Display-control arrangement correspondence and logical recoding in the Hedge and Marsh reversal of the Simon effect

The effect of irrelevant response dimension on stimulus response compatibility

The well-known Stroop, Simon, and Eriksen flanker effects reflect the influence of an irrelevant dimension of a stimulus on task performance. In contrast, this study investigated the effect of an irrelevant (color) dimension of a response on performance. In Experiment 1, participants performed a color-discrimination Simon task with left and right responses. The novel feature of the experiment was that two-colored labels were presented at the bottom of the display, on the left and right side respectively, which were irrelevant to the task and had nothing to do with response keys. The results revealed a Color Compatibility effect. Participants responded faster and more accurately when the color of the label appearing on the same side (left or right) as the correct response matched the color of the stimulus than when it did not. Experiment 2A replicated the Color Compatibility effect. Experiment 2B showed that the Color Compatibility effect in reaction times disappeared when color was irrelevant to both the stimulus and the response. The results suggest that the presence of an irrelevant color dimension at response may result in a stimulus-response compatibility (SRC) effect as long as the color is represented in working memory. These studies have implications for the dimensional overlap model and the broader understanding of stimulus-response compatibility effects.

Impaired conflict monitoring near the hands: Neurophysiological evidence

Recent evidence suggests that hand-stimulus proximity enhances the visuo-motor Simon effect. The present study used event-related potentials (ERP) to examine the timing at which hand-stimulus proximity modulates the Simon effect. The results show that the P1 and N1 components were not modulated by hand-stimulus proximity, suggesting that early sensory processing is not altered by hand-stimulus proximity. However, the interference effect (the difference between incompatible versus compatible trials) on the N2 component was significantly attenuated near the hands compared to far from the hands, indicating that hand-stimulus proximity impairs conflict monitoring. We also found significant effects on a later component, as the P3 was reduced and had a shorter latency for the hand-proximal condition relative to the hand-distal condition. These new findings suggest that the critical stage at which hand-stimulus proximity affects cognitive processing lies past the early perceptual processing, acting instead on later stages of processing related to executive functioning.

Temporal and spectral dynamics underlying cognitive control modulated by task-irrelevant stimulus-response learning

Behavioral and recent neuroimaging findings have shown reversal of interference effects due to manipulating proportion congruency (PC), which suggests that task-irrelevant stimulus-response (S-R) associations are strengthened and applied to predict responses. However, it is unclear how the strengthened S-R associations are represented and applied in the brain. We investigated with a between-subjects PC paradigm of the Hedge and Marsh task using electroencephalography (EEG). The behavioral results showed the reversal of the conflict effects, suggesting that task-irrelevant S-R associations were strengthened and used to prepare responses. The EEG results revealed the PC-related reversal of the conflict effects in the frontocentral N2 and parietal P3b amplitudes. Time-frequency analyses showed more pronounced PC-related reversal of the conflict effects in theta band (4-8 Hz) activity in frontocentral sites. These results suggest that the strengthened S-R associations due to PC manipulation modulated cognitive control. Importantly, the amplitude of lateralized readiness potential was higher in the high-PC condition than in the low-PC condition, suggesting that the strengthened short-term-memory spatial S-R associations that modulated cognitive control were applied similarly to long-term-memory spatial S-R associations.

Transfer of an implied incompatible spatial mapping to a Simon task

When location words left and right are presented in left and right locations and mapped to left and right keypress responses in the Hedge and Marsh (1975) task (Arend & Wandmacher, 1987), a compatible mapping of words to responses yields a benefit for stimulus-response location correspondence (sometimes called the Simon effect), whereas an incompatible mapping yields a benefit for noncorrespondence (called the Hedge and Marsh reversal). Experiment 1 replicated the correspondence benefit and its reversal by using Chinese location words [symbol: see text] (left) and [symbol: see text] (right) in the Hedge and Marsh task. Experiments 2 and 3 examined whether the tendency to respond with the noncorresponding response when the mapping is incompatible transfers to the task version in which the mapping is compatible, and Experiment 4 examined whether transfer similarly occurs from the compatible mapping to the task version with incompatible mapping. Transfer of the incompatible relation was apparent in a lack of correspondence benefit when the mapping was changed to compatible, but transfer of the compatible relation to the incompatible mapping did not occur. The results suggest that an association between noncorresponding stimulus-response locations is acquired when the word-response mapping is incompatible, even though this relation is only implicit, regardless of whether through misapplication of a logical recoding rule or spatial representations shared by the locations and words. These associations then continue to affect processing of location when the mapping is compatible.

