Neurobiology of value integration: when value impacts valuation

Cognitive mechanisms of learning in sequential decision-making under uncertainty: an experimental and theoretical approach

Learning to make adaptive decisions involves making choices, assessing their consequence, and leveraging this assessment to attain higher rewarding states. Despite vast literature on value-based decision-making, relatively little is known about the cognitive processes underlying decisions in highly uncertain contexts. Real world decisions are rarely accompanied by immediate feedback, explicit rewards, or complete knowledge of the environment. Being able to make informed decisions in such contexts requires significant knowledge about the environment, which can only be gained via exploration. Here we aim at understanding and formalizing the brain mechanisms underlying these processes. To this end, we first designed and performed an experimental task. Human participants had to learn to maximize reward while making sequences of decisions with only basic knowledge of the environment, and in the absence of explicit performance cues. Participants had to rely on their own internal assessment of performance to reveal a covert relationship between their choices and their subsequent consequences to find a strategy leading to the highest cumulative reward. Our results show that the participants' reaction times were longer whenever the decision involved a future consequence, suggesting greater introspection whenever a delayed value had to be considered. The learning time varied significantly across participants. Second, we formalized the neurocognitive processes underlying decision-making within this task, combining mean-field representations of competing neural populations with a reinforcement learning mechanism. This model provided a plausible characterization of the brain dynamics underlying these processes, and reproduced each aspect of the participants' behavior, from their reaction times and choices to their learning rates. In summary, both the experimental results and the model provide a principled explanation to how delayed value may be computed and incorporated into the neural dynamics of decision-making, and to how learning occurs in these uncertain scenarios.

The neurocomputational link between defensive cardiac states and approach-avoidance arbitration under threat

Avoidance, a hallmark of anxiety-related psychopathology, often comes at a cost; avoiding threat may forgo the possibility of a reward. Theories predict that optimal approach-avoidance arbitration depends on threat-induced psychophysiological states, like freezing-related bradycardia. Here we used model-based fMRI analyses to investigate whether and how bradycardia states are linked to the neurocomputational underpinnings of approach-avoidance arbitration under varying reward and threat magnitudes. We show that bradycardia states are associated with increased threat-induced avoidance and more pronounced reward-threat value comparison (i.e., a stronger tendency to approach vs. avoid when expected reward outweighs threat). An amygdala-striatal-prefrontal circuit supports approach-avoidance arbitration under threat, with specific involvement of the amygdala and dorsal anterior cingulate (dACC) in integrating reward-threat value and bradycardia states. These findings highlight the role of human freezing states in value-based decision making, relevant for optimal threat coping. They point to a specific role for amygdala/dACC in state-value integration under threat.

Additive Effects of Monetary Loss and Positive Emotion in the Human Brain

In many real-life scenarios, our decisions could lead to multiple outcomes that conflict with value. Hence, an appropriate neural representation of the net experienced value of conflicting outcomes, which play a crucial role in guiding future decisions, is critical for adaptive behavior. As some recent functional neuroimaging work has primarily focused on the concurrent processing of monetary gains and aversive information, very little is known regarding the integration of conflicting value signals involving monetary losses and appetitive information in the human brain. To address this critical gap, we conducted a functional MRI study involving healthy human male participants to examine the nature of integrating positive emotion and monetary losses. We employed a novel experimental design where the valence (positive or neutral) of an emotional stimulus indicated the type of outcome (loss or no loss) in a choice task. Specifically, we probed two plausible integration patterns while processing conflicting value signals involving positive emotion and monetary losses: interactive versus additive. We found overlapping main effects of positive (vs neutral) emotion and loss (vs no loss) in multiple brain regions, including the ventromedial prefrontal cortex, striatum, and amygdala, notably with a lack of evidence for interaction. Thus, our findings revealed the additive integration pattern of monetary loss and positive emotion outcomes, suggesting that the experienced value of the monetary loss was not modulated by the valence of the image signaling those outcomes. These findings contribute to our limited understanding of the nature of integrating conflicting outcomes in the healthy human brain with potential clinical relevance.

