Spatial coding in two dimensions

Novelty and learning in cognitive control: evidence from the Simon task

While information that is associated with inappropriate responses can interfere with an ongoing task and be detrimental to performance, cognitive control mechanisms and specific contextual conditions can alleviate interference from unwanted information. In the spatial correspondence (Simon) task, interference has been consistently shown to be reduced by spatial non-correspondence in the previous trial (i.e., correspondence sequence effect, CSE); however the mechanisms supporting this sequential effect are not well understood. Here we investigated the role of novelty and trial-to-trial changes in stimulus and response features in a Simon task, observing similar modulation of CSE for novel and non-novel stimulus changes. However, changing the response modality from trial to trial dampened CSE, and this dampening was more pronounced when the probability of switch trials was higher, suggesting a role for long-term learning. The results are consistent with recent accounts, which indicate that spatial interference can be prevented by cognitive control mechanisms triggered by learned bindings.

What Simon "knows" about cultural differences: The influence of cultural orientation and traffic directionality on spatial compatibility effects

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.

The Dynamic Interplay of Affective, Cognitive and Contextual Resources on Children's Creative Potential: The Modulatory Role of Trait Emotional Intelligence

In the present work we explored in two separate studies the modulatory role of trait emotional intelligence (EI) over the effect exerted on children's creative potential by two other key elements defining creativity, namely cognitive resources (here explored through basic executive functions, Study 1) and contextual-environmental factors (that is, teachers' implicit conceptions of the factors influencing children's creativity, Study 2). Confirming previous research, executive functions (particularly interference control and working memory) emerged as main predictors of children's creative performance; however, their positive effect arose especially when associated with a high trait EI level. In the same vein, teachers' implicit conception about children's creative potential and about their efficacy in teaching creativity emerged to exert a facilitatory effect on children' creative potential. This effect occurred particularly when associated with low trait EI levels, affecting differently girls and boys. Trait EI emerged from these studies as an important individual resource to consider in order to understand the potential benefit of other (cognitive and contextual-environmental) resources on children's creative potential. The implications on the role of trait EI as a constitutional element of children's creativity, capable of promoting the expression of their creative potential, are discussed.

Wearing the face mask affects our social attention over space

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).

Seeing through the cat's eyes: evidence of a spontaneous perspective taking process using a non-human avatar

In many daily face-to-face interactions, people are able to take the perspective of others, for example, coding right and left based on point-of-view of others. In the present study, we investigated whether observers are able to take the perspective of a non-human figure such as a cat, observing the same effects obtained with human or robot avatars. In both experiments, we used a centrally presented stimulus (i.e. a cat), with its tail lateralized to the left or to the right. Participants had to respond to the side of the tail with a lateralized keypress. In Experiment 1 (spatial perspective taking task), participants were required to explicitly adopt the cat's perspective to respond, whereas in Experiment 2 (SR compatibility task), this was not explicitly required. In both experiments, faster RTs are obtained when the cat is presented back, with a greater difference between front and back views when the tail is on the right; furthermore, there is no temporal modulation of the back-front effect. These common results between the two experiments are interpreted on the basis of the spatial perspective taking processes, elicited voluntarily (Experiment 1) or spontaneously (Experiment 2).

Assessing the impact of previous experience on lie effects through a transfer paradigm

Influential lines of research propose dual processes-based explanations to account for both the cognitive cost implied in lying and for that entailed in the resolution of the conflict posited by Simon tasks. The emergence and consistency of the Simon effect has been proved to be modulated by both practice effects and transfer effects. Although several studies provided evidence that the lying cognitive demand may vary as a function of practice, whether and how transfer effects could also play a role remains an open question. We addressed this question with one experiment in which participants completed a Differentiation of Deception Paradigm twice (baseline and test sessions). Crucially, between the baseline and the test sessions, participants performed a training session consisting in a spatial compatibility task with incompatible (condition 1) or compatible (condition 2) mapping, a non-spatial task (condition 3) and a no task one (condition 4). Results speak in favour of a modulation of individual performances by means of an immediate prior experience, and specifically with an incompatible spatial training.

Practice effects vs. transfer effects in the Simon task

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.

Response Priming with Horizontally and Vertically Moving Primes: A Comparison of German, Malaysian, and Japanese Subjects

Response priming refers to the finding that a prime preceding a target influences the response to the target. With German subjects, horizontally moving dots as primes, and static arrows as targets, there are typically faster responses to compatible (i.e., prime and target are associated with the same response) as compared to incompatible targets (i.e., positive compatibility effect, PCE) with short stimulus onset asynchronies (SOAs). In contrast, with longer SOAs, subjects respond faster to incompatible as compared to compatible targets (i.e., negative compatibility effect, NCE). In the present study, we extended the evidence by adding vertically oriented materials. Furthermore, we tested subjects from Malaysia and Japan, where the vertical orientation is more present in daily life, and compared them to German subjects to investigate whether the amount of experience with one orientation influences the compatibility effects on this orientation. Overall, we found pronounced PCEs in the short SOA (i.e., 150 ms) but only reduced PCEs in the longer SOAs (i.e., 350, 550, and 750 ms) across all countries and orientations. There were no differences between the German and Malaysian samples, but the Japanese sample showed larger PCEs in the longer SOAs compared to both other samples. Furthermore, we found larger PCEs for horizontal than vertical materials in the short SOA and larger PCEs for vertical than horizontal materials in the longer SOAs. We discuss our findings in light of theories and findings on compatibility effects as well as attentional mechanisms.

