Conflict adaptation: it is not what you expect

The Important Role of the Right Dorsolateral Prefrontal Cortex in Conflict Adaptation: A Combined Voxel-Based Morphometry and Continuous Theta Burst Stimulation Study

Humans can flexibly adjust their executive control to resolve conflicts. Conflict adaptation and conflict resolution are crucial aspects of conflict processing. Functional neuroimaging studies have associated the dorsolateral prefrontal cortex (DLPFC) with conflict processing, but its causal role remains somewhat controversial. Moreover, the neuroanatomical basis of conflict processing has not been thoroughly examined. In this study, the Stroop task, a well-established measure of conflict, was employed to investigate (1) the neuroanatomical basis of conflict resolution and conflict adaptation with the voxel-based morphometry analysis, (2) the causal role of DLPFC in conflict processing with the application of the continuous theta burst stimulation to DLPFC. The results revealed that the Stroop effect was correlated to the gray matter volume of the precuneus, postcentral gyrus, and cerebellum, and the congruency sequence effect was correlated to the gray matter volume of superior frontal gyrus, postcentral gyrus, and lobule paracentral gyrus. These findings indicate the neuroanatomical basis of conflict resolution and adaptation. In addition, the continuous theta burst stimulation over the right DLPFC resulted in a significant reduction in the Stroop effect of RT after congruent trials compared with vertex stimulation and a significant increase in the Stroop effect of accuracy rate after incongruent trials than congruent trials, demonstrating the causal role of right DLPFC in conflict adaptation. Moreover, the DLPFC stimulation did not affect the Stroop effect of RT and accuracy rate. Overall, our study offers further insights into the neural mechanisms underlying conflict resolution and adaptation.

Evidence for conflict monitoring during speech recognition in noise

During difficult tasks, conflict can benefit performance on a subsequent trial. One theory for such performance adjustments is that people monitor for conflict and reactively engage cognitive control. This hypothesis has been challenged because tasks that control for associative learning do not show such "cognitive control" effects. The current study experimentally controlled associative learning by presenting a novel stimulus on every trial of a picture-speech conflict task and found that performance adjustments still occur. Thirty-one healthy young adults listened to and repeated words presented in background noise while viewing pictures that were congruent or incongruent (i.e., phonological neighbors) with the word. Following conflict, participants had higher word recognition (+17% points) on incongruent but not congruent trials. This result was not attributable to posterror effects nor a speed-accuracy trade-off. An analysis of erroneous responses showed that participants made more phonologically related errors than nonrelated errors only on incongruent trials, demonstrating elevated phonological conflict when the picture was a neighbor of the target word. Additionally, postconflict improvements appear to be due to better resolution of phonological conflict in the mental lexicon rather than decreased attention to the picture or increased attention to the speech signal. Our findings provide new evidence for conflict monitoring and suggest that cognitive control helps resolve phonological conflict during speech recognition in noise.

Reduced flexibility of cognitive control: reactive, but not proactive control, underpins the congruency sequence effect

The congruency sequence effect (CSE) refers to facilitated conflict processing following incongruent than congruent trials, and reflects enhanced cognitive control during conflict processing. Although this effect is mostly conceived as being reactive, proactive control can also unlock it under specific circumstances according to previous studies (e.g., when an informative cue is used). However, whether or not humans can flexibly switch between these two complementing control modes remains unclear. To address this question, 55 participants completed the confound-minimized Stroop task in different blocks where the cue about the upcoming trial's congruency was either informative or not, and orthogonally to it, the cue-stimulus interval (CSI) was either short or long. We tested if the size of the CSE could change depending on the specific combination of these two factors, which would indicate that cognitive control depends on the subtle balance between reactive and proactive control, and is therefore flexible. However, results showed that the CSE was significant and comparable across the four combinations of CSI and Cue type, suggesting that it primarily stemmed from reactive control. We discuss our results against the dual mechanism of control (DMC) framework (Braver in Trends Cogn Sci 16:106-113, 2012).