Prosocial decision-making under time pressure: Behavioral and neural mechanisms

The present study employed a novel paradigm and functional magnetic resonance imaging (fMRI) to uncover the specific regulatory mechanism of time pressure and empathy trait in prosocial decision-making, compared to self-decision making. Participants were instructed to decide whether to spend their own monetary interest to alleviate themselves (or another person) from unpleasant noise threats under high and low time pressures. On the behavioral level, results showed that high time pressure had a significant effect on reducing participants' willingness to spend money on relieving themselves from the noise, while there is a similar but not significant trend in prosocial decision-making. On the neural level, for self-concerned decision-making, low time pressure activated the bilateral insula more strongly than high time pressure. For prosocial decision-making, high time pressure suppressed activations in multiple brain regions related to empathy (temporal pole, middle temporal gyrus, and inferior frontal gyrus), valuation (medial orbitofrontal cortex), and emotion (putamen). The functional connectivity strength among these regions, especially the connectivity between the medial orbitofrontal cortex and putamen, significantly predicted the effect of time pressure on prosocial decision-making at the behavioral level. Additionally, we discovered the activation of the medial orbitofrontal cortex partially mediated the effect of empathy trait scores on prosocial decision-making. These findings suggest that (1) there are different neural underpinnings for the modulation of time pressure for self and prosocial decision-making, and (2) the empathy trait plays a crucial role in the latter.

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.

Negative emotion reduces the discriminability of reward outcomes in the ventromedial prefrontal cortex

Reward and emotion are tightly intertwined, so there is a growing interest in mapping their interactions. However, our knowledge of these interactions in the human brain, especially during the consummatory phase of reward is limited. To address this critical gap, we conducted a functional magnetic resonance imaging study to investigate the effects of negative emotion on reward outcome processing. We employed a novel design where emotional valence (negative or neutral) indicated the type of outcome (reward or no-reward) in a choice task. We focused our functional magnetic resonance imaging analysis on the ventro-medial prefrontal cortex (vmPFC), ventral striatum and amygdala, which were frequently implicated in reward outcome processing. In these regions of interest, we performed multi-voxel pattern analysis to specifically probe how negative emotion modulates reward outcome processing. In vmPFC, using decoding analysis, we found evidence consistent with the reduced discriminability of multi-variate activity patterns of reward vs no-reward outcomes when signaled by a negative relative to a neutral image, suggesting an emotional modulation of reward processing along the plausible common value/valence dimension. These findings advance our limited understanding of the basic brain mechanisms underlying the influence of negative emotion on consummatory reward processing, with potential implications for mental disorders, particularly anxiety and depression.

Social incentives foster cooperation through guilt aversion: An effect that diminishes with primary psychopathic traits

The association between primary psychopathic traits and non-cooperative behaviors is well-identified. There is a lack of studies on how to motivate cooperative behaviors in individuals with primary psychopathic traits. This study investigated the effects of monetary incentives and social incentives on promoting cooperation in healthy adults with varying primary psychopathic traits. Participants played a one-shot public goods game (PGG) with other anonymous players in three different contexts: a social incentives context where participants' decisions would be judged by others, a monetary incentives context where participants' decisions would result in winning or losing money depending on their contributions, and a control condition where no additional incentives were implemented. We found that, compared to the control condition, both monetary and social incentives significantly improved participants' contributions to the public project-an indicator of cooperative behavior. However, the association between higher primary psychopathic traits and less cooperation was only observed in the context of social incentives. Computational modeling further revealed that this effect can be explained by the diminishing guilt aversion when participants deliberately violated their inferred expectations of themselves from others' perspectives. This study found that social incentives can encourage cooperative behaviors in non-clinical psychopathy, and identified the mental processes navigating this effect.

