Search

When participants respond to a task-relevant stimulus attribute by pressing a left or right key with the respective index finger, reaction time is shorter if task-irrelevant left-right stimulus location corresponds to that of the response key than if it does not. For right-handers, this Simon effect is larger for right-located than left-located stimuli; for left-handers this Simon-effect asymmetry is reversed. A similar asymmetry has been found for right-footers pressing pedals with their feet. For analyses that separate stimulus- and response-location factors, these asymmetries appear as a main effect of response location, with responses being faster with the dominant effector. If the Simon-effect asymmetry is strictly a function of effector dominance, it should reverse for left-footers responding with their feet. In Experiment 1, left-dominant persons showed faster responses with the left than right hand but with the right than left foot, a finding consistent with prior research on tapping actions. Right-dominant persons also showed the right-foot asymmetry but, unexpectedly, not the typical asymmetry with hand responses. To evaluate whether hand-presses yield results distinct from finger-presses, in Experiment 2 participants performed the Simon task with finger-presses and hand-presses. The opposing asymmetries for right- and left-dominant persons were evident for both response modes. Our results are consistent with the view that the Simon effect asymmetry is primarily due to differences in effector efficiency, usually but not always favoring the dominant effector.

We describe a mathematically simple yet precise model of activation suppression that can explain the negative-going delta plots often observed in standard Simon tasks. The model postulates a race between the identification of the relevant stimulus attribute and the suppression of irrelevant location-based activation, with the irrelevant activation only having an effect if the irrelevant activation is still present at the moment when central processing of the relevant attribute starts. The model can be fitted by maximum likelihood to observed distributions of RTs in congruent and incongruent trials, and it provides good fits to two previously-reported data sets with plausible parameter values. R and MATLAB software for use with the model is provided.

When two participants perform a go/no go task, sharing the same display but responding to different targets, their responses show a spatial compatibility effect. A shape on the side of a participan...

The spatial-numerical association of response codes (SNARC) effect showed that small/large numbers represented in the left/right space facilitated left/right responses, respectively. However, the processing stage (semantic representation or response selection) of the SNARC effect is still controversial. To investigate this issue, we adopted a modified magnitude comparison task in which the effects of SNARC, Stroop (semantic-representation stage), and Simon (response-selection stage) could be simultaneously induced. The processing stages of the SNARC effect were investigated by examining the interactions among these effects. According to the additive factor logic, if two effects are interactive, then they occur in the same stage; if two effects are additive, then they occur in different stages. Across two experiments, the SNARC effect interacted with the Stroop effect and with the Simon effect. These results suggested that the SNARC effect occurred in both the semantic-representation and response-selection stages and provided insight into that the SNARC effect might have two originating sources.

In recent years, some studies have started to explore the impact of individual general executive functions (EFs) on bilingual language control. To our knowledge, few studies have systematically examined various components of EFs on different levels of language control in bilinguals. In two experiments, we investigated the effects of two components of IC on different levels of bilingual language control. The language-switching task was used to tap into language control at different levels. The Simon task was used to measure interference suppression in Experiment 1, and a go/no-go task was used to measure response inhibition in Experiment 2. Experiment 1 found that the smaller the Simon effect was, the larger the asymmetry of switch costs was. Experiment 2 found that the shorter the go response time was, the larger the global slowing effect was. Taken together, these findings suggest that the interference suppression component of domain-general IC facilitates local level language control, while response inhibition impacts global level language control in bilinguals.

The Simon effect is a stimulus-response compatibility effect in which the spatial dimension of the stimulus is task-irrelevant. This effect is often larger in reaction time (RT) for the stimulus located on the dominant-hand side of participants, for most of which it is the right hand, due to dominant-hand keypress responses being faster than non-dominant-hand responses. Experiment 1 demonstrated that pedal-press responses with the left and right feet show a similar asymmetry, favoring the right response for right-footed persons. The asymmetric pattern for keypress responses was absent in results of Wallace (Journal of Experimental Psychology, 93, 163-168, 1972) when participants were not permitted to see the response keys or their hands placed on the keys at any time during the experiment, whereas we found the asymmetric pattern in a recent study when participants placed their hands on the keys prior to their being covered up. Experiments 2 and 3 showed that the Simon effect asymmetry for RT was evident even when participants were prevented from seeing the response device and their responding hands or feet. Although both hands and feet showed a Simon effect asymmetry in RT, consideration of incorrect responses suggested that whereas the asymmetry for hands is not due to a response bias, that for the feet may be due at least in part to such bias. Regardless, our results suggest that the Simon effect asymmetry is mainly an artifact of comparing conditions for which one response is made by the faster dominant right effector and the other with the slower non-dominant left effector.

In most of our daily activities and in team sports, we interact with other individuals and do not act in isolation. Using a social variant of the standard two-choice Simon task, this study aims to test if competitive/cooperative processing modes (i.e., metacontrol states) change the degree of bodily self-other integration between two persons in joint action. In addition, and more exploratory the study tested if this effect depends on a shared group experience with the partner. Two participants shared a visual Simon task, so that each person basically performed complementary parts of the task, which transfers the paradigm into a go/no-go Simon task for each person. Before running this joint Simon task, we set both participants either in a competitive or a cooperative control state by means of a dyadic game, a manipulation aimed at testing possible goal transfer across tasks. We found significant joint Simon effects for participants who were in a competitive state and for participants who were in a cooperative state. The joint Simon effect for participants being in a competitive state was significantly smaller than for participants being in a cooperative state. When experiencing the goal induction together with the partner, the joint Simon effect was significantly decreased as when the induction was performed alone. Both effects (metacontrol state induction and shared experience) seem to be statistically independent of each other. In line with predictions of metacontrol state theory, our study indicated that abstract cognitive goal states can be transferred from one task to another task, able to affect the degree of bodily self-other integration across different task situations.

