Stimulus-response Compatibility Task Research Articles

A comparison of the anticipated and pharmacological effects of alcohol on cognitive bias, executive function, craving and ad-lib drinking

Acute alcohol administration alters automatic processing of alcohol-related cues, impairs executive functions and increases alcohol seeking. Few studies have investigated the effects of expecting to receive alcohol on these measures. Thirty-one social drinkers completed three experimental sessions receiving either 0.65 g/kg alcohol, a placebo and a control beverage (which they knew was not alcoholic) before reporting craving and completing a test battery including a measure of automatic alcohol-approach tendencies (stimulus response compatibility task), a measure of executive function (Controlled Oral Word Association Task (COWAT)) and a taste test assessing ad-lib drinking. Results indicated that alcohol administration impaired performance on the COWAT and increased ad-lib drinking; however, there were no significant differences on these measures after administration of placebo versus control beverages. Craving was increased after alcohol and (to a lesser extent) after placebo. Automatic alcohol-approach tendencies were pronounced after both alcohol and placebo compared to the control beverage, with no difference between alcohol and placebo. Results suggest craving is sensitive to the anticipated and pharmacological effects of alcohol, alcohol-approach tendencies are particularly sensitive to the anticipated effects of alcohol, and measures of executive function and ad-lib drinking are affected by the pharmacological, but not the anticipated, effects of alcohol.

The effects of a nighttime nap on the error-monitoring functions during extended wakefulness.

To examine the effects of a 1-hr nighttime nap, and the associated sleep inertia, on the error-monitoring functions during extended wakefulness using the 2 event-related potential components thought to reflect error detection and emotional or motivational evaluation of the error, i.e., the error-related negativity/error-negativity (ERN/Ne) and error-positivity (Pe), respectively. Participants awakened at 07:00 the morning of the experimental day, and performed a stimulus-response compatibility (arrow-orientation) task at 21:00, 02:00, and 03:00. A cognitive task with EEG data recording was performed in a laboratory setting. Twenty young adults (mean age 21.3 ± 1.0 yr, 14 males) participated. Half of the participants took a 1-hr nap, and the others had a 1-hr awake-rest period from 01:00-02:00. Behavioral performance and amplitude of the Pe declined after midnight (i.e., 02:00 and 03:00) compared with the 21:00 task period in both groups. During the task period starting at 03:00, the participants in the awake-rest condition reported less alertness and showed fewer correct responses than those who napped. However, there were no effects of a nap on the amplitude of the ERN/Ne or Pe. Our results suggest that a 1-hr nap can alleviate the decline in subjective alertness and response accuracy during nighttime; however, error-monitoring functions, especially emotional or motivational evaluation of the error, might remain impaired by extended wakefulness even after the nap. This phenomenon could imply that night-shift workers experiencing extended wakefulness should not overestimate the positive effects of a nighttime 1-hr nap during extended wakefulness.

Foreshadowing of performance accuracy by event-related potentials: evidence from a minimal-conflict task.

BackgroundRecent studies employing stimulus-response compatibility tasks suggest that an increase in the amplitude of the positive deflection of the response-locked event-related potential (ERP) foreshadows errors on forthcoming trials. However, no studies have tested the generalizability of error-foreshadowing positivity to tasks without stimulus-response interference.Methodology/Principal FindingsThe present study adopted an alternating-response task, in which the participants responded to the pointing direction of an arrowhead (up or down). Although the arrowhead direction alternated for the majority of trials (95%), occasionally this pattern was broken by a repeated stimulus, termed a lure trial. We compared the matched-reaction-time correct-preceding ERP with the error-preceding ERP on lure-preceding trials. There was no evidence that errors are foreshadowed by the increase of a positive electroencephalogram (EEG) deflection. To the contrary, analyses of ERPs time-locked to electromyogram (EMG) onset on the five consecutive lure-preceding trials showed larger positive deflections on correct-preceding than error-preceding trials. The post-response negativity did not differ between correct-preceding and error-preceding trials.Conclusions/SignificanceThese results suggest that in minimal conflict tasks a decreased positivity may foreshadow incorrect performance several trials prior to the error, possibly reflecting the waning of task-related efforts. Therefore, error-foreshadowing brain signals may be task-specific.