Arousal-driven interactions between reward motivation and categorization of emotional facial expressions

Reward motivation and emotion share common dimensions of valence and arousal, but the nature of interactions between the two constructs is relatively unclear. On the one hand, based on the common valence dimension, valence-compatible interactions are expected where reward motivation would facilitate the processing of compatible (i.e., positive) emotion and hamper the processing of incompatible (i.e., negative) emotion. On the other hand, one could hypothesize valence-general interactions driven by the arousal dimension, where the processing of both positive and negative emotions would be facilitated under reward motivation. Currently, the evidence for valence-compatible vs. valence-general type interactions between reward motivation and goal-relevant emotion is relatively mixed. Moreover, as most of the previous work focused primarily on appetitive motivation, the influence of aversive motivation on goal-relevant emotion is largely unexplored. To address these important gaps, in the present study, we investigated the interactions between motivation and categorization of facial emotional expressions by manipulating the valence dimension of motivation (appetitive and aversive motivation levels) together with that of emotion (positive and negative valence stimuli). Specifically, we conducted two behavioral experiments to separately probe the influence of appetitive and aversive motivation (manipulated via an advance cue signaling the prospect of monetary gains in Experiment 1 and losses in Experiment 2, respectively) on the categorization of happy, fearful, and neutral faces. We tested the two competing hypotheses regarding the interactions between appetitive/aversive motivation and emotional face categorization: Valence-compatible vs. Valence-general. We found evidence consistent with valence-general interactions where both appetitive and aversive motivation facilitated the categorization of happy and fearful faces relative to the neutral ones. Our findings demonstrate that interactions between reward motivation and categorization of emotional faces are driven by the arousal dimension, not by valence.

A Systematic Review on Common and Distinct Neural Correlates of Risk-taking in Substance-related and Non-substance Related Addictions

Both substance-related as well as non-substance-related addictions may include recurrent engagement in risky actions despite adverse outcomes. We here apply a unified approach and review task-based neuroimaging studies on substance-related (SRAs) and non-substance related addictions (NSRAs) to examine commonalities and differences in neural correlates of risk-taking in these two addiction types. To this end, we conducted a systematic review adhering to the PRISMA guidelines. Two databases were searched with predefined search terms to identify neuroimaging studies on risk-taking tasks in individuals with addiction disorders. In total, 19 studies on SRAs (comprising a total of 648 individuals with SRAs) and 10 studies on NSRAs (comprising a total of 187 individuals with NSRAs) were included. Risk-related brain activation in SRAs and NSRAs was summarized individually and subsequently compared to each other. Results suggest convergent altered risk-related neural processes, including hyperactivity in the OFC and the striatum. As characteristic for both addiction types, these brain regions may represent an underlying mechanism of suboptimal decision-making. In contrast, decreased DLPFC activity may be specific to SRAs and decreased IFG activity could only be identified for NSRAs. The precuneus and posterior cingulate show elevated activity in SRAs, while findings regarding these areas were mixed in NSRAs. Additional scarce evidence suggests decreased ventral ACC activity and increased dorsal ACC activity in both addiction types. Associations between identified activation patterns with drug use severity underpin the clinical relevance of these findings. However, this exploratory evidence should be interpreted with caution and should be regarded as preliminary. Future research is needed to evaluate the findings gathered by this review.

The neural signature of the decision value of future pain

SignificanceWe often willingly experience pain to reach a goal. However, potential pain can also prevent reckless action. How do we consider future pain when deciding on the best course of action? To date, the precise neural mechanisms underlying the valuation of future pain remain unknown. Using functional MRI, we derive a whole-brain signature of the value of future pain capable of predicting participants' choices to accept pain in exchange for a reward. We show that this signature is characterized by a distributed pattern of activity with clear contributions from structures encoding reward and salience, notably the ventral and dorsal striatum. These findings highlight how the brain assigns value to future pain when choosing the best course of action.

The aversive value of pain in human decision-making

BACKGROUND

In order to decide between avoiding pain or pursuing competing rewards, pain must be assigned an abstract value that can be traded against that of competing goods. To assess the relationship between subjectively perceived pain and its value, we conducted an experiment where participants had to accept or decline different intensities of painful electric shocks in exchange of monetary rewards.

METHODS

Participants (n = 90) were divided into three groups that were exposed to different distributions of monetary rewards. Monetary offers ranged linearly from $0 to $5 or $10 in groups 1 and 2, respectively, and exponentially from $0 to $5 in group 3. Pain offers ranged from pain detection to pain tolerance thresholds. The value of pain was assessed by identifying the indifference points corresponding to a 50% chance of accepting a certain level of pain for a given monetary reward.

