Contextual valence modulates the neural dynamics of risk processing

Hyposensitivity to losses under risk but hypersensitivity to gains under ambiguity during feedback evaluation

Uncertainty is ubiquitous in human life and can be fractioned into risk (known probability distribution) and ambiguity (unknown probability distribution), each with distinct functional correlates. This event-related potential study examined how contextual valence influences the dissociation between risk and ambiguity during feedback evaluation through the lens of neural dynamics. We manipulated contextual valence as a gain versus a loss context. In the gain context, decisions resulted in either gains or nongains, while in the loss context, decisions led to losses or nonlosses. We recorded EEG from 40 participants while they completed a wheel-of-fortune task under conditions of risk and ambiguity in both contexts. We observed a stronger valence effect on the P3a in the loss context under risk, but a stronger valence effect on the P3b in the gain context under ambiguity. Further comparisons revealed that feedback evaluation was primarily driven by a smaller P3a in response to losses under risk, but by a larger P3a and P3b in response to gains under ambiguity. Parametric analyses found that both the reward positivity and P3a for gains and nongains were modulated by winning probability under risk, while the P3a for gains was influenced by ambiguity level under ambiguity. Our findings demonstrate the dissociable influences of contextual valence on feedback-related neural dynamics based on uncertainty type, supporting a critical role of valence-asymmetry in distinguishing risk from ambiguity.

Attachment Security Priming Reduces Risk-Taking and Emotional Responses to Loss

We examined the effects of attachment security priming on economic risky decisions and their neural underpinnings. Participants were exposed to either attachment security primes (N = 28) or control primes (N = 29) and then completed a gambling task while connected to an electroencephalogram system. We anticipated that attachment security priming would affect risky decision-making at both the behavioral and neural levels. Feedback-related negativity (FRN) and P3 components were analyzed. At the behavioral level, participants in the attachment security priming group selected less risky choices than those in the control group. At the neural level, participants exposed to attachment security primes exhibited attenuated FRN but no significant difference in P3 amplitude. The regression analysis showed that small P3 amplitude predicted large risk-taking tendencies in the control priming group, whereas P3 amplitude did not significantly predict risk-taking tendencies in the attachment security priming group. These findings suggest how boosted attachment security affects economic risky decisions: It lowers people's affective reactions to undesirable outcomes and buffers people's underestimation of the outcome salience. Specifically, attachment security seems to attenuate risk-taking by preventing people from down playing the significance of outcomes. Our findings extend existing knowledge by demonstrating attachment security priming ability to reduce risk-taking tendencies beyond naturalistic to economic decisions.

Neural markers of human aggression and cooperation are influenced by zero-sum or non-zero-sum groups

Cooperation and competition in social interaction are important to social development. There are many studies examining the neural mechanism underlying these behaviors; however, little is known about the potential role of payoff norms in social interactions. This study introduced two distinct payoff norms: zero-sum (ZS) and non-zero-sum (NZS). In the ZS group, only the player with the highest total score would receive a reward; while in the NZS group, rewards were determined by the combined total score of both players, and individual rewards were prorated according to each player's contribution to the total score. Electroencephalography was used to examine individuals' neural responses during the Chicken Game in these different groups. The behavioral findings revealed a higher rate of cooperation in the NZS group compared to the ZS group. Aggressive behaviors from opponents elicited larger feedback-related negativity (FRN) and lower P300 amplitudes in both groups. Notably, larger FRN and smaller P300 amplitudes were elicited by participants' aggressive behaviors compared to their cooperative behaviors in the ZS group, whereas larger P300 amplitudes were elicited by aggressive behaviors compared to cooperative behaviors in the NZS group. Additionally, a greater theta event-related synchronization (ERS) was observed solely when participants exhibited aggression in the NZS group. The type of group moderated the association between posterior theta-ERS and cooperative rates. Specifically, theta-ERS was negatively associated with cooperative rates in the NZS group, whereas a reversed association was found in the ZS group. These findings provide valuable insights into the neurobiological foundations of cooperation under different economic payoff norms.

