Dual Mechanisms of Cognitive Control

Study Overview

This project focuses on understanding the psychological and neural mechanisms that give rise to cognitive control. Cognitive control processes are a component of human mental function that is fundamentally important in a wide range of domains, including attention, working memory, episodic memory, and decision making. Cognitive control disruptions are thought to be a major source of functional impairment for individuals suffering from a variety of mental health disorders and neuropsychiatric diseases. 

We have developed a theoretically coherent and mechanistic model, called Dual Mechanisms of Cognitive Control (DMC). The central hypothesis of the DMC framework is that cognitive control operates via two distinct operating modes – proactive control and reactive control.  The proactive control mode can be conceptualized as a form of “early selection,” in which goal-relevant information is actively maintained in a sustained manner, prior to the occurrence of cognitively demanding events, in order to optimally bias attention, perception and action systems in a goal-driven manner. In contrast, in reactive control, attention is recruited as a “late correction” mechanism that is mobilized only as needed in a just-in-time manner, such as after a high interference event is detected. These two cognitive control modes represent a core dimension of individual variability, encompassing multiple domains of cognitive control function in healthy young adults, but also in more extreme forms, contributing to dysfunction present in various impaired populations (e.g., schizophrenia, depression, ADHD, aging).

Study Timespan: June 5, 2013 – March 30, 2023


Todd Braver

Todd Braver, Ph.D. - WashU Principal Investigator

Contact: Email

Study Protocol Overview

Data being collected

  • Standard HCP demographics
  • Imaging: The DMCC will collect longitudinal MR imaging data for structural, resting-state and task. Some subjects will also undergo retest imaging sessions.  a
  • Clinical:  No clinical interviews. Saliva to be collected, but no blood work or DNA. 
  • Behavioral: BIS, BISABAS, Demographic, DOSPERT, FFMQ, Fordyce, GRAPES, MAAS, NfCS, NEO FFI, PANAS, PHQ, PSQI, Scompassion, selfcontrol, SPSRQ, STAI, SWL, Operational and Symmetry Span, Ravens Matrices, Letter Set, and NIH Toolbox tasks.

Cohort Description

The study consists of 300 participants ranging in age from 18-40. This study plans to include as many of the original HCP Young Adult twin pairs as possible within its cohort, as participants not controls.  

Data Release Plans

The primary data release will occur after all data is collected, in 2023. A pilot data release may happen in 2019. 


  • Interactions of motivation and cognitive control

    Debbie M Yee, Todd S Braver
    Show Summary

    There is general agreement that both motivation and cognitive control play critical roles in shaping goal-directed behavior, but only recently has scientific interest focused around the question of motivation–control interactions. Here we briefly survey this literature, organizing contemporary findings around three issues: (1) whether motivation preferentially impacts cognitive control processes, (2) the neural mechanisms that underlie motivation–cognition interactions, and (3) why motivation might be relevant for overcoming the costs of control. Dopamine (DA) is discussed as a key neuromodulator in these motivation–cognition interactions. We conclude by highlighting open issues, specifically Pavlovian versus instrumental control distinctions and effects of motivational valence and conflict, which could benefit from future research attention.

  • The Role of Psychometrics in Individual Differences Research in Cognition: A Case Study of the AX-CPT.

    Shelly R Cooper, Corentin Gonthier, Deanna M Barch, Todd S Braver
    Frontiers in psychology, Sep 21, 2017 PMID: 28928690
    Show Summary

    Investigating individual differences in cognition requires addressing questions not often thought about in standard experimental designs, especially regarding the psychometric properties of the task. Using the AX-CPT cognitive control task as a case study example, we address four concerns that one may encounter when researching the topic of individual differences in cognition. First, we demonstrate the importance of variability in task scores, which in turn directly impacts reliability, particularly when comparing correlations in different populations. Second, we demonstrate the importance of variability and reliability for evaluating potential failures to replicate predicted correlations, even within the same population. Third, we demonstrate how researchers can turn to evaluating psychometric properties as a way of evaluating the feasibility of utilizing the task in new settings (e.g., online administration). Lastly, we show how the examination of psychometric properties can help researchers make informed decisions when designing a study, such as determining the appropriate number of trials for a task.

  • A role for proactive control in rapid instructed task learning.