RESULTS

The value of pain increased quadratically as a function of the anticipated pain intensity and was found to be relative to the mean and standard deviation of monetary offers. Moreover, decision times increased as a function of the intensity of accepted painful stimulations. Finally, inter-individual differences in psychological traits related to harm avoidance and persistence influenced the value of pain.

CONCLUSIONS

This is the first demonstration that the value of pain follows a curvilinear function and is relative to the mean and standard deviation of competing monetary rewards. These new observations significantly contribute to our understanding of how pain is assigned value when making decisions between avoiding pain and obtaining rewards.

SIGNIFICANCE

This work provides a description of the pain value function indicating how much people are willing to pay to avoid different intensities of pain. We found that the function was curvilinear, suggesting that the same unit of subjective pain has more value in the high vs. low pain range. Moreover, the pain value was influenced by the experimental manipulation of the rewards distribution and of the inter-individual differences in harm avoidance and persistence. Altogether, the present study provides a detailed account of how subjectively experienced pain is assigned value.

Dynamic Computation of Value Signals via a Common Neural Network in Multi-Attribute Decision-Making

Studies in decision neuroscience have identified robust neural representations for the value of choice options. However, overall values often depend on multiple attributes, and it is not well understood how the brain evaluates different attributes and integrates them to combined values. In particular, it is not clear whether attribute values are computed in distinct attribute-specific regions or within the general valuation network known to process overall values. Here, we used an fMRI choice task in which abstract stimuli had to be evaluated based on variations of the attributes color and motion. The behavioral data showed that participants responded faster when overall values were high and attribute value differences were low. On the neural level, we did not find that attribute values were systematically represented in areas V4 and V5, even though these regions are associated with attribute-specific processing of color and motion, respectively. Instead, attribute values were associated with activity in the posterior cingulate cortex, ventral striatum, and posterior inferior temporal gyrus. Further, overall values were represented in dorsolateral and ventromedial prefrontal cortex, and attribute value differences in dorsomedial prefrontal cortex, which suggests that these regions play a key role for the neural integration of attribute values.

A Preferential Role for Ventromedial Prefrontal Cortex in Assessing "the Value of the Whole" in Multiattribute Object Evaluation

Everyday decision-making commonly involves assigning values to complex objects with multiple value-relevant attributes. Drawing on object recognition theories, we hypothesized two routes to multiattribute evaluation: assessing the value of the whole object based on holistic attribute configuration or summing individual attribute values. In two samples of healthy human male and female participants undergoing eye tracking and functional magnetic resonance imaging (fMRI) while evaluating novel pseudo objects, we found evidence for both forms of evaluation. Fixations to and transitions between attributes differed systematically when the value of pseudo objects was associated with individual attributes or attribute configurations. Ventromedial prefrontal cortex (vmPFC) and perirhinal cortex were engaged when configural processing was required. These results converge with our recent findings that individuals with vmPFC lesions were impaired in decisions requiring configural evaluation but not when evaluating the sum of the parts. This suggests that multiattribute decision-making engages distinct evaluation mechanisms relying on partially dissociable neural substrates, depending on the relationship between attributes and value.SIGNIFICANCE STATEMENT Decision neuroscience has only recently begun to address how multiple choice-relevant attributes are brought together during evaluation and choice among complex options. Object recognition research makes a crucial distinction between individual attribute and holistic/configural object processing, but how the brain evaluates attributes and whole objects remains unclear. Using fMRI and eye tracking, we found that the vmPFC and the perirhinal cortex contribute to value estimation specifically when value was related to whole objects, that is, predicted by the unique configuration of attributes and not when value was predicted by the sum of individual attribute values. This perspective on the interactions between subjective value and object processing mechanisms provides a novel bridge between the study of object recognition and reward-guided decision-making.