Neural Correlates of Anhedonia in Major Depressive Disorder: Insights from Concurrent Analysis of Feedback-Related Negativity and Stimulus-Preceding Negativity

Purpose

Anhedonia, a core symptom of major depressive disorder (MDD), is explored in this study, focusing on the neural underpinnings through the examination of two event-related potential (ERP) components: feedback-related negativity (FRN) and stimulus-preceding negativity (SPN).

Patients and Methods

This cross-sectional study was conducted in China from March 2022 to March 2023. It involved 35 MDD patients and 31 healthy controls (HC) participating in a modified 2-door task with simultaneous EEG recordings. Depression severity and anhedonia were assessed using the Hamilton Depression Scale (HAMD) and the Temporal Experience of Pleasure Scale (TEPS-CV), respectively. FRN and SPN metrics, along with correlations with each other and clinical assessments, were examined.

Results

In comparison to the HC group, the MDD group exhibited significantly lower scores in TEPS-CV (t = 2.854, p = 0.006) and its subscales (t = -3.596, p = 0.001 and t = 2.434, p = 0.018, respectively), along with consistently reduced amplitudes of FRN (F 1.64= 4.726, p = 0.033) and SPN (F 1.64= 4.195, p = 0.045) across all conditions. Limited correlations were observed between ERP metrics and clinical indicators, except for positive correlations between FRN amplitudes (loss minus win) and HAMD scores (r = 0.392, p = 0.020), and SPN amplitudes after losing (SPN-L) and TEPS-CV consumption subscale scores (r = 0.357, p = 0.035). Notably, while the HC group displayed no significant FRN-SPN correlations, the MDD group exhibited positive FRN-SPN correlations under distinct conditions (r = 0.376, p = 0.026 and r = 0.355, p = 0.037, respectively).

Conclusion

Our data reveal subjective and objective anhedonia in both consumption and anticipation, suggesting a shared impairment in reward feedback processing and anticipatory neural mechanisms in individuals with MDD. These findings deepen our understanding of anhedonia's neural foundations and may guide targeted interventions for this core symptom.

Contextual valence influences the neural dynamics of time and magnitude representation during feedback evaluation

Contextual valence is an important dimension during value-based decision-making. Previous research has revealed behavioral and neural asymmetries between the gain context and the loss context. The present event-related potential study investigated the effects of contextual valence on neural dynamics underlying magnitude and time, two important reward dimensions, during feedback evaluation. Forty-two participants performed a simple guessing task in which they experienced both a gain context wherein high or low rewards were delivered immediately or six months later, and a loss context wherein high or low losses were delivered in the same way. Results showed that in the gain context, time and magnitude information were processed in a parallel way during the time windows of the reward positivity (RewP) and the P3. In the loss context, however, time and magnitude information were processed in a serial way such that time information was encoded during the RewP and P3 periods, whereas magnitude information was not tracked until the time window of the late positive potential. Our findings suggest that the neural dynamics underlying time and magnitude information are distinct between the gain and loss contexts, thus providing a novel perspective for the well-known gain-loss asymmetry.

Dissociated modulations of intranasal vasopressin on prosocial learning between reward-seeking and punishment-avoidance

BACKGROUND

As an integral ingredient of human sociality, prosocial behavior requires learning what acts can benefit or harm others. However, it remains unknown how individuals adjust prosocial learning to avoid punishment or to pursue reward. Given that arginine vasopressin (AVP) is a neuropeptide that has been involved in modulating various social behaviors in mammals, it could be a crucial neurochemical facilitator that supports prosocial learning.

METHODS

In 50 placebo controls and 54 participants with AVP administration, we examined the modulation of AVP on the prosocial learning characterized by reward and punishment framework, as well as its underlying neurocomputational mechanisms combining computational modeling, event-related potentials and oscillations.

