role for the PL cortex in allowing higher-order cues to modulate both learning about, and responding towards, different cues. We discuss these findings in the broader context of functioning in the medial prefrontal cortex (PFC).

Increased response conflict in recreational cocaine polydrug users

Recent studies suggest that recreational use of cocaine is associated with significant impairments in the same cognitive control functions that are affected by chronic use. Here we tested whether recreational cocaine use can impact the emergence and resolution of response conflict in conflict-inducing tasks. Recreational cocaine polydrug users (n = 17) and cocaine-free controls (n = 17), matched for sex, age, intelligence, and alcohol consumption, performed a Simon task-which is known to induce response conflict. Recreational users showed a larger Simon effect, indicating that they had more difficulty resolving stimulus-induced response conflict. This finding is consistent with the recent literature showing that even small doses of cocaine are sufficient to compromise key cognitive control functions.

Impaired response-conflict resolution in ageing when high salient distracters compete for response

Top-down attention selection can involve both excitatory processes (biasing attention towards targets) and inhibitory ones (biasing attention away from distracters). In fact, it seems that normal ageing has a differential effect on these two types of processes: While excitatory guidance may be stronger (Madden et al., 1999), inhibitory processes may be selectively weaker in ageing (Lustig et al., 2007). Though the degraded inhibition might be compensated by increased excitatory guidance, performance could be impaired in those scenarios where high-salience distracters compete for selection. In the present study we compared performance of young and old adults in a salience-based selection task which enabled us to separate competition for response from competition for perceptual representation. Superimposed faces and scenes where used in which either the face or the scene was more salient than the other. In Experiment 1 participants identified the face (ignoring the scene) or the scene (ignoring the face) while in Experiment 2 only the face had to be identified (and therefore the scenes did not elicit competing responses). Old adults showed an extraordinary impairment in identifying faces/scenes when the scenes/faces had high-salience but this only happened in the response competition condition (Experiment 1). When response competition was eliminated old adults' performance was comparable to young adults. The results support previous studies that have demonstrated impaired inhibition of incongruent distracters in ageing (Zhou et al., 2011) while further emphasizing that normal aging entails impaired ability to resolve conflicting responses rather than conflicting stimuli. Moreover, the results mimic our previous findings with left parietal patients (Mevorach et al., VSS 2012; using a similar design) and may therefore raise the hypothesis that degraded left parieto-occipital circuitry is the cause for reduced inhibitory top-down attention in old age. Meeting abstract presented at VSS 2013 Language: en