Action control in task switching: do action effects modulate N - 2 repetition costs in task switching?

Ideomotor theory posits that actions are controlled by the anticipation of their effects. In line with this theoretical framework, response-contingent action effects have been shown to influence performance in choice-reaction time tasks, both in single-task and task-switching context. Using a task-switching paradigm, the present study investigated whether task-contingent action effects influenced N - 2 repetition costs in task switching. N - 2 repetition costs are thought to be related to task-switch costs, and reflect inhibitory control in task switching. It was expected that task-contingent action effects reduce between-task interference, leading to reduced N - 2 repetition costs. An experimental group (N = 24) performed eight blocks of trials with task-contingent action effects, followed by one block with non-contingent action effects; a control group (N = 24) performed nine blocks of trials with non-contingent action effects. In line with our expectations, a three-way interaction of group, block, and task sequence was obtained, indicating differential data patterns for the two groups: In error rates, the group who had received contingent action effects throughout blocks 1-8 showed larger N - 2 repetition costs in the random block 9 than in block 8, whereas the control group showed a reversed data pattern. The RT data pattern was in the same direction, although no significant three-way interaction was obtained. Taken together, we tentatively conclude that task-contingent action effects reduce task inhibition in task switching, and we outline directions for future research on the role of action effects in multitasking performance.

Positive and negative action-effects improve task-switching performance.

Anticipation of one's own actions' effects drives goal-directed behavior. In multitasking environments, the learning of stable action-effect associations seems particularly important, because establishing reliable response-effect associations for multiple competing tasks may help to differentiate between these tasks and thereby improve task-switching performance. Action-effects not only have cognitive, but also motivational aspects and often the consequences of our actions are hedonically marked. Thus, the anticipated hedonic quality of action-effects may also become part of the task representation, and positive and negative affect may distinctly modulate task-switching performance. We report a pre-registered experiment (N = 120) designed to examine how positive, negative, and neutral valence of action-effects impact performance in a cued task-switching paradigm. Pictures from the IAPS database were used to manipulate the action-effects' valence. Affective valence determined reaction times: participants who learned positive or negative action-effects responded faster than participants in the control condition. In particular, task-switch trials were faster in both conditions than in the control condition, while task-repetition trials were comparable across valence conditions. Our results further suggest that performance improvements in the positive and negative valence conditions occurred for different reasons. Negative action-effects expedited responses specifically for the task that produced the unpleasant outcome, while positive affect more generally promoted performance of both tasks. These findings point toward distinct roles of positive and negative valence of action-effects in regulating multitasking performance.

Switching attention between modalities: further evidence for visual dominance.

The present study examined cross-modal selective attention using a task-switching paradigm. In a series of experiments, we presented lateralized visual and auditory stimuli simultaneously and asked participants to make a spatial decision according to either the visual or the auditory stimulus. We observed consistent cross-modal interference in the form of a spatial congruence effect. This effect was asymmetrical, with higher costs when responding to auditory than to visual stimuli. Furthermore, we found stimulus-modality-shift costs, indicating a persisting attentional bias towards the attended stimulus modality. We discuss our findings with respect to visual dominance, directed-attention accounts, and the modality-appropriateness hypothesis.

Action-Effect Associations in Voluntary and Cued Task-Switching.

The literature of action control claims that humans control their actions in two ways. In the stimulus-based approach, actions are triggered by external stimuli. In the ideomotor approach, actions are elicited endogenously and controlled by the intended goal. In the current study, our purpose was to investigate whether these two action control modes affect task-switching differently. We combined a classical task-switching paradigm with action-effect learning. Both experiments consisted of two experimental phases: an acquisition phase, in which associations between task, response and subsequent action effects were learned and a test phase, in which the effects of these associations were tested on task performance by presenting the former action effects as preceding effects, prior to the task (called practiced effects). Subjects either chose freely between tasks (ideomotor action control mode) or they were cued as to which task to perform (sensorimotor action control mode). We aimed to replicate the consistency effect (i.e., task is chosen according to the practiced task-effect association) and non-reversal advantage (i.e., better task performance when the practiced effect matches the previously learned task-effect association). Our results suggest that participants acquired stable action-effect associations independently of the learning mode. The consistency effect (Experiment 1) could be shown, independent of the learning mode, but only on the response-level. The non-reversal advantage (Experiment 2) was only evident in the error rates and only for participants who had practiced in the ideomotor action control mode.