Many theories of numerical cognition assume that numbers and space share a common representation at the response level. For example, observers are faster to respond to small numbers with their left hand and large numbers with their right hand (the SNARC effect). There is also evidence that viewing numbers can produce spatial shifts of attention, suggesting that attention may play a role in the spatial representation of numbers. In the present study, we assessed whether shifts of attention can influence numerical processing. Participants viewed a leftward or rightward peripheral cue followed by a centrally presented number, then judged whether the number was odd or even. Participants responded faster and made fewer errors when the number magnitude and response side were compatible, revealing a response-based SNARC effect. Participants also responded faster when the cue direction and response side were compatible, revealing a Simon effect. However, participants did not respond faster when the cue direction and number magnitude were compatible. Similar findings were observed when the association between numbers and space was relatively explicit. Moreover, although we failed to observe a response-based SNARC effect when number magnitude was directly relevant to observers' task, we observed a large Simon effect. Together, these findings suggest that although numbers and space share a common representation at the response level, attention does not play a substantial role in the spatial representation of numbers.

For the vertical Simon task, in which stimuli and responses are arrayed along the vertical dimension and stimulus location is irrelevant, a Simon effect (benefit for stimulus-response correspondence) is typically obtained. Results have been mixed about whether performing fewer than 100 trials of a spatially incompatible mapping prior to a Simon task reduces or eliminates this vertical Simon effect in a transfer session. Several reasons have been suggested to explain why previous studies show disparate results. Previously, we ruled out orientation of the response panel in the transverse or horizontal plane as a critical factor. The present experiments evaluated two other possible factors: finger/hand placement and relevant stimulus dimension. In Experiment 1, we found reduction of the vertical Simon effect for a circle-square discrimination after incompatible practice using a separate numeric keypad as the response device, regardless of whether the keypad was placed on a table and operated by index fingers or held in the hands and operated by thumbs. In Experiment 2, we replicated the reduction for the circle-square discrimination but found no evidence of reduction for a red-green color discrimination. Overall, our results suggest that the relevant discrimination of red-green color versus circle-square shape is responsible for the discrepancy in results across prior studies.

Two experiments examined whether the location-based Simon effect and word- or arrow-based Simon effects, and their interaction, emerge in the same task situations by presenting location words 左 and 右 (left and right, Experiment 1) or single-headed arrows (left and right pointing, Experiment 2) in the left–right visual field. These tasks include two attributes of task-irrelevant location information, physical location and either location word (Experiment 1) or arrow direction (Experiment 2), when they vary jointly for a single stimulus. Moreover, the location-based Simon effect in these tasks was compared to that obtained in a pure location-based Simon task. Results showed that (1) the location-, word- and arrow-based Simon effects occurred on both mean RT and delta plots; (2) the word- and arrow-based Simon effects interacted with the location-based Simon effect on mean RT; (3) the Simon effect in the pure location-based Simon task differed little from the location-based Simon effect in the two joint Simon tasks. These results indicate that different task-irrelevant spatial attributes can influence responses in the same task, and that one of them can influence the effect of the other on responses. This latter result offers evidence that the different attributes do not provide separate sources of activation.

Evidence is currently mixed regarding the way in which cognitive conflict modulates the effect of emotion on task performance. The present study aimed to address methodological differences across previous studies and investigate the conditions under which interference from emotional stimuli can either be elicited or eliminated under high cognitive conflict. Four behavioural experiments were conducted with a university sample using a gender-discrimination stimulus-response compatibility task. In line with our previous findings, Experiment 1 found that when emotion and cognitive conflict conditions were blocked, emotional faces increased reaction time interference during response compatible trials (low conflict) but not response incompatible trials (high conflict). However, when conflict and emotion conditions were randomised in different configurations across Experiments 2 (all trials randomised), 3 (emotion blocked, compatibility randomised) and 4 (compatibility blocked, emotion randomised), emotion interfered with task performance across both high and low conflict trials. These results suggest that predictability of both compatibility and emotion is required in order to obtain reduced emotional interference under high cognitive conflict. Consistent with prior reports, a top-down anticipatory control mechanism seems to be engaged in the presence of negative emotion when there are incompatible stimulus-response mappings.

Earlier findings suggest that positions of power decrease self-other integration and increase psychological distance to others. Until now, however, evidence for this relation rests exclusively on subjective measures. The current research instead employed a vertical joint Simon task to measure self-other integration. This task assesses the extent to which people represent their own actions in reference to their co-actor's, also referred to as the joint Simon effect. Building on cultural associations between power and vertical elevation, we manipulated whether participants were in an elevated (high-power) or lower (low-power) seating position. Experiments 1a and 1b reanalyzed existing datasets and found that elevated (vs. lower) seating position decreased the joint Simon effect, consistent with predictions. Experiment 2 provides a high-powered replication of this finding. Yet, further analyses revealed that feelings of power – measured as a manipulation check and indeed demonstrating that the manipulation was successful – did not mediate or moderate the effect of seating position on the joint Simon effect. Therefore, it is possible that the effect of seating elevation was driven through other aspects of that manipulation than feelings of power. We discuss these and suggest ways to test these alternative explanations.

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.

Research suggests that – particularly – the execution of precision-demanding far-aiming tasks necessitates an optimal coupling between perception and action. In this regard, the duration of the last fixation before initiating movement – i.e., the Quiet Eye (QE) – has been functionally related to subsequent motor performance. In the current study, we investigated potential mechanisms of QE by applying the Simon paradigm – i.e., cognitive interferences evoked by stimulus-effect incompatibilities over response selection. To this end, we had participants throw balls as precisely as possible, either with their left or right hand (hands condition, HC) or at left or right targets (targets condition, TC), respectively. Via monaural auditory stimuli, participants received information about the hand side and the target side, respectively, either with compatible (i.e., congruent stimulus-effect side) or incompatible (i.e., incongruent stimulus-effect side) stimulus-effect mappings. Results showed that participants reacted slower and showed later first fixation onsets at the target in incompatible vs. compatible trials, thus, replicating and extending the classical Simon effect. Crucially, in the HC, there were earlier QE onsets and longer QE durations in incompatible (vs. compatible) trials, suggesting an inhibition of cognitive interferences over response selection to preserve motor performance. These findings are in line with attentional explanations of QE, suggesting optimized attentional control with efficient management of limited cognitive resources (optimal-attentional-control explanation) or with the inhibition of alternative response parametrization (inhibition explanation).

