Exploring "phasic" vs. "tonic" accounts of the effect of switch probability on the auditory attention switch cost.

Task-switching experiments have shown that the "switch cost" (poorer performance for task switches than for repetitions) is smaller when the probability of a switch is high (e.g., 0.75) than when it is low (e.g., 0.25). Some theoretical accounts explain this effect in terms of top-down control deployed in advance of the task cue ("pre-cue reconfiguration"). We tested such accounts by manipulating the time available before the onset of the cue (the response-cue interval, RCI), reasoning that top-down pre-cue reconfiguration requires time and therefore its effect should increase with RCI. Participants heard a man and a woman simultaneously speaking number words and categorised the number (< 5 vs. > 5) spoken by the voice specified by a pictorial gender-related cue presented at an RCI of 100 ms or 2,200 ms. The target voice switched with a probability of 0.25 or 0.75 (in separate sessions). In Experiment 1, RTs revealed a large effect of switch probability on the switch cost in the short RCI, which did not increase in the long RCI. Errors hinted at such an increase, but it did not receive clear statistical support and was disconfirmed by a direct and better powered replication in Experiment 2, which fully confirmed the RT pattern from Experiment 1. Thus, the effect of switch probability on the switch cost required little/no time following the response to emerge-it was already at full magnitude at a short RCI-challenging accounts that assume "phasic" deployment of top-down task-set control in advance of the cue.

Reassessing the role of language dominance in n-2 language repetition costs as a marker of inhibition in multilingual language switching.

Speaking two or more languages shows bilingual flexibility, but flexible switching requires language control and often incurs performance costs. We examined inhibitory control assessing n-2 repetition costs when switching three languages (L1 [German], L2 [English], L3 [French]). These costs denote worse performance in n-2 repetitions (e.g., L2-L3-L2) than in n-2 nonrepetitions (e.g., L1-L3-L2), indicating persisting inhibition. In two experiments (n = 28 in Experiment 1; n = 44 in Experiment 2), n-2 repetition costs were observed, but only for L2. Looking into L2 trials specifically, we found n-2 repetition costs when switching back to L2 from the still weaker L3 but not when returning from the stronger L1, suggesting that L2 is a strong competitor for L3 (requiring L2 inhibition) but less so for L1. Finding n-2 repetition costs supports an inhibitory account of language control in general, but our study shows only partial evidence for the theoretically assumed more specific relation between language dominance and language inhibition (i.e., only for dominance relations with respect to L1 and L3 when switching back to L2). Taken together, the findings thus suggest the need for further refinement of the concept of language dominance and its relation to inhibition. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Examining the cognitive processes underlying resumption costs in task-interruption contexts: Decay or inhibition of suspended task goals?

To examine whether an ongoing primary task is inhibited when switching to an interruption task, we implemented the n - 2 backward inhibition paradigm into a task-interruption setting. In two experiments, subjects performed two primary tasks (block-wise manipulation) consisting of a predefined sequence of three subtasks. The primary tasks differed regarding whether the last subtask switched or repeated relative to the penultimate subtask, resulting in n - 1 switch subtasks (e.g., ABC) and n - 1 repetition subtasks (e.g., ACC) as the last subtask of the primary task. Occasionally, an interruption task was introduced before the last subtask of a primary task, changing the last subtask of the primary task from a n - 1 switch subtask to a n - 2 switch subtask (e.g., AB → secondary task → C) and from a n - 1 repetition subtask to a n - 2 repetition subtask (e.g., AC → secondary task → C). In two experiments with different degrees of response-set overlap between the interruption task and the subtasks of the primary task, we observed that switching back from the interruption task to the primary task resulted in n - 2 switch costs in the first subtask after the interruption (i.e., worse performance in n - 2 switch subtasks than in n - 2 repetition subtasks). This n - 2 switch cost was replicated in a third experiment in which we used a predefined sequence of four subtasks instead of three subtasks. Our finding of n - 2 switch costs suggest that the last subtask performed before the interruption remains activated when switching to the interruption task.

Repetition costs in task switching are not equal to cue switching costs: evidence from a cue-independent context.