External coding and salience in the tactile Simon effect

Previous studies have demonstrated a tactile Simon effect in which stimulus codes are generated based on the stimulated hand, not on limb position in external space (the somatotopic Simon effect). However, given evidence from visual Simon effect studies demonstrating that multiple stimulus codes can be generated for a single stimulus, we examined whether multiple stimulus codes can be generated for tactile stimuli as well. In our first experiment using four stimulators (two on each side of the hand), we found novel evidence for a hand-centered Simon effect, along with the typical somatotopic Simon effect. Next, we examined whether the potential salience of these somatotopic codes could be reduced, by testing only one hand with two stimulators attached. In Experiments 2-4, we found a strong hand-centered Simon effect with a diminished somatotopic Simon effect, providing evidence that stimulus salience can change the weighting of somatosensory stimulus coding. Finally, we also found novel evidence that the hand-centered Simon effect is coded in external, not somatotopic, coordinates. Furthermore, the diminished somatotopic Simon effect when testing on one hand only provides evidence that salience is an important factor in modulating the tactile Simon effect.

FEF Excitability in Attentional Bias: A TMS-EEG Study

The role of distinct cortical regions in guiding social orienting needs further investigation. Our aim was to explore the contribution of the frontal eye field (FEF) in early orienting of attention towards stimuli with social value. We used a TMS-EEG approach to investigate event related potentials (ERPs; no-TMS block) and TMS evoked potentials (TEPs; TMS block) during the cueing phase of a modified version of the dot-probe task, comparing competing (face vs. house) and not competing (house vs. house) conditions. Our results revealed an increased amplitude of ERP components in the competing condition, showing greater posterior N170 and fronto-central vertex positive potential (VPP) and an enhanced frontal negative component at 250-270 ms from cue onset. TMS pulses over the FEF induced similar N170 and VPP amplified components. In addition, in the ERPs, a reduced positivity at 400 ms was shown when the face appeared on the left side vs. the right side of space. In contrast, in the TMS blocks, we found lateralized effects on N170 depending on the side of face presentation. The enhanced cortical excitability induced by TMS over the right FEF significantly correlated with the performance on the behavioral task, suggesting a link between the FEF activity during the cueing phase of the dot-probe task and the subsequent behavioral response times to the targets.

Sharing Different Reference Frames: How Stimulus Setup and Task Setup Shape Egocentric and Allocentric Simon Effects

Different reference frames are used in daily life in order to structure the environment. The two-choice Simon task setting has been used to investigate how task-irrelevant spatial information influences human cognitive control. In recent studies, a Go/NoGo Simon task setting was used in order to divide the Simon task between a pair of participants. Yet, not only a human co-actor, but also even an attention-grabbing object can provide sufficient reference in order to reintroduce a Simon effect (SE) indicating cognitive conflict in Go/NoGo task settings. Interestingly, the SE could only occur when a reference point outside of the stimulus setup was available. The current studies exploited the dependency between different spatial reference frames (egocentric and allocentric) offered by the stimulus setup itself and the task setup (individual vs. joint Go/NoGot task setting). Two studies (Experiments 1 and 2) were carried out along with a human co-actor. Experiment 3 used an attention-grabbing object instead. The egocentric and allocentric SEs triggered by different features of the stimulus setup (global vs. local) were modulated by the task setup. When interacting with a human co-actor, an egocentric SE was found for global features of the stimulus setup (i.e., stimulus position on the screen). In contrast, an allocentric SE was yielded in the individual task setup illustrating the relevance of more local features of the stimulus setup (i.e., the manikin’s ball position). Results point toward salience shifts between different spatial reference frames depending on the nature of the task setup.

The Multimodal Go-Nogo Simon Effect: Signifying the Relevance of Stimulus Features in the Go-Nogo Simon Paradigm Impacts Event Representations and Task Performance

Numerous studies have shown that stimulus-response-compatibility (SRC) effects in the go-nogo version of the Simon task can be elicited as a result of performing the task together with another human or non-human agent (e.g., a Japanese-waving-cat, a working-clock, or a ticking-metronome). A parsimonious explanation for both social and non-social SRC effects is that highlighting the spatial significance of alternative (non-/social) action events makes action selection more difficult. This holds even when action events are task-irrelevant. Recent findings, however, suggest that this explanation holds only for cases of a modality correspondence between the Simon task as such (i.e., auditory or visual) and the alternative (non-/social) action event that needs to be discriminated. However, based on the fact that perception and action are represented by the same kind of codes, an event that makes the go-nogo decision more challenging should impact go-nogo Simon task performance. To tackle this issue, the present study tested if alternative stimulus events that come from a different sensory modality do impact SRC effects in the go-nogo version of the Simon task. This was tested in the presence and absence of alternative action events of a human co-actor. In a multimodal (auditory–visual) go-nogo Simon paradigm, participants responded to their assigned stimulus – e.g., a single auditory stimulus while ignoring the alternative visual stimulus or vice versa – in the presence or absence of a human co-actor (i.e., joint and single go-nogo condition). Results showed reliable SRCs in both, single and joint go-nogo Simon task conditions independent of the modality participants had to respond to. Although a correspondence between stimulus material and attention-grabbing event might be an efficient condition for SRCs to emerge, the driving force underlying the emergence of SRCs rather appears to be whether the attentional focus prevents or facilitates alternative events to be integrated. Thus, under task conditions in which the attentional focus is sufficiently broad to enable the integration and thus cognitive representation of alternative events, go-nogo decisions become more difficult, resulting in reliable SRCs in single and joint go-nogo Simon tasks.