A previous study used days as a sequence symbol to investigate the interaction mechanism between location and sequence in sequence symbol cognition; the study findings suggested that the spatial stimulus-response compatibility effect and the Simon effect could not co-exist with the SNARC-like effect when processing sequence symbols. The previous study did not include the influence of the difficulty of identifying sequence symbols on the Simon effect in the investigation, so it is unclear whether the conclusion about processing sequence symbols with considerable identification difficulty can be extended to the processing of sequence symbols with less identification difficulty. Therefore, the present study explored letters that have a low level of identification difficulty to investigate the interaction mechanism between location and sequence in sequence symbol cognition. Participants were asked to classify a probe letter, which was randomly displayed on the left or right side of the screen, according to its location (Experiment 1), its sequence (Experiment 2) or its colour (Experiment 3). The results indicated that (1) only the spatial stimulus-response compatibility effect and Simon effect were present in the letter location classification task and letter colour classification task, respectively. (2) The Simon effect co-existed with the SNARC-like effect, and these two effects interacted with each other in the letter sequence classification task. From these results, it can be concluded that the task determines whether the Simon effect and the SNARC-like effect can co-exist, with differences presented across sequence symbols.

The Simon effect, that is the advantage of the spatial correspondence between stimulus and response locations when stimulus location is task irrelevant, occurs even when the task is performed by two participants, each performing a go/no-go task. This effect, known as the joint Simon effect, does not emerge when participants sit outside each other's peripersonal space, thus suggesting that the presence of an active confederate in peripersonal space might provide a reference for response coding. The present study investigated whether this finding is due to the distance separating the participants and/or to the distance separating each participant and the other agent's response. In two experiments, pairs of participants performed a social detection task sitting outside each other's arm reach, with response keys located close to the participants or outside arm reach. When the response key was located outside the participant's arm reach, he/she could reach it by means of a tool. In Experiment 1, by means of a tool, participants could reach their response key only, while in Experiment 2, they could reach also their co-agent's response key. The joint Simon effect did not emerge when participants could not reach the co-actor's response, while it emerged when they could potentially reach the other participant's response using the tool, but only when turn taking was required. These results may be taken as evidence that the possibility to reach and act upon the co-actor's response key may be at the bases of compatibility effects observed in joint action contexts requiring complementary responses.

Although the joint Simon task (JST) has been investigated for more than a decade, its cause is still unclear. According to ideomotor views of action control, action effects are a commonly cited explanation. However, action effects are usually confounded with the actions producing such effects. We combined a JST with eye tracking and asked participants to respond by performing specific saccades. Saccades were followed by visual feedback (central vs. lateral feedback), serving as the action effect. This arrangement allowed us to isolate actions from action effects and, also to prevent each actor from seeing the reciprocal actions of the other actor. In this saccadic JST, we found a significant compatibility effect in the individual setting. The typical enhanced compatibility effect in the joint setting of the JST was absent with central action feedback and even when lateralized visual action feedback was provided. Our findings suggest that the perception of action effects alone might not be sufficient to modulate compatibility effects for eye movements. The presence of a compatibility effect in the individual setting shows the specific requirements of a saccadic compatibility task - the requirement to perform prosaccades to compatible and antisaccades to incompatible target locations. The lack of a difference between compatibility effects in joint and individual settings and the lack of a modulation of the compatibility effect through lateralized visual action feedback shows that the finding of a joint Simon effect that has frequently been reported for manual responses is absent for saccadic responses.

Task-irrelevant stimulus location can influence the response performance to task-relevant attributes, generating the location-based Simon effect. Using a Monte Carlo study and other methods, we examined whether the ex-Gaussian distribution provides a good fit to empirical reaction time (RT) distributions in the Simon task and whether reliable Simon effects occur on the ex-Gaussian parameters: (a) the mean (μ), (b) the standard deviation (σ) of the normal distribution, and (c) the tail (τ). Results showed that the ex-Gaussian function fits well to empirical RT distributions, and that these ex-Gaussian parameters are reliable between two trial blocks at the group level. At the individual level, correlation analysis showed that the Simon effect was reliable on the μ parameter but not on σ and τ. Moreover, a partial correlation analysis, with μs of the two blocks as controlling variables, showed that the Simon effect on τ was reliable. These results provide evidence that the ex-Gaussian function is a valuable tool for analyzing the Simon effect and can be considered as an alternative for analyzing RT distributions in Simon-type tasks.

According to the conflict monitoring theory (CMT), one of the most prominent theories of cognitive control, the exertion of cognitive control is triggered by the detection of conflicting response tendencies in the anterior cingulate cortex (ACC). Recent research has challenged this emphasis of response conflicts and has debated whether in addition to shielding after incongruent trials the relaxation after congruent trials also contributes to the sequential adaptation of control. To investigate the functionality of facilitative congruent trials in sequential adaptation of control, we conducted two experiments using a visual (Experiment 1) and an auditory (Experiment 2, preregistered) Simon task with stimuli presented laterally to the left or right (creating response congruent and incongruent trials) or without any particular spatial information (creating neutral trials). Both experiments showed converging results: in the error and reaction time data, the Simon effect was smaller following incongruent trials, larger following congruent trials, and the Simon effect following neutral trials was in-between. Results thus suggest that sequential control adaptations can originate from two processes: Increased shielding in response to incongruent trials and relaxation in response to congruent trials. Argumentations for a functional role of congruent and incongruent trials in the sequential adaptation of control suggest a more general theory of fluency monitoring instead of mere conflict monitoring. In addition, such extensions of the CMT provide theoretical explanations of how control is ever relaxed in response conflict tasks after being enhanced by conflict in the first place. Last but not least, the results may also be taken as a further hint that congruent stimuli may provide a positive affective signal for control relaxation just it has already been shown for incongruent stimuli as aversive signals for the up-regulation of control (shielding).

