Arbitration between controlled and impulsive choices.

The impulse to act for immediate reward often conflicts with more deliberate evaluations that support long-term benefit. The neural architecture that negotiates this conflict remains unclear. One account proposes a single neural circuit that evaluates both immediate and delayed outcomes, while another outlines separate impulsive and patient systems that compete for behavioral control. Here we designed a task in which a complex payout structure divorces the immediate value of acting from the overall long-term value, within the same outcome modality. Using model-based fMRI in humans, we demonstrate separate neural representations of immediate and long-term values, with the former tracked in the anterior caudate (AC) and the latter in the ventromedial prefrontal cortex (vmPFC). Crucially, when subjects' choices were compatible with long-run consequences, value signals in AC were down-weighted and those in vmPFC were enhanced, while the opposite occurred when choice was impulsive. Thus, our data implicate a trade-off in value representation between AC and vmPFC as underlying controlled versus impulsive choice

Neural dysfunction during temporal discounting in paediatric Attention-Deficit/Hyperactivity Disorder and Obsessive-Compulsive Disorder

Both Attention-Deficit/Hyperactivity Disorder (ADHD) and Obsessive-Compulsive Disorder (OCD) are associated with choice impulsivity, i.e. the tendency to prefer smaller immediate rewards over larger delayed rewards. However, the extent to which this impulsivity is mediated by shared or distinct underlying neural mechanisms is unclear. Twenty-six boys with ADHD, 20 boys with OCD and 20 matched controls (aged 12–18) completed an fMRI version of an individually adjusted temporal discounting (TD) task which requires choosing between a variable amount of money now or £100 in one week, one month or one year. Activations to immediate and delayed reward choices were compared between groups using a three-way ANCOVA. ADHD patients had steeper discounting rates on the task relative to controls. OCD patients did not differ from controls or patients with ADHD. Patients with ADHD and OCD showed predominantly shared activation deficits during TD in fronto-striato-insular-cerebellar regions responsible for self-control and temporal foresight, suggesting that choice impulsivity is mediated by overlapping neural dysfunctions in both disorders. OCD patients alone showed dysfunction relative to controls in right orbitofrontal and rostrolateral prefrontal cortex, extending previous findings of abnormalities in these regions in OCD to the domain of choice impulsiveness

Deep brain stimulation of the subthalamic nucleus modulates sensitivity to decision outcome value in Parkinson's disease.

Deep brain stimulation (DBS) of the subthalamic nucleus in Parkinson's disease is known to cause a subtle but important adverse impact on behaviour, with impulsivity its most widely reported manifestation. However, precisely which computational components of the decision process are modulated is not fully understood. Here we probe a number of distinct subprocesses, including temporal discount, outcome utility, instrumental learning rate, instrumental outcome sensitivity, reward-loss trade-offs, and perseveration. We tested 22 Parkinson's Disease patients both on and off subthalamic nucleus deep brain stimulation (STN-DBS), while they performed an instrumental learning task involving financial rewards and losses, and an inter-temporal choice task for financial rewards. We found that instrumental learning performance was significantly worse following stimulation, due to modulation of instrumental outcome sensitivity. Specifically, patients became less sensitive to decision values for both rewards and losses, but without any change to the learning rate or reward-loss trade-offs. However, we found no evidence that DBS modulated different components of temporal impulsivity. In conclusion, our results implicate the subthalamic nucleus in a modulation of outcome value in experience-based learning and decision-making in Parkinson's disease, suggesting a more pervasive role of the subthalamic nucleus in the control of human decision-making than previously thought.GRF gratefully acknowledges support by the German Research Council (Deutsche Forschungsgemeinschaft, KFO-219). Ray Dolan is supported by the Wellcome Trust (R.J.D., Senior Investigator Award 098362/Z/12/Z) and the the Senate of Berlin (R.J.D., Einstein Fellowship). Ben Seymour is funded by the Wellcome Trust and the National Institute of Information and Communications Technology, Japan; Peter Dayan is funded by the Gatsby Charitable Foundation

Components of reward-driven attentional bias and impulsivity

History of reward biases attentional selection. However, this reward-driven attentional bias (RDAB) has not been investigated within the context of the separable components of facilitated capture and impaired disengagement. Furthermore, separating these components may better clarify the relationship between RDAB and impulsivity. To this end, across 2 experiments, the current study aimed to firstly characterize capture and disengagement in RDAB and secondly test the relationship between components of RDAB and measures of impulsivity. Across both studies participants completed reward-training followed by a modified cueing paradigm using previously rewarded and previously unrewarded stimuli as cues. Results demonstrated robust effects of facilitated capture and significant effects of impaired disengagement, although these effects were restricted to individuals aware of the reward association, either incidentally or explicitly. Across both studies, neither capture nor disengagement independently predicted impulsivity; however, total RDAB predicted impulsivity in Study 1 only. Possible reasons for these findings are discussed.Master of Art

Does my brain want what my eyes like? - How food liking and choice influence spatio-temporal brain dynamics of food viewing.

