Risky Trials Research Articles

Puberty and risky decision-making in male adolescents

Pubertal development is a potential trigger for increases in risk-taking behaviours during adolescence. Here, we sought to investigate the relationship between puberty and neural activation during risky decision-making in males using functional magnetic resonance imaging (fMRI). Forty-seven males aged 12.5–14.5 years completed an fMRI risk-taking task (BART) and reported their tendencies for risky decision-making using a self-report questionnaire. Puberty was assessed through self-reported pubertal status and salivary testosterone levels. Testosterone concentration, but not physical pubertal status, was positively correlated with self-reported risk-taking behaviour, while neither was correlated with BART performance. Across the whole sample, participants had greater activation of the bilateral nucleus accumbens and right caudate on trials when they made a successful risky decision compared to trials when they made a safe choice or when their risky decision was unsuccessful. There was a negative correlation between pubertal stage and brain activation during unsuccessful risky decision-making trials compared within unsuccessful control trials. Males at a lower stage of pubertal development showed increased activation in the left insula, right cingulate cortex, dorsomedial prefrontal cortex (dmPFC), right putamen and right orbitofrontal cortex (OFC) relative to more pubertally mature males during trials when they chose to take a risk and the balloon popped compared to when they watched the computer make an unsuccessful risky decision. Less pubertally mature males also showed greater activation in brain regions including the dmPFC, right temporal and frontal cortices, right OFC, right hippocampus and occipital cortex in unsuccessful risky trials compared to successful risky trials. These results suggest a puberty-related shift in neural activation within key brain regions when processing outcomes of risky decisions, which may reduce their sensitivity to negative feedback, and in turn contribute to increases in adolescent risk-taking behaviours.

What Difference Does it Make? Risk-Taking Behavior in Obesity after a Loss is Associated with Decreased Ventromedial Prefrontal Cortex Activity.

Altered activity in decision-making neural circuitry may underlie the maladaptive food choices found in obesity. Here, we aimed to identify the brain regions purportedly underpinning risk-taking behavior in individuals with obesity. Twenty-three adult women with obesity and twenty-three healthy weight controls completed the Risky Gains Task during functional magnetic resonance imaging (fMRI). This task allows participants to choose between a safe option for a small, guaranteed monetary reward and risky options with larger rewards. fMRI analyses comparing losing trials to winning trials found that participants with obesity presented decreased activity in the left anterior insula in comparison to controls (p < 0.05, AlphaSim corrected). Moreover, left insula activation during losses vs. wins was negatively correlated with UPPS-P questionnaire sensation seeking scores. During safe vs. risky trials following a loss, the control group exhibited increased activation in the ventromedial prefrontal cortex (vmPFC) (p < 0.05, AlphaSim corrected) in comparison to the OB group. Moreover, vmPFC response in the obesity group during post-loss trials was negatively correlated with risky choices on the task overall. As a whole, our findings support that diminished tuning of the insula towards interoceptive signals may lead to a lack of input to the vmPFC when weighing the costs and benefits of risky choices.

Alcohol Dependence and Altered Engagement of Brain Networks in Risky Decisions.

Alcohol dependence is associated with heightened risk tolerance and altered decision-making. This raises the question as to whether alcohol dependent patients (ADP) are incapable of proper risk assessment. We investigated how healthy controls (HC) and ADP engage neural networks to cope with the increased cognitive demands of risky decisions. We collected fMRI data while 34 HC and 16 ADP played a game that included “safe” and “risky” trials. In safe trials, participants accrued money at no risk of a penalty. In risky trials, reward and risk simultaneously increased as participants were instructed to decide when to stop a reward accrual period. If the participant failed to stop before an undisclosed time, the trial would “bust” and participants would not earn the money from that trial. Independent Component Analysis was used to identify networks engaged during the anticipation and the decision execution of risky compared with safe trials. Like HC, ADP demonstrated distinct network engagement for safe and risky trials at anticipation. However, at decision execution, ADP exhibited severely reduced discrimination in network engagement between safe and risky trials. Although ADP behaviorally responded to risk they failed to appropriately modify network engagement as the decision continued, leading ADP to assume similar network engagement regardless of risk prospects. This may reflect disorganized network switching and a facile response strategy uniformly adopted by ADP across risk conditions. We propose that aberrant salience network (SN) engagement in ADP might contribute to ineffective network switching and that the role of the SN in risky decisions warrants further investigation.