Determining the scope of control underlying the congruency sequence effect: roles of stimulus-response mapping and response mode

Sequential modulation between two task congruencies has been examined to investigate the nature of the cognitive control mechanism underlying the congruency sequence effect (CSE). Previous results regarding what consecutive tasks must have in common to engender the cross-task CSE are inconsistent. The present study examined the roles of stimulus-response (S-R) mappings and response mode as critical factors in determining the scope of control. Two flanker-compatibility tasks having different stimulus and response sets alternated in turn, and the arbitrariness of S-R mappings alone (Experiment 1) or the arbitrariness of stimulus set and the distinctiveness of response modes (Experiment 2) were manipulated. Experiment 1 showed that non-arbitrary S-R mappings engendered a cross-task CSE even when the response modes were different. However, when S-R mappings were arbitrary in Experiment 2, sequential modulation was evident across two tasks only when their response modes were same, irrespective of the arbitrariness of the stimulus set. These results suggest that the arbitrariness of S-R mappings and response mode are salient task features that reconfigure task representation and consequently determine the scope of the control underlying the CSE.

Information presentation compatibility in a simple digital control panel design: eye-tracking study

Various designs of typical digital control panels were analyzed experimentally from both the effectiveness and efficiency points of view. Subjects performed information comparison tasks aimed at keeping vehicle velocity at the same level. The experiment involved two versions of speedometers for displaying current and target velocities (clock-face and digital). The stimuli were also differentiated by the target velocity value (20, 50 and 80 km/h) and the correct response type (increase or decrease). Subjects' performance results along with the eye-tracking data were qualitatively and quantitatively analyzed for all 24 experimental conditions.

Visual versus auditory Simon effect: A behavioural and physiological investigation

This study investigated whether the visual and auditory Simon effects could be accounted for by the same mechanism. In a single experiment, we performed a detailed comparison of the visual and the auditory Simon effects arising in behavioural responses and in pupil dilation, a psychophysiological measure considered as a marker of the cognitive effort induced by conflict processing. To address our question, we performed sequential and distributional analyses on both reaction times and pupil dilation. Results confirmed that the mechanisms underlying the visual and auditory Simon effects are functionally equivalent in terms of the interaction between unconditional and conditional response processes. The two modalities, however, differ with respect to the strength of their activation and inhibition. Importantly, pupillary data mirrored the pattern observed in behavioural data for both tasks, adding physiological evidence to the current literature on the processing of visual and auditory information in a conflict task.

Practice-induced and sequential modulations in the Simon task: evidence from pupil dilation

Recent evidence showed that pupil dilation (PD) reflects modulations in the magnitude of the Simon interference effect due to correspondence sequence. In the present study we used this measure to assess whether these modulations, thought to result from cognitive control mechanisms, are influenced by prior practice with an incompatible stimulus-response (S-R) mapping. To this end, PD and reaction times (RTs) were recorded while participants performed a Simon task before and after executing a spatially incompatible practice. The sequential analysis revealed that PD mirrored the conflict-adaptation pattern observed in RTs. Crucially, sequential modulations were not affected by prior practice. These findings support the view that the modulations of the Simon effect due to prior practice and those due to correspondence sequence result from two different mechanisms, and suggest that PD can help to better understand the mechanisms underlying response selection and cognitive control in the Simon task.

What spatial coordinate defines color-space synesthesia?

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Space is a central dimension in different types of synesthesia.

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We examined the spatial coordinate system that defines color-space synesthesia.

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Task required responding to the location of a target relative to a colored object.

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Only the synesthete’s responses were sensitive to the relative location of objects.

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An automatic object-based coding was observed in color-space synesthesia.

Synesthesia is characterized by the association between different stimuli modalities. For example, in sequence-space synesthesia, numbers, weekdays, months, and musical tones are visualized in specific spatial locations. Although sequence-space synesthesia tends to co-occur with other types of synesthesia (e.g., grapheme-color), our knowledge about how these individuals represent space is still limited. A central issue for understanding spatial processing refers to the coordinate system used to represent spatial locations. We report on a space-color synesthete (N.W.) who vividly experiences colors in specific spatial locations. We used a task where N.W. and control subjects were required to report the location of a gray square relative to a colored square. The color of the square was task-irrelevant. Participants responded to the following trial types: (1) central trials, where one stimulus appeared on the left and the other on the right side of fixation, and (2) relative location trials, where both stimuli appeared either on the left or on the right side of fixation. Results showed that the color of the target had a strong impact on N.W.’s responses on both trial types, but not on the controls’ responses. These results show that the spatial representation underlying N.W.’s synesthetic experience is automatic and sensitive to the relative location of objects.

Action-space coding in social contexts

In two behavioural experiments we tested whether performing a spatial task along with another agent changes space representation by rendering some reference frames more/less salient than others. To this end, we used a Simon task in which stimuli were presented in four horizontal locations thus allowing for spatial coding according to multiple frames of reference. In Experiment 1 participants performed a go/no-go Simon task along another agent, each being in charge of one response. In Experiment 2 they performed a two-choice Simon task along another agent, each being in charge of two responses. Results showed that when participants were in charge of only one response, stimulus position was coded only with reference to the centre of the screen hence suggesting that the co-actor's response, or the position of the co-actor, was represented and used as a reference for spatial coding. Differently, when participants were in charge of two responses, no effect of the social context emerged and spatial coding relied on multiple frames of reference, similarly to when the Simon task is performed individually. These findings provide insights on the influence played by the interaction between the social context (i.e. the presence of others) and task features on individual performance.

