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Aim: The purpose of this study was to evaluate the effect of different music on visual reaction time. Methodology: Thirty subjects with visual acuity logMAR 0.00 and near vision N6 in both eyes and no binocular vision anomaly or ocular anomaly were included in this research. Subjects with any kind of ocular disease, arthritis, or muscle disorders were excluded. Psychological Experimental Building Language (PEBL) version 2.1 software was used to check the visual reaction time. Subjects listened to four different types of instrumental music (symphony, hard rock, Indian classical, and techno) randomly while performing the PEBL visual reaction time task in a dark room. The volume of the music was maintained at 80 dB, and the brightness of the screen was maintained at 100% throughout the experiment. Readings were taken before listening to music, during listening to music, and after listening to music. Statistical analysis was performed using SPSS software. Results: Thirty subjects (15 male and 15 female) aged between 18 and 25 years, with mean age of 20 ±1 years, participated in this study. Statistical analysis was performed using paired t-test. The Shapiro-Wilk test showed a significance departure from the normality, W (30)=0.908, p=0.013. There was no significant difference in reaction time before listening and after listening to classical music (p<0.178), whereas there was a significant difference before listening and after listening to techno (p<0.008), symphony (p<0.005), and hard rock (p<0.002). In all four music styles--techno (p<0.586), symphony (p<0.629), rock (p<0.349), and Indian classical (p<0.829)--there was no statistically significant difference in reaction time before listening and during listening to music. There was a significant difference during listening and after listening to all four music stylres: techno (p<0.030), classical (p<0.039), symphony (p<0.000), and hard rock (p<0.014). CONCLUSION: Listening to instrumental music such as techno, Indian classical, symphony, and rock has the effect of reducing visual reaction time during listening. Longer visual reaction time is shown after listening to music. The visual reaction time before and after listening to classical music is longer as compared to other music; possibly because it was the most disliked music out of the four music styles. [ABSTRACT FROM AUTHOR]

Manual responses are often facilitated when the handle direction of a tool is aligned with the response hand in two-choice reaction-time tasks. This effect is discussed in terms of affordance perception, but that is still controversial. If manual responses are promoted by perceived affordance of grasping, the responses would conversely be suppressed when the danger of grasping is perceived. In this study, 36 right-handed university students performed a discrimination task using blades and non-bladed tools on a tablet screen by tapping on the left or right position near the tool with the left or right index finger. The results showed that the responses were not facilitated even when the direction of the handle was aligned with the response hand. The responses were quicker to blades than to non-bladed tools and especially facilitated when the direction of the edge of the blade and the response position coincided. These results do not support the prediction from affordance perception and can be interpreted as a Simon-type spatial compatibility effect caused by the proximity of attention-grabbing blades to response positions. [ABSTRACT FROM AUTHOR]

Previous studies have shown incorrect motor activation when making perceptual decisions under conflict, but the potential involvement of motor processes in conflict resolution is still unclear. The present study tested whether the effects of distracting information may be reduced when anticipated motor processing demands increase. Specifically, across two mouse-tracking Simon experiments, we manipulated blockwise motor demands (high vs. low) by requiring participants to move a mouse cursor to either large versus small (Experiment 1) or near versus far (Experiment 2) response boxes presented on the screen. We reasoned that participants would increase action control in blocks with high versus low motor demands and that this would reduce the distracting effect of location-based activation. The results support this hypothesis: Simon effects were reduced under high versus low motor demands and this modulation held even when controlling for time-varying fluctuations in distractor-based activation via distributional analyses (i.e., delta plots). Thus, the present findings indicate that anticipation of different motor costs can influence conflict processing. We propose that the competition between distractor-based and target-based activation is biased at premotor and/or motor stages in anticipation of motor demands, but also discuss alternative implementations of action control. [ABSTRACT FROM AUTHOR]

Many findings suggest that visual deprivation in early life negatively affects the development of spatial competence and that sighted and visually impaired individuals use different strategies to encode spatial positions. This study aims to assess the role of vision in developing spatial coordinates by running three studies in a sample of children and adolescents with and without visual impairments (n = 42, 16 female, 8–18 years old, 100% European), using visual and auditory versions of Simon task with uncrossed and crossed hands posture. The first study assessed that visual and auditory external coordinates mature in parallel in sighted children. The second showed that if vision is available but degraded, it is sufficient to calibrate spatial performance in the auditory system, even if the visual performance remains impaired. The third experiment showed that the total lack of visual experience results in an impaired spatial performance also in the other spared modalities. Our results suggest that vision impairments have different consequences on developing spatial competence. They also highlighted the necessity of early assessment and interventions in visually impaired children that take into account different residual abilities. Public Significance Statement: The results suggest a causal role of visual experience in the development of spatial abilities. Moreover, these findings evidence the necessity of different training for low-vision and blind children, as they show different abilities in the no-deprived sensory modalities. [ABSTRACT FROM AUTHOR]