Many models of the Simon effect assume that categorical spatial representations underlie the phenomenon. The present study tested this assumption explicitly in two experiments, both of which involv...

Lateralized responses to central targets are facilitated when distractors are presented ipsilaterally (congruent trials) compared with contralaterally (incongruent trials) to the response. This accessory Simon effect is explained by assuming that distractors generate a spatial code that conforms to, or conflicts with, the response. The effect typically diminishes as the distractor-target interval increases. However, it is unclear whether irrelevant spatial codes passively decay or are actively inhibited. Given that inhibition takes time to develop, its operation may reverse the Simon effect-indicated by impaired performance in congruent compared with incongruent trials-when the distractor is presented prior to the target. In the present study, the temporal separation between distractor and target was systematically manipulated. Participants responded to a centrally presented visual (Experiments 1 and 2) or auditory (Experiments 3 and 4) target. A lateralized auditory distractor either occurred prior to, or simultaneously with, the target. A Simon effect occurred when distractor and target were presented simultaneously or in close temporal proximity. The effect was reversed with longer distractor-target intervals, but only when targets and distractors were presented in the same modality (Experiments 3 and 4), suggesting that an inhibition process operates on distractor events, which is stronger in the case of matching target and distractor modalities. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

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.

We investigated how operationalizing bilingualism affects the results on a Simon task in a population of monolingual and bilingual native English speakers (N = 166). Bilingualism was measured in different ways within participants, and the measurements were used both as dichotomous and continuous variables. Our results show that the statistical significance and effect size varied across operationalizations. Specifically, the Composite Factor Score (the Language and Social Background Questionnaire’s general score), showed a bilingual disadvantage on reaction times regardless of how it was used (dichotomously or continuously). When dividing participants into monolinguals and bilinguals based on the Nonnative Language Social Use score (a Language and Social Background Questionnaire subscore), differences in accuracy and reaction times were found between the groups, but the Nonnative Language Social Use score did not predict accuracy when used as a continuous variable (only reaction times). Finally, earlier age of acquisition predicted faster reaction times, but only when used on a continuum. Effect sizes were between the small and medium range. No differences on the Simon effect were found. Our results call for cautiousness when comparing studies using different types of measurements, highlight the need for clarity and transparency when describing samples, and stresses the need for more research on the operationalization of bilingualism.

The Simon effect refers to the fact that, even though stimulus position is task-irrelevant, responses to a task-relevant stimulus dimension are faster and more accurate when the stimulus and response spatially correspond than when they do not. Although the Simon effect is a very robust phenomenon, it is modulated by practice or transfer from previous tasks. Practice refers to the modulation of the Simon effect as a function of number of trials. Transfer refers to the modulation of the Simon effect as a function of preceding tasks. The aim of the present study is to disentangle the role of practice and transfer in modulating the Simon effect and to investigate whether such modulation can be extended to a different response modality. Three experiments were conducted, which included three sessions: the Baseline session, the Inducer session and the Diagnostic session. The task performed in the Baseline and the Diagnostic sessions were comprised of location-irrelevant trials (i.e., they were Simon tasks). The task performed in the Inducer session required performing location-relevant trials (i.e., it was a spatial compatibility task with a compatible or an incompatible stimulus–response mapping). In the first and third experiments, participants were required to respond manually in all sessions. In the second experiment, the task performed in the Inducer session required manual response, while in the Baseline and Diagnostic sessions the tasks required ocular response. Results showed a reduced-Diagnostic Simon effect after both compatible and incompatible mapping in the Inducer session, regardless of whether response modality was the same or different. These results support the notion that the practice effect prevails over the transfer effect.

Visual processing near the hands is altered compared with stimuli far from the hands. Here, we aimed to test whether this alteration can be found in auditory processing. Participants were required to perform an auditory Simon task either with their hands close to the loudspeakers or far from the loudspeakers. Two experiments consistently showed that the auditory Simon effect was enhanced when the hands were close to the speakers compared with far from the speakers. This is consistent with previous findings of an enhanced visual Simon effect near the hands. Furthermore, the hand-proximity effects in auditory and visual Simon tasks (an enhanced Simon effect near hands compared with far from hands) were comparable, indicating hand-proximity effect is reliable across visual and auditory modalities. Thus, the present study extended the hand-proximity effect from vision to audition by showing that the auditory Simon effect was enhanced near the hands compared with far from the hands.

Consciousness and cognition 92, 103133 (2021). doi:10.1016/j.concog.2021.103133, Published by Academic Press, Orlando, Fla.

Schlaghecken, F., Blagrove, E., Mantantzis, K., Maylor, E. A., & Watson, D. G. [(2017). Look on the bright side: Positivity bias modulates interference effects in the Simon task. Journal of Experim...

Two experiments examined whether practicing discrete key pressing sequences eventually leads to a disregard of the key-specific stimuli, as suggested by sequence learning models, or whether these stimuli continue to be relied upon because the associated luminance increase attracts visuospatial attention. Participants practiced two sequences by reacting to two fixed series of seven letter stimuli, each displayed at a location that did or did not correspond with the required response location. Stimulus use was indicated by a Simon effect in that key presses were slowed when stimulus and key locations did not correspond. Experiment 1 demonstrated that letter stimuli continued to be used as the Simon effect occurred with each sequence element, and this remained quite stable across practice and did not differ for familiar and unfamiliar sequences. Experiment 2 showed that the Simon effect remained present even with meaningless stimuli that were often even harmful. These findings suggest that even in motor sequences that can be executed without element-specific stimuli attention attraction enforces stimulus use. The data further supported the assumptions that S-R translation and sequencing systems are racing to trigger individual responses, and that explicit sequence representations include spatial and verbal knowledge.