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

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

Independent effects of 2-D and 3-D locations of stimuli in a 3-D display on response speed in a Simon task

The Simon Effect is a phenomenon in which reaction times are usually faster when the stimulus location and the response correspond, even if the stimulus location is irrelevant to the task. Recent studies have demonstrated the Simon effect in a three-dimensional (3-D) display. The present study examined whether two-dimensional (2-D) and 3-D locations simultaneously affected the Simon effect for stimuli in which a target and fixation were located on the same plane (ground or ceiling) at different 3-D depths, and the perspective effect produced a difference in the 2-D vertical location of the target stimulus relative to the fixation. The presence of the ground and ceiling plane was controlled to examine the contextual effects of background. The results showed that the 2-D vertical location and 3-D depth simultaneously affected the speed of responses, and they did not interact. The presence of the background did not affect the magnitude of either the 2-D or the 3-D Simon effect. These results suggest that 2-D vertical location and 3-D depth are coded simultaneously and independently, and both affect response selection in which 2-D and 3-D representations overlap.

The Influence of Social and Nonsocial Variables on the Simon Effect

Abstract. Recently, the Simon effect (SE) has been observed in social contexts when two individuals share a two-choice task. This joint SE (JSE) has been interpreted as evidence that people co-represent their actions. However, it is still not clear if the JSE is driven by social factors or low-level mechanisms. To address this question, we applied a common paradigm to a joint Simon task (Experiments 1 and 4), a standard Simon task (Experiment 2), and a go/no-go task (Experiment 3). The results showed that both the JSE and the SE were modulated by the repetition/non-repetition of task features. Moreover, the JSE was differently modulated by the gender composition of the two individuals involved in the shared task and by their interpersonal relationship. Taken together, our results do not support a pure social explanation of the JSE, nevertheless, they show the independent role of different social factors in modulating the effect.

Re-examining the automaticity and directionality of the activation of the spatial-valence "good is up" metaphoric association

According to the Conceptual Metaphor Theory, people understand abstract concepts depending on the activation of more concrete concepts, but not vice versa. The present research aims to investigate the role of directionality and automaticity regarding the activation of the conceptual metaphor "good is up". Experiment 1 tested the automaticity of the spatial-to-valence metaphoric congruency effect by having participants judge the valence of a positive or negative word that appeared either at the top or at the bottom of the screen. They performed the task concurrently with a 6-digit verbal rehearsal task in the working-memory-load (WML) blocks and without this task in the non-WML blocks. The spatial-to-valence metaphoric congruency effect occurred for the positive words in the non-WML blocks (i.e., positive words are judged more quickly when they appeared at the top than at the bottom of the screen), but not in the WML blocks, suggesting that this metaphoric association might not be activated automatically. Experiments 2-6 investigated the valence-to-spatial metaphoric association and its automaticity. Participants processed a positive or negative prime, which appeared at the center of the screen, and then identified a letter (p/q) that subsequently appeared at the top or bottom of the screen. The valence-to-spatial metaphoric congruency effect did not occur in the WML (6-digit verbal rehearsal) or non-WML blocks, whether response modality to the prime was key-press or vocal, or whether the prime was a word or a picture. The effect only unexpectedly occurred when the task was simultaneously performed with a 4-dot-position visuospatial rehearsal task. Nevertheless, the data collapsed across multiple experiments showed a null valence-to-spatial metaphoric congruency effect, suggesting the absence of the valence-to-spatial metaphoric association in general. The implications of the current findings for the Conceptual Metaphor Theory and its alternatives are discussed.

Psychophysiological mechanisms underlying response selection in multidimensional space

In the outside world, response selection often requires the processing of information from different spatial dimensions. Yet, most neuroscientific approaches to the topic only employ variations in one dimension, namely the horizontal left-right axis. Hence, virtually nothing is known about the neuronal mechanisms underlying response selection in more than one dimension. We investigated this aspect with the help of a two-dimensional flanker task using EEG and source localization techniques. The data shows that response selection processes are differentially modulated across different dimensions. However, this modulation is restricted to conditions imposing increased demands on response selection. In such situations, a distributed fronto-parietal network mediates intensified conflict monitoring processes as well as response inhibition processes. In case response selection is carried out in the horizontal dimension, those brain areas are more active than during response selection in the vertical dimension. Attentional selection processes were not affected. The study's findings are of relevance to our understanding to everyday functioning where response selection is usually carried out in two or three dimensions and not a single dimension as usually investigated in cognitive neuroscience.