An effective interaction with the environment requires adaptation of one's own behaviour to environmental demands. We do so by using cues from our environment and relating these cues to our body to predict the outcomes of events. The recent literature on embodied cognition suggests that task-relevant stimuli, presented near the hands, receive more attentional capacity and are processed differently than stimuli, presented spatially more distant to our body. It has also been proposed that near-hand processing is beneficial to conflict resolution. In the current study, we tested the assumption of an attentional bias towards the near hand space in the context of our previous work by combining a cueing paradigm (allocation of visual attention) with a conflict processing paradigm (Simon task) in the near vs far hand space. In addition, the relevance of processing was manipulated by using affective (angry vs neutral smileys) gaze cues (i.e., varying the valence of the cues). Our results indicate that (a) the interaction of valence x cue congruency x hand proximity was significant, indicating that the cueing effect was larger for negative valence in the proximal condition. (b) The interaction of valence x Simon compatibility x stimulus-hand proximity interaction was significant, indicating that for negative valence processing, the Simon effect was smaller in the proximal than in the distal stimulus-hand condition. This effect was at least numerically but not significantly reversed in the neutral valence condition. (c) Overall, cue congruency, indicating the correct vs incorrect attention allocation to the target stimulus onset, did not reveal any effect on Simon compatibility x stimulus-hand proximity. Our results suggest that valence, the allocation of attention, and conflict, seem to be decisive factors determining the direction and strength of hand proximity effects. [ABSTRACT FROM AUTHOR]

Previous research has suggested that culture influences perception and attention. These studies have typically involved comparisons of Westerners with East Asians, motivated by assumed differences in the cultures' self-concept or position on the individualism-collectivism spectrum. However, other potentially important sources of cultural variance have been neglected, such as differences in traffic directionality shaped by the urban spatial environment (i.e., left-hand vs. right-hand traffic). Thus, existing research may potentially place too much emphasis on self-concepts or the individualism-collectivism dimension in explaining observed cultural differences in cognition. The present study investigated spatial cognition using a Simon task and tested participants from four nations (Australia, China, Germany, and Malaysia) that differ in both cultural orientation (collectivistic vs. individualistic) and traffic directionality (left-hand vs. right-hand traffic). The task used two possible reference frames underlying the Simon effect: a body-centered one based on global stimulus position relative to the screen's center versus an object-centered one based on local stimulus position relative to a context object. As expected, all groups showed a reliable Simon effect for both spatial reference frames. However, the global Simon effect was larger in participants from countries with left-hand traffic. In contrast, the local Simon effect was modulated by differences in cultural orientation, with larger effects in participants from collectivistic cultures. This pattern suggests that both sources of cultural variation, viz. cultural orientation and traffic directionality, contribute to differences in spatial cognition in distinct ways. [ABSTRACT FROM AUTHOR]

Previous studies have suggested that performance-contingent reward can modulate cognitive control by biasing irrelevant location-response associations in the Simon task. However, the influence of reward in the case of irrelevant words (Stroop task) or irrelevant flankers (Eriksen Flanker task) remains unclear. Across two preregistered experiments, the present study investigated the influence of reward on conflict processing with different types of distractors. Conflict effects on mean reaction time (RT) were reduced in the Simon task (Experiments 1 and 2) when incongruent versus congruent trials were rewarded, and this modulating effect of reward on conflict processing was also observed in the Eriksen flanker task (Experiment 2), but not in the Stroop task (Experiment 1). We propose that cognitive control adjustments to distractor-specific reward contingencies can be generalized across distractor types producing both perceptual-related (Flanker task) and motor-related (Simon task) conflict, but, if any, to a limited degree when distractors produce additional higher-level task conflict (Stroop task). In addition, distributional RT analyses (delta plots) revealed that rewarded distractor-response associations modulate cognitive control not only via biasing the strength (Simon and Eriksen tasks) but also the time-course of suppressing distractor processing (Eriksen task). Overall, the present study dissociated distractor-general and distractor-specific effects of reward on cognitive control. [ABSTRACT FROM AUTHOR]

Human actions are suspect to various compatibility phenomena. For example, responding is faster to the side where a stimulus appears than to the opposite side, referred to as stimulus–response (S–R) compatibility. This is even true, if the response is given to a different stimulus feature, while location itself is irrelevant (Simon compatibility). In addition, responses typically produce perceivable effects on the environment. If they do so in a predictable way, responses are faster if they produce a (e.g., spatially) compatible effect on the same side than on the other side. That it, a left response is produced faster if it results predictably in a left effect than in a right effect. This effect is called response-effect (R–E) compatibility. Finally, compatibility could also exist between stimuli and the effects, which is accordingly called stimulus-effect (S–E) compatibility. Such compatibility phenomena are also relevant for applied purposes, be it in laparoscopic surgery or aviation. The present study investigates Simon and R–E compatibility for touchless gesture interactions. In line with a recent study, no effect of R–E compatibility was observed, yet irrelevant stimulus location yielded a large Simon effect. Touchless gestures thus seem to behave differently with regard to compatibility phenomena than interactions via (other) tools such as levers. [ABSTRACT FROM AUTHOR]