Defensive freezing and its relation to approach-avoidance decision-making under threat

Successful responding to acutely threatening situations requires adequate approach-avoidance decisions. However, it is unclear how threat-induced states-like freezing-related bradycardia-impact the weighing of the potential outcomes of such value-based decisions. Insight into the underlying computations is essential, not only to improve our models of decision-making but also to improve interventions for maladaptive decisions, for instance in anxiety patients and first-responders who frequently have to make decisions under acute threat. Forty-two participants made passive and active approach-avoidance decisions under threat-of-shock when confronted with mixed outcome-prospects (i.e., varying money and shock amounts). Choice behavior was best predicted by a model including individual action-tendencies and bradycardia, beyond the subjective value of the outcome. Moreover, threat-related bradycardia (high-vs-low threat) interacted with subjective value, depending on the action-context (passive-vs-active). Specifically, in action-contexts incongruent with participants' intrinsic action-tendencies, stronger bradycardia related to diminished effects of subjective value on choice across participants. These findings illustrate the relevance of testing approach-avoidance decisions in relatively ecologically valid conditions of acute and primarily reinforced threat. These mechanistic insights into approach-avoidance conflict-resolution may inspire biofeedback-related techniques to optimize decision-making under threat. Critically, the findings demonstrate the relevance of incorporating internal psychophysiological states and external action-contexts into models of approach-avoidance decision-making.

Intrinsic functional connectivity of medial prefrontal cortex predicts the individual moral bias in economic valuation partially through the moral sensitivity trait

An individual's economic valuation of a given object is biased by the moral status of the persons to whom the object is attached. The neural basis for how such "moral bias" occurs, especially how it is maintained in the resting state, are largely unknown. In the current study, we explored this question by correlating the functional connectivity with participants' behavioral performance measured in a novel task which captured how the economic valuation was influenced by given moral information. Seed-based FC analysis showed that the functional connectivity between the mPFC and the orbital mPFC (omPFC), the mPFC and the precuneus, the mPFC and the left anterior cingulum, were significantly associated with the behavioral index of morality effect on economic valuation. Multivariate machine learning-based regression analysis showed that connections in the mPFC network, as well as in the putamen network could well predict the behavior performance, indicating that this mPFC network and the putamen network were crucial for this moral bias. Our results further revealed that the individuals' personal trait of moral sensitivity served as a mediator between the rsFC of mPFC network and the behavioral index of morality effect on economic valuation.

Approach-Avoidance Decisions Under Threat: The Role of Autonomic Psychophysiological States

Acutely challenging or threatening situations frequently require approach-avoidance decisions. Acute threat triggers fast autonomic changes that prepare the body to freeze, fight or flee. However, such autonomic changes may also influence subsequent instrumental approach-avoidance decisions. Since defensive bodily states are often not considered in value-based decision-making models, it remains unclear how they influence the decision-making process. Here, we aim to bridge this gap by discussing the existing literature on the potential role of threat-induced bodily states on decision making and provide a new neurocomputational framework explaining how these effects can facilitate or bias approach-avoid decisions under threat. Theoretical accounts have stated that threat-induced parasympathetic activity is involved in information gathering and decision making. Parasympathetic dominance over sympathetic activity is particularly seen during threat-anticipatory freezing, an evolutionarily conserved response to threat demonstrated across species and characterized by immobility and bradycardia. Although this state of freezing has been linked to altered information processing and action preparation, a full theoretical treatment of the interactions with value-based decision making has not yet been achieved. Our neural framework, which we term the Threat State/Value Integration (TSI) Model, will illustrate how threat-induced bodily states may impact valuation of competing incentives at three stages of the decision-making process, namely at threat evaluation, integration of rewards and threats, and action initiation. Additionally, because altered parasympathetic activity and decision biases have been shown in anxious populations, we will end with discussing how biases in this system can lead to characteristic patterns of avoidance seen in anxiety-related disorders, motivating future pre-clinical and clinical research.