The dimensional overlap (DO) theory categorizes various stimulus-response compatible effects (e.g., the manual Stroop, Simon, and SNARC effects) into two main types: stimulus-stimulus (S-S) and stimulus-response (S-R) dimensional overlap effects. The S-S type effect (e.g., the manual Stroop) occurs in the semantic-representation stage, while the S-R type effect (e.g., Simon) occurs in the response-selection stage. However, the processing stage of the SNARC effect, which is also categorized as an S-R type, remains controversial. To investigate this issue, we adopted a modified numeral parity judgment task that could simultaneously induce manual Stroop, Simon, and SNARC effects. According to the additive-factor logic, two effects occur in the same processing stage if they are interactive. In our task, we checked the interaction among the three effects to identify the locus of the SNARC effect. In two experiments with different target numbers (exp1: 1, 2, 7, 8; exp2: 0, 1, 2, 3, 6, 7, 8, 9), the manual Stroop, Simon, and SNARC effects were all observed, showing longer response times and higher error rates in the incongruent conditions than in the congruent conditions. Most importantly, only the interaction between SNARC and Simon effects was observed in the two experiments. This result suggests that the SNARC effect, as an S-R type effect like the Simon effect, occurs in the response-selection stage. In addition, the noninteraction of the manual Stroop and Simon effects and the manual Stroop and SNARC effects in our study repeatedly verifies the independence of the S-S and S-R effects. Our results further support the classification of the DO theory.

Studies have widely captured the spatial-numerical association of response codes (SNARC) effect in the processing of various types of numbers in which small numbers are responded to faster with the left hand than with the right hand and larger numbers are responded to faster with the right hand than with the left hand. Although a few studies have explored Arabic numbers to further investigate the influence of number location on the SNARC effect, it remains unclear whether the influence of number location on the SNARC effect is moderated by numerical semantic processing difficulty and the task performed. This study explored traditional Chinese numerical words and rotated them to certain angles, which can increase numerical semantic processing difficulty, to further investigate the influence of the stimulus–response compatibility effect and Simon effect on the SNARC effect in a space classification task (Experiment 1), numerical magnitude classification task (Experiment 2), numerical parity classification task (Experiment 3), and color classification task (Experiment 4). The results indicated that (a) the stimulus–response compatibility effect, not the SNARC effect, prevailed in the numerical space classification task; (b) the SNARC effect, not the Simon effect, prevailed in the numerical magnitude and parity classification task; and (c) the Simon effect and the SNARC effect coexisted in the color classification task. These results suggested that the influence of number location on the SNARC effect was moderated by the task performed. Implications for the theory of the SNARC effect and Simon effect are discussed.

Attention control is a core element of cognitive aging, but the specific mechanisms that differ with age are unclear. Here we used a novel auditory spatial attention task to evaluate stimulus processing at the level of early attention capture, later response selection, and the lingering effects of attention capture across trials in young and older adults. We found that the shapes of spatial attention capture gradients were remarkably similar in young and older adults, but only the older group had lingering effects of attention capture on the next trial. Response selection for stimulus-response incompatibilities took longer in older subjects, but primarily when attending to the midline location. The results suggest that the likelihood and spatial tuning of attention capture is comparable among groups, but once attention is captured, older subjects take longer to disengage. Age differences in response selection were supported, but may not be a general feature of cognitive aging.

In modern digital applications, users often interact with virtual representations of themselves or others, called avatars. We examined how these avatars and their perspectives influence stimulus-response compatibility in a Simon task. Participants responded to light/dark blue stimuli with left/right key presses in the presence of a task-irrelevant avatar. Changes in stimulus-response compatibility were used to quantify changes in the mental representation of the task and perspective taking toward this avatar. Experiments 1 and 2 showed that perspective taking for an avatar occurred in orthogonal stimulus-response mappings, causing a compatibility effect from the avatar's point of view. In the following two experiments we introduced a larger variety of angular disparities between the participant and avatar. In Experiment 3, the Simon effect with lateralized stimulus positions remained largely unaffected by the avatar, pointing toward an absence of perspective taking. In Experiment 4, after avatar hand movements were added in order to strengthen the participants' sense of agency over the avatar, a spatial compatibility effect from the avatar's perspective was observed again, and hints of the selective use of perspective taking on a trial-by-trial basis were found. Overall, the results indicate that users can incorporate the perspective of an avatar into their mental representation of a situation, even when this perspective is unnecessary to complete a task, but that certain contextual requirements have to be met.

Bruce Bridgeman and colleagues reported the first experiments providing evidence of two functionally distinct visual-processing systems. We summarize that work and subsequent research that resulted in modifications of this view. Then, we describe studies of stimulus-response correspondence effects that provide evidence for distinct representations of responses. More recently, Bridgeman and colleagues examined whether "action affects perception", concluding that the phenomena can be more accurately construed as "information affects memory". Although unconvinced about claims of action-affects-perception and embodied cognition, Bridgeman and colleagues concluded that processing of visual information in hand-space is facilitated and cited a phenomenon as supporting evidence. We discuss findings indicating that this phenomenon is due to general spatial coding principles. We think that all researchers should proceed in the manner of Bridgeman of developing novel explanations, devising critical tests between them and alternative possible explanations, and accepting the explanation that best conforms to the results, even if that explanation is a "less dramatic" option.

