Multivariate analysis of multimodal brain structure predicts individual differences in risk and intertemporal preference.

Large changes to brain structure (e.g., from damage or disease) can explain alterations in behavior. It is therefore plausible that smaller structural differences in healthy samples can be used to better understand and predict individual differences in behavior. Despite the brain's multivariate and distributed structure-to-function mapping, most studies have used univariate analyses of individual structural brain measures. Here we used a multivariate approach in a multimodal data set composed of volumetric, surface-based, diffusion-based, and functional resting-state MRI measures to predict reliable individual differences in risk and intertemporal preferences. We show that combining twelve brain structure measures led to better predictions across tasks than using any individual measure, and by examining model coefficients, we visualize the relative contribution of different brain measures from different brain regions. Using a multivariate approach to brain structure-to-function mapping that combines across many brain structure properties, along with reliably measured behavior phenotypes, may increase out-of-sample prediction accuracies and insight into neural underpinnings. Furthermore, this methodological approach may be useful to improve predictions and neural insight across basic, translational, and clinical research fields.

Risky effort.

Decision-making involves weighing up the outcome likelihood, potential rewards, and effort needed. Previous research has focused on the trade-offs between risk and reward or between effort and reward. Here we bridge this gap and examine how risk in effort levels influences choice. We focus on how two key properties of choice influence risk preferences for effort: changes in magnitude and probability. Two experiments assessed people's risk attitudes for effort, and an additional experiment provided a control condition using monetary gambles. The extent to which people valued effort was related to their pattern of risk preferences. Unlike with monetary outcomes, however, there was substantial heterogeneity in effort-based risk preferences: People who responded to effort as costly exhibited a "flipped" interaction pattern of risk preferences. The direction of the pattern depended on whether people treated effort as a loss of resources. Most, but not all, people treat effort as a loss and are more willing to take risks to avoid potentially high levels of effort.

Connection Failure: Differences in White Matter Microstructure Are Associated with 5-HTTLPR but Not with Risk Seeking for Losses.

S/S carriers of 5-HTTLPR have been found to be more risk seeking for losses compared to L/L carriers. This finding may be the result of reduced top-down control from the frontal cortex due to altered signal pathways involving the amygdala and ventral striatum. The serotonergic system is known to be involved in neurodevelopment and neuroplasticity. Therefore, the aim of this study was to investigate whether structural differences in white matter can explain the differences in risk-seeking behaviour. Lower structural connectivity in S/S compared to L/L carriers and a negative relationship between risk seeking for losses and connectivity were assumed. Diffusion-weighted imaging was used to compute diffusion parameters for the frontostriatal and uncinate tract in 175 genotyped individuals. The results showed no significant relationship between diffusion parameters and risk seeking for losses. Furthermore, we did not find significant differences in diffusion parameters of the S/S vs. L/L group. There were only group differences in the frontostriatal tract showing stronger structural connectivity in the S/L group, which is also reflected in the whole brain approach. Therefore, the data do not support the hypothesis that the association between 5-HTTLPR and risk seeking for losses is related to differences in white matter pathways implicated in decision-making.

Methamphetamine increases risky choice in rats, but only when magnitude and probability of reinforcement are manipulated within a session.

Risky choice is associated with maladaptive behaviors, particularly substance use disorders. Current animal models of risky choice are often confounded by other constructs like behavioral flexibility and suboptimal choice. The purpose of the current experiment was to determine if the psychostimulant methamphetamine, a drug whose popularity has increased in recent years, increases risky choice in an equivalent expected value (EEV) task. In the EEV task, rats are given a choice between two reinforcer alternatives that differ in magnitude and probability of delivery, but have equivalent expected value. Forty-eight Sprague Dawley rats were tested in three versions of the EEV task. In the first version of the EEV task, both reinforcer magnitude and probability were adjusted across blocks of trials for both alternatives. In the second and the third versions of the EEV task, reinforcer magnitude was held constant across each block of trials (either 1 vs. 2 pellets or 4 vs. 5 pellets). We found that male rats preferred the "riskier" option, except when reinforcer magnitudes were held constant at 4 and 5 pellets across each block of trials. Methamphetamine (0.5 mg/kg) increased preference for the risky option in both males and females, but only when both reinforcer magnitude and probability were manipulated across blocks of trials for each alternative. The current results demonstrate that both magnitude of reinforcement and probability of reinforcement interact to influence risky choice. Overall, this study provides additional support for using reinforcers with expected value to measure risky choice.