An effective interaction with the environment requires adaptation of one’s own behaviour to environmental demands. We do so by using cues from our environment and relating these cues to our body to predict the outcomes of events. The recent literature on embodied cognition suggests that task-relevant stimuli, presented near the hands, receive more attentional capacity and are processed differently than stimuli, presented spatially more distant to our body. It has also been proposed that near-hand processing is beneficial to conflict resolution. In the current study, we tested the assumption of an attentional bias towards the near hand space in the context of our previous work by combining a cueing paradigm (allocation of visual attention) with a conflict processing paradigm (Simon task) in the near vs far hand space. In addition, the relevance of processing was manipulated by using affective (angry vs neutral smileys) gaze cues (i.e., varying the valence of the cues). Our results indicate that (a) the interaction of valence × cue congruency × hand proximity was significant, indicating that the cueing effect was larger for negative valence in the proximal condition. (b) The interaction of valence × Simon compatibility × stimulus-hand proximity interaction was significant, indicating that for negative valence processing, the Simon effect was smaller in the proximal than in the distal stimulus-hand condition. This effect was at least numerically but not significantly reversed in the neutral valence condition. (c) Overall, cue congruency, indicating the correct vs incorrect attention allocation to the target stimulus onset, did not reveal any effect on Simon compatibility × stimulus-hand proximity. Our results suggest that valence, the allocation of attention, and conflict, seem to be decisive factors determining the direction and strength of hand proximity effects.

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.

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 fingerpresses 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. [ABSTRACT FROM AUTHOR]

In many tasks humans can trade speed against accuracy. This variation of strategy has different consequences for congruency effects in different conflict tasks. Recently, Mittelstädt et al. (2022) suggested that these differences are related to the dynamics of congruency effects as assessed by delta plots. With increasing delta plots in the Eriksen flanker task congruency effects were larger under accuracy set, and with decreasing delta plots in the Simon task they were smaller. Here we tested the hypothesis for a single task, making use of the observation that for the Simon task delta plots decline when the irrelevant feature is presented first, but increase when the relevant feature leads. The differences between congruency effects under speed and accuracy instructions confirmed the hypothesized relation to the slope of delta plots. In fact, for similar delta plots in the compared speed-accuracy conditions, the relation should be a straightforward consequence of the shorter and longer reaction times with speed and accuracy set, respectively. However, when relevant and irrelevant features were presented simultaneously, congruency effects were stronger under speed set at all reaction times. For this condition, a supplementary model-based analysis with an extended leaky, competing accumulator model suggested a stronger and longerlasting influence of the irrelevant stimulus feature. The congruency effects for reaction times were accompanied by congruency effects for error rates when delta plots were decreasing, but not when they were increasing. [ABSTRACT FROM AUTHOR]

Two-choice reaction tasks for which stimuli differ on irrelevant and relevant dimensions (e.g., Simon, flanker, and Stroop tasks) show congruency effects. The diffusion model for conflict tasks (DMC) has provided a quantitative account of the mechanisms underlying decisions in such conflict tasks, but it has not been applied to the congruency sequence effect (CSE) for which the congruency on the prior trial influences performance on the current trial. The present study expands analysis of the reaction time (RT) distributions reflected by delta plots to the CSE, and then extends the DMC to simulate the results. With increasing RT: (1) the spatial Simon effect was almost unchanged following congruent trials but initially became smaller and finally reversed following incongruent trials; (2) the arrow-based Simon effects increased following both congruent and incongruent trials, but more so for the former than the latter; (3) the flanker congruency effect varied quadratically following congruent trials but increased linearly following incongruent trials. These results were modeled by the CSE-DMC, extended from the DMC with two additional assumptions: (1) feature integration influences only the controlled processes; (2) following incongruent trials, the automatic process is weakened. The results fit better with the CSE-DMC than with two variants that separately had only one of the two additional assumptions. These findings indicate that the CSEs for different conflict tasks have disparate RT distributions and that these disparities are likely due to the controlled and automatic processes being influenced differently for each trial sequence. [ABSTRACT FROM AUTHOR]

Although previous studies have investigated how ordinal stimuli are encoded in contexts that vary in locational congruency, conclusions regarding the encoding mechanism are inconsistent. The present study utilized Chinese Heavenly Stem characters, which are an ordinal sequence used to record astronomical phenomena in ancient China and are still frequently used to date, as stimuli to investigate the influence of rotation angle and task demands on the encoding of ordinal stimuli in contexts that varied in locational congruency. We randomly presented six of these characters at varying rotation angles (0° or 180°) on the left or right side of the screen. Participants were then instructed to classify the stimulus order (Experiment 1), location (Experiment 2) and color (Experiment 3) in a bimanual classification task. The results were as follows: (a) When participants classified stimuli according to order, both the ordinal position effect and the Simon effect were detected for unrotated stimuli. However, only the ordinal position effect was detected for rotated stimuli. (b) When participants classified stimuli according to spatial location, we observed only the spatial stimulus-response compatibility effect. (c) When participants classified stimuli according to color, we observed the Simon effect in all trials. However, the ordinal position effect was detected only in location-congruent trials. These results suggest that encoding of ordinal stimuli in contexts that varied in locational congruency was moderated by the processing difficulty of the stimuli and the task demands. [ABSTRACT FROM AUTHOR]

