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In Simon-type interference tasks, participants are asked to perform a 2-choice reaction on a stimulus dimension while ignoring the stimulus position. Commonly, robust congruency effects are found; that is, reactions are faster when the relevant stimulus attribute and the assigned response match the location of the stimulus. Simon congruency effects are regularly attributed to a fast, nonverbal processing route. In 3 experiments, we tested the importance of verbal representations in the Simon effect by manipulating the format of representations (verbal vs. nonverbal) with stimulus material (i.e., words vs. gratings) and stimulus arrangement (i.e., horizontally vs. vertically). Results of the first experiment point to a modulation of the Simon effects by both factors when they were manipulated between subjects, up to an inversion of the Simon effect for words presented in vertical arrangement. We replicated the inverse congruency effect for verbal material in vertical arrangement when a within-participant design was used (Experiment 2) and when the impact of reading processes was ruled out (Experiment 3). One cause for this inversion might be the construction of language-based representations that counteract automatic processing given the stimulus arrangement. To investigate this, we assessed individual differences in the use of inner speech for self-instruction. Using hierarchical linear modeling analysis, we found that self-rated evaluative and motivational inner speech processes accounted for a significant portion of the Simon effect. This supports claims that individual differences predict performance even in simple cognitive tasks such as the Simon task and highlights the flexibility of basic cognitive processes.

Inhibition is often conceptualized as a unitary construct reflecting the ability to ignore and suppress irrelevant information. At the same time, it has been subdivided into inhibition of prepotent responses (i.e., the ability to stop dominant responses) and resistance to distracter interference (i.e., the ability to ignore distracting information). The present study investigated the unity and diversity of inhibition as a psychometric construct, and tested the hypothesis of an inhibition deficit in older age. We measured inhibition in young and old adults with 11 established laboratory tasks: antisaccade, stop-signal, color Stroop, number Stroop, arrow flanker, letter flanker, Simon, global-local, positive and negative compatibility tasks, and n-2 repetition costs in task switching. In both age groups, the inhibition measures from individual tasks had good reliabilities, but correlated only weakly among each other. Structural equation modeling identified a 2-factor model with factors for inhibition of prepotent responses and resistance to distracter interference. Older adults scored worse in the inhibition of prepotent response, but better in the resistance to distracter interference. However, the model had low explanatory power. Together, these findings call into question inhibition as a psychometric construct and the hypothesis of an inhibition deficit in older age.

Conflicts in working memory (WM) can occur when retrieval cues activate competing items, which impairs the efficiency of retrieval. It has recently been shown that WM retrieval adapts similarly to these conflicts as predicted by conflict monitoring theory for selective attention tasks. Here, we utilized event‐related potentials (ERPs) to investigate whether conflict and adaptive control in WM are reflected by the same neural markers that have previously been described for selective attention tasks. In our task, participants encoded two differently colored memory lists that contained four digits each (i.e., 2 5 7 1 and 4 5 9 1), and had to recognize whether a probe item from a specific list and position was correct or incorrect. Conflict during retrieval emerged when digits at corresponding positions (e.g., 2 and 5 at the first position) were different (incongruent), but not when these digits were the same (congruent). In behavioral data, we found a congruency sequence effect, that is, responses to incongruent probe items were slower, and this effect was reduced following trials with incongruent probe items. In ERPs, this behavioral marker of adaptive control was accompanied by two effects. First, congruency affected the amplitude of an N450, and this conflict effect was reduced after incongruent trials. Second, the posterior P3 amplitude varied with the congruency of the current and the previous trial. Both results resemble those found for the Stroop task and thus highlight the similarity between conflict and adaptive control in WM and selective attention tasks. Our study links theoretical ideas from two research fields—working memory (WM) and adaptive cognitive control. Utilizing event‐related potentials, our findings show that adaptive cognitive control in WM is reflected by the same neural markers as adaptive cognitive control of selective attention. Furthermore, our results suggest that adaptive cognitive control plays a critical role in optimizing the use of limited WM storage. [ABSTRACT FROM AUTHOR]