Sex differences in risk-based decision-making and the modulation of risk preference by dopamine-2 like receptors in rats.

Heightened risk-based decision-making is observed across several neuropsychiatric disorders including schizophrenia, bipolar disorder, and Parkinson's disease, yet no treatments exist that effectively normalize this aberrant behavior. Preclinical risk-based decision-making paradigms have identified the important modulatory roles of dopamine and sex in the performance of such tasks, though specific task parameters may alter such effects (e.g., punishment and reward values). Previous work has highlighted the role of dopamine 2-like receptors (D2R) during performance of the Risk Preference Task (RPT) in male rats, however sex was not considered as a factor in this study, nor were treatments identified that reduced risk preference. Here, we utilized the RPT to determine sex-dependent differences in baseline performance and impact of the D2R receptor agonist pramipexole (PPX), and antagonist sulpiride (SUL) on behavioral performance. Female rats exhibited heightened risk-preference during baseline testing. Consistent with human studies, PPX increased risk-preference across sex, though the effects of PPX were more pronounced in female animals. Importantly, SUL reduced risk-preference in these rats across sexes. Thus, under the task specifications of the RPT that does not include punishment, female rats were more risk-preferring and required higher PPX doses to promote risky choices compared to males. Furthermore, blockade of D2R receptors may reduce risk-preference of rats, though further studies are required.

Rare and extreme outcomes in risky choice.

Many real-world decisions involving rare events also involve extreme outcomes. Despite this confluence, decisions-from-experience research has only examined the impact of rarity and extremity in isolation. With rare events, people typically choose as if they underestimate the probability of a rare outcome happening. Separately, people typically overestimate the probability of an extreme outcome happening. Here, for the first time, we examine the confluence of these two biases in decisions-from-experience. In a between-groups behavioural experiment, we examine people's risk preferences for rare extreme outcomes and for rare non-extreme outcomes. When outcomes are both rare and extreme, people's risk preferences shift away from traditional risk patterns for rare events: they show reduced underweighting for events that are both rare and extreme. We simulate these results using a small-sample model of decision-making that accounts for both the underweighting of rare events and the overweighting of extreme events. These separable influences on risk preferences suggest that to understand real-world risk for rare events we must also consider the extremity of the outcomes.

Risky decisions are influenced by individual attributes as a function of risk preference.

It has long been assumed in economic theory that multi-attribute decisions involving several attributes or dimensions - such as probabilities and amounts of money to be earned during risky choices - are resolved by first combining the attributes of each option to form an overall expected value and then comparing the expected values of the alternative options, using a unique evidence accumulation process. A plausible alternative would be performing independent comparisons between the individual attributes and then integrating the results of the comparisons afterwards. Here, we devise a novel method to disambiguate between these types of models, by orthogonally manipulating the expected value of choice options and the relative salience of their attributes. Our results, based on behavioral measures and drift-diffusion models, provide evidence in favor of the framework where information about individual attributes independently impacts deliberation. This suggests that risky decisions are resolved by running in parallel multiple comparisons between the separate attributes - possibly alongside an additional comparison of expected value. This result stands in contrast with the assumption of standard economic theory that choices require a unique comparison of expected values and suggests that at the cognitive level, decision processes might be more distributed than commonly assumed. Beyond our planned analyses, we also discovered that attribute salience affects people of different risk preference type in different ways: risk-averse participants seem to focus more on probability, except when monetary amount is particularly high; risk-neutral/seeking participants, in contrast, seem to focus more on monetary amount, except when probability is particularly low.

Less cortical complexity in ventromedial prefrontal cortex is associated with a greater preference for risky and immediate rewards.

In our everyday lives, we are often faced with situations in which we have to make choices that involve risky or delayed rewards. However, the extent to which we are willing to accept larger risky (over smaller certain) or larger delayed (over smaller immediate) rewards vary across individuals. Here we investigated the relationship between cortical surface complexity in medial prefrontal cortex and individual differences in risky and intertemporal preferences. We found that lower cortical complexity in ventromedial prefrontal cortex (vmPFC) was associated with a greater preference for risky and immediate rewards. In addition to these common structural associations in mPFC, we also found associations between lower cortical complexity and a greater preference for immediate rewards that extended into left dorsomedial prefrontal cortex and right vmPFC. Taken together, the shared association suggests that lower cortical complexity in vmPFC may be a structural marker for individual differences in impulsive behavior.

Testing the somatic marker hypothesis in decisions-from-experience with non-stationary outcome probabilities.