Proactive and reactive control in S‐R compatibility: A brain potential analysis

We investigated how proactive and reactive control facilitates performance in mixed stimulus-response compatibility (SRC) tasks. SRC effects were eliminated in mixed tasks and reversed following incompatible trials. In mixed tasks, early preferential response activation was present in stimulus-locked lateralized readiness potentials (LRPs) but reduced following incompatible trials. In event-related potentials (ERPs), stimulus-locked N2 was enhanced in all mixed trials but was not significantly influenced by the preceding trial. A response-locked fronto-central negative component (N-120), peaking just before the response, was largest for mixed compatible trials preceded by incompatible trials. This N-120 was paired with an enhancement to the peak of the response-locked LRP. Proactive control is involved in selection of an S-R mapping via the indirect route of a dual-route model. Reactive control corrects the S-R mapping, particularly when alternating between S-R mappings.

Approach and avoidance movements are unaffected by cognitive conflict: A comparison of the Simon effect and stimulus–response compatibility

Participants in this study reached from central fixation to a lateral position that either contained or was opposite to the stimulus. Cognitive conflict was induced when the stimulus and response directions did not correspond. In the Simon task, the response direction was cued by the color of the lateral stimulus, and corresponding and noncorresponding trials varied randomly in the same block of trials, resulting in high uncertainty and long reaction times (RTs). In the stimulus-response compatibility (SRC) task, participants reached toward or away from the stimulus in separate blocks of trials, resulting in low uncertainty and short RTs. In the SRC task, cognitive conflict in noncorresponding trials slowed down RTs but hardly affected reach trajectories. In the Simon task, both RTs and reach trajectories were strongly influenced by stimulus-response correspondence. Despite the overall longer RTs in the Simon task, reaches were less direct and deviated toward the stimulus in noncorresponding trials. Thus, cognitive conflict was resolved before movement initiation in the SRC task, whereas it leaked into movement execution in the Simon task. Current theories of the Simon effect, such as the gating of response activation or response code decay, are inconsistent with our results. We propose that the SRC task was decomposed as approaching and avoiding the stimulus, which is sustained by stereotyped visuomotor routines. With complex stimulus-response relationships (Simon task), responses had to be coded as leftward and rightward, with more uncertainty about how to execute the action. This uncertainty permitted cognitive conflict to leak into the movement execution.

Altered Brain Activation in Military Personnel with One or More Traumatic Brain Injuries Following Blast

Explosive blast is a frequent cause of traumatic brain injury (TBI) among personnel deployed to Afghanistan and Iraq. Functional magnetic resonance imaging (fMRI) with an event-related stimulus-response compatibility task was used to compare 15 subjects with mild, chronic blast-related TBI with 15 subjects who had not experienced a TBI or blast exposure during deployment. Six TBI subjects reported multiple injuries. Relative to the control group, TBI subjects had slightly slower responses during fMRI and increased somatic complaints and symptoms of post-traumatic stress disorder (PTSD) and depression. A between-group analysis indicated greater activation during stimulus-response incompatibility in TBI subjects within the anterior cingulate gyrus, medial frontal cortex, and posterior cerebral areas involved in visual and visual-spatial functions. This activation pattern was more extensive after statistically controlling for reaction time and symptoms of PTSD and depression. There was also a negative relationship between symptoms of PTSD and activation within posterior brain regions. These results provide evidence for increased task-related activation following mild, blast-related TBI and additional changes associated with emotional symptoms. Limitations of this study include no matching for combat exposure and different recruitment strategies so that the control group was largely a community-based sample, while many TBI subjects were seeking services.

Alcohol approach tendencies in heavy drinkers: Comparison of effects in a relevant stimulus-response compatibility task and an approach/avoidance Simon task.

