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In most attentional-control tasks, incongruent trials (i.e., trials with a conflict between two responses) are intermixed with congruent trials (i.e., trials without conflict). Typically, performance is slower and more error-prone on incongruent trials than on congruent trials. This congruency effect has been found to be smaller after incongruent trials than after congruent trials. This finding-labeled the congruency sequence effect (CSE)-has been assumed to reflect a dynamic adjustment of attentional control, which enables participants to enhance goal-relevant features and to inhibit irrelevant features. Only a few studies have investigated the impact of aging on the CSE, and their results are mixed. Compared to young adults, older adults were found to show a similar CSE, no CSE, a larger CSE, or a smaller CSE. This discrepancy in results has been interpreted as the consequence of using different tasks. To test for this, we conducted new analyses on 9 tasks-the color Stroop, number Stroop, arrow flanker, letter flanker, Simon, global-local, positive compatibility, and negative compatibility task-from our previous study (Rey-Mermet, Gade, & Oberauer, 2018). Both a null-hypothesis significance testing approach and a Bayesian hypothesis testing approach showed a similar CSE in both age groups for most tasks. Only in the Stroop tasks, the CSE was larger for older adults. These results are incompatible with the hypothesis of a general age-related deficit in attentional control. At the same time, they question the construct validity of the CSE. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Cues help in retrieving and implementing task-sets, that are actual representations of the to-be performed task in working memory. However, whereas previous studies revealed that the effectiveness of selecting and implementing task-sets based on cues depends on the type of cue (i.e., transparent words vs. arbitrary shapes), it is still unclear which characteristics of cues are responsible for these differences and whether the impact of the cue is bound to task-set retrieval only or also impacts task-set representations. For instance, the amount of interference during actual task performance has been reported to alter dependent on cue type as do preparation gains such as the reduction of switch cost. To investigate the effectiveness of cue characteristics (i.e., cue transparency and cue format), we manipulated those within- and between-participants in three experiments. Main dependent measures were switch costs in reaction times and error rates that occur when participants have to switch task-sets, and thus update working memory content. Our results consistently show beneficial effects of transparent cues for the reduction of switch cost. The influence of cue format was manifest in within-participants manipulation only and was mainly found in error rates. Overall, our data suggest that the amount of interference experienced in actual task performance can be significantly modulated dependent on cue type, suggesting flexible adaptation of the cognitive system to contextual information.

The present study investigates the influence of preparation on inhibitory effects in cued task switching. In three experiments, we assessed n - 2 repetition costs as marker of inhibition of the just executed and now irrelevant task by comparing performance in task sequences such as ABA (i.e., n - 2 repetitions, with A, B and C standing for different tasks) to task sequences such as CBA (i.e., n - 2 switches). Specifically, we varied the cue-target interval (CTI) to examine cue-based preparation effects. In addition, we manipulated cue type (i.e., abstract, verbal, and direct cues) across the three experiments. We obtained significant reductions of n - 2 repetition costs with prolonged CTI when using abstract cues (i.e., coloured frames) and task names (i.e., digit), but not when using the task-specific stimulus-response mapping as cue for the upcoming task. These data suggest that cue-based preparation is not a uniform process but depends on the information provided by the cue., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The aim of the present study was to examine the contribution of overlapping response sets to the occurrence of task inhibition, measured as n-2 task repetition cost. We had subjects switch among four tasks. Three tasks overlapped on both stimulus set and response set. A fourth, neutral, univalent task never overlapped on the stimulus set but, across three experiments, varied in terms of the degree of overlap in the response set. We found that overlap in response set affects task inhibition. We suggest that response set overlap increases the competition among tasks and, thus, triggers task inhibition to resolve this competition.

Inhibition of abandoned tasks in task switching can be inferred when a worse performance is found with n - 2 task repetitions (ABA sequences) than with nonrepetitions (CBA sequences). Recent evidence has shown that this inhibition effect decreases with long intertrial intervals (i.e., response-cue intervals, RCIs). Two alternatives have been proposed to account for this decrease. One alternative attributes the observed decrease to the decay of inhibition itself. The other alternative proposes that decay of the activation of competing tasks reduces the interference and leads to less inhibition. To decide between these alternatives, we manipulated RCI trialwise. The results favor the decay-of-activation account as an explanation for the decreased inhibition effect. This links the amount of inhibition to the activation level of the competing tasks, whereas evidence for the decay of inhibition remains weak.

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.