A number of studies have shown that the motor actions of one individual can affect the attention of an observer. In one notable example, "social inhibition of return," observers are relatively slow to initiate a response to a location where another individual has just responded. In the present article we examine the degree to which this phenomenon can be considered a social effect. We find that unlike the related social, or "joint," Simon effect, social inhibition of return is not influenced by competitive versus cooperative interaction, nor by live versus recorded interaction. We do find however that co-actors need to turn-take in order for the effect to occur. Thus, so-called "social" inhibition of return only reaches a minimal threshold to be considered a social phenomenon.

The Dimension-Action model maintains that response selection in the visual system is modular, such that response selection based on a target’s feature occurs within modules. This study suggests that response selection processes based on a target’s spatial location occur within modules as well, where spatial locations are coded along with the feature information. From this perspective, the typical Simon effect, in which interference occurs between a target’s feature and its spatial location, occurs within modules. This study explored whether the unique characteristic of the spatial Simon, namely, its reduction with increased reaction time is typical of spatial intra-dimension but not of spatial cross-dimension Simon effects, using the accessory Simon task. Experiment 1 demonstrated that intra-dimension Simon effects were reduced with increased reaction time, a reduction that was modulated by the task relevance of the distractor. In contrast, cross-dimension accessory Simon effects were positive and increased with reaction time. Experiment 2 demonstrated that intra-dimension Simon effects were not reduced when space was conveyed symbolically by arrows. Overall, the study suggests that interference in the accessory Simon task is influenced not only by the nature of the irrelevant spatial information but also by the modular locus of the targets and distractors.

Different features of objects can be associated with different responses, so that their concurrent presence results in conflict. The Simon effect is a prominent example of this type of response conflict. In two experiments, we ask whether it is modulated by the anatomical or spatial relation between responses. Predictions were derived from an extended variant of the leaky, competing accumulator (LCA) model proposed by Usher and McClelland (Psychological Review, 108, 550-592, 2001). The relation between responses was represented by the lateral-inhibition parameter of the model. For the anatomical distance between responses the expectations were largely confirmed, but not for spatial distance. First, the Simon effect was stronger when responses were performed with two fingers of the same hand than with different hands. Second, the Simon effect was larger only for responses with different hands at short reaction times and disappeared at long ones, whereas for responses with fingers of the same hand, the Simon effect was essentially the same for shorter and longer reaction times. This difference resulted in smaller variability of reaction times in noncorresponding than in corresponding conditions. The dependence of decision processes, as modelled by the LCA model, on the anatomical relation between responses supports the broad hypothesis that the accumulation of evidence on the state of the world is intricately linked with the activation of response codes, that is, the selection of the appropriate actions.

The location-, word-, and arrow-based Simon effects are usually attributed to the result of a direct route (the spatially corresponding stimulus-response association, activated automatically) that interferes with an indirect route (the association of task-relevant information and response, activated in accordance with the instructed stimulus-response mapping). We examined whether and how distinct direct routes (stimulus-location-response position and location word-response position or arrow direction-response position associations) affect responding on the basis of the same indirect route (a stimulus color-response association) in a Simon-like task. For this task, left-right keypresses were made to indicate the ink colors of location words or left- or right-pointing arrows, presented eccentrically in left or right locations. The location-based Simon effect occurred at the levels of mean reaction time (RT) and RT distribution in the word Simon-like task, whereas the word-based Simon effect only occurred at the level of RT distribution. In the arrow Simon-like task, the location-based Simon effect did not occur at the level of mean RT, but did at the level of RT distribution, whereas the opposite pattern occurred for the arrow-based Simon effect. These results could imply that one direct route influences the effects of the other direct route on the responses, depending on the task context.

Meals, especially when taken in company, may affect the diner’s mood. In line with findings that mood may alter cognitive control, a previous study by the authors found that after solitary meals, the Simon effect was diminished as compared to a premeal condition, whereas a social meal did not reduce the Simon effect. Here, we investigated whether this finding generalizes across different demands in cognitive control and, therefore, applied a flanker task. Obtained questionnaire data indicated differential effects in mood and relaxation of a social as compared to a solitary meal. Replicating our previous findings, the flanker compatibility effect decreased after a solitary meal but increased after a social meal. The present results support our previous findings with new evidence that a meal taken in a social context attenuates subsequent cognitive control processes compared with a solitary meal.

The Joint Simon Effect (JSE) is known to reflect the natural and spontaneous tendency to integrate actions from another individual into our own action system during joint action. This tendency to co-represent others' actions positively correlates with the dispositional tendency to take others' perspective. However, a quick episode of social exclusion has been shown to erase the tendency to co-represent others' actions. From a theoretical viewpoint, excluded individuals should still show signs of co-representation as ostracism tends to increase attention paid to others and Perspective Taking. In this context, this study challenges the idea that social exclusion eliminates all forms of co-representation (or JSE) by using an in-person version of the Task. We also intend to replicate findings on a positive link between Perspective Taking and the size of the JSE. To this end, participants played either an inclusive or exclusive version of the Cyberball game, then performed a joint go-nogo Simon Task. Perspective Taking was measured by using the Interpersonal Reactivity Index. By contrast to previous results, our results revealed that excluded individuals co-represented others' actions as much as included ones. However, a positive correlation between Perspective Taking and the JSE was limited to included participants. We discuss these findings in terms of methodological differences and in the light of the social exclusion literature.

Task-irrelevant spatial information, conveyed by stimulus location, location word, or arrow direction, can influence the response to task-relevant attributes, generating the location-, word-, and arrow-based Simon effects. We examined whether different mechanisms are involved in the generation of these Simon effects by fitting a mathematical ex-Gaussian function to empirical response time (RT) distributions. Specifically, we tested whether which ex-Gaussian parameters (μ, σ, and τ) show Simon effects and whether the location-, word, and arrow-based effects are on different parameters. Results show that the location-based Simon effect occurred on mean RT and μ but not on τ, and a reverse Simon effect occurred on σ. In contrast, a positive word-based Simon effect was obtained on all these measures (including σ), and a positive arrow-based Simon effect was evident on mean RT, σ, and τ but not μ. The arrow-based Simon effect was not different from the word-based Simon effect on τ or σ but was on μ and mean RT. These distinct results on mean RT and ex-Gaussian parameters provide evidence that spatial information conveyed by the various location modes are different in the time-course of activation.

