Medial Prefrontal Cortical Activity Reflects Dynamic Re-Evaluation During Voluntary Persistence

Deciding how long to keep waiting for future rewards is a nontrivial problem, especially when the timing of rewards is uncertain. We carried out an experiment in which human decision makers waited for rewards in two environments in which reward-timing statistics favored either a greater or lesser degree of behavioral persistence. We found that decision makers adaptively calibrated their level of persistence for each environment. Functional neuroimaging revealed signals that evolved differently during physically identical delays in the two environments, consistent with a dynamic and context-sensitive reappraisal of subjective value. This effect was observed in a region of ventromedial prefrontal cortex that is sensitive to subjective value in other contexts, demonstrating continuity between valuation mechanisms involved in discrete choice and in temporally extended decisions analogous to foraging. Our findings support a model in which voluntary persistence emerges from dynamic cost/benefit evaluation rather than from a control process that overrides valuation mechanisms

Deciding to Curtail Persistence

Imagine that a few seconds ago you called a restaurant to book a reservation and were placed on hold. How soon do you expect to be helped? Are you having any difficulty waiting? Now imagine 5 minutes have gone by and you are still hearing hold music. Is it getting more difficult? Have your expectations changed? How much longer will you give them? Voluntary persistence toward delayed rewards has often been framed, in the psychological literature, as a self-control problem. This view presumes that it is generally beneficial to direct one\u27s behavior toward valuable prospects in the future, but that the fallible nature of self-control makes people sometimes succumb to immediate temptations instead. In laboratory studies, individuals who wait longer for delayed rewards have been deemed to possess greater self-control capacity. In real life, though, how long it is worth holding out for future rewards can be a more vexed question. Not all long-run rewards is complicated by the fact that future events are uncertain in both their substance and their timing. When it comes to choosing how long to wait for everything from city buses to customer service representatives, decision makers can as easily err by waiting too long--chasing sunk costs-- as by waiting too little. In this chapter we review research suggesting that the challenge of delaying gratification does not emerge merely from psychological limitations but instead reflects the genuine complexity of the environments in which real-world decisions take place

Decision Makers Calibrate Behavioral Persistence on the Basis of Time-Interval Experience

A central question in intertemporal decision making is why people reverse their own past choices. Someone who initially prefers a long-run outcome might fail to maintain that preference for long enough to see the outcome realized. Such behavior is usually understood as reflecting preference instability or self-control failure. However, if a decision maker is unsure exactly how long an awaited outcome will be delayed, a reversal can constitute the rational, utility-maximizing course of action. In the present behavioral experiments, we placed participants in timing environments where persistence toward delayed rewards was either productive or counterproductive. Our results show that human decision makers are responsive to statistical timing cues, modulating their level of persistence according to the distribution of delay durations they encounter. We conclude that temporal expectations act as a powerful and adaptive influence on people’s tendency to sustain patient decisions. Highlights ► Participants decided how long to wait for temporally uncertain rewards. ► The distribution of possible delays determines whether persistence is productive. ► Different conditions, matched for reward rate, required high or low persistence. ► With experience, decision makers appropriately adjusted their willingness to wait. ► Apparent failures of persistence can reflect adaptive temporal judgments

The Valuation System: A Coordinate-Based Meta-Analysis of BOLD fMRI Experiments Examining Neural Correlates of Subjective Value

Numerous experiments have recently sought to identify neural signals associated with the subjective value (SV) of choice alternatives. Theoretically, SV assessment is an intermediate computational step during decision making, in which alternatives are placed on a common scale to facilitate value-maximizing choice. Here we present a quantitative, coordinate-based meta-analysis of 206 published fMRI studies investigating neural correlates of SV. Our results identify two general patterns of SV-correlated brain responses. In one set of regions, both positive and negative effects of SV on BOLD are reported at above-chance rates across the literature. Areas exhibiting this pattern include anterior insula, dorsomedialprefrontal cortex, dorsal and posterior striatum, and thalamus. The mixture of positive and negative effects potentially reflects an underlying U-shaped function, indicative of signal related to arousal or salience. In a second set of areas, including ventromedial prefrontal cortex and anterior ventral striatum, positive effects predominate. Positive effects in the latter regions are seen both when a decision is confronted and when an outcome is delivered, as well as for both monetary and primary rewards. These regions appear to constitute a “valuation system,” carrying a domain-general SV signal and potentially contributing to value-based decision making