In many tasks humans can trade speed against accuracy. This variation of strategy has different consequences for congruency effects in different conflict tasks. Recently, Mittelstädt et al. (2022) suggested that these differences are related to the dynamics of congruency effects as assessed by delta plots. With increasing delta plots in the Eriksen flanker task congruency effects were larger under accuracy set, and with decreasing delta plots in the Simon task they were smaller. Here we tested the hypothesis for a single task, making use of the observation that for the Simon task delta plots decline when the irrelevant feature is presented first, but increase when the relevant feature leads. The differences between congruency effects under speed and accuracy instructions confirmed the hypothesized relation to the slope of delta plots. In fact, for similar delta plots in the compared speed-accuracy conditions, the relation should be a straightforward consequence of the shorter and longer reaction times with speed and accuracy set, respectively. However, when relevant and irrelevant features were presented simultaneously, congruency effects were stronger under speed set at all reaction times. For this condition, a supplementary model-based analysis with an extended leaky, competing accumulator model suggested a stronger and longer-lasting influence of the irrelevant stimulus feature. The congruency effects for reaction times were accompanied by congruency effects for error rates when delta plots were decreasing, but not when they were increasing.

Recent studies suggest that covering the face inhibits the recognition of identity and emotional expressions. However, it might also make the eyes more salient, since they are a reliable index to orient our social and spatial attention. This study investigates (1) whether the pervasive interaction with people with face masks fostered by the COVID-19 pandemic modulates the processing of spatial information essential to shift attention according to other’s eye-gaze direction (i.e., gaze-cueing effect: GCE), and (2) whether this potential modulation interacts with motor responses (i.e., Simon effect). Participants were presented with face cues orienting their gaze to a congruent or incongruent target letter location (gaze-cueing paradigm) while wearing a surgical mask (Mask), a patch (Control), or nothing (No-Mask). The task required to discriminate the identity of the lateralized target letters by pressing one of two lateralized response keys, in a corresponding or a non-corresponding position with respect to the target. Results showed that GCE was not modulated by the presence of the Mask, but it occurred in the No-Mask condition, confirming previous studies. Crucially, the GCE interacted with Simon effect in the Mask and Control conditions, though in different ways. While in the Mask condition the GCE emerged only when target and response positions corresponded (i.e., Simoncorresponding trials), in the Control condition it emerged only when they did not correspond (i.e., Simon-non-corresponding trials). These results indicate that people with face masks induce us to jointly orient our visual attention in the direction of the seen gaze (GCE) in those conditions resembling (or associated with) a general approaching behavior (Simon-corresponding trials). This is likely promoted by the fact that we tend to perceive wearing the mask as a personal safety measure and, thus, someone wearing the face mask is perceived as a trustworthy person. In contrast, people with a patch on their face can be perceived as more threatening, therefore inducing a GCE in those conditions associated with a general avoidance behavior (Simon-noncorresponding trials). [ABSTRACT FROM AUTHOR]

The cognitive processes underlying the ability of human performers to trade speed for accuracy is often conceptualized within evidence accumulation models, but it is not yet clear whether and how these models can account for decision-making in the presence of various sources of conflicting information. In the present study, we provide evidence that speed-accuracy tradeoffs (SATs) can have opposing effects on performance across two different conflict tasks. Specifically, in a single preregistered experiment, the mean reaction time (RT) congruency effect in the Simon task increased, whereas the mean RT congruency effect in the Eriksen task decreased, when the focus was put on response speed versus accuracy. Critically, distributional RT analyses revealed distinct delta plot patterns across tasks, thus indicating that the unfolding of distractor-based response activation in time is sufficient to explain the opposing pattern of congruency effects. In addition, a recent evidence accumulation model with the notion of time-varying conflicting information was successfully fitted to the experimental data. These fits revealed task-specific time-courses of distractor-based activation and suggested that time pressure substantially decreases decision boundaries in addition to reducing the duration of non-decision processes and the rate of evidence accumulation. Overall, the present results suggest that time pressure can have multiple effects in decision-making under conflict, but that strategic adjustments of decision boundaries in conjunction with different time-courses of distractor-based activation can produce counteracting effects on task performance with different types of distracting sources of information. [ABSTRACT FROM AUTHOR]