Implicitly strengthened task-irrelevant stimulus-response associations modulate cognitive control: Evidence from an fMRI study

The dynamics of cognitive control have been investigated by the proportion congruency effect. However, the theory that this effect is due to attentional modulation has been challenged by contingency learning accounts. This raises the question of how the cognitive control system operates during and after increasing the strength of task-irrelevant stimulus-response (S-R) associations. We employed a novel paradigm that elicits positive and reversed Simon effects via task rule manipulations, and combined it with a between subjects proportion congruency manipulation. The pattern of enhancement and reversal of the positive and reversed Simon effects across conditions suggested that participants used strengthened task-irrelevant S-R associations to predict responses. Functional neuroimaging identified proportion congruency effects that interacted with task S-R associations, showing greater activity when strengthened task-irrelevant S-R associations conflicted with task-defined S-R associations in frontoparietal regions, including bilateral superior parietal lobule (SPL) and dorsal premotor cortex (dPMC), presupplementary motor area/anterior midcingulate cortex (Pre-SMA/aMCC), and left dorsolateral prefrontal cortex (DLPFC). These results suggest that the aMCC and DLPFC shifted to responding mainly to the conflict induced by the strengthened irrelevant S-R associations. The SPL and dPMC might represent the strengthened irrelevant S-R associations. Hum Brain Mapp 37:756-772, 2016. © 2015 Wiley Periodicals, Inc.

Is automatic imitation a specialized form of stimulus-response compatibility? Dissociating imitative and spatial compatibilities

In recent years research on automatic imitation has received considerable attention because it represents an experimental platform for investigating a number of interrelated theories suggesting that the perception of action automatically activates corresponding motor programs. A key debate within this research centers on whether automatic imitation is any different than other long-term S-R associations, such as spatial stimulus-response compatibility. One approach to resolving this issue is to examine whether automatic imitation shows similar response characteristics as other classes of stimulus-response compatibility. This hypothesis was tested by comparing imitative and spatial compatibility effects with a two alternative forced-choice stimulus-response compatibility paradigm. The stimulus on each trial was a left or right hand with either the index or middle finger tapping down. Speeded responses were performed with the index or middle finger of the right hand in response to the identity or the left-right spatial position of the stimulus finger. Two different tasks were administered: one that involved responding to the stimulus (S-R) and one that involved responding to the opposite stimulus (OS-R; i.e., the one not presented on that trial). Based on previous research and a connectionist model, we predicted standard compatibility effects for both spatial and imitative compatibility in the S-R task, and a reverse compatibility effect for spatial compatibility, but not for imitative compatibility, in the OS-R task. The results from the mean response times, mean percentage of errors, and response time distributions all converged to support these predictions. A second noteworthy result was that the recoding of the finger identity in the OS-R task required significantly more time than the recoding of the left-right spatial position, but the encoding time for the two stimuli in the S-R task was equivalent. In sum, this evidence suggests that the processing of spatial and imitative compatibility is dissociable with regard to two different processes in dual processing models of stimulus-response compatibility.