Recent task-switching studies highlighted the presence of feature binding processes. These studies documented that even a task-irrelevant feature (the context, henceforth) may be bound with the task and the response in each trial. When the context repeated in the following trial, it supposedly retrieved the bound features, causing benefits when the task and the response repeated and costs otherwise (i.e. full repetition benefits). In the present study, we aim to rule out an alternative explanation for such full repetition benefits in task switching. These benefits were observed in studies that used a cue-related context so that full repetition conditions always implied a cue repetition. Therefore, these full repetition benefits may be ascribed to the priming of cue encoding, instead of the binding of the context. In the present study, we implemented a similar context manipulation but used univalent target stimuli and did not present any cue. Hence, the varying context was never cue-related. We still found full repetition benefits but only when the context appeared before the target and not when they appeared simultaneously. Thus, full repetition benefits can be observed in the absence of priming of cue encoding. However, the context must occupy a prominent position (i.e. at the beginning of the trial). These results, therefore, reinforce the hypothesis that full repetition benefits stem from binding processes that take place on a trial-by-trial basis and involve both task-relevant (the task and the response) and task-irrelevant features (the context).

Comparing partial repetition costs in two- and four-choice tasks: Evidence for abstract relational codes.

Responses are slower in two-choice tasks when either a previous stimulus feature or the previous response repeats than when all features repeat or all features change. Current views of action control posit that such partial repetition costs (PRCs) index the time to update a prior "binding" between a stimulus feature and the response or to resolve processing conflicts between retrieved and current features. However, violating a heuristic that stimulus feature repetitions and changes "signal" repetitions or changes of the previous response, respectively, may also contribute to such costs. To determine whether such relational codes affect performance, we compared PRCs in two- and four-choice tasks. While a stimulus feature repetition signals a response repetition in both tasks, a stimulus feature change signals a specific alternative response only in a two-choice task. Consistent with the signaling hypothesis, we observed similar complete repetition benefits in the two- and four-choice tasks but smaller complete change benefits in the four-choice task. We also investigated whether the smaller complete change benefit in the four-choice task-that is, the signaling effect-varies with the validity of the signal in the previous trial. In all four experiments, we observed a larger signaling effect after trials in which stimulus changes or repetitions corresponded to response changes or repetitions, respectively, than after trials in which stimulus changes did not correspond with response changes. We conclude that signaling contributes to PRCs, which indicates that bindings include relational codes. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Repetition costs in sequence chunking.

We examined how flexibly we plan sequences of actions when we switch between multiple action sequences. Mastering a sequential skill is assumed to involve integrating successive actions into groups known as chunks that can be efficiently planned and smoothly executed. Chunking is suggested by gains in planning efficiency for long compared to short action sequences following practice and learning associations between actions and perceptual outcomes. Less is understood about how efficiently we plan sequential chunks when we switch between multiple action sequences. Do we plan learned chunks less efficiently when we switch to a different action sequence? We examined this question by comparing the initiation and execution latencies of long versus short action sequences, performed from memory, when sequences switched or repeated across trials. Additionally, each action within the sequences generated predictable perceptual outcomes that were either spatially compatible or spatially incompatible with the action sequences. Results suggested repetition costs (instead of benefits) when performing long sequences. Repetition, as opposed to switching, prolonged initiation and increased the error rate of long compared to short sequences. We attribute these results to the flexible coordination of chunk planning and execution. Repetition may prolong advanced planning of long sequences in order to resolve conflict between multiple chunks, and switching may allow the planning of later chunks to be postponed until execution. We propose that the chunking of action sequences can both facilitate and interfere with action-switching performance.

Response-repetition costs in task switching do not index a simple response-switch bias: Evidence from manipulating the number of response alternatives.

Response repetitions aid performance when a task repeats but impair performance when a task switches. Although this interaction is robust, theoretical accounts remain controversial. Here, we used an un-cued, predictable task-switching paradigm with univalent targets to explore whether a simple bias to switch the response when the task switches can explain the interaction. In Experiment 1A (n = 40), we replicated the basic interaction in a two-choice task. In Experiment 1B (n = 60), we observed the same interaction in a three-choice task, wherein a bias to switch the response when the task switches cannot prime a specific alternative response because both remaining response alternatives are equally likely. Exploratory comparisons revealed a larger interaction between task repetition and response repetition in the three-choice task than in the two-choice task for mean response time (RT) and the opposite pattern for mean error rate (ER). Critically, in the three-choice task, response-repetition costs in task switches were significant in both RT and ER. Since a bias to switch the response cannot prime a specific response alternative in a three-choice task, we conclude that such a bias cannot account for response-repetition costs in task-switch trials.

Disentangling task-selection failures from task-execution failures in task switching: an assessment of different paradigms.