Introduction: The Somatic Marker Hypothesis (SMH) posits that in experience-based choice, people develop physiological reactions that mark options as either positive or negative. These somatic markers aid decision making because they differentiate between "good" and "bad" options during pre-choice deliberation. Methods: We examined this proposed role for somatic states in two decision-from-experience tasks (each N = 36) in which participants selected repeatedly with full feedback (i.e., for obtained and forgone outcomes) between two unlabeled options that returned wins or losses, with half receiving an additional summary of past outcomes. The probabilities of good and bad outcomes changed at an unannounced point. Participants completed a 100-trial game with a switch in the optimal option after trial 40 (Study 1) or a 200-trial game with switch points after trial 40 and trial 120 (Study 2). Skin conductance (SC) was measured continuously as an index of emotional intensity, from which we extracted measures of anticipatory SC (pre-choice) and outcome SC (post-choice). Results: Participants reliably selected the optimal option prior to any switches. They also altered their choices appropriately when the payoffs changed, though optimal play following payoff switches was reduced. Losses resulted in a greater outcome SC than wins, but only in Study 1, as did the finding that the outcome SC was greater when the forgone outcome was positive. Anticipatory SC did not reliably predict optimal play in either study. Discussion: These results provide little support for the SMH. Our studies point to the importance of using diverse tasks and measures and very large sample sizes when testing the role of somatic states in decision making.

Decision making and executive functions in problematic pornography use.

Introduction: Previous research on cognitive functions in Compulsive Sexual Behavior Disorder (CSBD) and problematic pornography use (PPU) reported inconsistent findings and mostly included sexual pictures in the used tasks. The role of general executive functions and cognitive competences (without the presence of appetitive stimuli) in the context of PPU is largely unexplored. Methods: This study investigated differences between individuals with high versus low problem severity of PPU regarding decision making and executive functions. The sample of the laboratory study consisted of N = 102 male adults. Besides measures of trait impulsivity, we used standard neuropsychological tests (Trail Making Test and three-back working memory task) and an intertemporal risky choice paradigm, the Cards & Lottery Task (CLT). Results: The results show heightened impulsivity (urgency and deficits in perseverance) in individuals with high PPU, but no differences regarding performance in the CLT and executive function tasks. Discussion: The findings indicate that PPU might be associated with impulsive behavior when experiencing strong emotions (urgency) and deficient cognitive performance especially in the presence of sexual stimuli but not in general.

Protective behaviors during COVID-19 confinement measures in Greece: the role of anxiety, perceived risk and risky-choice framing.

Confinement measures at the beginning of the COVID-19 pandemic imposed major changes on the global population. The aim of this study was to explore the level to which the public adhered to protective guidelines by adopting the most appropriate behaviors at that time (such as hand washing with soap and using sanitizer gel) and to identify the determinants of these behaviors. A purposive sample of 1013 individuals was invited and voluntarily participated in the online survey. The questionnaire collected information on demographic data, hand washing, risk perception, anxiety (through the S = Anxiety scale of STAI) and risky-choice framing. Results showed increased levels of anxiety, a moderate perception of the risk of catching coronavirus and increased adoption of protective behaviors, such as handwashing and cleaning surfaces with disinfectant/antiseptic products. Multiple ordinal logistic regression models showed that being female, more educated and cleaning home with disinfectant / antiseptic products predicted handwashing with soap. Additionally, having an increased perception of getting the coronavirus, being older and cleaning the home with disinfectant / antiseptic products predicted handwashing with antiseptics. Public health interventions should take into consideration the unified cleaning pattern and the combined effect of sociodemographic variables and risk perception on the adoption of protective behaviour in the context of a health crisis which is out of people's control.

On the Anatomy of Health-related Actions for Which People Could Reasonably be Held Responsible: A Framework.

Should we let personal responsibility for health-related behavior influence the allocation of healthcare resources? In this paper, we clarify what it means to be responsible for an action. We rely on a crucial conceptual distinction between being responsible and holding someone responsible, and show that even though we might be considered responsible and blameworthy for our health-related actions, there could still be well-justified reasons for not considering it reasonable to hold us responsible by giving us lower priority. We transform these philosophical considerations into analytical use first by assessing the general features of health-related actions and the corresponding healthcare needs. Then, we identify clusters of structural features that even adversely affected people cannot reasonably deny constitute actions for which they should be held responsible. We summarize the results in an analytical framework that can be used by decision-makers when considering personal responsibility for health as a criterion for setting priorities.

The effect of perceptual organization on numerical and preference-based decisions shows inter-subject correlation.