Recent studies suggest that covering the face inhibits the recognition of identity and emotional expressions. However, it might also make the eyes more salient, since they are a reliable index to orient our social and spatial attention. This study investigates (1) whether the pervasive interaction with people with face masks fostered by the COVID-19 pandemic modulates the processing of spatial information essential to shift attention according to other’s eye-gaze direction (i.e., gaze-cueing effect: GCE), and (2) whether this potential modulation interacts with motor responses (i.e., Simon effect). Participants were presented with face cues orienting their gaze to a congruent or incongruent target letter location (gaze-cueing paradigm) while wearing a surgical mask (Mask), a patch (Control), or nothing (No-Mask). The task required to discriminate the identity of the lateralized target letters by pressing one of two lateralized response keys, in a corresponding or a non-corresponding position with respect to the target. Results showed that GCE was not modulated by the presence of the Mask, but it occurred in the No-Mask condition, confirming previous studies. Crucially, the GCE interacted with Simon effect in the Mask and Control conditions, though in different ways. While in the Mask condition the GCE emerged only when target and response positions corresponded (i.e., Simon-corresponding trials), in the Control condition it emerged only when they did not correspond (i.e., Simon-non-corresponding trials). These results indicate that people with face masks induce us to jointly orient our visual attention in the direction of the seen gaze (GCE) in those conditions resembling (or associated with) a general approaching behavior (Simon-corresponding trials). This is likely promoted by the fact that we tend to perceive wearing the mask as a personal safety measure and, thus, someone wearing the face mask is perceived as a trustworthy person. In contrast, people with a patch on their face can be perceived as more threatening, therefore inducing a GCE in those conditions associated with a general avoidance behavior (Simon-non-corresponding trials).

Inhibition of return (IOR) refers to slower responses to targets presented at previously cued locations. Contrasting target discrimination performance over various eye movement conditions has shown the level of activation of the reflexive oculomotor system determines the nature of the effect. Notably, an inhibitory effect of a cue nearer to the input end of the processing continuum is observed when the reflexive oculomotor system is actively suppressed, and an inhibitory effect nearer the output end of the processing continuum is observed when the reflexive oculomotor system is actively engaged. Furthermore, these two forms of IOR interact differently with the Simon effect. Drift diffusion modeling has suggested that two parameters can theoretically account for the speed-accuracy tradeoff rendered by the output-based form of IOR: increased threshold and decreased trial noise. In Experiment 1, we demonstrate that the threshold parameter best accounts for the output-based form of IOR by measuring it with intermixed discrimination and localization targets. Experiment 2 employed the response-signal methodology and showed that the output-based form has no effect on the accrual of information about the target’s identity. These results converge with the response bias account for the output form of IOR.

Cognitive control is an important ability instantiated in many situations such as conflict control (e.g., Stroop/Simon task) and the control of eye movements (e.g., saccades). However, it is unclear whether eye movement control shares a common cognitive control system with the conflict control. In Experiment 1, we asked participants to make a prosaccade or antisaccade and then to identify the color of a lateralized color word (i.e., a Stroop–Simon stimulus). The stimulus onset asynchrony (SOA) between the saccadic cue and the Stroop–Simon stimulus was manipulated to be either short (200 ms) or long (600 ms). Results showed that the Stroop effect at the response level and the (negative) Simon effect were smaller when the SOA was short than long, demonstrating a decline of response control over time after making a saccade. Moreover, this temporal change of the Simon effect was more pronounced in the antisaccade session than in the prosaccade session. Furthermore, individuals who had better performance in the antisaccade task performed better in the response control of Stroop interference. When the saccade task was removed in Experiment 2, the temporal declines of the response control observed in Experiment 1 were absent. Experiment 3 replicated the key results of Experiment 1 by replacing the Stroop–Simon task with a typical Simon task and separately testing the typical Stroop and Simon tasks. Overall, our findings suggest that a common system is shared between the control of eye movements and the conflict control at the response level. [ABSTRACT FROM AUTHOR]

Spatial influences may be introduced to an experimental task by manipulations performed on the stimulus or the response or by virtue of the type of stimuli under study. Identification of spatial influences is especially pertinent in investigations of laterality, as isolation of processing to one hemisphere may inadvertently introduce spatial confounds. Because, however, space is not a relevant task feature, it may not always be obvious that it should be taken into consideration. Failure to anticipate these spatial influences can affect the conclusions drawn from results. The current work examines potential spatial influences in an experimental paradigm previously used to investigate perceptual asymmetries for duration estimation in which both stimulus presentation and response selection were lateralized. Potential spatial influences (including the spatial-temporal association of response codes – STEARC, spatial attention, and the Simon effect) are identified and systematically tested over 5 experiments. Results suggest that previously observed perceptual asymmetries in this experimental paradigm may be the result of a spatial confound, specifically, that of the Simon effect. Using vertical response options with the lateral stimulus presentation, however, mitigated the spatial influence. Altogether, the current work demonstrates the importance of carefully considering potential spatial confounds prior to commencement of laterality studies. [ABSTRACT FROM AUTHOR]

We examined the effects of individual versus joint action on aSimon task using motion tracking to explore the implicitcognitive dynamics underlying responses. In both individual andjoint conditions, participants were slower to respond, and weredifferentially attracted to the distracter response location, whenthe spatial component of the stimulus was incompatible with theresponse location. When two people completed similar twochoice tasks together, the results were not statistically differentfrom the individual condition, even though the magnitude of thestimulus-response compatibility effect was slightly larger.Neither was there an increased effect when the partner had nostimulus-response conflict to resolve. We found no evidence foran action conflict when the responses of the two partners weredifferent. These data imply that the literature regarding the JointSimon task is still in the process of determining the relevantevents that interact with and support joint action.