Differentiating errors on the basis of the distinct cognitive mechanisms that may have generated them has provided neuropsychologists with useful diagnostic tools. For example, perseverative errors arising from the inability of the patient to set a new criterion for responding are considered one of the hallmarks of cognitive inflexibility. Similarly, in the task-switching paradigm it is possible to distinguish between task-confusion errors, produced by a failure in task selection, and response-confusion errors, arising when the correct task is selected, but the wrong response is given. Nonetheless, only a few studies so far have exploited the existence of different kinds of errors in multitasking situations to inform theories of cognitive flexibility. In the present study, we set out to use a variety of methodologies employed so far in the literature for disentangling errors due to task-selection failure from errors due to task-execution failure. In three experiments, we assessed the capacity of each method to produce error categories that can be mapped as clearly as possible to the cognitive mechanism(s) underlying them using multinomial processing tree modelling. Subsequently, the distinction between task- and response-confusion errors was used to test their differential impact on inhibitory mechanisms in task switching as measured by N-2 repetition costs. Our results are encouraging regarding the possibility of correctly detecting response- and task-selection failures, thus allowing us to assess their differential impact on N-2 repetition costs.

Partial repetition costs index a mixture of binding and signaling.

People respond more slowly in two-choice tasks when either a previous stimulus feature or the previous response repeats in partial repetition trials than when (a) both repeat in complete repetition trials or (b) both alternate in complete alternation trials. The binding account posits that such partial repetition costs index a memory-retrieval conflict, which occurs because partial repetition trials trigger the retrieval of a previous stimulus feature or response that conflicts with a current stimulus feature or response. However, such costs may additionally reflect a simple decision-making heuristic that uses the repetition or alternation of a previous stimulus feature as a "signal" to bias response selection toward a repetition or an alternation of the previous response. To determine whether signaling contributes to partial repetition costs, we employed a four-choice task. Here, a stimulus feature repetition still signals a response repetition, but a stimulus feature alternation does not signal which of the three remaining responses to make. Consistent with an influence of signaling, we sometimes observed complete repetition advantages without complete alternation advantages. Exploratory analyses further revealed that partial repetition costs measured more broadly were smaller in the four-choice task than in a matched two-choice task. These findings suggest that partial repetition costs index a mixture of binding and signaling.

Are some effector systems harder to switch to? In search of cost asymmetries when switching between manual, vocal, and oculomotor tasks.

In task-switching studies, performance is typically worse in task-switch trials than in task-repetition trials. These switch costs are often asymmetrical, a phenomenon that has been explained by referring to a dominance of one task over the other. Previous studies also indicated that response modalities associated with two tasks may be considered as integral components for defining a task set. However, a systematic assessment of the role of response modalities in task switching is still lacking: Are some response modalities harder to switch to than others? The present study systematically examined switch costs when combining tasks that differ only with respect to their associated effector systems. In Experiment 1, 16 participants switched (in unpredictable sequence) between oculomotor and vocal tasks. In Experiment 2, 72 participants switched (in pairwise combinations) between oculomotor, vocal, and manual tasks. We observed systematic performance costs when switching between response modalities under otherwise constant task features and could thereby replicate previous observations of response modality switch costs. However, we did not observe any substantial switch-cost asymmetries. As previous studies using temporally overlapping dual-task paradigms found substantial prioritization effects (in terms of asymmetric costs) especially for oculomotor tasks, the present results suggest different underlying processes in sequential task switching than in simultaneous multitasking. While more research is needed to further substantiate a lack of response modality switch-cost asymmetries in a broader range of task switching situations, we suggest that task-set representations related to specific response modalities may exhibit rapid decay.

Correction: Assessing the Evidence for Asymmetrical Switch Costs and Reversed Language Dominance Effects - A Meta-Analysis.

[This corrects the article DOI: 10.5334/joc.186.].

Assessing the Evidence for Asymmetrical Switch Costs and Reversed Language Dominance Effects - A Meta-Analysis.

Two seemingly counterintuitive phenomena - asymmetrical language switch costs and the reversed language dominance effect - prove to be particularly controversial in the literature on language control. Asymmetrical language switch costs refer to the larger costs for switching into the dominant language compared to switching into the less dominant language, both relative to staying in either one language. The reversed language dominance effect refers to longer reaction times when in the more dominant of the two languages in situations that require frequent language switching (i.e., mixed-language blocks). The asymmetrical language switch costs are commonly taken as an index for processes of transient, reactive inhibitory language control, whereas the reversed language dominance effect is taken as an index for sustained, proactive inhibitory language control. In the present meta-analysis, we set out to establish the empirical evidence for these two phenomena using a Bayesian linear mixed effects modelling approach. Despite the observation of both phenomena in some studies, our results suggest that overall, there is little evidence for the generality and robustness of these two effects, and this holds true even when conditions - such as language proficiency and preparation time manipulations - were included as moderators of these phenomena. We conclude that asymmetrical switch costs and the reversed language dominance effect are important for theory development, but their utility for theory testing is limited due to their lack of robustness and the absence of confirmed moderatory variables.