Several recent studies suggest that alcohol-related cues elicit automatic approach tendencies in heavy drinkers. A variety of tasks have been used to demonstrate these effects, including Relevant Stimulus-Response Compatibility (R-SRC) tasks and variants of Simon tasks. Previous work with normative stimuli suggests that the R-SRC task may be more sensitive than Simon tasks because the activation of approach tendencies may depend on encoding of the stimuli as alcohol-related, which occurs in the R-SRC task but not in Simon tasks. Our aim was to directly compare these tasks for the first time in the context of alcohol use. We administered alcohol versions of an R-SRC task and a Simon task to 62 social drinkers, who were designated as heavy or light drinkers based on a median split of their weekly alcohol consumption. Results indicated that, compared to light drinkers, heavy drinkers were faster to approach, rather than avoid, alcohol-related pictures in the R-SRC task but not in the Simon task. Theoretical implications and methodological issues are discussed.

To Approach or Avoid Alcohol? Automatic and Self‐Reported Motivational Tendencies in Alcohol Dependence

Background:Motivational conflict is central to alcohol dependence, with patients reporting motivation to limit their drinking at the same time as urges to drink alcohol. In addition, dual process models of addiction emphasise the power of automatic cognitive processes, particularly automatic approach responses elicited by alcohol-related cues, as determinants of drinking behavior. We aimed to examine the strength of automatic and self-reported alcohol approach and avoidance tendencies among alcohol-dependent inpatients relative to matched controls.Methods:A total of 63 alcohol-dependent patients undergoing detoxification and 64 light-drinking controls completed a stimulus-response compatibility (SRC) task, which assesses the speed of categorization of alcohol-related pictures by making symbolic approach and avoidance movements. We also included modified versions of the SRC task to assess automatic motivational conflict, that is, strong approach and avoidance tendencies elicited simultaneously by alcohol-related cues.Results:There were no differences between alcohol-dependent patients and controls on the SRC task, although individual differences in the quantity of alcohol consumed before entering treatment were significantly positively correlated with the strength of approach (but not avoidance) tendencies elicited by alcohol-related cues. Automatic approach tendencies were also positively correlated with self-reported “approach” inclinations and negatively correlated with self-reported “avoidance” inclinations.Conclusions:Although alcohol-dependent patients and matched controls did not differ on automatic approach and avoidance tendencies elicited by alcohol-related cues, individual differences in the quantity of alcohol consumed before entering treatment were associated with the strength of automatic approach tendencies elicited by alcohol cues.

Components of behavioural impulsivity and automatic cue approach predict unique variance in hazardous drinking

Hazardous drinking is associated with both increased impulsivity and automatic approach tendencies elicited by alcohol-related cues. However, impulsivity is a multi-factorial construct, and it is currently unclear if all components of impulsivity are associated with heavy drinking. Furthermore, emerging evidence suggests that the relationships between hazardous drinking and automatic alcohol cognitions may be moderated by individual differences in impulsivity. The aim of this study was to investigate the independence of measures of impulsivity and their association with hazardous drinking, and to examine if the relationship between hazardous drinking and automatic alcohol approach tendencies would be moderated by individual differences in impulsivity. Ninety-seven social drinkers (65 female) completed questionnaire measures of trait impulsivity, alcohol consumption and hazardous drinking. Participants also completed computerised measures of automatic alcohol approach tendencies (stimulus-response compatibility (SRC) task), and two behavioural measures of impulsivity (Go/No-go and delay discounting tasks). Principal component analysis revealed that the two measures of behavioural impulsivity were distinct from each other and from self-reported trait impulsivity, although self-reported non-planning impulsivity loaded on to two factors (trait impulsivity and delay discounting). Furthermore, all measures of impulsivity predicted unique variance in hazardous drinking as did automatic alcohol approach tendencies, although the latter relationship was not moderated by impulsivity. These results indicate that multiple components of impulsivity and automatic alcohol approach tendencies explain unique variance in hazardous drinking.