RESULTS

We found a self-bias that individuals learn to avoid punishment asymmetrically more severely than reward-seeking. Importantly, AVP increased behavioral performances and learning rates when making decisions to avoid losses for others and to obtain gains for self. These behavioral effects were underpinned by larger responses of stimulus-preceding negativity (SPN) to anticipation, as well as higher punishment-related feedback-related negativity (FRN) for prosocial learning and reward-related P300 for proself benefits, while FRN and P300 neural processes were integrated into theta (4-7 Hz) oscillation at the outcome evaluation stage.

CONCLUSIONS

These results suggest that AVP context-dependently up-regulates altruism for concerning others' losses and reward-seeking for self-oriented benefits. Our findings provide insight into the selectively modulatory roles of AVP in prosocial behaviors depending on learning contexts between proself reward-seeking and prosocial punishment-avoidance.

Intertemporal Decision-making and Risk Decision-making Among Habitual Nappers Under Nap Sleep Restriction: A Study from ERP and Time-frequency

Sleep restriction affects people's decision-making behavior. Nap restriction is a vital subtopic within sleep restriction research. In this study, we used EEG to investigate the impact of nap sleep restriction on intertemporal decision-making (Study 1) and decision-making across risky outcomes (Study 2) from ERP and time-frequency perspectives. Study 1 found that habitual nappers restricting their naps felt more inclined to choose immediate, small rewards over delayed, large rewards in an intertemporal decision-making task. P200s, P300s, and LPP in our nap-restriction group were significantly higher than those in the normal nap group. Time-frequency results showed that the delta band (1 ~ 4 Hz) power of the restricted nap group was significantly higher than that of the normal nap group. In Study 2, the nap-restriction group was more likely to choose risky options. P200s, N2s, and P300s in the nap deprivation group were significantly higher than in the normal nap group. Time-frequency results also found that the beta band (11 ~ 15 Hz) power of the restricted nap group was significantly lower than that of the normal nap group. The habitual nappers became more impulsive after nap restriction and evinced altered perceptions of time. The time cost of the LL (larger-later) option was perceived to be too high when making intertemporal decisions, and their expectation of reward heightened when making risky decisions-believing that they had a higher probability of receiving a reward. This study provided electrophysiological evidence for the dynamic processing of intertemporal decision-making, risky decision-making, and the characteristics of nerve concussions for habitual nappers.

Distinct neural dynamics underlying risk and ambiguity during valued-based decision making

Uncertainty can be fractioned into risk and ambiguity psychologically and neurobiologically. However, whether and how risk and ambiguity are dissociated in terms of neural dynamics during value-based decision making remain elusive. The present event-related potential (ERP) study addressed these issues by asking participants to perform a wheel-of-fortune task either during a risky context (Experiment 1; N = 30) where outcome probability was known or during an ambiguous context (Experiment 2; N = 30) where outcome probability was unknown. Results revealed that the cue-P3 was more enhanced for risk versus ambiguity during the anticipatory phase, whereas the RewP was more increased for ambiguity than risk during the consummatory phase. Moreover, the SPN and the fb-P3 components were further modulated by the levels of risk and ambiguity, respectively. These findings demonstrate a neural dissociation between risk and ambiguity, which unfolds from the anticipatory phase to the consummatory phase.

Valence precedes value in neural encoding of prediction error

Event-related potentials that follow feedback in reinforcement learning tasks have been proposed to reflect neural encoding of prediction errors. Prior research has shown that in the interval of 240-340 ms multiple different prediction error encodings appear to co-occur, including a value signal carrying signed quantitative prediction error and a valence signal merely carrying sign. The effects used to identify these two encoders, respectively a sign main effect and a sign × size interaction, do not reliably discriminate them. A full discrimination is made possible by comparing tasks in which the reinforcer available on a given trial is set to be either appetitive or aversive against tasks where a trial allows the possibility of either. This study presents a meta-analysis of reinforcement learning experiments, the majority of which presented the possibility of winning or losing money. Value and valence encodings were identified by conventional difference wave methodology but additionally by an analysis of their predicted behavior using a Bayesian analysis that incorporated nulls into the evidence for each encoder. The results suggest that a valence encoding, sensitive only to the available outcomes on the trial at hand precedes a later value encoding sensitive to the outcomes available in the wider experimental context. The implications of this for modeling computational processes of reinforcement learning in humans are discussed.