Somatotopic representation of location: evidence from the Simon effect

Representing the locations of tactile stimulation can involve somatotopic reference frames in which locations are defined relative to a position on the skin surface, and also external reference frames that take into account stimulus position in external space. Locations in somatotopic and external reference frames can conflict in terms of left/right assignment when the hands are crossed or positioned outside of their typical hemispace. To investigate the spatial codes of the representation of both tactile stimuli and responses to touch, a Simon effect task, often used in the visual modality to examine issues of spatial reference frames, was deployed in the tactile modality. Participants performed the task with stimuli delivered to the hands with arms in crossed or uncrossed postures and responses were produced with foot pedals. Across all 4 experiments, participants were faster on somatotopically congruent trials (e.g., left hand stimulus, left foot response) than on somatotopically incongruent trials (left hand stimulus, right foot response), regardless of arm or leg position. However, some evidence of an externally based Simon effect also appeared in 1 experiment in which arm (stimulus) and leg (response) position were both manipulated. Overall, the results demonstrate that tactile stimulus and response codes are primarily generated based on their somatotopic identity. However, stimulus and response coding based on an external reference frame can become more salient when both hands and feet can be crossed, creating a situation in which somatotopic and external representations can differ for both stimulus and response codes.

The carry-over effect of competition in task-sharing: evidence from the joint Simon task

The Simon effect, that is the advantage of the spatial correspondence between stimulus and response locations when stimulus location is a task-irrelevant dimension, occurs even when the task is performed together by two participants, each performing a go/no-go task. Previous studies showed that this joint Simon effect, considered by some authors as a measure of self-other integration, does not emerge when during task performance co-actors are required to compete. The present study investigated whether and for how long competition experienced during joint performance of one task can affect performance in a following joint Simon task. In two experiments, we required pairs of participants to perform together a joint Simon task, before and after jointly performing together an unrelated non-spatial task (the Eriksen flanker task). In Experiment 1, participants always performed the joint Simon task under neutral instructions, before and after performing the joint flanker task in which they were explicitly required either to cooperate with (i.e., cooperative condition) or to compete against a co-actor (i.e., competitive condition). In Experiment 2, they were required to compete during the joint flanker task and to cooperate during the subsequent joint Simon task. Competition experienced in one task affected the way the subsequent joint task was performed, as revealed by the lack of the joint Simon effect, even though, during the Simon task participants were not required to compete (Experiment 1). However, prior competition no longer affected subsequent performance if a new goal that created positive interdependence between the two agents was introduced (Experiment 2). These results suggest that the emergence of the joint Simon effect is significantly influenced by how the goals of the co-acting individuals are related, with the effect of competition extending beyond the specific competitive setting and affecting subsequent interactions.

Congruency sequence effect without feature integration and contingency learning

The magnitude of congruency effects, such as the flanker-compatibility effects, has been found to vary as a function of the congruency of the previous trial. Some studies have suggested that this congruency sequence effect is attributable to stimulus and/or response priming, and/or contingency learning, whereas other studies have suggested that the control process triggered by conflict modulates the congruency effect. The present study examined whether sequential modulation can occur without stimulus and response repetitions and contingency learning. Participants were asked to perform two color flanker-compatibility tasks alternately in a trial-by-trial manner, with four fingers of one hand in Experiment 1 and with the index and middle fingers of two hands in Experiment 2, to avoid stimulus and response repetitions and contingency learning. A significant congruency sequence effect was obtained between the congruencies of the two tasks in Experiment 1 but not in Experiment 2. These results provide evidence for the idea that the sequential modulation is, at least in part, an outcome of the top-down control process triggered by conflict, which is specific to response mode.

Is automatic imitation based on goal coding or movement coding? A comparison of goal-directed and goal-less actions

A key issue for research on automatic imitation is whether it occurs primarily at the level of movements, that is, by automatically activating a representation of the movement/effector involved in the execution of the observed action, or at the level of goals, that is, by triggering a representation of the action goal, irrespective of how the motor act is physically instantiated. The present study presents two experiments aimed at investigating the contribution of movement coding and goal coding to automatic imitation, by assessing participants' performance in a spatial compatibility task where the observed stimuli were goal-directed and goal-less actions, which have been demonstrated to elicit, respectively, goal and movement coding. We found a significant automatic imitation effect both when the stimuli were goal-less actions and when they were actions directed toward a goal. However, the effect was stronger for the goal-less actions, even after controlling for saliency effects. These results suggest that goal coding contributes to automatic imitation, but to a lesser degree compared to movement coding. The implications of these results for theory and research on automatic imitation are discussed.

The influence of prior practice and handedness on the orthogonal Simon effect

When stimuli are arranged vertically and responses horizontally, right-handed participants respond faster with right responses to stimuli presented above fixation and with left responses to stimuli presented below fixation, even when stimulus position is task-irrelevant (orthogonal Simon effect). The aim of the present work was twofold. First, we assessed whether the orthogonal Simon effect evident in right-handed participants is present also for left-handed participants (Experiment 1). Second, we investigated whether for both groups of participants the orthogonal Simon effect is influenced by the stimulus-response (S-R) mapping used for an orthogonal spatial S-R compatibility task performed 5 min before (Experiment 2). Our results showed that the orthogonal Simon effect significantly differed in the two groups, with left-handers showing an advantage for the up-left/down-right mapping (Experiment 1). Interestingly, the orthogonal Simon effect was strongly influenced by prior practice regardless of the participants’ handedness (Experiment 2). These results suggest that the short-term S-R associations acquired during practice can override the long-term, hardwired associations established on the basis of handedness.