The Role of Subjective Experiences in Conflict Tasks: A Review

Cognitive control research is concerned with the question how we install adaptive behaviour in the case of (cognitive) conflict. In this review we focus on the role that awareness of this conflict plays in our ability to exert cognitive control. We will argue that visual conflict is not the only building block of metacognitive experiences of conflict and discuss how they are related to cognitive control. So, a first aim of the current review is to understand how these different metacognitive judgements are created. To do so, we draw some remarkable parallels with research on metacognition in decision making and memory research. Next, we elaborate on the relationship between metacognition and adaptive behaviour, with a specific focus on the role of subjective experiences in the Gratton effect. The grey areas that persist in the current literature are highlighted. In addition to deciphering the mechanisms of metacognitive judgements in cognitive control, this overview also aims to further enlarge our understanding of metacognitive abilities at a more general level.

Monitoring and Control in Language Production

Language research has provided insight into how speakers translate a thought into a sequence of sounds that ultimately becomes words, phrases, and sentences. Despite the complex stages involved in this process, relatively little is known about how we avoid and handle production and comprehension errors that would otherwise impede communication. We review current research on the mechanisms underlying monitoring and control of the language system, especially production, with particular emphasis on whether such monitoring is issued by domain-general or domain-specific procedures.

Disentangling posterror and postconflict reduction of interference

Conflict monitoring theory (CMT; Botvinick, Braver, Barch, Carter, & Cohen Psychological Review, 108, 624-652, 2001) states that response conflict, the simultaneous activation of two competing responses, increases task focus and reduces interference from irrelevant information. CMT also defines errors as conflict, and reduced interference effects have consistently been reported following errors (Ridderinkhof Psychological Research, 66, 312-323, 2002). However, previous computations of this posterror reduction of interference (PERI) have overlooked the congruency of the previous trial. This is problematic, because most errors are made on incongruent trials, creating a confound between (previous) accuracy and (previous) congruency. Therefore, it is likely that reduced interference following errors is in fact the congruency sequence effect (i.e., reduced interference following incongruent, relative to congruent, trials). Our results corroborate this idea by demonstrating that participants indeed showed significant PERI following a congruent trial, but inverse PERI following an incongruent trial. These findings are discussed in light of the adaptation-by-binding account (Verguts & Notebaert Psychological Review, 115, 518-525, 2008, Trends in Cognitive Sciences, 13, 252-257, 2009).

Interrelation of resting state functional connectivity, striatal GABA levels, and cognitive control processes

Important issues for cognitive control are response selection processes, known to depend on fronto-striatal networks with recent evidence suggesting that striatal gamma-amino butyric acid (GABA) levels play an important role. Regional GABA concentrations have also been shown to modulate intrinsic connectivity, e.g. of the default mode network. However, the interrelation between striatal GABA levels, basal ganglia network (BGN) connectivity, and performance in cognitive control is elusive. In the current study, we measure striatal GABA levels using magnetic resonance spectroscopy (MRS) and resting state parameters using functional magnetic resonance imaging (fMRI). Resting state parameters include activity within the BGN, as determined by the low frequency power (LFP) within the network, and the functional connectivity between the BGN and somatomotor network (SMN). Specifically, we examine the interrelation between GABA, resting state parameters, and performance (i.e., accuracy) in conflict monitoring using a Simon task. Response control was affected by striatal GABA+ levels and activity within the BGN, especially when response selection was complicated by altered stimulus-response mappings. The data suggest that there are two mechanisms supporting response selection accuracy. One is related to resting state activity within the BGN and modulated by striatal GABA+ levels. The other is related to decreased cortico-striatal network connectivity, unrelated to the GABAergic system. The inclusion of all three factors (i.e., striatal GABA+ levels, activity within the BGN, and BGN-SMN network connectivity) explained a considerable amount of variance in task accuracy. Striatal neurobiochemical (GABA+) and parameters of the resting state BGN represent important modulators of response control.

Going, going, gone? Proactive control prevents the congruency sequence effect from rapid decay

The congruency sequence effect, the finding of a reduced congruency effect following incongruent trials in conflict tasks, has received considerable attention in the research on cognitive control over the last two decades. This effect can reflect either the expectancy-guided, preparatory biasing of attention in anticipation of the upcoming stimulus (i.e. proactive control), or the phasic enhancement of the attentional set in response to conflict on the previous trial (i.e. reactive control). A recent study by Egner et al. in Front Psychol 1 (2010) set out to contrast these two alternatives, by exploring the congruency sequence effect across a wide range of inter-trial intervals. It was found that congruency sequence effects were subject to rapid decay over time. This decay fits well with the notion of reactive control, while at the same time speaking against the involvement of proactive regulation—which should also (and even mainly) be evident at longer intervals. In the present study, we first replicate the reduction of the congruency sequence effect with increasing inter-trial interval in a face-word Stroop task. In a second experiment, we show that congruency sequence effects are observed at longer intervals, too, when the proportion of trials with the longest inter-trial interval is increased. Our findings indicate that proactive control can prevent the congruency sequence effect from decaying rapidly.

