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The decision to engage cognitive control is driven by expected reward-value: neural and behavioral evidence.

Dixon ML, Christoff K - PLoS ONE (2012)

Bottom Line: Subjects rarely engaged cognitive control when the expected outcome was of equal or lesser value as compared to the value of the automatic response, but frequently engaged cognitive control when it was expected to yield a larger monetary outcome.Together, these findings suggest that individuals are more likely to act in a reflective, rule-based manner when they expect that it will result in a desired outcome.Finally, in contrast to current models of LPFC function, our results suggest that the LPFC plays a direct role in representing motivational incentives.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of British Columbia, Vancouver, British Columbia, Canada. mattdixon@psych.ubc.ca

ABSTRACT
Cognitive control is a fundamental skill reflecting the active use of task-rules to guide behavior and suppress inappropriate automatic responses. Prior work has traditionally used paradigms in which subjects are told when to engage cognitive control. Thus, surprisingly little is known about the factors that influence individuals' initial decision of whether or not to act in a reflective, rule-based manner. To examine this, we took three classic cognitive control tasks (Stroop, Wisconsin Card Sorting Task, Go/No-Go task) and created novel 'free-choice' versions in which human subjects were free to select an automatic, pre-potent action, or an action requiring rule-based cognitive control, and earned varying amounts of money based on their choices. Our findings demonstrated that subjects' decision to engage cognitive control was driven by an explicit representation of monetary rewards expected to be obtained from rule-use. Subjects rarely engaged cognitive control when the expected outcome was of equal or lesser value as compared to the value of the automatic response, but frequently engaged cognitive control when it was expected to yield a larger monetary outcome. Additionally, we exploited fMRI-adaptation to show that the lateral prefrontal cortex (LPFC) represents associations between rules and expected reward outcomes. Together, these findings suggest that individuals are more likely to act in a reflective, rule-based manner when they expect that it will result in a desired outcome. Thus, choosing to exert cognitive control is not simply a matter of reason and willpower, but rather, conforms to standard mechanisms of value-based decision making. Finally, in contrast to current models of LPFC function, our results suggest that the LPFC plays a direct role in representing motivational incentives.

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Related in: MedlinePlus

Trial Structure for the fMRI Experiment.After a variable duration fixation cross, an instruction cue signaled the currently relevant rules (profile of faces = male/female rule; book = abstract/concrete rule) and whether or not to expect a monetary reward (blue vase = no money; bills = 25¢). This was followed by a variable duration delay period and then a word or face stimulus, during which subjects made a button response. Finally, a screen revealed whether money had been earned on that trial and cumulative winnings. On key trials, a second instruction cue appeared before the stimulus. Across the two instruction cues, we varied whether there was repetition of the rules, expected reward, both, or neither.
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pone-0051637-g002: Trial Structure for the fMRI Experiment.After a variable duration fixation cross, an instruction cue signaled the currently relevant rules (profile of faces = male/female rule; book = abstract/concrete rule) and whether or not to expect a monetary reward (blue vase = no money; bills = 25¢). This was followed by a variable duration delay period and then a word or face stimulus, during which subjects made a button response. Finally, a screen revealed whether money had been earned on that trial and cumulative winnings. On key trials, a second instruction cue appeared before the stimulus. Across the two instruction cues, we varied whether there was repetition of the rules, expected reward, both, or neither.

Mentions: In our paradigm (see Material and Methods and Figure 2), each trial started with an instruction cue that indicated one of two rules to use (male/female face discrimination, versus abstract/concrete word discrimination), and also indicated one of two expected motivational outcomes (25¢ monetary reward, versus no monetary reward). Following presentation of the instruction cue, subjects made a button response to a face or word stimulus. The key feature of the task is that on certain trials, a second instruction cue appeared prior to the stimulus, and relative to the first instruction cue, we manipulated whether there was repetition of the rules, repetition of the outcome, repetition of the rule-outcome pairing, or presentation of a novel rule-outcome pairing. (Although this task differs in surface features from the behavioral tasks, it shares the core cognitive control requirement of active maintenance of task rules due to the constant switching of rules from trial to trial. Moreover, this task was designed to minimize response and perceptual conflict, thus allowing us to examine the neural representation of rule-outcome associations in the absence of potential confounding variables.)