Influence of auditory and audiovisual stimuli on the right-left prevalence effect

When auditory stimuli are used in two-dimensional spatial compatibility tasks, where the stimulus and response configurations vary along the horizontal and vertical dimensions simultaneously, a right-left prevalence effect occurs in which horizontal compatibility dominates over vertical compatibility. The right-left prevalence effects obtained with auditory stimuli are typically larger than that obtained with visual stimuli even though less attention should be demanded from the horizontal dimension in auditory processing. In the present study, we examined whether auditory or visual dominance occurs when the two-dimensional stimuli are audiovisual, as well as whether there will be cross-modal facilitation of response selection for the horizontal and vertical dimensions. We also examined whether there is an additional benefit of adding a pitch dimension to the auditory stimulus to facilitate vertical coding through use of the spatial-musical association of response codes (SMARC) effect, where pitch is coded in terms of height in space. In Experiment 1, we found a larger right-left prevalence effect for unimodal auditory than visual stimuli. Neutral, non-pitch coded, audiovisual stimuli did not result in cross-modal facilitation, but did show evidence of visual dominance. The right-left prevalence effect was eliminated in the presence of SMARC audiovisual stimuli, but the effect influenced horizontal rather than vertical coding. Experiment 2 showed that the influence of the pitch dimension was not in terms of influencing response selection on a trial-to-trial basis, but in terms of altering the salience of the task environment. Taken together, these findings indicate that in the absence of salient vertical cues, auditory and audiovisual stimuli tend to be coded along the horizontal dimension and vision tends to dominate audition in this two-dimensional spatial stimulus-response task.

Emergence of the go/no-go Simon effect by means of practice and mixing paradigms

In two experiments, we tested whether the emergence of the go/no-go Simon effect could be determined by the strengthening of one specific S-R link in location-relevant trials performed right before (practice paradigm) or simultaneously (mixing paradigm) with the location-irrelevant (Simon) trials. Results showed a clear carry-over effect of the association between stimulus position and spatial response from the first task to the second one (Experiment 1) and when the two tasks were performed simultaneously (Experiment 2), even if participants were required to respond with the same key to only half of the stimuli (go/no-go tasks). We found that associative learning between the stimulus and response positions occurring during the go/no-go compatibility task, that is when location was relevant, influenced the way the go/no-go location-irrelevant task (Simon task) was performed. Our findings suggest that the STM links formed during a go/no-go spatial compatibility task are strong enough to influence the go/no-go Simon task.

Pointing hand stimuli induce spatial compatibility effects and effector priming

The present study investigated the automatic influence of perceiving a picture that indicates other's action on one's own task performance in terms of spatial compatibility and effector priming. Participants pressed left and right buttons with their left and right hands respectively, depending on the color of a central dot target. Preceding the target, a left or right hand stimulus (pointing either to the left or right with the index or little finger) was presented. In Experiment 1, with brief presentation of the pointing hand, a spatial compatibility effect was observed: responses were faster when the direction of the pointed finger and the response position were spatially congruent than when incongruent. The spatial compatibility effect was larger for the pointing index finger stimulus compared to the pointing little finger stimulus. Experiment 2 employed longer duration of the pointing hand stimuli. In addition to the spatial compatibility effect for the pointing index finger, the effector priming effect was observed: responses were faster when the anatomical left/right identity of the pointing and response hands matched than when the pointing and response hands differed in left/right identity. The results indicate that with sufficient processing time, both spatial/symbolic and anatomical features of a static body part implying another's action simultaneously influence different aspects of the perceiver's own action. Hierarchical coding, according to which an anatomical code is used only when a spatial code is unavailable, may not be applicable if stimuli as well as responses contain anatomical features.

Observational learning without a model is influenced by the observer's possibility to act: evidence from the Simon task

We assessed whether observational learning in perceptual-motor tasks is affected by the visibility of an action producing perceived environmental effects and by the observer's possibility to act during observation. To this end, we conducted three experiments in which participants were required to observe a spatial compatibility task in which only the effects of computer-generated responses were visible before executing a Simon task. In Experiment 1, we compared the effects of a passively observed practice with either a spatially compatible or incompatible stimulus-response (S-R) association. In Experiment 2, during the observed spatially incompatible practice participants were prevented from potentially acting, either because a plexiglas barrier separated the participant from the response device rendering it out of reach; or because the participant's hands were tied; or the device affording a response was absent. In Experiment 3, the plexiglas presented an opening that could allow the participant to potentially reach and interact with it. As when the practice is physically performed, we found an elimination of the Simon effect following a spatially incompatible observed practice, suggesting that participants learned an incompatible S-R association by observing and transferred this knowledge to the subsequent Simon task. No evidence of transfer of learning was found when, during passive observation, the participant's hands were tied, or a barrier prevented him/her from potentially interacting with the device, or no response device was present. Differently, a transfer-of-learning effect was observed when the barrier presented an opening. These results suggest that learning can derive from the mere observation of action effects, even when an action is not visible, as long as the observer has the potential to act.

Look what I am doing: does observational learning take place in evocative task-sharing situations?

Two experiments were conducted to investigate whether physical and observational practice in task-sharing entail comparable implicit motor learning. To this end, the social-transfer-of-learning (SToL) effect was assessed when both participants performed the joint practice task (Experiment 1 – complete task-sharing), or when one participant observed the other performing half of the practice task (Experiment 2 – evocative task-sharing). Since the inversion of the spatial relations between responding agent and stimulus position has been shown to prevent SToL, in the present study we assessed it in both complete and evocative task-sharing conditions either when spatial relations were kept constant or changed from the practice to the transfer session. The same pattern of results was found for both complete and evocative task-sharing, thus suggesting that implicit motor learning in evocative task-sharing is equivalent to that obtained in complete task-sharing. We conclude that this motor learning originates from the simulation of the complementary (rather than the imitative) action.