The Neural and Psychological Processes of Peer-Influenced Online Donation Decision: An Event-Related Potential Study

With the rapid development of information and communication technology (ICT), social media-based donation platforms emerged.¹ These platforms innovatively demonstrate peer information (e.g., number of donated peers) on the donation page, which inevitably brings the peer influence into donors’ donation decision process. However, how the peer influence will affect the psychological process of donation decisions are remained unknown. This study used the number of donated peers to examine the effects of peer influence on donors’ donation decisions and extracted event-related potential (ERP) from electroencephalographic data to explore the underlying psychological process. The behavioral results indicated that the number of donated peers positively influenced donors’ willingness to donate. The ERP results suggested that a larger number of donated peers might indicate a higher level of conformity and greater perceived emotional rewards, as a larger P2 amplitude was observed. Following the early processing of emotional stimuli, cognitive detection of decisional risk took place, and the donors reckoned a smaller number of donated peers as a high potential risk, which was reflected by a larger N2 amplitude. In the later stage, the larger number of donated peers, which represented a higher magnitude of prospective emotional rewards, led to a higher incentive to donate, and reflected in a larger amplitude of P3. Additionally, implications and future directions were discussed.

Altered Neural Processing of Reward and Punishment in Women With Methamphetamine Use Disorder

It has been suggested that the altered function of reward and punishment is an important vulnerability factor leading to the development of drug use disorders. Previous studies have identified evidence of neurophysiological dysfunction in the reward process of individuals with substance use disorders. To date, only a few event-related potential (ERP) studies have examined the neural basis of reward and punishment processing in women with methamphetamine (MA) use disorders. The current ERP research aims to investigate the neurophysiological mechanisms of reward and punishment in women with MA use disorder using a monetary incentive delay task. Nineteen women with MA use disorder (MA group) and 20 healthy controls (HC group) were recruited in this study. The behavioral data showed that the reaction time (RT) was faster and the response accuracy (ACC) was higher for the potential reward and punishment conditions compared to neutral conditions. During the monetary incentive anticipation stage, the Cue-P3, and stimulus-preceding negativity (SPN) were larger in the MA group than in the HC group. The SPN under the potential reward condition was larger than that under the neutral condition in the MA group but not in the HC group. During the monetary incentive consummation stage, the feedback-related negativity and feedback P3 (FB-P3) following positive feedback were significantly larger than negative feedback in the potential reward condition for the HC group, but not for the MA group. However, the FB-P3 following negative feedback was significantly larger than positive feedback in the potential punishment condition for the MA group, but not the HC group. The results suggest that women with MUD have stronger expectations of generic reward and stronger response of generic harm avoidance, which could be targeted in designing interventions for women with MA use disorder.

Comparing the motivational value of rewards and losses in an EEG-pupillometry study