Do Political and Economic Choices Rely on Common Neural Substrates? A Systematic Review of the Emerging Neuropolitics Literature

The methods of cognitive neuroscience are beginning to be applied to the study of political behavior. The neural substrates of value-based decision-making have been extensively examined in economic contexts; this might provide a powerful starting point for understanding political decision-making. Here, we asked to what extent the neuropolitics literature to date has used conceptual frameworks and experimental designs that make contact with the reward-related approaches that have dominated decision neuroscience. We then asked whether the studies of political behavior that can be considered in this light implicate the brain regions that have been associated with subjective value related to “economic” reward. We performed a systematic literature review to identify papers addressing the neural substrates of political behavior and extracted the fMRI studies reporting behavioral measures of subjective value as defined in decision neuroscience studies of reward. A minority of neuropolitics studies met these criteria and relatively few brain activation foci from these studies overlapped with regions where activity has been related to subjective value. These findings show modest influence of reward-focused decision neuroscience on neuropolitics research to date. Whether the neural substrates of subjective value identified in economic choice paradigms generalize to political choice thus remains an open question. We argue that systematically addressing the commonalities and differences in these two classes of value-based choice will be important in developing a more comprehensive model of the brain basis of human decision-making

Functionally Dissociable Influences on Learning Rate in a Dynamic Environment

Maintaining accurate beliefs in a changing environment requires dynamically adapting the rate at which one learns from new experiences. Beliefs should be stable in the face of noisy data but malleable in periods of change or uncertainty. Here we used computational modeling, psychophysics, and fMRI to show that adaptive learning is not a unitary phenomenon in the brain. Rather, it can be decomposed into three computationally and neuroanatomically distinct factors that were evident in human subjects performing a spatial-prediction task: (1) surprise-driven belief updating, related to BOLD activity in visual cortex; (2) uncertainty-driven belief updating, related to anterior prefrontal and parietal activity; and (3) reward-driven belief updating, a context-inappropriate behavioral tendency related to activity in ventral striatum. These distinct factors converged in a core system governing adaptive learning. This system, which included dorsomedial frontal cortex, responded to all three factors and predicted belief updating both across trials and across individuals

Neurocognitive Correlates of Treatment Response in Children with Tourette\u27s Disorder

This paper examined neurocognitive functioning and its relationship to behavior treatment response among youth with Tourette\u27s Disorder (TD) in a large randomized controlled trial. Participants diagnosed with TD completed a brief neurocognitive battery assessing inhibitory functions, working memory, and habit learning pre- and post-treatment with behavior therapy (CBIT, Comprehensive Behavioral Intervention for Tics) or psychoeducation plus supportive therapy (PST). At baseline, youth with tics and Attention Deficit Hyperactivity Disorder (ADHD) exhibited some evidence of impaired working memory and simple motor inhibition relative to youth with tics without ADHD. Additionally, a small negative association was found between antipsychotic medications and youth\u27s performance speed. Across treatment groups, greater baseline working memory and aspects of inhibitory functioning were associated with a positive treatment response; no between-group differences in neurocognitive functioning at post-treatment were identified. Within the behavior therapy group, pre-treatment neurocognitive status did not predict outcome, nor was behavior therapy associated significant change in neurocognitive functioning post-treatment. Findings suggest that co-occurring ADHD is associated with some impairments in neurocognitive functioning in youth with Tourette\u27s Disorder. While neurocognitive predictors of behavior therapy were not found, participants who received behavior therapy exhibited significantly reduced tic severity without diminished cognitive functioning

