On the reliability of behavioral measures of cognitive control: retest reliability of task-inhibition effect, task-preparation effect, Stroop-like interference, and conflict adaptation effect

This study examined the reliability (retest and split-half) of four common behavioral measures of cognitive control. In Experiment 1 (N = 96), we examined N – 2 task repetition costs as a marker of task-level inhibition, and the cue-stimulus interval (CSI) effect as a marker of time-based task preparation. In Experiment 2 (N = 48), we examined a Stroop-like face-name interference effect as a measure of distractor interference control, and the sequential congruency effect (“conflict adaptation effect”) as a measure of conflict-triggered adaptation of cognitive control. In both experiments, the measures were assessed in two sessions on the same day, separated by a 10 min-long unrelated filler task. We observed substantial experimental effects with medium to large effect sizes. At the same time, split-half reliabilities were moderate, and retest reliabilities were poor, for most measures, except for the CSI effect. Retest reliability of the Stroop-like effect was improved when considering only trials preceded by congruent trials. Together, the data suggest that these cognitive control measures are well suited for assessing group-level effects of cognitive control. Yet, except for the CSI effect, these measures do not seem suitable for reliably assessing interindividual differences in the strength of cognitive control, and therefore are not suited for correlational approaches. We discuss possible reasons for the discrepancy between robustness at the group level and reliability at the level of interindividual differences.

Do bilinguals outperform monolinguals in switching tasks? Contrary evidence for nonlinguistic and linguistic switching tasks

The benefits of bilingualism in executive functions are highly debated. Even so, in switching tasks, these effects seem robust, although smaller than initially thought (Gunnerud et al., 2020; Ware et al., 2020). By handling two languages throughout their lifespan, bilinguals appear to train their executive functions and show benefits in nonlinguistic switching tasks compared to monolinguals. Nevertheless, because bilinguals need to control for the interference of another language, they may show a disadvantage when dealing with task-switching paradigms requiring language control, particularly when those are performed in their less dominant language. The present work explored this issue by studying bilingualism’s effects on task-switching within the visual and language domains. On the one hand, our results show that bilinguals were overall faster and presented reduced switch costs compared to monolinguals when performing perceptual geometric judgments with no time for task preparation. On the other hand, no bilingual advantage was found when a new sample of comparable bilinguals and monolinguals completed a within-language switching task. Our results provide clear evidence favoring the bilingual advantage, yet only when the task imposes greater executive demands and does not involve language control.

Electrophysiological Evidence of Anticipatory Cognitive Control in the Stroop Task

The Stroop task has been largely used to explore the ability to inhibit the automatic process of reading when reporting the ink color of incongruent color-words. Given the extensive literature regarding the processes involved in task performance, here we aimed at exploring the anticipatory brain activities during the Stroop task using the event-related potential (ERP) method. To accomplish this, eighteen participants performed two different blocks where neutral words were intermixed with congruent and incongruent words, respectively. Results revealed consistent pre-stimulus activity over the frontal, premotor and parietal brain areas. The premotor and the parietal activities were also modulated by the Stroop effect, being more enhanced in the incongruent than in the congruent blocks. Present findings add on the current literature pointing at an unexplored locus of anticipatory cognitive control during task preparation, thus offering a new way to investigate top-down preparatory processes of performance control in the Stroop task.

Further investigating effects of task repetition proportion on n – 2 repetition costs: Task shielding as a potential modulating factor?

Previous research has shown that n – 2 repetition costs are reduced when the experimental procedure allows for task repetitions. The present study aimed to further elucidate possible mechanisms underlying this effect. To this end, three experiments were conducted in which the possibility of task repetitions was tied to individual tasks. In Experiment I, the specific repetition proportions varied between participants. The reduction of n – 2 repetition costs was stronger when the relative amount of task repetitions associated with a particular task was high, suggesting that inhibition is reduced when the presence of repetitions tied to a specific task can easily be detected. In Experiment II, task preparation time varied between blocks to investigate whether cue-based preparation underlies this reduction of n – 2 repetition costs. While the duration of the preparation interval had no effect in this respect, additional combined analyses of both experiments revealed an influence of stimulus congruency: n – 2 repetition costs were highest when repetitions were precluded and the task stimulus was incongruent, whereas no effect of stimulus congruence on n – 2 repetition costs was observed with tasks that possibly repeated. This data pattern was replicated in Experiment III. This result is interpreted in terms of task shielding which is reduced for tasks without repetitions, making these tasks more vulnerable to crosstalk from competing tasks when they are still in an inhibited state.

Task-based language teaching for beginner-level young learners

The purpose of this article is to discuss how task-based language teaching (TBLT) can work with beginner-level learners by using input-based tasks. It begins by dismissing a common critique of TBLT, namely that learners need to be taught some language before they can perform tasks, by arguing that input-based tasks make TBLT possible with beginner-level learners and that such an approach is entirely compatible with what research has shown about the early stages of L2 acquisition. A review of the research that has investigated input-based tasks follows and serves to identify key features in the design and implementation of tasks. Designing input-based tasks involves considering the choice of topic, the non-verbal devices that are central to the tasks, the pre-selection of target language, the verbal input for the task, and the task outcomes. Implementation options include task preparation, use of the learners’ first language, input modification and elaboration, focus-on-form and feedback, and task repetition.

The effect of performing versus preparing a task on the subsequent switch cost

Behaviour occurs not as isolated incidents, but within an ongoing sequence of events. The task-switching paradigm provides a useful way to investigate the impact of different events upon subsequent performance. An implication of two-stage task-switching models is that preparing a task without performing it might affect task readiness only to a limited extent. However, recent research has surprisingly shown larger switch costs following preparation (“cue-only” trials) than following performance (“completed” trials). We set out to conduct a rigorous comparison of the size of switch costs following cue-only versus completed trials. In Experiments 1 and 2, we controlled the timing between critical trial events. This had the effect of roughly equating, but not reversing, the relative size of switch costs. In Experiment 3, we restructured the paradigm to equate the predictability of cue and target events. Switch costs following cue-only trials were now smaller than those following completed trials. These studies confirm that task preparation alone is sufficient to drive subsequent switch costs. They also indicate that task performance might increase the size of these costs, consistent with two-stage task-switching models. Switch costs appear to be affected by both the timing and predictability of trial events.

The art of planning ahead: when do we prepare for the future and when is it effective? (under review)

Preparing for the future during ongoing activities is an essential skill. Yet, it is currently unclear to what extent we can prepare for the future in parallel with another task. In two experiments, we investigated how characteristics of a present task influenced whether and when participants prepared for the future, as well as its usefulness. We focused on the influence of concurrent working memory load, assuming that working memory would interfere most strongly with preparation. In both experiments, participants performed a novel sequential dual-task paradigm, in which they could voluntary prepare for a second task while performing a first task. We identified task preparation by means of eye tracking, through detecting when participants switched their gaze from the first to the second task. The results showed that participants prepared productively, as evidenced by faster RTs on the second task, with only a small cost to the present task. The probability of preparation and its productiveness decreased with general increases in present task difficulty. In contrast to our prediction, we found some but no consistent support for influence of concurrent working memory load on preparation. Only for concurrent high working memory load (i.e., two items in memory), we observed strong interference with preparation. We conclude that preparation is affected by present task difficulty, potentially due to decreased opportunities for preparation and changes in multitasking strategy. Furthermore, the interference from holding two items may reflect that concurrent preparation is compromised when working memory integration is required by both processes.