Does conflict help or hurt cognitive control? Initial evidence for an inverted U-shape relationship between perceived task difficulty and conflict adaptation

Sequential modulation of congruency effects in conflict tasks indicates that cognitive control quickly adapts to changing task demands. We investigated in four experiments how this behavioral congruency-sequence effect relates to different levels of perceived task difficulty in a flanker and a Stroop task. In addition, online measures of pupil diameter were used as a physiological index of effort mobilization. Consistent with motivational accounts predicting that increased levels of perceived task difficulty will increase effort mobilization only up to a certain limit, reliable dynamic conflict-driven adjustment in cognitive control was only observed when task difficulty was relatively low. Instead, tasks tentatively associated with high levels of difficulty showed no or reversed conflict adaptation. Although the effects could not be linked consistently to effects in self-reported task difficulty in all experiments, regression analyses showed associations between perceived task difficulty and conflict adaptation in some of the experiments, which provides some initial evidence for an inverted U-shape relationship between perceived difficulty and adaptations in cognitive control. Furthermore, high levels of task difficulty were associated with a conflict-driven reduction in pupil dilation, suggesting that pupil dilation can be used as a physiological marker of mental overload. Our findings underscore the importance of developing models that are grounded in motivational accounts of cognitive control.

Adaptive effort investment in cognitive and physical tasks: a neurocomputational model

Despite its importance in everyday life, the computational nature of effort investment remains poorly understood. We propose an effort model obtained from optimality considerations, and a neurocomputational approximation to the optimal model. Both are couched in the framework of reinforcement learning. It is shown that choosing when or when not to exert effort can be adaptively learned, depending on rewards, costs, and task difficulty. In the neurocomputational model, the limbic loop comprising anterior cingulate cortex (ACC) and ventral striatum in the basal ganglia allocates effort to cortical stimulus-action pathways whenever this is valuable. We demonstrate that the model approximates optimality. Next, we consider two hallmark effects from the cognitive control literature, namely proportion congruency and sequential congruency effects. It is shown that the model exerts both proactive and reactive cognitive control. Then, we simulate two physical effort tasks. In line with empirical work, impairing the model's dopaminergic pathway leads to apathetic behavior. Thus, we conceptually unify the exertion of cognitive and physical effort, studied across a variety of literatures (e.g., motivation and cognitive control) and animal species.

Generalizing attentional control across dimensions and tasks: evidence from transfer of proportion-congruent effects

Three experiments investigated transfer of list-wide proportion congruent (LWPC) effects from a set of congruent and incongruent items with different frequency (inducer task) to a set of congruent and incongruent items with equal frequency (diagnostic task). Experiments 1 and 2 mixed items from horizontal and vertical Simon tasks. Tasks always involved different stimuli that varied on the same dimension (colour) in Experiment 1 and on different dimensions (colour, shape) in Experiment 2. Experiment 3 mixed trials from a manual Simon task with trials from a vocal Stroop task, with colour being the relevant stimulus in both tasks. There were two major results. First, we observed transfer of LWPC effects in Experiments 1 and 3, when tasks shared the relevant dimension, but not in Experiment 2. Second, sequential modulations of congruency effects transferred in Experiment 1 only. Hence, the different transfer patterns suggest that LWPC effects and sequential modulations arise from different mechanisms. Moreover, the observation of transfer supports an account of LWPC effects in terms of list-wide cognitive control, while being at odds with accounts in terms of stimulus-response (contingency) learning and item-specific control.