Individual differences in cognitive processing have been the subject of intensive research. One important type of such individual differences is the tendency for global versus local processing, which was shown to correlate with a wide range of processing differences in fields such as decision making, social judgments and creativity. Yet, whether these global/local processing tendencies are correlated within a subject across different domains is still an open question. To address this question, we develop and test a novel method to quantify global/local processing tendencies, in which we directly set in opposition the local and global information instead of instructing subjects to specifically attend to one processing level. We apply our novel method to two different domains: (1) a numerical cognition task, and (2) a preference task. Using computational modeling, we accounted for classical effects in choice and numerical-cognition. Global/local tendencies in both tasks were quantified using a salience parameter. Critically, the salience parameters extracted from the numerical cognition and preference tasks were highly correlated, providing support for robust perceptual organization tendencies within an individual.

Effect of exogenous testosterone in the context of energy deficit on risky choice: Behavioural and neural evidence from males.

Previous research has shown greater risk aversion when people make choices about lives than cash. We tested the hypothesis that compared to placebo, exogenous testosterone administration would lead to riskier choices about cash than lives, given testosterone's association with financial risk-taking and reward sensitivity. A double-blind, placebo-controlled, randomized trial was conducted to test this hypothesis (Clinical Trials Registry: NCT02734238, www.clinicaltrials.gov). We collected functional magnetic resonance imaging (fMRI) data from 50 non-obese males before and shortly after 28 days of severe exercise-and-diet-induced energy deficit, during which testosterone (200 mg testosterone enanthate per week in sesame oil) or placebo (sesame seed oil only) was administered. Because we expected circulating testosterone levels to be reduced due to severe energy deficit, testosterone administration served a restorative function to mitigate the impact of energy deficit on testosterone levels. The fMRI task involved making choices under uncertainty for lives and cash. We also manipulated whether the outcomes were presented as gains or losses. Consistent with prospect theory, we observed the reflection effect such that participants were more risk averse when outcomes were presented as gains than losses. Brain activation in the thalamus covaried with individual differences in exhibiting the reflection effect. Testosterone did not impact choice, but it increased sensitivity to negative feedback following risky choices. These results suggest that exogenous testosterone administration in the context of energy deficit can impact some aspects of risky choice, and that individual differences in the reflection effect engage a brain structure involved in processing emotion, reward and risk.

The association between experience-based risky choice and mathematical ability.

Mathematical ability has always been considered an important influencing factor in description-based risky choices. Experience-based risky choices, which occur frequently in daily life, are very different from description-based risky choices. The association between experience-based risky choice and mathematical ability remains unknown. This study adopts the feedback paradigm for experience-based risky choice to explore the association between multiple mathematical abilities and experience-based risky choice. The results show that, in experience-based risky choice, mathematical ability did not influence the decision to pursue higher expected value, but it did influence preference for risky. Thus, our study contributes to a more comprehensive view of mathematical ability and risky choice.

Measuring feelings about choices and risks: The Berlin Emotional Responses to Risk Instrument (BERRI).

We introduce a brief instrument specifically validated for measuring positive and negative feelings about risks-the Berlin Emotional Responses to Risk Instrument (BERRI). Based on seven studies involving diverse adults from three countries (n = 2120), the BERRI was found to robustly estimate anticipatory affective reactions derived from subjective evaluations of positive (i.e., assured, hopeful, and relieved) and negative emotions (i.e., anxious, afraid, and worried). The brief BERRI outperformed a 14-item assessment, uniquely tracking costs/benefits associated with cancer screening among men and women (Studies 1 and 2). Predictive validity was further documented in paradigmatic risky choice studies wherein options varied over probabilities and severities across six contexts (health, social, financial, technological, ethical, and environmental; Study 3). Studies 4-6, conducted during the Ebola epidemic and COVID-19 pandemic, indicated BERRI responses were sensitive to subtle effects caused by emotion-related framing manipulations presented in different cultures and languages (the United States, Spain, and Poland). Study 7 indicated BERRI responses remained stable for 2 weeks. Although the BERRI can provide an estimate of overall affect, choices were generally better explained by the unique influences of positive and negative affect. Overall, results suggest the novel, brief instrument can be an efficient tool for high-stakes research on decision making and risk communication.

Clarifying the role of an unavailable distractor in human multiattribute choice.