Errors in task switching: Investigating error aftereffects in a N-2 repetition cost paradigm.

Studies of switching between tasks and studies of error commission have both provided solid behavioral measures of executive control. Nonetheless, a gap remains between these strands of research. In three experiments we sought to reduce this gap by assessing the impact of task errors on N-2 repetition costs, an effect supposedly related to task-set inhibition. Based on previous literature reporting a task-switch benefit following task errors, due to incidental learning of the erroneously executed task-set, we predicted N-2 repetition costs to be decreased after task errors in Trial N-2, relative to correct responses. Furthermore, we predicted this effect to be present only when corrective control mechanisms would not have the time to build up on the post-error trial (i.e., following fast post-error trial only). This hypothesis was tested in a three-tasks paradigm using incongruent stimuli, under the assumption that errors on such trials are partly due to task confusions. Consistent with our predictions, N-2 repetition costs following N-2 errors were found to be reduced when responses in Trial N-1 were fast but were present when the N-1 response was slow. Taken together, our results suggest that task execution leads to associative strengthening of the corresponding task-set, irrespective of response accuracy, and that such automatic strengthening can be counteracted by slowly acting control mechanisms. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Examining binding effects on task switch costs and response-repetition effects: Variations of the cue modality and stimulus modality in task switching.

Typically, response-repetition effects are obtained in task-switching experiments: In task repetitions, performance is enhanced when the response, too, repeats (response-repetition benefits), whereas in task switches, performance is impaired when the response repeats (response-repetition costs). A previous study introduced cue modality switches in a cued task-switching paradigm with visual stimuli and obtained enhanced response-repetition benefits when the cue modality repeated (Koch, Frings, & Schuch Psychological Research, 82, 570-579, 2018). In the present study, we aimed to replicate this finding with auditory stimuli (Exp. 1), and further examined whether response-repetition effects could be modulated by introducing stimulus modality switches (Exp. 2). We found clear evidence that the cue modality and stimulus modality affect task switch costs. The task switch costs were higher with a repeated cue modality or stimulus modality. However, cue modality switches or stimulus modality switches did not affect the response-repetition effects. We suggest that response-repetition effects are elicited by response-associated bindings, which are not necessarily affected by all episodic task features to the same extent. Our results are also in line with theoretical accounts that assume a hierarchical organization of task selection and response selection.

Putting a stereotype to the test: The case of gender differences in multitasking costs in task-switching and dual-task situations.

According to a popular stereotype, women are better at multitasking than men, but empirical evidence for gender differences in multitasking performance is mixed. Previous work has focused on specific aspects of multitasking or has not considered gender differences in abilities contributing to multitasking performance. We therefore tested gender differences (N = 96, 50% female) in sequential (i.e., task switching) and concurrent (i.e., dual tasking) multitasking, while controlling for possible gender differences in working memory, processing speed, spatial abilities, and fluid intelligence. Applying two standard experimental paradigms allowed us to test multitasking abilities across five different empirical indices (i.e., performance costs) for both reaction time (RT) and accuracy measures, respectively. Multitasking resulted in substantial performance costs across all experimental conditions without a single significant gender difference in any of these ten measures, even when controlling for gender differences in underlying cognitive abilities. Thus, our results do not confirm the widespread stereotype that women are better at multitasking than men at least in the popular sequential and concurrent multitasking settings used in the present study.

What absent switch costs and mixing costs during bilingual language comprehension can tell us about language control.

In the current study, we set out to investigate language control, which is the process that minimizes cross-language interference, during bilingual language comprehension. According to current theories of bilingual language comprehension, language-switch costs, which are a marker for reactive language control, should be observed. However, a closer look at the literature shows that this is not always the case. Furthermore, little to no evidence for language-mixing costs, which are a marker for proactive language control, has been observed in the bilingual language comprehension literature. This is in line with current theories of bilingual language comprehension, as they do not explicitly account for proactive language control. In the current study, we further investigated these two markers of language control and found no evidence for comprehension-based language-switch costs in six experiments, even though other types of switch costs were observed with the exact same setup (i.e., task-switch costs, stimulus modality-switch costs, and production-based language-switch costs). Furthermore, only one out of three experiments showed comprehension-based language-mixing costs, providing the first tentative evidence for proactive language control during bilingual language comprehension. The implications of the absence and occurrence of these costs are discussed in terms of processing speed and parallel language activation. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Investigating the impact of dynamic and static secondary tasks on task-switch cost.