The decision to engage cognitive control is driven by expected reward-value: neural and behavioral evidence.

Dixon ML, Christoff K - PLoS ONE (2012)

Trial Structure for the fMRI Experiment.After a variable duration fixation cross, an instruction cue signaled the currently relevant rules (profile of faces = male/female rule; book = abstract/concrete rule) and whether or not to expect a monetary reward (blue vase = no money; bills = 25¢). This was followed by a variable duration delay period and then a word or face stimulus, during which subjects made a button response. Finally, a screen revealed whether money had been earned on that trial and cumulative winnings. On key trials, a second instruction cue appeared before the stimulus. Across the two instruction cues, we varied whether there was repetition of the rules, expected reward, both, or neither.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3526643&req=5

pone-0051637-g002: Trial Structure for the fMRI Experiment.After a variable duration fixation cross, an instruction cue signaled the currently relevant rules (profile of faces = male/female rule; book = abstract/concrete rule) and whether or not to expect a monetary reward (blue vase = no money; bills = 25¢). This was followed by a variable duration delay period and then a word or face stimulus, during which subjects made a button response. Finally, a screen revealed whether money had been earned on that trial and cumulative winnings. On key trials, a second instruction cue appeared before the stimulus. Across the two instruction cues, we varied whether there was repetition of the rules, expected reward, both, or neither.
Mentions: In our paradigm (see Material and Methods and Figure 2), each trial started with an instruction cue that indicated one of two rules to use (male/female face discrimination, versus abstract/concrete word discrimination), and also indicated one of two expected motivational outcomes (25¢ monetary reward, versus no monetary reward). Following presentation of the instruction cue, subjects made a button response to a face or word stimulus. The key feature of the task is that on certain trials, a second instruction cue appeared prior to the stimulus, and relative to the first instruction cue, we manipulated whether there was repetition of the rules, repetition of the outcome, repetition of the rule-outcome pairing, or presentation of a novel rule-outcome pairing. (Although this task differs in surface features from the behavioral tasks, it shares the core cognitive control requirement of active maintenance of task rules due to the constant switching of rules from trial to trial. Moreover, this task was designed to minimize response and perceptual conflict, thus allowing us to examine the neural representation of rule-outcome associations in the absence of potential confounding variables.)

Bottom Line: Subjects rarely engaged cognitive control when the expected outcome was of equal or lesser value as compared to the value of the automatic response, but frequently engaged cognitive control when it was expected to yield a larger monetary outcome.Together, these findings suggest that individuals are more likely to act in a reflective, rule-based manner when they expect that it will result in a desired outcome.Finally, in contrast to current models of LPFC function, our results suggest that the LPFC plays a direct role in representing motivational incentives.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of British Columbia, Vancouver, British Columbia, Canada. mattdixon@psych.ubc.ca

ABSTRACT
Cognitive control is a fundamental skill reflecting the active use of task-rules to guide behavior and suppress inappropriate automatic responses. Prior work has traditionally used paradigms in which subjects are told when to engage cognitive control. Thus, surprisingly little is known about the factors that influence individuals' initial decision of whether or not to act in a reflective, rule-based manner. To examine this, we took three classic cognitive control tasks (Stroop, Wisconsin Card Sorting Task, Go/No-Go task) and created novel 'free-choice' versions in which human subjects were free to select an automatic, pre-potent action, or an action requiring rule-based cognitive control, and earned varying amounts of money based on their choices. Our findings demonstrated that subjects' decision to engage cognitive control was driven by an explicit representation of monetary rewards expected to be obtained from rule-use. Subjects rarely engaged cognitive control when the expected outcome was of equal or lesser value as compared to the value of the automatic response, but frequently engaged cognitive control when it was expected to yield a larger monetary outcome. Additionally, we exploited fMRI-adaptation to show that the lateral prefrontal cortex (LPFC) represents associations between rules and expected reward outcomes. Together, these findings suggest that individuals are more likely to act in a reflective, rule-based manner when they expect that it will result in a desired outcome. Thus, choosing to exert cognitive control is not simply a matter of reason and willpower, but rather, conforms to standard mechanisms of value-based decision making. Finally, in contrast to current models of LPFC function, our results suggest that the LPFC plays a direct role in representing motivational incentives.

Show MeSH
Related in: MedlinePlus