Creatures of habit (and control): a multi-level learning perspective on the modulation of congruency effects

The congruency sequence effect (CSE) describes the finding that congruency effects in classic probes of selective attention (like the Stroop, Simon, and flanker tasks) are smaller following an incongruent than following a congruent trial. The past two decades have generated a large literature on determinants and boundary conditions for the CSE and similar, congruency-proportion based modulations of congruency effects. A prolonged and heated theoretical discussion has been guided primarily by a historically motivated dichotomy between "top-down control" versus "associative bottom-up" explanations for these effects. In the present article, I attempt to integrate and contextualize the major empirical findings in this field by arguing that CSEs (and related effects) are best understood as reflecting a composite of multiple levels of learning that differ in their level of abstraction. Specifically, learning does not only involve the trial-by-trial encoding, binding, and cued retrieval of specific stimulus-response associations, but also of more abstract trial features. Moreover, these more abstract trial or event features can be both external, such as the spatial and temporal context in which a stimulus occurs, as well as internal, like the experience of difficulty, and the attentional control settings that were employed in dealing with the stimulus. From this perspective, top-down control and bottom-up priming processes work in concert rather than in opposition. They represent different levels of abstraction in the same learning scheme and they serve a single, common goal: forming memory ensembles that will facilitate fast and appropriate responding to recurring stimuli or events in the environment.

In Touch With the Simon Effect *The first two authors contributed equally

Cognitive control has been extensively studied using the auditory and visual modalities. In the current study, a tactile version of the Simon task was created in order to test control mechanisms in a modality that was less studied, to provide comparative and new information. A significant Simon effect – reaction time gap between congruent (i.e., stimulus and response in the same relative location) and incongruent (i.e., stimulus and response in opposite locations) stimuli – provided grounds to further examine both general and tactile-specific aspects of cognitive control in three experiments. By implementing a neutral condition and conducting sequential and distributional analysis, the present study: (a) supports two different independent mechanisms of cognitive control – reactive control and proactive control; (b) reveals facilitation and interference within the tactile Simon effect; and (c) proposes modality differences in activation and processing of the spatially driven stimulus-response association.

Long trial durations normalise the interference effect and sequential updating during healthy aging

We examined the effect of a task-irrelevant dimension on response times in young adults and seniors. We used the Simon task with congruent trials where the target and manual response were on the same side, incongruent trials where the target and response were on opposite sides, and neutral trials where the target appeared along the vertical meridian. We observed two age-related effects. First, there was a larger congruency effect in senior participants that was driven by greater interference; namely, their responses were slower on incongruent relative to neutral trials. Second, there was a Gratton effect; namely, a diminished Simon effect was found in young adults but not in seniors when the preceding trial was incongruent. However, these effects of aging were normalised when the inter-trial interval was increased; the Simon effect and interference were reduced and a Gratton effect appeared for seniors. We conclude that aging may impair the ability to quickly adapt to changing environmental circumstances when they require reformulating current behavioral strategies.

The congruency sequence effect 3.0: a critical test of conflict adaptation

Over the last two decades, the congruency sequence effect (CSE) -the finding of a reduced congruency effect following incongruent trials in conflict tasks- has played a central role in advancing research on cognitive control. According to the influential conflict-monitoring account, the CSE reflects adjustments in selective attention that enhance task focus when needed, often termed conflict adaptation. However, this dominant interpretation of the CSE has been called into question by several alternative accounts that stress the role of episodic memory processes: feature binding and (stimulus-response) contingency learning. To evaluate the notion of conflict adaptation in accounting for the CSE, we construed versions of three widely used experimental paradigms (the colour-word Stroop, picture-word Stroop and flanker task) that effectively control for feature binding and contingency learning. Results revealed that a CSE can emerge in all three tasks. This strongly suggests a contribution of attentional control to the CSE and highlights the potential of these unprecedentedly clean paradigms for further examining cognitive control.

What determines the specificity of conflict adaptation? A review, critical analysis, and proposed synthesis

Over the past decade, many cognitive control researchers have studied to what extent adaptations to conflict are domain-general or rather specific, mostly by testing whether or not the congruency sequence effect (CSE) transfers across different conditions (e.g., conflict type, task sets, contexts, et cetera). The CSE refers to the observation that congruency effects in conflict tasks tend to be reduced following incongruent relative to following congruent trials, and is considered a prime measure of cognitive control. By investigating the transfer of this CSE across different conflict types, tasks, or contexts, researchers made several inferences about the scope of cognitive control. This method gained popularity during the last few years, spawning an interesting, yet seemingly inconsistent set of results. Consequently, these observations gave rise to a number of equally divergent theories about the determinants and scope of conflict adaptation. In this review, we offer a systematic overview of these past studies, as well as an evaluation of the theories that have been put forward to account for the results. Finally, we propose an integration of these various theoretical views in a unifying framework that centers on the role of context (dis)similarity. This framework allows us to generate new predictions about the relation between task or context similarity and the scope of cognitive control. Specifically, while most theories imply that increasing contextual differences will result in reduced transfer of the CSE, we propose that context similarity and across-context control follow a U-shaped function instead.

