Separate Valuation Subsystems for Delay and Effort Decision Costs

Cognitive Neuroscience Center, Centre National de la Recherche Scientifique, Unité mixte de recherche 5229, Reward and Decision Making Team, 69675 Bron, France.
The Journal of Neuroscience : The Official Journal of the Society for Neuroscience (Impact Factor: 6.34). 10/2010; 30(42):14080-90. DOI: 10.1523/JNEUROSCI.2752-10.2010
Source: PubMed


Decision making consists of choosing among available options on the basis of a valuation of their potential costs and benefits. Most theoretical models of decision making in behavioral economics, psychology, and computer science propose that the desirability of outcomes expected from alternative options can be quantified by utility functions. These utility functions allow a decision maker to assign subjective values to each option under consideration by weighting the likely benefits and costs resulting from an action and to select the one with the highest subjective value. Here, we used model-based neuroimaging to test whether the human brain uses separate valuation systems for rewards (erotic stimuli) associated with different types of costs, namely, delay and effort. We show that humans devalue rewards associated with physical effort in a strikingly similar fashion to those they devalue that are associated with delays, and that a single computational model derived from economics theory can account for the behavior observed in both delay discounting and effort discounting. However, our neuroimaging data reveal that the human brain uses distinct valuation subsystems for different types of costs, reflecting in opposite fashion delayed reward and future energetic expenses. The ventral striatum and the ventromedial prefrontal cortex represent the increasing subjective value of delayed rewards, whereas a distinct network, composed of the anterior cingulate cortex and the anterior insula, represent the decreasing value of the effortful option, coding the expected expense of energy. Together, these data demonstrate that the valuation processes underlying different types of costs can be fractionated at the cerebral level.

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    • "Human studies mirror these effects, indicating that individual differences in dopamine release predict willingness to expend effort for high value rewards and that amphetamine administration increases effortful behavior (Treadway et al., 2012; Wardle et al., 2011). Anterior cingulate cortex (ACC) structure and function also predicts effort-cost computation in animal and human studies, potentially via interactions with the dopamine system (Croxson et al., 2009; Endepols et al., 2010; Prevost et al., 2010; Walton et al., 2002; Walton et al., 2009). There are several reasons to expect that SZ patients would display abnormalities in effort-cost computation, including structural and "
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    ABSTRACT: The current study examined whether effort-cost computation was associated with negative symptoms of schizophrenia (SZ). Participants included outpatients diagnosed with SZ (n=27) and demographically matched healthy controls (n=32) who completed a Progressive Ratio task that required incrementally greater amounts of physical effort to obtain monetary reward. Breakpoint, the point at which participants was no longer willing to exert effort for a certain reward value, was examined as an index of effort-cost computation. There were no group differences in breakpoint for low, medium, or high value rewards on the Progressive Ratio task. However, lower breakpoint scores were associated with greater severity of avolition and anhedonia symptoms in SZ patients. Findings provide further evidence that impaired effort-cost computation is linked to motivational abnormalities in SZ.
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    • "During the T-maze paradigm, animals choose between two reinforcers whose values vary in both size and delay. Human delay-discounting studies have shown that activity of the ventral striatum correlates with the subjective value of a reward and decreases with an increase of the delay preceding the reward, assuming that the NAc helps to value immediate and delayed outcome (Kable and Glimcher, 2007; Prevost et al., 2010). A Pavlovian conditioning task using lithium-devalued food reward revealed that both core and shell are necessary for the evaluation of expected outcomes, as devalued rats with lesions of either core or shell showed similar response levels to lesioned, non-devalued rats (Singh et al., 2010), suggesting that NAc deactivation might impair the ability of delays to discount the reward. "
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    • "negative variation; CRN, cue-related negativity; DRL, Driven Right Leg; EEG, electroencephalography ; ERN, error-related negativity; ERP, event-related potential; FRN, feedback-related negativity; RM-ANOVA, repeated measures analysis of variance; SCP, statistical cluster plot; UDTR, up-down transformed-rule. Neuroscience 273 (2014) 100–117 and anterior cingulate cortex have been implicated in task monitoring when participants made errors while bidding for rewards (Hare et al., 2008), when participants evaluate task effort needed to obtain primary rewards (Prevost et al., 2010), and when evaluating conflict between high-risk or low-risk choices (Kuhnen and Knutson, 2005). Neuroimaging, however, is not ideal for examining the interaction of processes that may occur over very fast timescales. "
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