Computational and Neurobiological Substrates of Cost-Benefit Integration in Altruistic Helping Decision

Although altruistic behaviors, e.g., sacrificing one's own interests to alleviate others' suffering, are widely observed in human society, altruism varies greatly across individuals. Such individual differences in altruistic preference have been hypothesized to arise from both individuals' dispositional empathic concern for others' welfare and context-specific cost-benefit integration processes. However, how cost-benefit integration is implemented in the brain and how it is linked to empathy remain unclear. Here, we combine a novel paradigm with the model-based functional magnetic resonance imaging (fMRI) approach to examine the neurocomputational basis of altruistic behaviors. Thirty-seven adults (16 females) were tested. Modeling analyses suggest that individuals are likely to integrate their own monetary costs with nonlinearly transformed recipients' benefits. Neuroimaging results demonstrate the involvement of an extended common currency system during decision-making by showing that selfish and other-regarding motives were processed in dorsal anterior cingulate cortex (ACC) and right inferior parietal lobe in a domain-general manner. Importantly, a functional dissociation of adjacent but different subregions within anterior insular cortex (aINS) was observed for different subprocesses underlying altruistic behaviors. While dorsal aINS (daINS) and inferior frontal gyrus (IFG) were involved in valuation of benefactors' costs, ventral aINS and middle INS (vaINS/mINS), as empathy-related regions, reflected individual variations in valuating recipients' benefits. Multivariate analyses further suggest that both vaINS/mINS and dorsolateral prefrontal cortex (DLPFC) reflect individual variations in general altruistic preferences which account for both dispositional empathy and context-specific other-regarding tendency. Together, these findings provide valuable insights into our understanding of psychological and neurobiological basis of altruistic behaviors.SIGNIFICANCE STATEMENT Altruistic behaviors play a crucial role in facilitating solidarity and development of human society, but the mechanisms of the cost-benefit integration underlying these behaviors are still unclear. Using model-based neuroimaging approaches, we clarify that people integrate personal costs and non-linearly transformed other's benefits during altruistic decision-making and the implementations of the integration processes are supported by an extended common currency neural network. Importantly, multivariate analyses reveal that both empathy-related and cognitive control-related brain regions are involved in modulating individual variations of altruistic preference, which implicate complex psychological and computational processes. Our results provide a neurocomputational account of how people weigh between different attributes to make altruistic decisions and why altruistic preference varies to a great extent across individuals.

The ventral hippocampus is necessary for cue-elicited, but not outcome driven approach-avoidance conflict decisions: a novel operant choice decision-making task

Approach-avoidance conflict is induced when an organism encounters a stimulus that carries both positive and negative attributes. Accumulating evidence implicates the ventral hippocampus (VH) in the detection and resolution of approach-avoidance conflict, largely on the basis of maze-based tasks assaying innate and conditioned responses to situations of conflict. However, its role in discrete trial approach-avoidance decision-making has yet to be elucidated. In this study, we designed a novel cued operant conflict decision-making task in which rats were required to choose and respond for a low reward option or high reward option paired with varying shock intensities on a differential reinforcement of low rates of responding schedule. Post training, the VH was chemogenetically inhibited while animals performed the task with the usual outcomes delivered, and with the presentation of cues associated with the reward vs. conflict options only (extinction condition). We found that VH inhibition led to an avoidance of the conflict option and longer latency to choose this option when decision-making was being made on the basis of cues alone with no outcomes. Consistent with these findings, VH-inhibited animals spent more time in the central component of the elevated plus maze (EPM), indicating a potential deficit in decision-making under innate forms of approach-avoidance conflict. Taken together, these findings implicate the VH in cue-driven approach-avoidance decisions in the face of motivational conflict.

Neural Computations of Threat

A host of learning, memory, and decision-making processes form the individual's response to threat and may be disrupted in anxiety and post-trauma psychopathology. Here we review the neural computations of threat, from the first encounter with a dangerous situation, through learning, storing, and updating cues that predict it, to making decisions about the optimal course of action. The overview highlights the interconnected nature of these processes and their reliance on shared neural and computational mechanisms. We propose an integrative approach to the study of threat-related processes, in which specific computations are studied across the various stages of threat experience rather than in isolation. This approach can generate new insights about the evolution, diagnosis, and treatment of threat-related psychopathology.