Colour Correspondence Effects between Controlled Objects and Targets

It is increasingly popular to use movement trajectories as a measure of mental processes related to task performance. Often this is accomplished by moving a cursor to a target on a computer screen. However, the relation between features of the cursor and the targets is rarely, if at all, considered. In five experiments, we examined whether moving a cursor to a target was affected by the relation between their colours, even when this relation was task irrelevant. In Experiments 1–3, a mouse-controlled cursor was moved to one of two coloured targets. Results showed colour correspondence effects in latency to initiate a response, duration of movement times, and movement trajectories when the relationship between cursor and target colours was task relevant (Experiment 1) and when only the cursor colour was task relevant (Experiment 2), but not when only the target was task relevant (Experiment 3). Follow-up experiments using single targets showed that colour correspondence effects occurred as long as attention was dedicated to the colour of the cursor, even when neither the cursor nor the target colour was relevant to selecting the correct movement (Experiments 4 and 5). Furthermore, when the relation between cursor and target colours is task irrelevant, colour correspondence effects for response initiation times are uncorrelated with those for movement times and movement trajectories. We interpret the observed correspondence effect in terms of response coding, although attention cueing may also play a role, and suggest that greater consideration of cursor features is needed when examining movement trajectories in choice reaction tasks.

Congruency reversals in an accessory signal Simon task with auditory and visual stimuli

In visual two-choice reaction-time tasks, a Simon-like effect occurs when a peripheral accessory signal is presented shortly before or together with the response signal. However, the effect reverses when the peripheral signal appears shortly after the response signal. This pattern also occurs when the peripheral signal appears relative to a go (nogo) signal, with the relevant signal presented well in advance. The reversal has been explained as the inhibition of exogenous response-code activation as soon as an action plan has been developed. In three experiments we investigated whether the inhibition also occurred with auditory and crossmodal stimuli. A Simon effect appeared in all experiments, but the reversal only occurred when peripheral and relevant response signals were auditory, and not when the relevant and irrelevant signals were in a different modality. We suggest that planned actions are protected against exogenous interference by a modality-specific inhibitory process, determined by the relevancy of the modality of the peripheral accessory signal.

Parallel and distributed neural models of the ideomotor principle: An investigation of imitative cortical pathways

Humans' capacity to imitate has been extensively investigated through a wide-range of behavioral and developmental studies. Yet, despite the huge amount of phenomenological evidence gathered, we are still unable to relate this behavioral data to any specific neural substrate. In this paper, we investigate how principles from psychology can be the result of neural computations and therefore attempt to bridge the gap between monkey neurophysiology and human behavioral data, and hence between these two complementary disciplines. Specifically, we address the principle of ideomotor compatibility, by which 'observing the movements of others influences the quality of one's own performance' and develop two neural models which account for a set of related behavioral studies [Brass, M., Bekkering, H., Wohlschläger, A., & Prinz, W. (2000). Compatibility between observed and executed finger movements: comparing symbolic, spatial and imitative cues. Brain and Cognition 44, 124-143]. We show that the ideomotor effect could be the result of two distinct cognitive pathways, which can be modeled by means of biologically plausible neural architectures. Furthermore, we propose a novel behavioral experiment to confirm or refute either of the two model pathways.

The enhanced Simon effect for older adults is reduced when the irrelevant location information is conveyed by an accessory stimulus

The Simon effect, better performance when irrelevant stimulus location corresponds with the response location than when it does not, typically is larger for older than younger adults. However, Simon and Pouraghabagher [Simon, R. J., & Pouraghabagher, A. R. (1978). The effect of aging on the stages of processing in a choice reaction time task. Journal of Gerontology, 33, 553-561] found no age difference using an accessory-stimulus Simon task in which the relevant dimension was the color of a visual stimulus and the irrelevant dimension the location of a tone. Experiment 1 confirmed that older adults show a larger Simon effect than younger adults for the visual Simon task and that this age-related deficit is reduced or eliminated for the auditory-accessory task. Experiment 2 provided evidence suggesting that a small part of the age-related deficit in the visual Simon task is due to having to code the location of the relevant stimulus, but Experiment 3 showed that the majority of the deficit is due to the relevant and irrelevant information being conveyed by the same stimulus. Reaction-time distribution analyses show similar functions for younger and older adults, suggesting that the time course of activation is similar for both age groups.