The heterogeneous world of congruency sequence effects: an update

Congruency sequence effects (CSEs) refer to the observation that congruency effects in conflict tasks are typically smaller following incongruent compared to following congruent trials. This measure has long been thought to provide a unique window into top-down attentional adjustments and their underlying brain mechanisms. According to the renowned conflict monitoring theory, CSEs reflect enhanced selective attention following conflict detection. Still, alternative accounts suggested that bottom-up associative learning suffices to explain the pattern of reaction times and error rates. A couple of years ago, a review by Egner (2007) pitted these two rivalry accounts against each other, concluding that both conflict adaptation and feature integration contribute to the CSE. Since then, a wealth of studies has further debated this issue, and two additional accounts have been proposed, offering intriguing alternative explanations. Contingency learning accounts put forward that predictive relationships between stimuli and responses drive the CSE, whereas the repetition expectancy hypothesis suggests that top-down, expectancy-driven control adjustments affect the CSE. In the present paper, we build further on the previous review (Egner, 2007) by summarizing and integrating recent behavioral and neurophysiological studies on the CSE. In doing so, we evaluate the relative contribution and theoretical value of the different attentional and memory-based accounts. Moreover, we review how all of these influences can be experimentally isolated, and discuss designs and procedures that can critically judge between them.

Expectation mismatch: differences between self-generated and cue-induced expectations

Expectation of upcoming stimuli and tasks can lead to improved performance, if the anticipated situation occurs, while expectation mismatch can lead to less efficient processing. Researchers have used methodological approaches that rely on either self-generated expectations (predictions) or cue-induced expectations to investigate expectation mismatch effects. Differentiating these two types of expectations for different contents of expectation such as stimuli, responses, task sets and conflict level, we review evidence suggesting that self-generated expectations lead to larger facilitating effects and conflict effects on the behavioral and neural level - as compared to cue-based expectations. On a methodological level, we suggest that self-generated as compared to cue-induced expectations allow for a higher amount of experimental control in many experimental designs on expectation effects. On a theoretical level, we argue for qualitative differences in how cues vs. self-generated expectations influence performance. While self-generated expectations might generally involve representing the expected event in the focus of attention in working memory, cues might only lead to such representations under supportive circumstances (i.e., cue of high validity and attended).

Conscious and unconscious context-specific cognitive control

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 etal., 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 etal., 2012). However, these studies have not yielded unequivocal results (e.g., Kunde, 2003; Heinemann etal., 2009; Van Gaal etal., 2010a; Desender etal., 2013; Reuss etal., 2014). In the present study, we aim at replicating the experiment of Heinemann etal. (2009) in which the proportion of congruent and incongruent trials 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.

Reactive and Proactive Control Adjustments under Increased Depressive Symptoms: Insights from the Classic and Emotional-Face Stroop Task

The current research investigated differences in reactive and proactive cognitive control as a function of depressive symptomatology. Three participant groups with varying symptom levels (Beck Depression Inventory–II, BDI–II score) completed both the classic and an emotional-face Stroop task separately under speed and accuracy instructions. All groups made equivalent speed–accuracy trade-offs independent of task, suggesting that proactive adjustments are unaffected by depressive symptoms. Additionally, groups made equivalent reactive control adjustments (Stroop effects, congruency sequence effects) in the classic Stroop task, suggesting that these reactive control adjustments are spared across a wide range of BDI–II scorers. In contrast, the high BDI–II group displayed a selective impairment in the resolution of conflict in the emotional-face Stroop task. Thus, while proactive control and many aspects of reactive control were unaffected by the level of depressive symptoms, specific impairments occurred when current task demands required the trial-to-trial regulation of emotional processing.