The effect of concurrent reward on aversive information processing in the brain

Neural networks for the processing of appetitive and aversive information, in isolation, have been well characterized. However, how the brain integrates competing signals associated with simultaneous appetitive and aversive information is less clear. In particular, it is unknown how the presence of concurrent reward modulates the processing of an aversive event throughout the brain. Here, we utilized a four-armed bandit task in an fMRI study to measure the representation of an aversive electric shock with and without the simultaneous receipt of monetary reward. Using a region of interest (ROI) approach, we first identified regions activated by the experience of aversive electric shock, and then measured how this shock-related activation is modulated by concurrent reward using independent data. Informed by prior literature and our own preliminary data, analyses focused on the dorsolateral prefrontal cortex, anterior and posterior insula, anterior cingulate cortex, and the thalamus and somatosensory cortex. We hypothesized that the neural response to punishment in these ROIs would be attenuated by the presence of concurrent reward. However, we found no evidence of concurrent reward attenuating the neural response to punishment in any ROI and also no evidence of concurrent punishment attenuating the neural response to reward in exploratory analyses. Altogether, our findings are consistent with the idea that neural networks responsible for the processing of reward and punishment signals are largely independent of one another, and that representations of overall value or utility are arrived at through the integration of separate reward and punishment signals at later stages of information processing.

Neurocomputational mechanisms underlying immoral decisions benefiting self or others

Immoral behavior often consists of weighing transgression of a moral norm against maximizing personal profits. One important question is to understand why immoral behaviors vary based on who receives specific benefits and what are the neurocomputational mechanisms underlying such moral flexibility. Here, we used model-based functional magnetic resonance imaging to investigate how immoral behaviors change when benefiting oneself or someone else. Participants were presented with offers requiring a tradeoff between a moral cost (i.e. profiting a morally bad cause) and a benefit for either oneself or a charity. Participants were more willing to obtain ill-gotten profits for themselves than for a charity, driven by a devaluation of the moral cost when deciding for their own interests. The subjective value of an immoral offer, computed as a linear summation of the weighed monetary gain and moral cost, recruited the ventromedial prefrontal cortex (PFC) regardless of beneficiaries. Moreover, paralleling the behavioral findings, this region enhanced its functional coupling with mentalizing-related regions while deciding whether to gain morally tainted profits for oneself vs charity. Finally, individual differences in moral preference differentially modulated choice-specific signals in the dorsolateral PFC according to who benefited from the decisions. These findings provide insights for understanding the neurobiological basis of moral flexibility.

Subjective value then confidence in human ventromedial prefrontal cortex

Two fundamental goals of decision making are to select actions that maximize rewards while minimizing costs and to have strong confidence in the accuracy of a judgment. Neural signatures of these two forms of value: the subjective value (SV) of choice alternatives and the value of the judgment (confidence), have both been observed in ventromedial prefrontal cortex (vmPFC). However, the relationship between these dual value signals and their relative time courses are unknown. Twenty-eight men and women underwent fMRI while performing a two-phase approach-avoidance (Ap-Av) task with mixed-outcomes of monetary rewards paired with painful shock stimuli. Neural responses were measured during offer valuation (offer phase) and choice valuation (commit phase) and analyzed with respect to observed decision outcomes, model-estimated SV and confidence. During the offer phase, vmPFC tracked SV and the decision but not confidence. During the commit phase, vmPFC tracked confidence, computed as the quadratic extension of SV, but not the offer valuation nor the decision. In fact, vmPFC responses from the commit phase were selective for confidence even for reject decisions wherein confidence and SV are inversely related. Conversely, activation of the cognitive control network, including within lateral prefrontal cortex (lPFC) and dorsal anterior cingulate cortex (dACC) was associated with ambivalence, during both the offer and commit phases. Taken together, our results reveal complementary representations in vmPFC during value-based decision making that temporally dissociate such that offer valuation (SV) emerges before decision valuation (confidence).