Decisions between two economic goods can be swayed by a third unavailable 'decoy' alternative, which does not compete for choice, notoriously violating the principles of rational choice theory. Although decoy effects typically depend on the decoy's position in a multiattribute choice space, recent studies using risky prospects (i.e., varying in reward and probability) reported a novel 'positive' decoy effect operating on a single value dimension: the higher the 'expected value' (EV) of an unavailable (distractor) prospect was, the easier the discrimination between two available target prospects became, especially when their expected-value difference was small. Here, we show that this unidimensional distractor effect affords alternative interpretations: it occurred because the distractor's EV covaried positively with the subjective utility difference between the two targets. Looking beyond this covariation, we report a modest 'negative' distractor effect operating on subjective utility, as well as classic multiattribute decoy effects. A normatively meaningful model (selective integration), in which subjective utilities are shaped by intra-attribute information distortion, reproduces the multiattribute decoy effects, and as an epiphenomenon, the negative unidimensional distractor effect. These findings clarify the modulatory role of an unavailable distracting option, shedding fresh light on the mechanisms that govern multiattribute decisions.

Toward an attentional turn in research on risky choice.

For a long time, the dominant approach to studying decision making under risk has been to use psychoeconomic functions to account for how behavior deviates from the normative prescriptions of expected value maximization. While this neo-Bernoullian tradition has advanced the field in various ways-such as identifying seminal phenomena of risky choice (e.g., Allais paradox, fourfold pattern)-it contains a major shortcoming: Psychoeconomic curves are mute with regard to the cognitive mechanisms underlying risky choice. This neglect of the mechanisms both limits the explanatory value of neo-Bernoullian models and fails to provide guidance for designing effective interventions to improve decision making. Here we showcase a recent "attentional turn" in research on risk choice that elaborates how deviations from normative prescriptions can result from imbalances in attention allocation (rather than distortions in the representation or processing of probability and outcome information) and that thus promises to overcome the challenges of the neo-Bernoullian tradition. We argue that a comprehensive understanding of preference formation in risky choice must provide an account on a mechanistic level, and we delineate directions in which existing theories that rely on attentional processes may be extended to achieve this objective.

Differential transcriptome profile underlying risky choice in a rat gambling task.

Background and aims: Proper measurement of expected risk is important for making rational decisions, and maladaptive decision making may underlie various psychiatric disorders. However, differentially expressed genetic profiling involved in this process is still largely unknown. A rodent version of the gambling task (rGT) has been developed to measure decision-making by adopting the same principle of Iowa Gambling Task in humans. In the present study, we examined using next-generation sequencing (NGS) technique whether there are differences in gene expression profiles in the medial prefrontal cortex (mPFC) and the nucleus accumbens (NAc) when rats make different choices toward risk in rGT. Methods: Rats were trained in a touch screen chamber to learn the relationships between 4 different light signals on the window of the screen and accompanied reward outcomes or punishments set up with different magnitudes and probabilities. Once they showed a stabilized pattern of preference upon free choice, rats were classified into risk-averse or risk-seeking groups. After performing the rGT, rats were decapitated, the mPFC and the NAc was dissected out, and NGS was performed with the total RNA extracted. Results: We found that 477 and 36 genes were differentially expressed (approximately 75 and 83% out of them were downregulated) in the mPFC and the NAc, respectively, in risk-seeking compared to risk-averse rats. Among those, we suggested a few top ranked genes that may contribute to promoting risky choices. Discussion and conclusions: Our findings provide insights into transcriptional components underlying risky choices in rats.

Biased confabulation in risky choice.

When people make risky decisions based on past experience, they must rely on memory. The nature of the memory representations that support these decisions is not yet well understood. A key question concerns the extent to which people recall specific past episodes or whether they have learned a more abstract rule from their past experience. To address this question, we examined the precision of the memories used in risky decisions-from-experience. In three pre-registered experiments, we presented people with risky options, where the outcomes were drawn from continuous ranges (e.g., 100-190 or 500-590), and then assessed their memories for the outcomes experienced. In two preferential tasks, people were more risk seeking for high-value than low-value options, choosing as though they overweighted the outcomes from more extreme ranges. Moreover, in two preferential tasks and a parallel evaluation task, people were very poor at recalling the exact outcomes encountered, but rather confabulated outcomes that were consistent with the outcomes they had seen and were biased towards the more extreme ranges encountered. This common pattern suggests that the observed decision bias in the preferential task reflects a basic cognitive process to overweight extreme outcomes in memory. These results highlight the importance of the edges of the distribution in providing the encoding context for memory recall. They also suggest that episodic memory influences decision-making through gist memory and not through direct recall of specific instances.