Abstract. In the social Simon task, two participants perform a spatial compatibility task together, each of them responding to only one stimulus (e.g., one participant reacts to red, the other to green stimuli). Participants show joint spatial compatibility effects (SCEs), that is, they respond faster when their go-stimulus appears on their half of the screen. Effects are absent when the same go/no-go task is performed without a coactor. Joint SCEs were originally explained in terms of shared task representations, but recent research suggests that effects result from spatial response coding: in joint go/no-go tasks, participants perceive themselves as the right/left participant operating a right/left response key. While previous research showed that the spatial alignment of keys and seats influences the effect, the present research demonstrates that merely instructing participants to be the right/left participant operating a right/left response key instead of labeling participants and keys with arbitrary numbers substantially increases joint SCEs.

Inhibition of irrelevant and conflicting information and responses is crucial for goal-directed behaviour and adaptive functioning. In the Simon task, for example, responses are slowed if their mappings are spatially incongruent with stimuli that must be discriminated on a nonspatial dimension. Previous work has shown that practice with incongruent spatial mappings can reduce or even reverse the Simon effect. We asked whether such practice transfers between the manual and oculomotor systems and if so to what extent this occurs across a range of behavioural tasks. In two experiments, one cohort of participants underwent anti-saccade training, during which they repeatedly inhibited the reflexive impulse to look toward a briefly presented target. Additionally, two active-control training groups were included, in which participants either trained on Pro-saccade or Fixation training regimens. In Experiment 1, we probed whether the Simon effect and another inhibitory paradigm, the Stroop task, showed differential effects after training. In Experiment 2, we included a larger battery of inhibitory tasks (Simon, Stroop, flanker and stop-signal) and noninhibitory control measures (multitasking and visual search) to assess the limits of transfer. All three training regimens led to behavioural improvements in the trained-upon task, but only the anti-saccade training group displayed benefits that transferred to the manual response modality. This transfer of training benefit replicated across the two experiments but was restricted to the Simon effect. Evidence for transfer of inhibition training across motor systems offers important insights into the nature of stimulus-response representations and their malleability.

Previous studies observed compatibility effects in different interference paradigms such as the Simon and flanker task even when the task was distributed across two co-actors. In both Simon and flanker tasks, performance is improved in compatible trials relative to incompatible trials if one actor works on the task alone as well as if two co-actors share the task. These findings have been taken to indicate that actors automatically co-represent their co-actor's task. However, recent research on the joint Simon and joint flanker effect suggests alternative non-social interpretations. To which degree both joint effects are driven by the same underlying processes is the question of the present study, and it was scrutinized by manipulating the visibility of the co-actor. While the joint Simon effect was not affected by the visibility of the co-actor, the joint flanker effect was reduced when participants did not see their co-actors but knew where the co-actors were seated. These findings provide further evidence for a spatial interpretation of the joint Simon effect. In contrast to recent claims, however, we propose a new explanation of the joint flanker effect that attributes the effect to an impairment in the focusing of spatial attention contingent on the visibility of the co-actor.

When a two-choice "Simon task" is distributed between two people, performance in the shared go/no-go task resembles performance in the whole task alone. This finding has been described as the joint Simon effect (JSE). Unlike the individual go/no-go task, not only is the typical joint Simon task shared with another person, but also the imperative stimuli dictate whose turn it is to respond. Therefore, in the current study, we asked whether removing the agent discrimination component of the joint Simon task influences co-representation. Participants performed the typical joint Simon task, which was compared to two turn-taking versions of the task. For these turn-taking tasks, pairs predictably alternated turns on consecutive trials, with their respective imperative stimulus presented either on 100% of their turns (fully predictable group) or on 83% of their turns (response-uncertainty group, 17% no-go catch trials). The JSE was absent in the fully predictable, turn-taking task, but emerged similarly under the response-uncertainty condition and the typical joint Simon task condition where there is both turn and response-execution-related uncertainty. These results demonstrate that conflict related to agent discrimination is likely not a critical factor driving the JSE, whereas conflict surrounding the need to execute a response (and hence the degree of preparation) appears fundamental to co-representation.

Sharing tasks with other persons can simplify our work and life, but seeing and hearing other people's actions may also be very distracting. The joint Simon effect (JSE) is a standard measure of referential response coding when two persons share a Simon task. Sequential modulations of the joint Simon effect (smJSE) are interpreted as a measure of event-file processing containing stimulus information, response information and information about the just relevant control-state active in a given social situation. This study tested effects of physical (Experiment 1) and virtual (Experiment 2) separation of shared workspaces on referential coding and event-file processing using a joint Simon task. In Experiment 1, participants performed this task in individual (go-nogo), joint and standard Simon task conditions with and without a transparent curtain (physical separation) placed along the imagined vertical midline of the monitor. In Experiment 2, participants performed the same tasks with and without receiving background music (virtual separation). For response times, physical separation enhanced event-file retrieval indicated by an enlarged smJSE in the joint Simon task with curtain than without curtain (Experiment1), but did not change referential response coding. In line with this, we also found evidence for enhanced event-file processing through physical separation in the joint Simon task for error rates. Virtual separation did neither impact event-file processing, nor referential coding, but generally slowed down response times in the joint Simon task. For errors, virtual separation hampered event-file processing in the joint Simon task. For the cognitively more demanding standard two-choice Simon task, we found music to have a degrading effect on event-file retrieval for response times. Our findings suggest that adding a physical separation optimizes event-file processing in shared workspaces, while music seems to lead to a more relaxed task processing mode under shared task conditions. In addition, music had an interfering impact on joint error processing and more generally when dealing with a more complex task in isolation.