Implicit learning of stimulus regularities increases cognitive control

In this study we aim to examine how the implicit learning of statistical regularities of successive stimuli affects the ability to exert cognitive control. In three experiments, sequences of flanker stimuli were segregated into pairs, with the second stimulus contingent on the first. Response times were reliably faster for the second stimulus if its congruence tended to match the congruence of the preceding stimulus, even though most participants were not explicitly aware of the statistical regularities (Experiment 1). In contrast, performance was not enhanced if the congruence of the second stimuli tended to mismatch the congruence of the first stimulus (Experiment 2). The lack of improvement appears to result from a failure of learning mismatch contingencies (Experiment 3). The results suggest that implicit learning of inter-stimulus relationships can facilitate cognitive control.

Context specificity of post-error and post-conflict cognitive control adjustments

There has been accumulating evidence that cognitive control can be adaptively regulated by monitoring for processing conflict as an index of online control demands. However, it is not yet known whether top-down control mechanisms respond to processing conflict in a manner specific to the operative task context or confer a more generalized benefit. While previous studies have examined the taskset-specificity of conflict adaptation effects, yielding inconsistent results, control-related performance adjustments following errors have been largely overlooked. This gap in the literature underscores recent debate as to whether post-error performance represents a strategic, control-mediated mechanism or a nonstrategic consequence of attentional orienting. In the present study, evidence of generalized control following both high conflict correct trials and errors was explored in a task-switching paradigm. Conflict adaptation effects were not found to generalize across tasksets, despite a shared response set. In contrast, post-error slowing effects were found to extend to the inactive taskset and were predictive of enhanced post-error accuracy. In addition, post-error performance adjustments were found to persist for several trials and across multiple task switches, a finding inconsistent with attentional orienting accounts of post-error slowing. These findings indicate that error-related control adjustments confer a generalized performance benefit and suggest dissociable mechanisms of post-conflict and post-error control.

Dissociable Effects of Motivation and Expectancy on Conflict Processing: An fMRI Study

Previous studies suggest that both motivation and task difficulty expectations activate brain regions associated with cognitive control. However, it remains an open question whether motivational and cognitive determinants of control have similar or dissociable impacts on conflict processing on a neural level. The current study tested the effects of motivation and conflict expectancy on activity in regions related to processing of the target and the distractor information. Participants performed a picture–word interference task in which we manipulated the size of performance-dependent monetary rewards (level of motivation) and the ratio of congruent to incongruent trials within a block (level of conflict expectancy). Our results suggest that motivation improves conflict processing by facilitating task-relevant stimulus processing and task difficulty expectations mainly modulate the processing of distractor information. We conclude that motivation and conflict expectancy engage dissociable control strategies during conflict resolution.

ERP correlates of dual mechanisms of control in the counting Stroop task

Event-related brain potentials (ERPs) were used to examine the neural correlates of proactive and reactive cognitive control within the context of the Dual Mechanisms of Control theory. Individuals performed the counting Stroop task and the proportion of congruent and incongruent trials was varied across blocks. The Stroop effect was smaller in the mostly incongruent block than in the mostly congruent block. The ERP data revealed a double dissociation between the medial frontal negativity (MFN) and the medial posterior negativity (MPN), where the amplitude of the MFN was greater in the mostly incongruent block and the amplitude of the MPN was greater in the mostly congruent block. The ERP data also revealed slow wave activity that distinguished the mostly incongruent and mostly congruent blocks. These findings support the idea that different regions of the cingulate and anterior frontal cortex underpin proactive and reactive control.

When predictions take control: the effect of task predictions on task switching performance

In this paper, we aimed to investigate the role of self-generated predictions in the flexible control of behavior. Therefore, we ran a task switching experiment in which participants were asked to try to predict the upcoming task in three conditions varying in switch rate (30, 50, and 70%). Irrespective of their predictions, the color of the target indicated which task participants had to perform. In line with previous studies (Mayr, 2006; Monsell and Mizon, 2006), the switch cost was attenuated as the switch rate increased. Importantly, a clear task repetition bias was found in all conditions, yet the task repetition prediction rate dropped from 78 over 66 to 49% with increasing switch probability in the three conditions. Irrespective of condition, the switch cost was strongly reduced in expectation of a task alternation compared to the cost of an unexpected task alternation following repetition predictions. Hence, our data suggest that the reduction in the switch cost with increasing switch probability is caused by a diminished expectancy for the task to repeat. Taken together, this paper highlights the importance of predictions in the flexible control of behavior, and suggests a crucial role for task repetition expectancy in the context-sensitive adjusting of task switching performance.