Objective: The present study investigated whether and how different human–robot interactions in a physically shared workspace influenced human stimulus–response (SR) relationships. Background: Human work is increasingly performed in interaction with advanced robots. Since human–robot interaction often takes place in physical proximity, it is crucial to investigate the effects of the robot on human cognition. Method: In two experiments, we compared conditions in which humans interacted with a robot that they either remotely controlled or monitored under otherwise comparable conditions in the same shared workspace. The cognitive extent to which the participants took the robot's perspective served as a dependent variable and was evaluated with a SR compatibility task. Results: The results showed pronounced compatibility effects from the robot's perspective when participants had to take the perspective of the robot during the task, but significantly reduced compatibility effects when human and robot did not interact. In both experiments, compatibility effects from the robot's perspective resulted in statistically significant differences in response times and in error rates between compatible and incompatible conditions. Conclusion: We concluded that SR relationships from the perspective of the robot need to be considered when designing shared workspaces that require users to take the perspective of the robot. Application: The results indicate changed compatibility relationships when users share their workplace with an interacting robot and therefore have to take its perspective from time to time. The perspective-dependent processing times are expected to be accompanied by corresponding error rates, which might affect—for instance—safety and efficiency in a production process. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

To explore the time course of space- and object-based attentional selection processes I analysed the shapes of the response time (RT) and accuracy distributions of left/right arrow identification responses in the two-rectangle paradigm. After cueing one of the four ends of two horizontally or vertically oriented rectangles the arrow typically appears at the cued location (valid), or sometimes at an uncued location in the same (invalid-same) or other rectangle (invalid-different). The data point to a multiple-route model in which (a) an informative cue generates response channel activation before arrow signals emerge, (b) the task-irrelevant arrow location is represented in multiple egocentric and allocentric reference frames around 150 ms after target onset, with the former including a reference frame centered on the currently attended location, (c) the task-irrelevant spatial codes activate premature response tendencies that are actively inhibited to allow gating of arrow direction signals, (d) after an invalid cue the onset of the arrow triggers an “attention shift” – acting between 150 and 240 ms after target onset – that strongly interferes with task performance in certain conditions (invalid-same cueing with horizontal rectangles, and invalid-different cueing with vertical rectangles), and (e) participants differ in which task-irrelevant codes they preferentially inhibit. These results pave the way for future confirmatory studies to temporally characterize and disentangle the contributions of different types of response channel activation processes, from those of reactive cognitive control processes including active and selective response suppression.

Abstract Background Car accidents due to unexpected forward or backward runaway by older drivers are a serious social problem. Although the cause of these accidents is often attributed to stepping on the accelerator instead of the brake, it is difficult to induce such pedal application errors systematically with usual drive simulators. We developed a simple personal computer system that induces the pedal errors, and investigate the effects of age on the error behaviors. Methods The system consisted of a laptop computer and a three-pedal foot mouse. It measured response time, accuracy, and flexibility of pedal operation to visual stimuli. The system displayed two open circles on the computer display, lighting one of the circles in a random order and interval. Subjects were instructed to press the foot pedal with their right foot as quickly as possible when the circle was lit; the ipsilateral pedal to the lit circle in a parallel mode and the contralateral pedal in a cross mode. When the correct pedal was pressed, the light went off immediately, but when the wrong pedal was pressed, the buzzer sounded and the light remained on until the correct pedal was pressed. During a 6-min trial, the mode was switched between parallel and cross every 2 min. During the cross mode, a cross mark appears on the display. The pedal responses were evaluated in 52 subjects divided into young (20–29 years), middle-aged (30–64 years), and older (65–84 years) groups. Additionally, the repeatability of the pedal response characteristic indicators was examined in 14 subjects who performed this test twice. Results The mean response time was 95 ms (17%) longer in the older group than in the young group. More characteristically, however, the older group showed 2.1 times more frequent pedal errors, fell into long hesitations (response freezing > 3 s) 16 times more often, and took 1.8 times longer period to correct the wrong pedal than the young groups. The indicators of pedal response characteristics showed within-individual repeatability to the extent that can identify the age-dependent changes. Conclusions Hesitations and extended error correction time can be associated with increased crash risk due to unexpected runaway by older drivers. The system we have developed may help to uncover and evaluate physiological characteristics related to crash risk in the elderly population.