We found earlier that performance-contingent rewards lead to faster performance than equivalent losses [Carsten, Hoofs, Boehler, & Krebs, 2019. Motivation Science, 5(3). http://dx.doi.org/10.1037/mot0000117]. Here, we further tested the hypothesis that motivation to gain rewards is higher than to avoid losses, even when incentive values are matched. As implicit markers of motivation, we assessed electroencephalography (EEG) focusing on the P3 after target and feedback onset, and the Feedback-Related Negativity (FRN), as well as simultaneously recorded pupil size. Comparing only reward and loss prospect trials in Experiment 1, we found no consistent differences in behavior and electrophysiological markers of motivation, although pupil data suggested higher arousal after feedback in potential-loss trials. Including additional no-incentive trials in Experiment 2, we found consistent evidence that motivation to gain rewards was higher than to avoid losses: In line with behavior, the target-P3 was most pronounced for reward-related stimuli, followed by loss and no-incentive ones. This same ranking was found in the P3 and the FRN after positive outcomes (i.e., reward, avoided loss, and correct feedback in no-incentive trials). Negative outcomes featured a different pattern in line with the pupil response, which suggests that losses are emotionally salient events, without invigorating behavior proportionally. In sum, these findings suggest that the motivation to gain rewards is more pronounced than motivation to avoid equivalent losses, at least in tasks promoting transient increases in attention triggered by incentive prospect. These motivational differences may arise as avoided losses are not profitable in the long term, in contrast to gained rewards.

Feedback processing is enhanced following exploration in continuous environments

Decision-making is typically studied by presenting participants with a small set of options. However, real-world behaviour, like foraging, often occurs in continuous environments. The degree to which human decision-making in discrete tasks generalizes to continuous tasks is questionable. For example, successful foraging comprises both exploration (learning about the environment) and exploitation (taking advantage of what is known). Although progress has been made in understanding the neural processes related to this trade-off in discrete tasks, it is currently unclear how, or whether, the same processes are involved in continuous tasks. To address this, we recorded electroencephalographic data while participants "dug for gold" by selecting locations on a map. Participants were cued beforehand that the map contained either a single patch of gold, or many patches of gold. We then used a computational model to classify participant responses as either exploitations, which were driven by previous reward locations and amounts, or explorations. Our participants were able to adjust their strategy based on reward distribution, exploring more in multi-patch environments and less in single-patch environments. We observed an enhancement of the feedback-locked P300, a neural signal previously linked to exploration in discrete tasks, which suggests the presence of a general neural system for managing the explore-exploit trade-off. Furthermore, the P300 was accompanied by an exploration-related enhancement of the late positive potential that was greatest in the multi-patch environment, suggesting a role for motivational processes during exploration.

Contextual valence modulates the effect of choice on incentive processing

Previous research has demonstrated that reward-related neural activity is enhanced for choice relative to no-choice opportunities in the gain context. The current event-related potential study examined whether this modulatory effect of choice can be observed in both the gain and the loss contexts across anticipatory and consummatory phases of incentive processing. Thirty-two participants performed a simple choice task during which choices were made either by themselves (a choice condition) or by a computer (a no-choice condition) during a gain context (gain vs nongain) and a loss context (nonloss vs loss). Behaviorally, participants reported a higher level of perceived control in the choice than the no-choice condition as well as in the gain than loss context. During the anticipatory phase, the choice relative to the no-choice condition elicited an increased cue-P3 in the loss context and an enhanced stimulus-preceding negativity in the gain context. During the consummatory phase, the choice condition elicited a larger reward positivity (ΔRewP) than the no-choice condition in the gain relative to the loss context but a comparable feedback P3 across contexts. These findings demonstrate that the crucial role of voluntary choice in reward processing is contingent upon contextual valence.

Electrophysiological indexes of option characteristic processing

Decision making is vital to human behavior and can be divided into multiple stages including option assessment, behavioral output, and feedback evaluation. Studying how people evaluate option characteristics in the option assessment stage would provide important knowledge on human decision making. Using the event-related potential (ERP) method, the present study investigated the neural mechanism of evaluating two types of option characteristics (i.e., reward magnitude and degree of uncertainty) in the temporal dimension. Thirty-five volunteers participated in a monetary gambling task, where they either accepted or rejected gambles. The ERP results showed a double dissociation pattern, with the early P1 component being sensitive to magnitude but insensitive to degree of uncertainty, while both the N2 and P3 components showed the opposite pattern. The results suggest that these two fundamental option features are assessed rapidly and separately in the human brain. Specifically, small magnitude elicited a larger P1 than did large magnitude, indicating that the perceptual and attentional processing of options is modulated by magnitude. Both the N2 and P3 amplitudes evoked by the risky context were larger than those evoked by the ambiguous one, reflecting that more cognitive conflicts and resources are involved in the former condition. Furthermore, the P1, but not the N2 or P3, amplitude was sensitive to decisions, suggesting that early attentional processes may contribute to human decision making. These findings may provide insight into the temporal mechanisms of option characteristic processing.