Dynamic interactions in the fronto-parietal network during a manual stimulus–response compatibility task

Attentional orienting can be modulated by stimulus-driven bottom-up as well as task-dependent top-down processes. In a recent study we investigated the interaction of both processes in a manual stimulus-response compatibility task. Whereas the intraparietal sulcus (IPS) and the dorsal premotor cortex (dPMC) were involved in orienting towards the stimulus side facilitating congruent motor responses, the right temporoparietal junction (TPJ), right dorsolateral prefrontal cortex (DLPFC) as well as the preSMA sustained top-down control processes involved in voluntary reorienting. Here we used dynamic causal modelling to investigate the contributions and task-dependent interactions between these regions. Thirty-six models were tested, all of which included bilateral IPS, dPMC and primary motor cortex (M1) as a network transforming visual input into motor output as well as the right TPJ, right DLPFC and the preSMA as task-dependent top-down regions influencing the coupling within the dorsal network. Our data showed the right temporoparietal junction to play a mediating role during attentional reorienting processes by modulating the inter-hemispheric balance between both IPS. Analysis of connection strength supported the proposed role of the preSMA in controlling motor responses promoting or suppressing activity in primary motor cortex. As the results did not show a clear tendency towards a role of the right DLPFC, we propose this region, against the usual interpretation of an inhibitory influence in stimulus-response compatibility tasks, to subserve generic monitoring processes. Our DCM study hence provides evidence for context-dependent top-down control of right TPJ and DLPFC as well as the preSMA in stimulus-response compatibility.

Executive control in chronic schizophrenia: A perspective from manual stimulus-response compatibility task performance

Background Antisaccade deficits are a well-documented pathophysiological characteristic in schizophrenia. However, it is yet unclear whether these findings reflect a specific oculomotor deficit, general psychomotor impairment or disturbance in executive control mechanisms. Methods Performance in a manual stimulus-response compatibility (SRC) task and a neuropsychological test-battery covering different cognitive and motor domains were obtained in 28 patients with chronic schizophrenia. It was compared with a normative cohort of healthy subjects and validated by comparison with a sub-sample of that cohort consisting of 28 age, gender and education matched controls. Results Patients showed significantly worse performance than controls in tests requiring maintenance or manipulating of multiple components but were unimpaired in simple motor, memory or executive tasks. In the SRC task patients had a significantly worse performance in the congruent condition and also a significantly higher increase in error rate from the congruent to the incongruent condition. There were, however, neither a group difference nor a group-by-condition interaction with respect to reaction times. Interpretation : Our results provide evidence against an isolated oculomotor deficit but also against an undifferentiated psychomotor dysfunction in chronic schizophrenia. Rather, in synopsis with previous reports on antisaccade performance, it becomes evident that the degree of impairment follows closely the amount of executive control required in a task, which in turn may relate to dysfunctional top-down bias of the prefrontal cortex arising from unstable task instructions.

Grasping the concept of personal property

The concept of property is integral to personal and societal development, yet understanding of the cognitive basis of ownership is limited. Objects are the most basic form of property, so our physical interactions with owned objects may elucidate nuanced aspects of ownership. We gave participants a coffee mug to decorate, use and keep. The experimenter also designed a mug of her own. In Experiment 1, participants performed natural lifting actions with each mug. Participants lifted the Experimenter’s mug with greater care, and moved it slightly more towards the Experimenter, while they lifted their own mug more forcefully and drew it closer to their own body. In Experiment 2, participants responded to stimuli presented on the mug handles in a computer-based stimulus–response compatibility task. Overall, participants were faster to respond in trials in which the handles were facing in the same direction as the response location compared to when the handles were facing away. The compatibility effect was abolished, however, for the Experimenter’s mug – as if the action system is blind to the potential for action towards another person’s property. These findings demonstrate that knowledge of the ownership status of objects influences visuomotor processing in subtle and revealing ways.

Weight, gender, and snack appeal

In this study, we hypothesized that overweight/obese persons have an exaggerated approach tendency toward high calorie foods. Testing this hypothesis, a stimulus response compatibility (SRC) task was used to assess approach-avoidance tendencies toward food in both overweight/obese participants ( n = 42), and normal weight controls ( n = 46). The SRC task is a reaction time task measuring how fast one approaches and avoids pictures of food and non-foods according to given instructions. It was found that overweight/obese men are slower at avoiding particularly high calorie snack foods. But this does not appear to be the case for overweight/obese women who showed nearly as fast avoidance as approach toward the high calorie food cues. It is concluded that overweight/obese women, rather than men, are ambivalent toward high calorie foods, which is the likely result of high dietary restraint.