How food valuation and decision-making influence the perception of food is of major interest to better understand food intake behavior and, by extension, body weight management. Our study investigated behavioral responses and spatio-temporal brain dynamics by means of visual evoked potentials (VEPs) in twenty-two normal-weight participants when viewing pairs of food photographs. Participants rated how much they liked each food item (valuation) and subsequently chose between the two alternative food images. Unsurprisingly, strongly liked foods were also chosen most often. Foods were rated faster as strongly liked than as mildly liked or disliked irrespective of whether they were subsequently chosen over an alternative. Moreover, strongly liked foods were subsequently also chosen faster than the less liked alternatives. Response times during valuation and choice were positively correlated, but only when foods were liked; the faster participants rated foods as strongly liked, the faster they were in choosing the food item over an alternative. VEP modulations by the level of liking attributed as well as the subsequent choice were found as early as 135-180ms after food image onset. Analyses of neural source activity patterns over this time interval revealed an interaction between liking and the subsequent choice within the insula, dorsal frontal and superior parietal regions. The neural responses to food viewing were found to be modulated by the attributed level of liking only when foods were chosen, not when they were dismissed for an alternative. Therein, the responses to disliked foods were generally greater than those to foods that were liked more. Moreover, the responses to disliked but chosen foods were greater than responses to disliked foods which were subsequently dismissed for an alternative offer. Our findings show that the spatio-temporal brain dynamics to food viewing are immediately influenced both by how much foods are liked and by choices taken on them. These valuation and choice processes are subserved by brain regions involved in salience and reward attribution as well as in decision-making processes, which are likely to influence prospective dietary choices in everyday life

The Glucose Model of Mediation: Physiological Bases of Willpower as Important Explanations for Common Mediation Behavior

Success in life requires the ability to resist urges and control behavior. This ability is commonly called “willpower,” the capacity to overcome impulses and engage in conscious acts of self-control. Social psychologists believe willpower is a finite resource dependent on physiological bases including glucose (from food and drink), sleep and other forms of rest, and the absence of stress. In short, people who are hungry, exhausted, or highly stressed tend to have less willpower than those who are well-fed, well-rested, and relatively stress-free. In addition, a person who exerts self-control (uses willpower) tends to reduce temporarily the amount of willpower remaining, so decision-making and other aspects of self-control are weakened during this depleted state. Restoring willpower (and thus restoring decision-making abilities) can often be achieved by physiological replenishment, such as: ingesting glucose, sleep (and other forms of rest) and breaks from stress. The physiological bases of willpower combine with the importance of deadlines to offer a compelling explanation for why so many mediations follow a predictable pattern. Most significantly, the physiological bases of willpower go a long way to explaining why many mediations scheduled for a single day begin with stalwart opening positions and end with a signed settlement agreement late in the day. This Article provides a physiological explanation of typical mediation behavior and shows that an awareness of physiology reveals ethical issues with current mediation practice. Part I of this Article discusses the science, specifically the Strength and Glucose Models of Self-Control and their applications across studies of medicine, morality and negotiation. Part II outlines the course of a typical daylong mediation and shows the extent to which common mediation behavior is well-explained by the physiology of willpower when people are operating under deadlines. Part III examines the significance of the Glucose Model of Mediation by identifying ethical issues relating to willpower depletion in mediation

An Evaluation of Agreements Between Managed Care Organizations and Community-Based Mental Illness and Addiction Disorder Treatment and Prevention Providers

This Issue Brief, prepared for the Substance Abuse and Mental Health Services Administration (SAMHSA), examines contracts between managed care organizations (MCOs) and community-based providers of mental illness and addiction disorder treatment and prevention services (MI/AD providers). Building upon initial research published in 1997, this brief explores in depth one of the most hidden aspects of managed care: the relationship between the managed care organizations and health care providers

The role of habit in compulsivity.

Compulsivity has been recently characterized as a manifestation of an imbalance between the brain׳s goal-directed and habit-learning systems. Habits are perhaps the most fundamental building block of animal learning, and it is therefore unsurprising that there are multiple ways in which the development and execution of habits can be promoted/discouraged. Delineating these neurocognitive routes may be critical to understanding if and how habits contribute to the many faces of compulsivity observed across a range of psychiatric disorders. In this review, we distinguish the contribution of excessive stimulus-response habit learning from that of deficient goal-directed control over action and response inhibition, and discuss the role of stress and anxiety as likely contributors to the transition from goal-directed action to habit. To this end, behavioural, pharmacological, neurobiological and clinical evidence are synthesised and a hypothesis is formulated to capture how habits fit into a model of compulsivity as a trans-diagnostic psychiatric trait.CM Gillan is supported by a Sir Henry Wellcome Postdoctoral Fellowship (101521/Z/12/Z).This is the final version of the article. It was first available from Elsevier via https://doi.org/10.1016/j.euroneuro.2015.12.03