The time course of incentive processing in anticipatory and consummatory anhedonia

BACKGROUND

Anhedonia, the reduced capacity to experience pleasure, has long been regarded as a cardinal symptom in depression and schizophrenia. Recent evidence highlights that anhedonia is not a single construct but consists of an anticipatory component and a consummatory component, which is captured by the Temporal Experience of Pleasure Scale (TEPS). The current event-related potential study examined the electrophysiological underpinnings of anticipatory and consummatory aspects of anhedonia as assessed by the TEPS in a non-clinical sample.

METHODS

EEG was recorded during both anticipatory and consummatory phases of incentive processing in an anticipatory-anhedonia (ANT) group, a consummatory-anhedonia (CON) group, and a control (CNT) group selected from a large sample based on their TEPS scores.

RESULTS

The ANT relative to the CON group exhibited a reduced cue-P3 during the anticipatory phase, a less positive feedback-related negativity (FRN) and a blunted feedback P3 (fb-P3) during the consummatory phase. Moreover, correlation results revealed a dissociation between anticipatory and consummatory anhedonia, which occurred in an unexpected way such that higher levels of anticipatory anhedonia were associated with reduced fb-P3 amplitudes whereas higher levels of consummatory anhedonia with enhanced cue-P3 and FRN amplitudes.

LIMITATION

The sample size for each group was relatively small.

CONCLUSIONS

Anticipatory and consummatory anhedonia as measured by the TEPS might be driven by abnormal motivational salience, which was represented by the cue-P3 during the anticipatory phase and the FRN and fb-P3 during the consummatory phase of incentive processing.

Feedback-related negativity reflects omission of monetary gains: Evidence from ERP gambling study

Feedback processing is an important aspect of learning. In the human brain, feedback processing is often examined by measuring an event-related potential, the feedback-related negativity component. Typically, the feedback-related negativity component is investigated by directly comparing gain with loss feedback randomized across trials; however, this method does not control for confounds associated with unexpected feedback. For this study we used a blocked design gambling task to investigate the sensitivity of feedback-related negativity to positive and negative feedback separately for gains and losses. While there appeared to be no significant feedback-related negativity in the loss domain, results revealed an enlarged feedback-related negativity during the omission of gains compared to the reception of gains. These findings further support the reward positivity hypothesis which declares that the feedback-related negativity is associated with the processing of outcomes in the context of gains as opposed to losses, irrespective of unexpectedness.

How choice influences risk processing: An ERP study

The current study examined how the experience of choice by which individuals exercise control modulates risk processing during the anticipatory phase as indexed by the stimulus-preceding negativity (SPN), and the consummatory phase as indexed by the feedback-related negativity (FRN) and feedback P3 (fb-P3). Twenty-four participants performed a simple gambling task during which they could win or lose either a small (a low-risk condition) or a large (a high-risk condition) amount of points by either choosing freely between two doors (a choice condition) or accepting a computer-selected door (a no-choice condition) while their EEG was recorded. As expected, participants rated the high-risk condition as more risky than the low-risk condition and reported higher feelings of control for the choice versus no-choice condition. Regardless of the involvement of choice, risk processing in this task was associated with greater fb-P3 amplitudes. However, during the choice condition, risk processing was associated with a more negative SPN during the anticipatory phase and a more positive FRN during the consummatory phase, which was absent (the SPN) or reduced (the FRN) in the no-choice condition. These findings suggest that the modulation of risk processing by choice occurs during both the anticipatory phase and the consummatory phase, which may be driven by motivation salience imposed by control.