Adaptive behavior is fundamental to cognitive control and executive functioning. This study investigates how cognitive control mechanisms and episodic feature retrieval interact to influence adaptiveness, focusing particularly on theta (4 to 8 Hz) oscillatory dynamics. We conducted two variations of the Simon task, incorporating response-incompatible, response-compatible, and neutral trials. Experiment 1 demonstrated that cognitive adjustments-specifically, cognitive shielding following incompatible trials and cognitive relaxation following compatible ones-are reflected in midfrontal theta power modulations associated with the Simon effect. Experiment 2 showed that reducing feature overlap between trials leads to less pronounced sequential modulations in behavior and midfrontal theta activity, supporting the hypothesis that cognitive control and feature integration share a common neural mechanism. These findings highlight the interaction of cognitive control processes and episodic feature integration in modulating behavior. The results advocate for hybrid models that combine top-down and bottom-up processes as a comprehensive framework to understand cognitive control dynamics and adaptive behavior., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

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. This study probed the relations between auditory attentional selection and effort by examining selectivity of spatial processing at early and later cognitive stages as a function of effort during the vigilance decrement. The results showed dissociations between attentional selection and vigilance effort using behavioral, diffusion decision modeling, and psychophysiological measures. Potential differences in the cognitive computations that underlie selection and effort are discussed as they relate to the observed dissociations. [ABSTRACT FROM AUTHOR]

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. Our findings resolve the debate on the mechanism of reward‐modulated response conflict resolution. The reward‐enhanced global motor inhibition adds to suggesting gain modulation as a common computational mechanism in the neural system. Our paradigm is useful in assessing parallel dysfunctions of the motor system and the reward system in self‐control disorders. [ABSTRACT FROM AUTHOR]

Introduction: Despite their popularity in Neuropsychology, reaction time analysis based on the subtraction and additive factors methods is critiqued for not paying adequate attention to the dynamical nature of cognition. Mouse-tracking methods aim to cater to this need by allowing researchers to explore response dynamics during cognitive tasks by recording mouse trajectories. Methods: A mouse-tracking adaptation of the Simon task is developed to explore decision-making dynamics in different stimulus-response compatibility conditions. The study focuses on the effects of stimulus design decisions on mouse trajectories, including relocation of the choice buttons from the top corners to the bottom and the mid-session reversal of stimulus-response mapping on mouse responses. Results: Consistent with previous studies, significant stimulus-response compatibility effects were observed, where contrasts over mouse-tracking measures had larger effect sizes than simple reaction time contrasts. Moreover, in the conflict trials, asymmetric response trajectories towards the left and right corners were observed. Moving the response buttons from top to bottom increased the degree of asymmetry between the mouse trajectories towards the bottom-left and bottom-right corners during the conflict condition. Finally, in the reverse Simon task, the switch to a new color-response mapping inflicted the largest effect on the average number of y-flips. Conclusion: Mouse tracking provides measures suitable for exploring decision-making dynamics beyond classical reaction time analysis, provided asymmetries due to the starting position and response layout are considered during experiment design. [ABSTRACT FROM AUTHOR]

We examined the effects of individual versus joint action andracial similarity and dissimilarity on a Simon task usingmouse tracking to explore the implicit cognitive dynamicsunderlying responses. Participants were slower to respondwhen working with a partner than when working alone, andtheir mouse movements also differed across conditions.Participants paired with a different-race partner took longer torespond than participants paired with a same-race partner. Weargue that, in the joint conditions, participants’ longerresponses were the result of automatic inhibitory processesthat arise within the social context.

Most cognitive control effects, although numerously reported in computer task studies, have rarely been tested outside the laboratory. The purpose of this study was twofold. First, we aimed to improve the ecological validity of a well-studied congruency effect. The Simon effect (Simon, 1969) is the observation that an irrelevant stimulus location can facilitate or impede task performance when it is congruent or incongruent with the response location. Secondly, we wanted to investigate the role of action experience on the Simon effect. In this study, experienced bowlers were asked to hit either the left- or rightmost pin, depending on the pitch of a tone. Irrelevant to the task, this tone could be presented in the congruent or incongruent ear. Our results demonstrate that the Simon effect can be observed outside the laboratory and that weekly training at bowling may help in shielding against irrelevant location stimuli. [ABSTRACT FROM AUTHOR]

In the current review, we argue that experimental results usually interpreted as evidence for cognitive resource limitations could also reflect functional necessities of human information processing. First, we point out that selective processing of only specific features, objects, or locations at each moment in time allows humans to monitor the success and failure of their own overt actions and covert cognitive procedures. We then proceed to show how certain instances of selectivity are at odds with commonly assumed resource limitations. Next, we discuss examples of seemingly automatic, resource-free processing that challenge the resource view but can be easily understood from the functional perspective of monitoring cognitive procedures. Finally, we suggest that neurophysiological data supporting resource limitations might actually reflect mechanisms of how procedural control is implemented in the brain.

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.