Number representation: a question of look? The distance effect in comparison of English and Turkish number words.

Cohen Kadosh found that Hebrew number words and Arabic digits elicited different distance effects. The numerical distance effect (i.e., faster reaction times and smaller error rates for numbers with larger distance to a standard number, e.g., 5) was smaller for number words than for digits. The author suggested that the result indicated a notation-dependent (i.e., nonabstract) numerical representation. Alternatively, however, it is possible that the distance effect was decreased by perceptual features of the Hebrew number words used as stimuli. To test this hypothesis, we replicated the study of Cohen Kadosh, but with English and Turkish number words compared to Arabic digits. The perceptual features of Turkish number words lead to the hypothesis that the opposite effect should be present: an increased distance effect for number words compared to Arabic digits. On the other hand, English number words show features similar to those of Hebrew number words, thus leading to the expectation of a decreased distance effect for them. Our results confirmed our hypotheses. We conclude that the distance effect can be influenced also by perceptual features in addition to the impact of numerical representations.

Crossmodal attention switching: auditory dominance in temporal discrimination tasks.

Visual stimuli are often processed more efficiently than accompanying stimuli in another modality. In line with this "visual dominance", earlier studies on attentional switching showed a clear benefit for visual stimuli in a bimodal visual-auditory modality-switch paradigm that required spatial stimulus localization in the relevant modality. The present study aimed to examine the generality of this visual dominance effect. The modality appropriateness hypothesis proposes that stimuli in different modalities are differentially effectively processed depending on the task dimension, so that processing of visual stimuli is favored in the dimension of space, whereas processing auditory stimuli is favored in the dimension of time. In the present study, we examined this proposition by using a temporal duration judgment in a bimodal visual-auditory switching paradigm. Two experiments demonstrated that crossmodal interference (i.e., temporal stimulus congruence) was larger for visual stimuli than for auditory stimuli, suggesting auditory dominance when performing temporal judgment tasks. However, attention switch costs were larger for the auditory modality than for visual modality, indicating a dissociation of the mechanisms underlying crossmodal competition in stimulus processing and modality-specific biasing of attentional set.

The influence of action effects in task-switching.

According to ideomotor theories, intended effects caused by a certain action are anticipated before action execution. In the present study, we examined the question of whether action effects play a role in cued task-switching. In our study, the participants practiced task-response-effect mappings in an acquisition phase, in which action effects occur after a response in a certain task context. In the ensuing transfer phase, the previously practiced mappings were changed in a random, unpredictable task-response-effect mapping. When changed into unpredictable action-effects, RT as well as switch-costs increased, but this occurred mainly in trials with short preparation time and not with long preparation time. Moreover, switch costs were generally smaller with predictable action-effects than with unpredictable action-effects. This suggests that anticipated task-specific action effects help to activate the relevant task-set before task execution when the task is not yet already prepared based on the cue.

The role of preparation and cue-modality in crossmodal task switching.

The present study examined the effects of cue-based preparation and cue-target modality mapping in crossmodal task switching. In two experiments, we randomly presented lateralized visual and auditory stimuli simultaneously. Subjects were asked to make a left/right judgment for a stimulus in only one of the modalities. Prior to each trial, the relevant stimulus modality was indicated by a visual or auditory cue. The cueing interval was manipulated to examine preparation. In Experiment 1, we used a corresponding mapping of cue-modality and stimulus modality, whereas in Experiment 2 the mapping of cue and stimulus modalities was reversed. We found reduced modality-switch costs with a long cueing interval, showing that attention shifts to stimulus modalities can be prepared, irrespective of cue-target modality mapping. We conclude that perceptual processing in crossmodal switching can be biased in a preparatory way towards task-relevant stimulus modalities.