Spatial Stimulus-response Correspondence Research Articles

Working memory load and its impact on space-based and motion-based stimulus-response correspondence (SRC) effects

ABSTRACT If spatial stimulus-response correspondence (SRC) effect results from automatic processes, cognitive load should not affect this effect. However, if spatial SRC effect is based on the interference of cognitive codes, cognitive load should influence it. Furthermore, the motion-based SRC effect should be affected by the cognitive load, as this SRC effect is related to the cognitive codes interference. In this study, participants performed combined tasks for space-based and motion-based SRC effects without working memory load (WML), or under spatial and verbal WML to see if cognitive load affects both SRC effects or just one. Results demonstrated that space-based SRC remained intact from WML, while the motion-based SRC was influenced by WML, although only in limited degree. This supports the notion that automatic processes underlie space-based SRC effect, whereas the motion-based SRC effect is related to cognitive codes interference, but the latter requires further investigation.

Space and Motion Stimulus-Response Correspondence (SRC) Effects in a Single Task.

Previous research indicated that congruency between stimulus location and response position (spatial stimulus-response correspondence [SRC]) and stimulus motion and response movement congruency (motion SRC) are distinct SRC phenomena. This study further explored this issue and tested whether these two SRC effects are independent. This was conducted by investigating these two SRC effects in a single task. A stimulus with leftward or rightward motion was presented on the left or the right side of the screen and the participant had to move the joysticks held with the left and right hands leftward or rightward in response to the stimulus color. In this setting, the stimulus and response shared two types of correspondence: spatial and motion. The results demonstrated that two SRC effects occurred and interacted (interaction evident only in reaction times [RTs]). RT distribution analysis and accuracy delta plots for each SRC effect indicated that spatial and motion SRC are distinct phenomena based on different processes.

Eye-blinks in choice response tasks uncover hidden aspects of information processing.

Spontaneous eye-blinks occur much more often than it would be necessary to maintain the tear film on the eyes. Various factors like cognitive demand, task engagement, or fatigue are influencing spontaneous blink rate. During cognitive information processing there is evidence that blinks occur preferably at moments that can be assigned to input stream segmentation. We investigated blinking behavior in three different visual choice response experiments (Experiment 1: spatial Stimulus-Response correspondence, Experiment 2: Change Detection, Experiment 3: Continuous performance Test - AX version). Blinks during the experimental tasks were suppressed when new information was expected, as well as during cognitive processing until the response was executed. Blinks in go trials occurred within a short and relatively constant interval after manual responses. However, blinks were not a side effect of manual behavior, as they occurred in a similar manner in no-go trials in which no manual response was executed. In these trials, blinks were delayed when a prepared response had to be inhibited, compared to trials in which no response was intended. Additionally, time on task effects for no-go blinks mirrored those obtained in go trials. Thus, blinks seem to provide a reliable measure for cognitive processing beyond (or rather additional to) manual responses.

The impact of response frequency on spatial stimulus–response correspondence effects

The present study explored how response preparation, varied by relative response frequency, affects response conflict as expressed in the Simon effect. Previous studies showed that valid response cues, when presented before the imperative stimulus, increase rather than decrease the Simon effect. This finding was explained by the hypothesis that response cues trigger shifts of attention to the side of the prepared response, and that these attention shifts modulate processing of the imperative stimulus. We investigated whether cues are necessary for inducing shifts of attention and thereby modulating the Simon effect, or whether response preparation without cues is sufficient. In two experiments, participants performed a Simon task with one response being more frequent than the other. Results showed larger Simon effects for the more frequent (i.e. prepared) response than for the less frequent (i.e. unprepared) response. These results suggest that response preparation (rather than the cue that induces the preparation) triggers a shift of spatial attention which modulates the Simon effect.

Space positional and motion SRC effects: A comparison with the use of reaction time distribution analysis.

The analysis of reaction time (RT) distributions has become a recognized standard in studies on the stimulus response correspondence (SRC) effect as it allows exploring how this effect changes as a function of response speed. In this study, we compared the spatial SRC effect (the classic Simon effect) with the motion SRC effect using RT distribution analysis. Four experiments were conducted, in which we manipulated factors of space position and motion for stimulus and response, in order to obtain a clear distinction between positional SRC and motion SRC. Results showed that these two types of SRC effects differ in their RT distribution functions as the space positional SRC effect showed a decreasing function, while the motion SRC showed an increasing function. This suggests that different types of codes underlie these two SRC effects. Potential mechanisms and processes are discussed.

Independence of serial position and response conflict in pre-planned manual response sequences

The present study investigates the effect of spatial stimulus–response correspondence (i.e. Simon effect) in pre-planned manual response sequences. Participants performed pre-cued response sequences consisting of three (Experiment 1) or four (Experiments 2 and 3) key-presses at different locations. Importantly, participants performed each response to a visual go signal, which appeared at a location corresponding to one response in the sequence. This task allowed investigating interference gradients across spatially noncorresponding conditions. We observed a Simon effect at each serial position, that is, RT for the corresponding condition was always shorter than RT for each noncorresponding condition. However, we failed to observe interference gradients from both preceding and subsequent responses in the sequence. These results are inconsistent with (1) a primacy gradient of activations representing serial order and (2) the temporary suppression of an executed response as a mechanism for preventing response repetitions. However, results provide indirect evidence for positional models of serial order.