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. [ABSTRACT FROM AUTHOR]

The present study investigated mechanisms of adaptive cognitive control in working memory (WM). WM is conceived as a system for short-term maintenance, updating and manipulation of representations required for goal-directed action. Adaptive control refers to the finding of flexible adjustments of control processes based on conflict. For instance, a higher frequency of incongruent stimuli, that is, stimuli evoking conflicting response tendencies, leads to a higher level of cognitive control as reflected by smaller congruency effects (i.e., the difference between congruent and incongruent items). Likewise, conflict on the previous trial leads to a higher level of cognitive control on the current trial. To investigate adaptive control in WM, we used a modified Sternberg paradigm. Participants memorized two differently colored lists of four digits (i.e., 2 5 7 1), in which corresponding positions in both lists contained the same digits (congruent items) or different digits (incongruent items). Participants were required to make a match/mismatch judgement (Experiment 1 and 2) or to recollect the correct digit at a probed position in one of the two lists (Experiment 3). In all experiments, we could replicate both hallmark effects of adaptive control, the proportion congruency effect, and the congruency sequence effect. Our results strongly support the assumption that WM representations can be dynamically adapted based on the amount of conflict, and that adaptive control of WM follows the same principles that have previously been shown for selective attention. [ABSTRACT FROM AUTHOR]

A key feature of the human cognitive system is its ability to deal with an ever-changing environment. One prototypical example is the observation that we adjust our information processing depending on the conflict-likelihood of a context (context-specific proportion congruency effect, CSPC, Crump et al., 2006). Recently, empirical studies started to question the role of consciousness in these strategic adaptation processes (for reviews, see Desender and Van den Bussche, 2012; Kunde et al., 2012). However, these studies have not yielded unequivocal results (e.g., Kunde, 2003; Heinemann et al., 2009; Van Gaal et al., 2010a; Desender et al., 2013; Reuss et al., 2014). In the present study, we aim at replicating the experiment of Heinemann et al. (2009) in which the proportion of congruent and incongruenttrials between different contexts was varied in a masked priming task. Their results showed a reduction of the congruency effect for the context with more incongruent trials. However, this CSPC effect was only observed when the prime-target conflict was conscious, rather than unconscious, suggesting that context-specific control operates within the boundaries of awareness. Our replication attempt however contrasts these findings. In the first experiment we found no evidence for a CSPC effect in reaction times (RTs), neither in the conscious nor in the unconscious condition. The error rate analysis did show a CSPC effect, albeit not one modulated by consciousness. In the second experiment we found an overall CSPC effect in RTs, independent of consciousness. The error rates did not display a CSPC pattern. These mixed results seem to nuance the findings of Heinemann etal. (2009) and highlight the need for replication studies in psychology research. [ABSTRACT FROM AUTHOR]

When using lever tools, subjects have to deal with two, not necessarily concordant effects of their motor behavior: the body-related proximal effects, like tactile sensations from the moving hand, and/or more external distal effects, like the moving effect points of the lever. As a consequence, spatial compatibility relationships between stimulus (S; at which the effect points of the lever aim at), responding hand (R) and effect point of the lever (E) play a critical role in response generation. In the present study we examine whether the occurrence of compatibility effects needs real tool movements or whether a similar response pattern can be already evoked by pure mental imaginations of the tool effects. In general, response times and errors observed with real and imagined tool movements showed a similar pattern of results, but there were also differences. With incompatible relationships and thus more difficult tasks, response times were reduced with imagined tool movements than compared with real tool movements. On the contrary, with compatible relationships and thus high overlap between proximal and distal action effects, response times were increased with imagined tool movements. Results are only in parts consistent with the ideomotor theory of motor control. [ABSTRACT FROM AUTHOR]

In a study of the formation of representations of task sequences and its influence on task inhibition, participants first performed tasks in a predictable sequence (e.g., ABACBC) and then performed the tasks in a random sequence. Half of the participants were explicitly instructed about the predictable sequence, whereas the other participants did not receive these instructions. Task-sequence learning was inferred from shorter reaction times (RTs) in predictable relative to random sequences. Persisting inhibition of competing tasks was indicated by increased RTs in n− 2 task repetitions (e.g., AB A) compared with n− 2 nonrepetitions (e.g., CB A). The results show task-sequence learning for both groups. However, task inhibition was reduced in predictable relative to random sequences among instructed-learning participants who formed an explicit representation of the task sequence, whereas sequence learning and task inhibition were independent in the noninstructed group. We hypothesize that the explicit instructions led to chunking of the task sequence, and that n− 2 repetitions served as chunk points (ABA-CBC), so that within-chunk facilitation modulated the inhibition effect. [ABSTRACT FROM AUTHOR]