We examined the possible dissociation between two modes of valence: affective valence (valence of e emotional response) and semantic valence (stored knowledge about valence of an object or event). In Experiment 1, 50 participants viewed affective pictures that were repeatedly presented while their facial electromyography (EMG) activation and heart rate response were continuously recorded. Half of the participants provided self-report ratings about the valence of their feelings and half about the valence of the stimulus. Next, all participants performed an affective Simon task. In Experiment 2, 30 new participants performed the affective Simon task with the repeated exposure embedded within the task. The results showed that measures related to affective valence (feelings-focused self-reports, heart rate, and facial EMG activations) attenuated with repeated exposure to pleasant and unpleasant pictures, whereas measures related to semantic valence (knowledge-focused self-reports and congruency effect of affective Simon task) did not. These findings strongly suggest that affective and semantic valence represent two distinct psychological constructs. (PsycINFO Database Record

In Simon-type interference tasks, participants are asked to perform a 2-choice reaction on a stimulus dimension while ignoring the stimulus position. Commonly, robust congruency effects are found; that is, reactions are faster when the relevant stimulus attribute and the assigned response match the location of the stimulus. Simon congruency effects are regularly attributed to a fast, nonverbal processing route. In 3 experiments, we tested the importance of verbal representations in the Simon effect by manipulating the format of representations (verbal vs. nonverbal) with stimulus material (i.e., words vs. gratings) and stimulus arrangement (i.e., horizontally vs. vertically). Results of the first experiment point to a modulation of the Simon effects by both factors when they were manipulated between subjects, up to an inversion of the Simon effect for words presented in vertical arrangement. We replicated the inverse congruency effect for verbal material in vertical arrangement when a within-participant design was used (Experiment 2) and when the impact of reading processes was ruled out (Experiment 3). One cause for this inversion might be the construction of language-based representations that counteract automatic processing given the stimulus arrangement. To investigate this, we assessed individual differences in the use of inner speech for self-instruction. Using hierarchical linear modeling analysis, we found that self-rated evaluative and motivational inner speech processes accounted for a significant portion of the Simon effect. This supports claims that individual differences predict performance even in simple cognitive tasks such as the Simon task and highlights the flexibility of basic cognitive processes. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

We combined analyses of reaction time (RT) distributions with experimental manipulations of different processing stages (perception, decision, motor execution) in a Simon task to investigate which changes in Simon effects could be explained entirely by fading irrelevant response activation. Consistent with fading activation accounts, the Simon effect on mean RT was usually smaller for conditions with slower responses (Expts. 1–3 but not Expt. 4), and delta plot analyses revealed that it was always smaller for the slower responses within each condition. Critically, however, these analyses also revealed that some experimental manipulations produced upward or downward shifts in the RT delta plots, thus altering the Simon effect on mean RT in ways that could not be explained by fading activation. The results demonstrate the power of combining RT distributional analyses with experimental manipulations to reveal mechanisms contributing to the Simon effect that would not be revealed using only mean RT. We consider alternatives to fading activation accounts of decreasing delta plots and discuss the contribution of different cognitive stages in modulating Simon effects.

Although domain-specificity is prevalent in models of human cognition, its presence is not always easy to verify. For example, according to one prominent model, experiencing conflict from an incongruent distractor in a Stroop-like task triggers an upregulation of domain-specific control that facilitates the resolution of the same, but not a different, type of conflict in the next trial. The only evidence for this view, however, comes from tasks wherein confounds can mimic the effects of domain-specific control. In the present study, I report that Stroop-incongruent and Simon-incongruent distractors in a hybrid Stroop-Simon task trigger selective reductions of the Stroop and Simon effects in the next trial (i.e., distractor-specific congruency sequence effects [CSEs]), regardless of whether confounds are absent (Experiment 1) or present (Experiment 2). However, I also report that the Stroop and Simon effects interact when confounds are absent (Experiment 1) and in trials with slow reaction times when confounds are present (Experiment 2). These within-trial interactions suggest that the Stroop and Simon effects index overlapping conflicts, rather than independent conflicts. Thus, they prevent one from drawing any conclusions about whether the distractor-specific CSEs index domain-specific (i.e., conflict-specific) or domain-general (i.e., conflict-general) control. This outcome challenges prior data suggesting domain-specific control in the hybrid Stroop-Simon task. However, it fits with recent findings suggesting independent within- and across-trial conflict control processes. It also fits with an emerging view wherein across-trial conflict control processes engender CSEs by retrieving an episodic memory of previous-trial control settings. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

International audience; This study seeks to investigate whether users activate cognitive representations of their partner’s action when they are involved in tactile collaborative tasks. The social Simon effect is a spatial stimulus–response interference induced by the mere presence of a partner in a go/nogo task. It has been extensively studied in the visual and auditory sensory modalities, but never before in the tactile modality. We compared the performances of 28 participants in three tasks: (1) a standard Simon task where participants responded to two different tactile stimuli applied to their fingertips with either their left or right foot, (2) an individual go/nogo task where participants responded to only one stimulus and (3) a social go/nogo task where they again responded to only one stimulus, but were partnered with another person who responded to the complementary stimulus. The interference effect due to spatial incongruence between the side where participants received the stimulus and the foot used to answer increased significantly in the standard Simon task compared to the social go/nogo task. Such a difference was not observed between the social and individual go/nogo tasks. Performances were nevertheless enhanced in the social go/nogo task, but irrespectively of the stimulus–response congruency. This study is the first to report a negative result for the social Simon effect in the tactile modality. Results suggest that cognitive representation of the co-actor is weaker in this modality.