In the current review, we argue that experimental results usually interpreted as evidence for cognitive resource limitations could also reflect functional necessities of human information processing. First, we point out that selective processing of only specific features, objects, or locations at each moment in time allows humans to monitor the success and failure of their own overt actions and covert cognitive procedures. We then proceed to show how certain instances of selectivity are at odds with commonly assumed resource limitations. Next, we discuss examples of seemingly automatic, resource-free processing that challenge the resource view but can be easily understood from the functional perspective of monitoring cognitive procedures. Finally, we suggest that neurophysiological data supporting resource limitations might actually reflect mechanisms of how procedural control is implemented in the brain. [ABSTRACT FROM AUTHOR]

Deciding what information we attend to has implications on our ability to remain valuable and productive in our respective academic and economic domains. This study investigated if attentional switching due to information technology interruptions would deplete resources in a unique way and impair performance on a response inhibition task. Three groups (120 women, 57 men, Mage = 21.56, age range: 18-40 years) were compared on the Simon task after participants either did or did not receive interruptions during a self-regulation task. Unexpectedly, a larger Simon effect was found for participants who did not receive interruptions. These results conform to previous evidence showing sustained directed attention may result in depletion and effect subsequent inhibitory control. Although not supporting predictions, these results may provide a basis for further research, particularly because younger generations are developing in a more connected world than preceding generations. By understanding these differences, younger generations may better adapt to technological advances and leverage them to their advantage. [ABSTRACT FROM AUTHOR]

Aims and objectives/purpose/research questions: Language brokering (LB) is an informal translation experience where bilinguals serve as linguistic and cultural intermediaries for family members. LB may have long-term socio-emotional and cognitive outcomes, yet little is known about its effects on executive functions (EFs). This study examines how first language (L1) proficiency and negative emotions tied to language brokering experiences affect EF performance on a Simon task (ST). Design/methodology/approach: Fifty-three Mexican American Spanish–English bilinguals with LB experience performed a ST, and reported their feelings towards LB for their mother. Data and analysis: Mean reaction times (RTs) and accuracy rates for correct ST trials were analyzed using linear mixed effects modeling, with trial type, proficiency and negative emotions tied to LB experience as factors and their interactions as additional predictors. Findings/conclusions: The L1 proficiency and negative emotions tied to brokering experiences have divergent, but combined effects on EF. Contrary to our hypotheses, low L1 proficiency predicted better performance and the smallest Simon effect was found for brokers with low L1 proficiency and low negative emotional brokering experiences. However, high L1 proficiency predicted better performance (smallest RTs) regardless of negative emotions tied to brokering experiences. Originality: This study takes a different perspective on the examination of individual differences among bilinguals, in which we examine how negative emotions tied to brokering experiences coupled with L1 proficiency relates to EF performance. Significance/implications: Our results provide support for the need to understand how individual differences in bilingual language experiences, such as L1 proficiency and negative emotions tied to LB, interact with performance on the ST. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Online experiments offer several advantages over traditional laboratory experiments. However, for reaction time experiments, precise stimulus presentation and response detection is crucial. The precision of online experiments could be compromised due to increased variance arising from varying hardware configurations among participants, lack of control over experimental conditions, and the absence of an examiner. In this study, we conducted an online experiment using the avatar-Simon task to investigate whether small differences in reaction times could be examined using online experiments conducted with the experimental toolkit PsyToolkit. In the avatar-Simon task, participants respond to the color of vertically presented stimuli in front of avatars by pressing a left or right button. Reactions are faster when the position of the stimulus, defined from the avatar's point of view, matches the position of the response. Compared to the previous laboratory experiment, we observed lower effect sizes and more timeouts but were able to replicate the avatar-Simon effect overall. Based on further distributional and reliability analyses, PsyToolkit appears to be suitable tool to detect behavioral effects in the range of tens of milliseconds. We discuss differences and similarities with the original laboratory study and suggest how to address potential problems associated with online experiments.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Car accidents due to unexpected forward or backward runaway by older drivers are a serious social problem. Although the cause of these accidents is often attributed to stepping on the accelerator instead of the brake, it is difficult to induce such pedal application errors systematically with usual drive simulators. We developed a simple personal computer system that induces the pedal errors, and investigate the effects of age on the error behaviors. Methods: The system consisted of a laptop computer and a three-pedal foot mouse. It measured response time, accuracy, and flexibility of pedal operation to visual stimuli. The system displayed two open circles on the computer display, lighting one of the circles in a random order and interval. Subjects were instructed to press the foot pedal with their right foot as quickly as possible when the circle was lit; the ipsilateral pedal to the lit circle in a parallel mode and the contralateral pedal in a cross mode. When the correct pedal was pressed, the light went off immediately, but when the wrong pedal was pressed, the buzzer sounded and the light remained on until the correct pedal was pressed. During a 6-min trial, the mode was switched between parallel and cross every 2 min. During the cross mode, a cross mark appears on the display. The pedal responses were evaluated in 52 subjects divided into young (20–29 years), middle-aged (30–64 years), and older (65–84 years) groups. Additionally, the repeatability of the pedal response characteristic indicators was examined in 14 subjects who performed this test twice. Results: The mean response time was 95 ms (17%) longer in the older group than in the young group. More characteristically, however, the older group showed 2.1 times more frequent pedal errors, fell into long hesitations (response freezing > 3 s) 16 times more often, and took 1.8 times longer period to correct the wrong pedal than the young groups. The indicators of pedal response characteristics showed within-individual repeatability to the extent that can identify the age-dependent changes. Conclusions: Hesitations and extended error correction time can be associated with increased crash risk due to unexpected runaway by older drivers. The system we have developed may help to uncover and evaluate physiological characteristics related to crash risk in the elderly population. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]