Stimulus-dependent modulation of perceptual and motor learning in a serial reaction time task

In two experiments, we investigated the impact of spatial attributes on the representation acquired during a serial reaction time task. Two sequences were used, in which structural regularities occurred either in the horizontal or in the vertical locations of successive stimuli. After training with the dominant hand, participants were required to respond with the non-dominant hand to either the original sequence or to a mirror-ordered version of the original sequence that required finger movements homologous to those used during training. We observed that a difference in reaction times between the two transfer conditions was smaller in the vertical sequence than in the horizontal sequence. This pattern of results was independent of whether three fingers (Experiment 1) were used or only one finger (Experiment 2) was used for responding. This result suggests that perceptual and motor learning mechanisms may be weighted differently depending on the context in which the stimulus is presented.

A driving-emulation task to study the integration of goals with obligatory and prohibitory traffic signs

This research aims to analyse how drivers integrate the information provided by traffic signs with their general goals (i.e. where they want to go). Some previous studies have evaluated the comparative advantages of obligatory and prohibitory traffic signs using a judgement task. In this work, a new experimental task with greater similarity to driving situations is proposed. Participants imagine they are driving a vehicle and must make right or left turn manoeuvres according to a previously indicated objective and the information from obligatory and prohibitory traffic signs. Eighty-two participants took part in two different experiments. According to the results, an obligatory traffic sign is associated with faster and more accurate responses only when the participant's initial objective is allowed. When the initial objective was not allowed, an advantage in accuracy was observed with prohibitory traffic signs and there was no significant difference in reaction time between the two types of sign. These results suggest that having an obligatory traffic sign may facilitate a correct response when the driver's goal is effectively allowed, whereas a prohibitory traffic sign could be more effective in preventing error when the driver has a not-allowed goal in mind. However, processing a prohibitory sign requires an extra inference (i.e. deciding which is the allowed manoeuvre), and thus the potential advantage in reaction time of the prohibitory sign may disappear. A second experiment showed that the results could not be explained by a potential congruency effect between the location (left or right) of the road signs and the position of the key or the hand used to respond (such as the Simon effect or the spatial Stroop effect). Also, an increase in the difficulty of the task (using an incongruent hand to respond) affected performance more strongly in experimental conditions that required making inferences. This made the advantage of the obligatory sign over the prohibitory sign in this condition more noteworthy. The evidence gathered in the current study could be of particular interest in some applied research areas, such as the assessment of road traffic signalling strategies or the ergonomic design of GPS navigation systems.

Effects of visual cue and response assignment on spatial stimulus coding in stimulus-response compatibility

Tlauka and McKenna ( 2000 ) reported a reversal of the traditional stimulus-response compatibility (SRC) effect (faster responding to a stimulus presented on the same side than to one on the opposite side) when the stimulus appearing on one side of a display is a member of a superordinate unit that is largely on the opposite side. We investigated the effects of a visual cue that explicitly shows a superordinate unit, and of assignment of multiple stimuli within each superordinate unit to one response, on the SRC effect based on superordinate unit position. Three experiments revealed that stimulus-response assignment is critical, while the visual cue plays a minor role, in eliciting the SRC effect based on the superordinate unit position. Findings suggest bidirectional interaction between perception and action and simultaneous spatial stimulus coding according to multiple frames of reference, with contribution of each coding to the SRC effect flexibly varying with task situations.

Facilitation and interference components in the joint Simon task

Two experiments were conducted to assess whether the joint Simon effect is composed of facilitation and interference and whether facilitation is increased by a joint spatially compatible practice performed before performing the joint Simon task. In both experiments, participants were required to perform a Simon task along another person. Trials could be corresponding, non-corresponding, and neutral. In Experiment 1, participants performed only the Simon task. In Experiment 2, participants first practiced on a joint spatial compatibility task with a compatible mapping and, after a 5-min delay, transferred to a joint Simon task. Results indicated that the joint Simon effect consisted primarily of interference, which was significantly increased by a spatially compatible practice performed jointly. These results allow us to better define in what ways the presence of the other influences performance, in showing that when participants perform a task along with another individual, they display a disadvantage (i.e., slower RTs) when they have to respond to stimuli appearing on the other agent's side.

Response-repetition effects in task switching - dissociating effects of anatomical and spatial response discriminability

In task switching, response repetitions typically lead to performance benefits for task repetitions but costs for task switches. We examined whether this cost-benefit pattern is affected by response discriminability (RD), varying (a) the anatomical response separation (within-hand vs. between-hand responses) and (b) the spatial separation (close vs. far response keys). We assumed that anatomical RD increases response competition generally, whereas spatial RD increases the salience of left-right coding and thus facilitates response selection. In two experiments, we found that spatial RD increased the response-repetition costs in task switches but similarly decreased the response-repetition benefit in task repetitions. The effect of spatial RD was response-specific but did not interact with task switching. This data pattern is consistent with a recent account that proposed that facilitated response selection increases response "self-inhibition" after response execution. In contrast, the influence of anatomical RD primarily consisted of an overall increase of reaction-time level in all conditions, whereas error rates decreased, suggesting a general shift in response criterion. Taken together, the data suggest that a self-inhibition mechanism on the level of motor response codes contributes to response-repetition effects in task switching, which is possibly independent of task-specific mechanisms of strengthening of associations.