Measuring thinspiration and fear of fat indirectly. A matter of approach and avoidance

The concepts thinspiration and fear of fat are crucial regarding the development and maintenance of body image disturbances and eating pathology. This study aimed to advance our current understanding of these two motivational concepts. Unlike previous studies that have primarily relied on self report measures to investigate thinspiration and fear of fat, we applied an indirect measure, namely a Stimulus Response Compatibility (SRC) task. During our SRC task, undergraduate female students were instructed to symbolically approach and avoid pictures of thin and chubby models. Hence, the participants’ reaction times during the SRC task provided an index of the automatic affective and motivational valence of the models. Results showed that participants were faster to approach than to avoid thin models, however, there was no difference in approach–avoidance responses regarding chubby models. Analyses revealed that the approach–avoidance responses were related to important eating-related, cognitive schemata, e.g., the participants’ level of drive for thinness, thin-ideal internalization, body dissatisfaction and their weight control behaviors. These findings clearly support the application of an indirect measure such as the SRC task in order to examine the concepts thinspiration and fear of fat, and highlight the need for further research that validates and extends current results.

Auditory Warning Signals Affect Mechanisms of Response Selection

Irrelevant tone (accessory) stimuli facilitate performance in simple and choice reaction time tasks. In the present study, we combined accessory stimulation with a selective attention paradigm in order to investigate its influence on mechanisms of response selection. In the framework of a spatial stimulus-response compatibility task (Simon task), we tested whether accessory stimuli selectively affect bottom up triggered response activation processes (e.g., direct route processing), processing of task-relevant stimulus features (indirect route processing), or both/none. Results suggest a two-component effect of accessory stimuli within this selective attention task. First, accessory stimuli increased the Simon effect due to beneficial direct route processing. Second, accessory stimuli generally decreased reaction times indicating facilitation of indirect route processing.

Post-error behavioral adjustments are facilitated by activation and suppression of task-relevant and task-irrelevant information processing.

Error monitoring by the posterior medial frontal cortex (pMFC) has been linked to post-error behavioral adaptation effects and cognitive control dynamics in lateral prefrontal cortex (LPFC). It remains unknown, however, whether control adjustments following errors produce post-error behavioral adjustments (PEBAs) by inhibiting inappropriate responses or facilitating goal-directed ones. Here we used functional magnetic resonance imaging to investigate the hemodynamic correlates of PEBAs in a stimulus-response compatibility task. Our task was designed to test whether PEBAs are implemented by suppressing motor responses primed by irrelevant stimulus features (face location), redirecting attention to relevant features (face gender), or both or neither of these possibilities. Independent of PEBAs, error-related pMFC activation was followed by post-error recruitment of prefrontal and parietal control regions and, crucially, both (1) suppressed response-related activity in sensorimotor cortex and (2) enhanced target processing in face-sensitive sensory cortex ("fusiform face area"). More importantly, by investigating the covariation between post-error hemodynamic activity and individual differences in PEBAs, we showed that modulation of task-related motor and sensory processing was dependent on whether participants produced generally slower responses ("post-error slowing"; PES) or selectively reduced interference effects ("post-error reduction of interference"; PERI), respectively. Each of these behaviorally dependent effects was mediated by distinct LPFC control mechanisms (PES: inferior frontal junction; PERI: superior frontal sulcus). While establishing relationships between PEBAs and cognitive control, our findings suggest that the neural architecture underlying sequential behavioral adaptation may be determined primarily by how control is executed by the individual when adjustments are needed.