    Michael W Cole, Lauren M Patrick, Nachshon Meiran, Todd S Braver
    Acta psychologica, Jun 28, 2017 PMID: 28651787
    Show Summary

    Humans are often remarkably fast at learning novel tasks from instructions. Such rapid instructed task learning (RITL) likely depends upon the formation of new associations between long-term memory representations, which must then be actively maintained to enable successful task implementation. Consequently, we hypothesized that RITL relies more heavily on a proactive mode of cognitive control, in which goal-relevant information is actively maintained in preparation for anticipated high control demands. We tested this hypothesis using a recently developed cognitive paradigm consisting of 60 novel tasks involving RITL and 4 practiced tasks, with identical task rules and stimuli used across both task types. A robust behavioral cost was found in novel relative to practiced task performance, which was present even when the two were randomly inter-mixed, such that task-switching effects were equated. Novelty costs were most prominent under time-limited preparation conditions. In self-paced conditions, increased preparation time was found for novel trials, and was selectively associated with enhanced performance, suggesting greater proactive control for novel tasks. These results suggest a key role for proactive cognitive control in the ability to rapidly learn novel tasks from instructions.

  • Inducing Proactive Control Shifts in the AX-CPT.

    Corentin Gonthier, Brooke N Macnamara, Michael Chow, Andrew R A Conway, Todd S Braver
    Frontiers in psychology, Dec 07, 2016 PMID: 27920741
    Show Summary

    The Dual Mechanisms of Control (DMC) account (Braver, 2012) proposes two distinct mechanisms of cognitive control, proactive and reactive. This account has been supported by a large number of studies using the AX-CPT paradigm that have demonstrated not only between-group differences, but also within-subjects variability in the use of the two control mechanisms. Yet there has been little investigation of task manipulations that can experimentally modulate the use of proactive control in healthy young adults; such manipulations could be useful to better understand the workings of cognitive control mechanisms. In the current study, a series of three experiments demonstrate how individuals can be systematically biased toward and away from the utilization of proactive control, via strategy training and no-go manipulations, respectively. These results provide increased support for the DMC framework, and provide a new basis from which to examine group-based differences and neural mechanisms underlying the two control modes.

  • Dissociating proactive and reactive control in the Stroop task.

    Corentin Gonthier, Todd S Braver, Julie M Bugg
    Memory & cognition, Feb 11, 2016 PMID: 26861210
    Show Summary

    The Dual Mechanisms of Control framework posits the existence of two distinct control mechanisms, proactive and reactive, which may operate independently. However, this independence has been difficult to study with most experimental paradigms. The Stroop task may provide a useful way of assessing the independence of control mechanisms because the task elicits two types of proportion congruency effects, list-wide and item-specific, thought to reflect proactive and reactive control respectively. The present research tested whether these two proportion congruency effects can be used to dissociate proactive and reactive control. In 2 separate participant samples, we demonstrate that list-wide and item-specific proportion congruency effects are stable, exist in the same participants, and appear in different task conditions. Moreover, we identify two distinct behavioral signatures, the congruency cost and the transfer cost, which doubly dissociate the two effects. Together, the results are consistent with the view that proactive and reactive control reflect independent mechanisms.

  • Proactive control of irrelevant task rules during cued task switching.

    Julie M Bugg, Todd S Braver
    Psychological research, Jul 29, 2015 PMID: 26215433
    Show Summary

    In task-switching paradigms, participants are often slower on incongruent than congruent trials, a pattern known as the task-rule congruency effect. This effect suggests that irrelevant task rules or associated responses may be retrieved automatically in spite of task cues. The purpose of the present study was to examine whether the task-rule congruency effect may be modulated via manipulations intended to induce variation in proactive control. Manipulating the proportion of congruent to incongruent trials strongly influenced the magnitude of the task-rule congruency effect. The effect was significantly reduced in a mostly incongruent list relative to a mostly congruent list, a pattern that was observed for not only biased but also 50 % congruent items. This finding implicates a role for global attentional control processes in the task-rule congruency effect. In contrast, enhancing the preparation of relevant (cued) task rules by the provision of a monetary incentive substantially reduced mixing costs but did not affect the task-rule congruency effect. These patterns support the view that there may be multiple routes by which proactive control can influence task-switching performance; however, only select routes appear to influence the automatic retrieval of irrelevant task rules.

Contact This Study

Use this form for general inquiries. To inquire about participation in this study or to acquire study data, please visit   https://pages.wustl.edu/dualmechanisms

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