Affective differences in Iowa Gambling Task performance associated with sexual risk taking and substance use among HIV-positive and HIV-negative men who have sex with men

ABSTRACTWe investigated the relationship between emotional distress and decision making in sexual risk and substance use behavior among 174 (ages 25 to 50 years, 53% black) men who have sex with men (MSM), a population at increased risk for HIV. The sample was stratified by HIV status. Measures of affective decision making, depression, anxiety, sex acts, and substance use during the past 60 days were collected at our research center. Negative binomial regression models were used to examine the relationship between age, HIV status, anxiety, depression, and IGT performance in the prediction of number of risky sex acts and substance use days. Among those without anxiety or depression, both number of risky sex acts and drug use days decreased with better performance during risky trials (i.e., last two blocks) of the IGT. For those with higher rates of anxiety, but not depression, IGT risk trial performance and risky sex acts increased concomitantly. Anxiety also interacted with IGT performance across all trials to predict substance use, such that anxiety was associated with greater substance use among those with better IGT performance. The opposite was true for those with depression, but only during risk trials. HIV-positive participants reported fewer substance use days than HIV-negative participants, but there was no difference in association between behavior and IGT performance by HIV status. Our findings suggest that anxiety may exacerbate risk-taking behavior when affective decision-making ability is intact. The relationship between affective decision making and risk taking may be sensitive to different profiles of emotional distress, as well as behavioral context. Investigations of affective decision making in sexual risk taking and substance use should examine different distress profiles separately, with implications for HIV prevention efforts.

Age and Social Context Modulate the Effect of Anxiety on Risk-taking in Pediatric Samples.

Although risk-taking has been studied from a developmental perspective, no study has examined how anxiety, age, risk-valence and social context interact to modulate decision-making in youths. This study probes this question using a risk-taking task, the Stunt Task, in clinically anxious children (n = 17, 10F, age = 8.3-12.1years), healthy children (n = 13, 4F, age = 9.3-12.2years), clinically anxious adolescents (n = 18, 6F, age = 12.3-17.7years), and healthy adolescents (n =14, 10F, age = 12.5-17.3years). Social context was manipulated: in one condition, participants were led to believe that a group of peers were observing and judging their performance (peer-judge), while, in the other condition, they were led to believe that peers were not observing them (control). Only anxious children showed an influence of social context on their risk-taking behavior. Specifically, anxious children bet significantly less and had slower reaction times (RT) during the peer-judge than control condition. However, across social conditions, risk-valence modulated RT differently in function of age and diagnosis. Anxious children were slower on the positive-valence risky trial, whereas anxious adolescents were slower on the negative-valence risky trials relative to their respective healthy peers. In conclusion, clinically anxious children were the only group that was sensitive (risk-averse) to the effect of a negative peer-judge context. The negative peer-judge context did not affect risky decision-making in adolescents, whether they were anxious or healthy. Future work using a stronger aversive social context might be more effective at influencing risky behavior in this age group.

Ramping ensemble activity in dorsal anterior cingulate neurons during persistent commitment to a decision.

We frequently need to commit to a choice to achieve our goals; however, the neural processes that keep us motivated in pursuit of delayed goals remain obscure. We examined ensemble responses of neurons in macaque dorsal anterior cingulate cortex (dACC), an area previously implicated in self-control and persistence, in a task that requires commitment to a choice to obtain a reward. After reward receipt, dACC neurons signaled reward amount with characteristic ensemble firing rate patterns; during the delay in anticipation of the reward, ensemble activity smoothly and gradually came to resemble the postreward pattern. On the subset of risky trials, in which a reward was anticipated with 50% certainty, ramping ensemble activity evolved to the pattern associated with the anticipated reward (and not with the anticipated loss) and then, on loss trials, took on an inverted form anticorrelated with the form associated with a win. These findings enrich our knowledge of reward processing in dACC and may have broader implications for our understanding of persistence and self-control.

The effect of probability discounting on reward seeking: a three-dimensional perspective.