Many researchers have employed secondary tasks, which have to be performed in parallel with a primary task requirement, to examine how successful task selection is accomplished in the context of task switching. The influence of such a secondary task on the observed switch cost (i.e., the cost arising when the currently relevant task differs from the task performed most recently) is seen as indicative that cognitive processes such as self-instruction are involved. Most secondary tasks chosen so far have required the repeated utterance of a word or syllable or a rhythmic movement of the foot. In the present study, we manipulated the dynamics of the to-be-performed secondary task (i.e., a repeated utterance or movement, or a static task that involved similar muscles-holding a spattle in the mouth or pressing keys). Additionally, we tested for modality-specific influences by asking participants to perform a dynamic or nondynamic (i.e., static) secondary task with two effector systems, namely oral and manual. Overall, our secondary tasks led to a reduced (rather than an increased) switch cost, as compared to a control condition without any secondary task. This reduction in switch cost was dependent on the secondary-task dynamics but independent of the effectors involved, showing larger switch-cost reductions for dynamic secondary tasks. To explain this finding, we suggest that performing secondary tasks interferes with the formation of episodic-memory traces that would lead to retrieval benefits in the case of a task repetition, so that our reduced task-switch costs actually represent reduced repetition benefits.

On the costs of parallel processing in dual-task performance: The case of lexical processing in word production.

Previous dual-task picture-naming studies suggest that lexical processes require capacity-limited processes and prevent other tasks to be carried out in parallel. However, studies involving the processing of multiple pictures suggest that parallel lexical processing is possible. The present study investigated the specific costs that may arise when such parallel processing occurs. We used a novel dual-task paradigm by presenting 2 visual objects associated with different tasks and manipulating between-task similarity. With high similarity, a picture-naming task (T1) was combined with a phoneme-decision task (T2), so that lexical processes were shared across tasks. With low similarity, picture-naming was combined with a size-decision T2 (nonshared lexical processes). In Experiment 1, we found that a manipulation of lexical processes (lexical frequency of T1 object name) showed an additive propagation with low between-task similarity and an overadditive propagation with high between-task similarity. Experiment 2 replicated this differential forward propagation of the lexical effect and showed that it disappeared with longer stimulus onset asynchronies. Moreover, both experiments showed backward crosstalk, indexed as worse T1 performance with high between-task similarity compared with low similarity. Together, these findings suggest that conditions of high between-task similarity can lead to parallel lexical processing in both tasks, which, however, does not result in benefits but rather in extra performance costs. These costs can be attributed to crosstalk based on the dual-task binding problem arising from parallel processing. Hence, the present study reveals that capacity-limited lexical processing can run in parallel across dual tasks but only at the expense of extraordinary high costs.

Highly proficient bilinguals implement inhibition: Evidence from n-2 language repetition costs.

Several, but not all, models of language control assume that highly proficient bilinguals implement little to no inhibition during bilingual language production. In the current study, we tested this assumption with a less equivocal marker of inhibition (i.e., n-2 language repetition costs) than previous language switching studies have. N-2 language repetition costs denote worse performance when switching back to a recently abandoned language (i.e., worse performance in ABA language sequences than CBA sequences, where A, B, and C refer to different languages). Whereas this marker has solely been used to investigate second-language learners in prior studies, we examined highly proficient bilinguals. The results showed that substantial n-2 language repetition costs can be observed with highly proficient bilinguals. Moreover, this inhibition effect was substantial for all 3 languages, but larger for the 2 dominant languages (Turkish and German) relative to the less proficient language (English). These findings indicate that even highly proficient bilinguals implement inhibition to restrict language production to the target language.

The flip side of the auditory spatial selection benefit: larger attentional mixing costs for target selection by ear than by gender in auditory task switching.

In cued auditory task switching, one of two dichotically presented number words, spoken by a female and a male, had to be judged according to its numerical magnitude. One experimental group selected targets by speaker gender and another group by ear of presentation. In mixed-task blocks, the target-defining feature (male/female vs. left/right) was cued prior to each trial, but in pure blocks it remained constant. Compared to selection by gender, selection by ear led to better performance in pure blocks than in mixed blocks, resulting in larger "global" mixing costs for ear-based selection. Selection by ear also led to larger "local" switch costs in mixed blocks, but this finding was partially mediated by differential cue-repetition benefits. Together, the data suggest that requirements of attention shifting diminish the auditory spatial selection benefit.