The Virtual Co-Actor: The Social Simon Effect does not Rely on Online Feedback from the Other

The social Simon effect (SSE) occurs if two participants share a Simon task by making a Go/No-Go response to one of two stimulus features. If the two participants perform this version of the Simon task together, a Simon effect occurs (i.e., performance is better with spatial stimulus–response correspondence), but no effect is observed if participants perform the task separately. The SSE has been attributed to the automatic co-representation of the co-actor's actions, which suggests that it relies on online information about the other's actions. To test this implication, we investigated whether the SSE varies with the presence and amount of online action-related feedback from the other person. Experiment 1 replicated the SSE with auditory stimuli. Experiment 2, in which participants were blindfolded, demonstrated that visual feedback from the other's actions is not necessary for the SSE to occur. Experiment 3 replicated Experiment 2 with a regular and a soundless keyboard. A comparable SSE was obtained in both conditions, suggesting that even auditory online input from the other's actions is not necessary. Taken together, our data suggest that the SSE does not rely on online information about the co-actor's actions but that a priori offline information about another actor's presence is sufficient to generate the effect.

Visual Motion Induces Effector Movement

A left-hand response to a left-hand stimulus is faster than a right-hand response to the same stimulus, even when spatial location is irrelevant to the task at hand. The existence of this spatial stimulus-response correspondence effect suggests that spatial properties of actions to be performed can be pre-specified by spatial properties of perceived events, so that actions are induced by perceptual content. If this view is correct, one should be able to show that not only spatial positions of actions can be pre-specified by properties of perceived events, but other features of actions as well. Specifically, I attempt to show that the direction of a to-be-executed movement can be specified by the direction of a moving stimulus. To study this question a variant of the Simon paradigm was developed: subjects were required to monitor a spot-like stimulus moving from left to right or from right to left on a display. At some point in time the spot would change its colour (from white to blue or red) and the subject had to respond differentially to the respective colour. Two aspects of this situation were varied. First, the type of the action-relevant signal was varied: it could either be a dynamic moving signal or a static non-moving one. Second, the type of response was varied: subjects were required to respond to the colour either with a dynamic response (moving a stylus to the left or right) or with a more static response (pressing a button on the left or on the right).

Conditional and unconditional automaticity: A dual-process model of effects of spatial stimulus-response correspondence.

Conditional and unconditional automaticity: A dual-process model of effects of spatial stimulus-response correspondence.

Conditional and unconditional automaticity: a dual-process model of effects of spatial stimulus-response correspondence.

Distributional analyses and event-related brain potential were used to show that effects of irrelevant spatial stimulus-response correspondence consist of 2 qualitatively different automatic components that can be distinguished on the basis of their dependencies on relative response speed and on computational requirements of the primary task. One component reflects priming of the spatially corresponding response by an abrupt stimulus onset that does not depend on the nature of the primary task. This unconditional component exhibits a biphasic pattern, with initial facilitation later turning into inhibition, analogous to that found for spatial cuing in visual detection tasks. The 2nd component reflects automatic generalization of task-defined transformations of relevant stimulus information to spatial codes; this conditional component does not depend on relative response speed. Possible connectionist implementations of the conditional mechanism are discussed.

The role of attention for the Simon effect.

It has been claimed that spatial attention plays a decisive role in the effect of irrelevant spatial stimulus-response correspondence (i.e., the Simon effect), especially the way the attentional focus is moved onto the stimulus (lateral shifting rather than zooming). This attentional-movement hypothesis is contrasted with a referential-coding hypothesis, according to which spatial stimulus coding depends on the availability of frames or objects of reference rather than on certain attentional movements. In six experiments, reference objects were made available to aid spatial coding, which either appeared simultaneously with the stimulus (Experiments 1-3), or were continuously visible (Experiments 4-6). In contrast to previous experiments and to the attentional predictions, the Simon effect occurred even though the stimuli were precued by large frames surrounding both possible stimulus positions (Experiment 1), even when the reference object's salience was markedly reduced (Experiment 2), or when the precueing frames were made more informative (Experiment 3). Furthermore, it was found that the Simon effect is not reduced by spatial correspondence between an uninformative spatial precue and the stimulus (Experiment 4), and it does not depend on the location of spatial precues appearing to the left or right of both possible stimulus locations (Experiment 5). This was true even when the precue was made task-relevant in order to ensure attentional focusing (Experiment 6). In sum, it is shown that the Simon effect does not depend on the kind of attentional operation presumably performed to focus onto the stimulus. It is argued that the available data are consistent with a coding approach to the Simon effect which, however, needs to be developed to be more precise as to the conditions for spatial stimulus coding.

Learning and performance on a key-pressing task as function of the degree of spatial stimulus-response correspondence.

Learning and performance on a key-pressing task as function of the degree of spatial stimulus-response correspondence.