Rats will work for electrical stimulation of the medial forebrain bundle. The rewarding effect arises from the volleys of action potentials fired by the stimulation and subsequent spatio-temporal integration of their post-synpatic impact. The proportion of time allocated to self-stimulation depends on the intensity of the rewarding effect as well as on other key determinants of decision-making, such as subjective opportunity costs and reward probability. We have proposed that a 3D model relating time allocation to the intensity and cost of reward can distinguish manipulations acting prior to the output of the spatio-temporal integrator from those acting at or beyond it. Here, we test this proposition by varying reward probability, a variable that influences the computation of payoff in the 3D model downstream from the output of the integrator. On riskless trials, reward was delivered on every occasion that the rat held down the lever for a cumulative duration called the “price,” whereas on risky trials, reward was delivered with probability 0.75 or 0.50. According to the model, the 3D structure relating time allocation to reward intensity and price is shifted leftward along the price axis by reductions in reward probability; the magnitude of the shift estimates the change in subjective probability. The predictions were borne out: reducing reward probability shifted the 3D structure systematically along the price axis while producing only small, inconsistent displacements along the pulse-frequency axis. The results confirm that the model can accurately distinguish manipulations acting at or beyond the spatio-temporal integrator and strengthen the conclusions of previous studies showing similar shifts following dopaminergic manipulations. Subjective and objective reward probabilities appeared indistinguishable over the range of 0.5 ≤ p ≤ 1.0.

The Prisoners' (Plea Bargain) Dilemma

How can a prosecutor, who has only limited resources, credibly threaten so many defendants with costly and risky trials and extract plea bargains involving harsh sentences? Had defendants refused to settle, many of them would not have been charged or would have escaped with lenient sanctions. But such collective stonewalling requires coordination among defendants, which is difficult if not impossible to attain. Moreover, the prosecutor, by strategically timing and targeting her plea offers, can create conflicts of interest among defendants, frustrating any attempt at coordination. The substantial bargaining power of the resource-constrained prosecutor is therefore the product of the collective action problem that plagues defendants. This conclusion suggests that, despite the common view to the contrary, the institution of plea bargains may not improve the well-being of defendants. Absent the plea bargain option, many defendants would not have been charged in the first place. Thus, we can no longer count on the fact that plea bargains are entered voluntarily to argue that they are desirable for all parties involved.

Reduced posterior mesofrontal cortex activation by risky rewards in substance-dependent patients

Substance-dependent individuals show disadvantageous decision-making, as well as alterated frontocortical recruitment when performing experimental tasks. We investigated whether substance-dependent patients (SDP) would show blunted recruitment of posterior mesofrontal cortex (PMC) by a conflict between concurrently increasing reward and risk of penalty in a monetary game of “chicken.” SDP and controls performed: motor control (no reward) trials, guaranteed reward trials in which reward was not at risk, and risky trials where subjects were required to terminate their reward accrual before a secret varying time limit or else “bust” and forfeit that trial's winnings (low penalty) or the current trial's winnings plus an equal amount of previous winnings (high penalty). Reward accrual duration at risk of “busting” correlated negatively with trait neuroticism. The contrast between winning guaranteed reward versus non-reward activated the caudate head bilaterally in SDP but not controls. Accumulation of money at risk of low- or high-penalty (contrasted with accumulating guaranteed money) activated the PMC in both groups, but with a greater magnitude and more anterior extent in controls. Pre-decision signal increase in a PMC volume of interest negatively correlated with risk-taking in low-penalty trials, and was blunted in SDP relative to controls under both penalty conditions after controlling for individual differences in actual risk-taking and the higher neuroticism of SDP. These data suggest that SDP are characterized by a combination of: (a) striatal hypersensitivity to reward, and (b) under-recruitment of the specialized conflict-monitoring circuitry of the PMC when reward entails potential penalties.

The Prisoners' (Plea Bargain) Dilemma

How can a prosecutor, who has only limited resources, credibly threaten so many defendants with costly and risky trials and extract plea bargains involving harsh sentences? Had defendants refused to settle, many of them would not have been charged or would have escaped with lenient sanctions. But such collective stonewalling requires coordination among defendants, which is difficult if not impossible to attain. Moreover, the prosecutor, by strategically timing and targeting her plea offers, can create conflicts of interest among defendants, frustrating any attempt at coordination. The substantial bargaining power of the resource-constrained prosecutor is therefore the product of the collective action problem that plagues defendants. This conclusion suggests that, despite the common view to the contrary, the institution of plea bargains may not improve the well-being of defendants. Absent the plea bargain option, many defendants would not have been charged in the first place. Thus, we can no longer count on the fact that plea bargains are entered voluntarily to argue that they are desirable for all parties involved.