The Effects of Acute Stress on the Calibration of Persistence

People frequently fail to wait for delayed rewards after choosing them. These preference reversals are sometimes thought to reflect self-control failure. Other times, however, continuing to wait for a delayed reward may be counterproductive (e.g., when reward timing uncertainty is high). Research has demonstrated that people can calibrate how long to wait for rewards in a given environment. Thus, the role of self-control might be to integrate information about the environment to flexibly adapt behavior, not merely to promote waiting. Here we tested effects of acute stress, which has been shown to tax control processes, on persistence, and the calibration of persistence, in young adult human participants. Half the participants (n = 60) performed a task in which persistence was optimal, and the other half (n = 60) performed a task in which it was optimal to quit waiting for reward soon after each trial began. Each participant completed the task either after cold pressor stress or no stress. Stress did not influence persistence or optimal calibration of persistence. Nevertheless, an exploratory analysis revealed an “inverted-U” relationship between cortisol increase and performance in the stress groups, suggesting that choosing the adaptive waiting policy may be facilitated with some stress and impaired with severe stress

An Empirical Examination of Symptom Substitution Associated with Behavior Therapy for Tourette\u27s Disorder

Over the past six decades, behavior therapy has been a major contributor to the development of evidence-based psychotherapy treatments. However, a long-standing concern with behavior therapy among many nonbehavioral clinicians has been the potential risk for symptom substitution. Few studies have been conducted to evaluate symptom substitution in response to behavioral treatments, largely due to measurement and definitional challenges associated with treated psychiatric symptoms. Given the overt motor and vocal tics associated with Tourette’s disorder, it presents an excellent opportunity to empirically evaluate the potential risk for symptom substitution associated with behavior therapy. The present study examined the possible presence of symptom substitution using four methods: (a) the onset of new tic symptoms, (b) the occurrence of adverse events, (c) change in tic medications, and (d) worsening of co-occurring psychiatric symptoms. Two hundred twenty-eight participants with Tourette’s disorder or persistent motor or vocal tic disorders were randomly assigned to receive behavioral therapy or supportive therapy for tics. Both therapies consisted of eight sessions over 10 weeks. Results indicated that participants treated with behavior therapy were not more likely to have an onset of new tic symptoms, experience adverse events, increase tic medications, or have an exacerbation in co-occurring psychiatric symptoms relative to participants treated with supportive therapy. Further analysis suggested that the emergence of new tics was attributed with the normal waxing and waning nature of Tourette’s disorder. Findings provide empirical support to counter the long-standing concern of symptom substitution in response to behavior therapy for individuals with Tourette\u27s disorder

Plasma Androgens in Women with Acne Vulgaris

We have studied a group of young adult women of mean age 23.8 ± 6.5 (SD) years with only acne (A, n =46), only hirsutism (H, n = 10), and acne plus hirsutism (A+H, n = 19) who sought dermatologic care. We measured the androgens, total and free testosterone (T), free 17β-hydroxysteroids (17-β), dehydroepiandrosterone sulfate (DS), and the androgen precursors 17α-hydroxypregnenolone (17-Preg) and 17α-hydroxyprogesterone (17-Prog), as well as testosterone-estrogen binding globulin in all patients. Plasma hormone levels of the patients were compared to those of 23 controls of mean age 25.6 ± 6.6 years who had neither acne nor hirsutism. Mean levels of all hormones measured, except 17-Preg, were elevated in the women with acne. Fifty-two percent of Group A, 66% of Group H, and 63% of Group A+H patients had at least one abnormal hormone level. The most frequently elevated plasma androgens in all the women with acne were: free T 25%, free 17-β 23%, and DS 19%. Total T was high in only 12%. Elevations of plasma androgens were present in some women who did not have hirsutism or irregular menses. Identification of endocrine abnormalities in women with acne may potentially offer an opportunity for hormonal therapy