Event-Related Potentials in Relation to Risk-Taking: A Systematic Review

Event-related potentials (ERPs) have been used to investigate neural mechanisms underlying risk-related decisions over the last 16 years. We aimed to systematically evaluate associations between risk-taking and ERP components elicited during decisions and following feedback. A total of 79 articles identified from PsychINFO and PubMed databases met the inclusion criteria. Selected articles assessed early ERP components (feedback-related negativity/FRN, error-related negativity/ERN, and medial frontal negativity/MFN) and the mid-latency P3 component, all using gambling paradigms that involved selecting between choices of varying risk (e.g., Iowa Gambling Task, Balloon Analogue Risk Task, and two-choice gambling tasks). The P3 component was consistently enhanced to the selection of risky options and when positive feedback (as compared to negative feedback) was provided. Also consistently, the early negative components were found to be larger following feedback indicating monetary losses as compared to gains. In the majority of studies reviewed here, risk was conceptualized in the context of simple economical decisions in gambling tasks. As such, this narrow concept of risk might not capture the diversity of risky decisions made in other areas of everyday experience, for example, social, health, and recreational risk-related decisions. It therefore remains to be seen whether the risk-sensitivity of the ERP components reviewed here generalizes to other domains of life.

Stimulus-preceding negativity represents a conservative response tendency

Humans tend to be conservative and typically will retain their initial decision even if an option to change is provided. We investigated whether the stimulus-preceding negativity (SPN), an event-related potential associated with the affective-motivational anticipation of feedback in gambling tasks, represents the strong response tendency to retain an initial decision. We compared SPNs in three different card-gambling tasks wherein the participants were given the opportunity to change their initial decision after they chose one of three cards. In two of these tasks, the winning probability was equiprobable (1/3 and 1/2, respectively) whether or not the participants changed their initial decision. However, in the Monty Hall dilemma task, changing the initial decision stochastically doubled the probability of winning (2/3) compared with retaining (1/3). In this counterintuitive probabilistic dilemma task, after the participant chose an option among three cards, a nonreward (losing) option is revealed. Then, the participants are offered a chance to change their mind and asked to make their final decision: to retain their initial choice or change to the alternate option. In all tasks, maintenance of previous behaviors was observed, although the rate of retaining earlier choices tended to be lower in the Monty Hall dilemma task than in the other two tasks. The SPNs were larger on retain trials than on change trials irrespective of task. These results suggest that underlying brain activities associated with the strong tendency to retain the initial decision can be observed by the SPN and thus it reflects expectancy of outcomes in terms of self-chosen behaviors.

Blunted neural responses to monetary risk in high sensation seekers

The sensation-seeking trait is a valid predictor of various risk-taking behaviors. However, the neural underpinnings of risk processing in sensation seeking are yet unclear. The present event-related potential (ERP) study examined electrophysiological correlates associated with different stages of risky reward processing in sensation seeking. Twenty-one high sensation seekers (HSS) and 22 low sensation seekers (LSS) performed a simple two-choice gambling task. Behaviorally, whereas LSS exhibited a risk-averse pattern, HSS showed a risk-neutral pattern. During the anticipation stage, an increased stimulus-preceding negativity was elicited by high-risk compared to low-risk choices in LSS but not in HSS. During the outcome-appraisal stage, the feedback-related negativity, when calculated as the difference between losses and gains, was enhanced in response to the high-risk versus low-risk outcomes, which appeared for LSS but not for HSS. Further, HSS as compared to LSS exhibited a diminished P300 to both gains and losses. These findings suggest that risk-taking behavior in sensation seeking is expressed as blunted neural responses to risk in the anticipation stage and in the outcome-appraisal stage, which represents a candidate target for drug prevention.