Dissociating Bottom-Up and Top-Down Processes in a Manual Stimulus–Response Compatibility Task

Speed and accuracy of motor responses to lateralized stimuli are influenced by the spatial overlap between stimulus location and required response. Responses showing high spatial overlap with peripheral cues benefit from a bottom-up driven enhancement of attention to the respective location, whereas low overlap requires top-down modulated reorienting of resources. Here we investigated the interaction between these two processes using a spatial stimulus-response compatibility task. Subjects had to react to lateralized visual stimuli with a button press using either the ipsilateral (congruent condition) or the contralateral (incongruent condition) index finger. Stimulus-driven bottom-up processes were associated with significant contralateral activation in V5, the intraparietal sulcus (IPS) and the premotor cortex (PMC). Incongruent versus congruent responses evoked significant activation in bilateral IPS and PMC, highly overlapping with the activations found for stimulus-driven bottom-up processes, as well as additional activation in bilateral anterior insula and right dorsolateral prefrontal cortex (DLPFC) and temporoparietal junction (TPJ). Moreover, a region anterior to the bottom-up driven activation in the IPS was associated with top-down modulated directionality-specific reorienting of motor attention during incongruent motor responses. Based on these results, we propose that stimulus-driven activation of contralateral IPS and PMC represent key neuronal substrates for the behavioral advantage observed when reacting toward a congruently lateralized stimulus. Additional activation in bilateral insula and right DLPFC and TPJ during incongruent responses should reflect top-down control mechanisms mediating contextual (i.e., task) demands. Furthermore, this study provides evidence for both overlapping and disparate substrates of bottom-up and top-down modulated attentional processes in the IPS.

Effects of Severity of Traumatic Brain Injury and Brain Reserve on Cognitive-Control Related Brain Activation

Functional magnetic resonance imaging (fMRI) has revealed more extensive cognitive-control related brain activation following traumatic brain injury (TBI), but little is known about how activation varies with TBI severity. Thirty patients with moderate to severe TBI and 10 with orthopedic injury (OI) underwent fMRI at 3 months post-injury using a stimulus response compatibility task. Regression analyses indicated that lower total Glasgow Coma Scale (GCS) and GCS verbal component scores were associated with higher levels of brain activation. Brain-injured patients were also divided into three groups based upon their total GCS score (3-4, 5-8, or 9-15), and patients with a total GCS score of 8 or less produced increased, diffuse activation that included structures thought to mediate visual attention and cognitive control. The cingulate gyrus and thalamus were among the areas showing greatest increases, and this is consistent with vulnerability of these midline structures in severe, diffuse TBI. Better task performance was associated with higher activation, and there were differences in the over-activation pattern that varied with TBI severity, including greater reliance upon left-lateralized brain structures in patients with the most severe injuries. These findings suggest that over-activation is at least partially effective for improving performance and may be compensatory.

Dissociable bottom-up and top-down processes in the intraparietal sulcus revealed by a stimulus-response compatibility task

Dissociable bottom-up and top-down processes in the intraparietal sulcus revealed by a stimulus-response compatibility task

Transfer of orthogonal stimulus–response mappings to an orthogonal Simon task

When up-down stimulus locations are mapped to left-right keypresses, an overall advantage for the up-right/down-left mapping is often obtained that varies as a function of response eccentricity. This orthogonal stimulus-response compatibility (SRC) effect also occurs when stimulus location is irrelevant, a phenomenon called the orthogonal Simon effect, and has been attributed to correspondence of stimulus and response code polarities. The Simon effect for horizontal stimulus-response (S-R) arrangements has been shown to be affected by short-term S-R associations established through the mapping used for a prior SRC task in which stimulus location was relevant. We examined whether such associations also transfer between orthogonal SRC and Simon tasks and whether correspondence of code polarities continues to contribute to performance in the Simon task. In Experiment 1, the orthogonal Simon effect was larger after practising with an up-right/down-left mapping of visual stimuli to responses than with the alternative mapping, for which the orthogonal Simon effect tended to reverse. Experiment 2 showed similar results when practice was with high (up) and low (down) pitch tones, though the influence of practice mapping was not as large as that in Experiment 1, implying that the short-term S-R associations acquired in practice are at least in part not modality specific. In Experiment 3, response eccentricity and practice mapping were shown to have separate influences on the orthogonal Simon effect, as expected if both code polarity and acquired S-R associations contribute to performance.