Three-dimensional spatial stimulus-response (S-R) compatibility for visual signals with hand and foot controls

This study investigated the performance of 24 participants in eight different three-dimensional spatial stimulus-response (S-R) mapping conditions. The stimulus visual signals were positioned at the corners of an imaginary cube, and responses were made by hands and feet. There was a significant interaction of visual signal position and response device position which demonstrated the existence of a strong spatial S-R compatibility effect in the task. Relatively faster reaction times and lower error percentages were obtained for the compatible S-R conditions. The spatial compatibility effect in the up-down dimension was the strongest, and the effect in the left-right dimension was stronger than the effect in the front-rear dimension. The findings of this study could be translated into practical and useful ergonomics recommendations for designing visual displays and control devices in three-dimensional space for improving overall human-machine system performance.

Response-specifying cue for action interferes with perception of feature-sharing stimuli

Perceiving a visual stimulus is more difficult when a to-be-executed action is compatible with that stimulus, which is known as blindness to response-compatible stimuli. The present study explored how the factors constituting the action event (i.e., response-specifying cue, response intention, and response feature) affect the occurrence of this blindness effect. The response-specifying cue varied along the horizontal and vertical dimensions, while the response buttons were arranged diagonally. Participants responded based on one dimension randomly determined in a trial-by-trial manner. The response intention varied along a single dimension, whereas the response location and the response-specifying cue varied within both vertical and horizontal dimensions simultaneously. Moreover, the compatibility between the visual stimulus and the response location and the compatibility between that stimulus and the response-specifying cue was separately determined. The blindness effect emerged exclusively based on the feature correspondence between the response-specifying cue of the action task and the visual target of the perceptual task. The size of this stimulus-stimulus (S-S) blindness effect did not differ significantly across conditions, showing no effect of response intention and response location. This finding emphasizes the effect of stimulus factors, rather than response factors, of the action event as a source of the blindness to response-compatible stimuli.

Modulation of spatial Stroop by object-based attention but not by space-based attention

Earlier studies have shown that the spatial Stroop effect systematically decreases when a peripheral precue is presented at the same location as the target, compared to an uncued location condition. In this study, two experiments were conducted to explore whether the cueing modulation of spatial Stroop is object based and/or space based. In Experiment 1, we found evidence favouring the view that the cueing modulation of the spatial Stroop effect is entirely object based, as no differences were found in conflict reduction for the same-location and same-object conditions. In Experiment 2, the cue was predictive, and a similar object-based modulation of spatial Stroop was still observed. However, the direction of such modulation was affected by the rectangles’ orientation. Overall, the pattern of results obtained favours the object-integration (Lupiáñez & Milliken, 1999; Lupiáñez, Milliken, Solano, Weaver, & Tipper, 2001) and referential-coding accounts (Danziger, Kingstone, & Ward, 2001) and seems to provide evidence against the attention-shift account (Rubichi, Nicoletti, Iani, & Umilta, 1997; Stoffer, 1991).

Influence of display type and cue format on task-cuing effects: dissociating switch cost and right-left prevalence effects

In previous studies of task switching and of the right-left prevalence effect, researchers have used a procedure in which the stimulus on each trial occurs in one of four quadrants, and responses are made by pressing one of two diagonally arranged response keys. Across these studies, discrepant effects of cuing interval have been reported. These discrepancies need clarification because cue-based preparation effects are frequently interpreted as reflecting cognitive control processes. In Experiment 1, we compared performance with display formats used by Meiran (1996; Meiran, Chorev, & Sapir, 2000; small display, cues located at sides of quadrants and displayed until response) to study task switching and by Proctor and colleagues (Proctor, Koch, & Vu, 2006; large display, cues located at center of display and shown until target onset) to study right-left prevalence. We found a decrease in task-switch cost with increasing cuing interval with the Meiran display, but not with the Proctor display, but the right-left prevalence effect was of similar size for the two display formats and was relatively unaffected by cuing interval. To determine the basis of the discrepant task-switch results, we used small and large displays in Experiments 2 and 3, respectively, with cue type and cue offset varied. With the side cues, the task-switch cost decreased in all cases at the longer cuing interval, but with the centered cues, it decreased only when the display size was small. Thus, the effects of cuing interval on switch costs are sensitive to variations of display characteristics, whereas cuing interval and display characteristics have little influence on the right-left prevalence effect, suggesting that prevalence effect is due to processes that are independent from those producing the switch cost.

Preparation for horizontal or vertical dimensions affects the right-left prevalence effect

When stimulus and response simultaneously vary in both horizontal and vertical dimensions, the stimulus-response compatibility effect is often larger for the horizontal dimension. We investigated the role of preparation for each dimension in this right-left prevalence. In Experiment 1, tasks based on horizontal and vertical dimensions were mixed in random order, and the relevant dimension in each trial was cued with a variable cue-target stimulus onset asynchrony (SOA). A right-left prevalence effect was observed only when participants prepared for the upcoming task. Experiment 2 replicated the absence of the prevalence effect for the simultaneous presentation of cue and target using a fixed SOA of 0 msec. In Experiment 3, the right-left prevalence emerged with a 0-msec SOA when participants prepared for e achdimension basedon its frequency. These resultssuggest that participants' internal set can be greater for the horizontal dimension, leading to the right-left prevalence effect.