Performance of task sequences is assumed to rely on activation and inhibition of tasks. Ah empirical marker of task inhibition is the so-called n--2 repetition cost, which is assessed by comparing performance in trial n--2 task repetitions (i.e., ABA) with that in n--2 task switches (i.e., CBA). Current theoretical accounts assume that inhibition acts on the level of task representations (i.e., task sets). However, another potential target of task inhibition could be the representation of the task cue. To decide between these two alternatives, the authors used a 2:1 cue-to-task mapping design. They found significant n--2 task repetition costs both with n--2 cue repetitions and n--2 cue switches. These costs were about equal (Experiment 1), and this data pattern was found for both short and long cuing intervals (Experiment 2). Together, the data suggest that task inhibition acts on task sets and not on cue representations. Keywords: cognitive control, task sequence performance, inhibition, cue-based processes On reconnait generalement que la performance lors de l'execution d'une sequence de taches repose sur l'activation et l'inhibition de la tache. Un indicateur empirique de l'inhibition de la tache, le << cout associe a la repetition de la tache >>, est evalue par la comparaison de la performance a des repetitions de taches n/2 lors de la phase d'essai (c.-a-d. aba) avec la performance a une permutation de taches n/2 (c.-a-d. CBA). Selon les theories actuelles, cette inhibition a une incidence sur le niveau de representation de la tache (c.-a-d. series de taches). Toutefois, une autre cible po tentielle de l'inhibition de la tache pourrait etre la representation de l'indice d'activation de la tache. Pour verifier la deuxieme hypothese, nous avons concu un modele de mappage indice-tache. Nous avons observe des couts de repetition n/2 significatifs, autant avec les repetitions n/2 qu'avec les pernmtations de l'indice n/2. Ces couts etaient pratiquement identiques (experience 1) et le meme schema de donnees produit par les intervalles d'amorce courts et les intervalles d'amorce longs a ete observe. Dans l'ensemble, ces donnees semblent indiquer que l'inhibition de la tache a une incidence sur la serie de taches et non sur la representation de l'amorce.

Cognitive flexibility can be studied using the task-switching paradigm. This paradigm requires subjects to adapt behaviour to changing contexts as indicated by a cue. In our study, we addressed the question of how cue-based implementation of mental 'task sets' occurs. We assumed that cues build up associations to the tasks that they indicate. These associations lead to retrieval of the associated task set once the cue shows up again. In three experiments, we tested this assumption using a negative transfer paradigm. First participants were exposed to one cue-task mapping. After a training phase, the cue-task mapping changed in either of two ways. Whereas one group of participants got new cues, the other experienced a reversal of the learnt cue-task mapping. Our results show that participants build up cue-task associations and that these formerly learnt associations can hamper the implementation of new cue-task mappings (particular with mapping reversal). Prolonged preparation time decreased the cost of changing the cue-task mapping but did not change the overall pattern of results.

Bilingualism has been proposed to affect cognitive flexibility, but findings in the literature are mixed. One reason for this might be the different trajectories of how participants acquired the second language, either through immersion or formal education. The present study investigates differences and commonalities of becoming bilingual depending on trajectory.To assess cognitive flexibility, participants completed a task-switching and a language-switching paradigm, which were well-matched to each other. Language capabilities were assessed by self-report, objective fluency measures, and balance quotients. We assessed participants of five bilingual populations who together spoke five different languages.We analyzed global mixing costs, reflecting proactive language and task control, as well as local switch costs, reflecting reactive language and task control processes. The impact of language capabilities on mixing costs was assessed using linear mixed models. We also report correlations among language capability measures, sociodemographic variables, and working memory.We observed reliable mixing costs but no switch costs. Task and language mixing costs were smaller in participants who had a later age of L2 onset and higher L2 phonemic fluency, namely those who followed the formal education path to bilingualism. L2 phonemic fluency was the most consistent predictor for overall performance speed and reduced mixing costs.Using three different study sites and participants differing in their trajectory of becoming bilingual, this study provides a more diverse picture than many previous studies. Furthermore, using small language populations, the study shows the benefits of language fluency measures that are widely available.The present study bolsters the conceptualization of bilingualism as a multifaceted experience. Nonetheless, in the current study, bilingualism led to comparable outcomes in cognitive flexibility. Finally, measuring language capabilities should carefully consider cognitive processes not related to language that could explain variability in performance. [ABSTRACT FROM AUTHOR]