The Neural Basis of Approach-Avoidance Conflict: A Model Based Analysis

Approach-avoidance conflict arises when the drives to pursue reward and avoid harm are incompatible. Previous neuroimaging studies of approach-avoidance conflict have shown large variability in reported neuroanatomical correlates. These prior studies have generally neglected to account for potential sources of variability, such as individual differences in choice preferences and modeling of hemodynamic response during conflict. In the present study, we controlled for these limitations using a hierarchical Bayesian model (HBM). This enabled us to measure participant-specific per-trial estimates of conflict during an approach-avoidance task. We also employed a variable epoch method to identify brain structures specifically sensitive to conflict. In a sample of 28 human participants, we found that only a limited set of brain structures [inferior frontal gyrus (IFG), right dorsolateral prefrontal cortex (dlPFC), and right pre-supplementary motor area (pre-SMA)] are specifically correlated with approach-avoidance conflict. These findings suggest that controlling for previous sources of variability increases the specificity of the neuroanatomical correlates of approach-avoidance conflict.

Neurocomputational mechanisms at play when weighing concerns for extrinsic rewards, moral values, and social image

Humans not only value extrinsic monetary rewards but also their own morality and their image in the eyes of others. Yet violating moral norms is frequent, especially when people know that they are not under scrutiny. When moral values and monetary payoffs are at odds, how does the brain weigh the benefits and costs of moral and monetary payoffs? Here, using a neurocomputational model of decision value (DV) and functional (f)MRI, we investigated whether different brain systems are engaged when deciding whether to earn money by contributing to a “bad cause” and when deciding whether to sacrifice money to contribute to a “good cause,” both when such choices were made privately or in public. Although similar principles of DV computations were used to solve these dilemmas, they engaged 2 distinct valuation systems. When weighing monetary benefits and moral costs, people were willing to trade their moral values in exchange for money, an effect accompanied by DV computation engaging the anterior insula and the lateral prefrontal cortex (PFC). In contrast, weighing monetary costs against compliance with one’s moral values engaged the ventral putamen. Moreover, regardless of the type of dilemma, a brain network including the anterior cingulate cortex (ACC), anterior insula, and the right temporoparietal junction (TJP) was more engaged in public than in private settings. Together, these findings identify how the brain processes three sources of motivation: extrinsic rewards, moral values, and concerns for image.

Distinct brain systems are engaged when weighing whether to earn money by contributing to a ‘bad cause’ and when weighing whether to lose money to contribute to a ‘good cause,’ regardless of whether such choices are made privately or in public.

Neural mediation of greed personality trait on economic risk-taking

Dispositional greed, characterized by the insatiable hunger for more and the dissatisfaction for not having enough, has often been associated with heightened impulsivity and excessive risk-taking. Despite its far-reaching implications in social sciences and economics, however, the exact neural mechanisms of how greed personality influences risk-taking are still ill understood. In the present study, we showed the correlation between subject's greed personality trait (GPT) score and risk-taking was selectively mediated by individual's loss aversion, but not risk attitude. In addition, our neuroimaging results indicated that gain and loss prospects were jointly represented in the activities of the ventral striatum and medial orbitofrontal cortex (mOFC). Furthermore, mOFC responses also encoded the neural loss aversion signal and mediated the association between individual differences in GPT scores and behavioral loss aversion. Our findings provide a basis for understanding the specific neural mechanisms that mediate the effect of greed personality trait on risk-taking behavior.

The functional role of ventral anterior cingulate cortex in social evaluation: disentangling valence from subjectively rewarding opportunities

Despite robust associations between the ventral anterior cingulate cortex (vACC) and social evaluation, the role of vACC in social evaluation remains poorly understood. Two hypotheses have emerged from existing research: detection of positive valence and detection of opportunities for subjective reward. It has been difficult to understand whether one or both hypotheses are supported because previous research conflated positive valence with subjective reward. Therefore, the current functional magnetic resonance imaging study drew on a social evaluation paradigm that disentangled positive valence and subjective reward. Participants evaluated in-group and out-group politicians in a social evaluation paradigm that crossed trait valence with opportunity for subjectively rewarding affirmation (i.e. a chance to affirm positive traits about in-group politicians and affirm negative traits about out-group politicians). Participants rated in-group politicians more positively and out-group politicians more negatively. One subregion of vACC was modulated by positive valence and another relatively posterior region of vACC was modulated by opportunity for subjective reward (i.e. a politician × valence interaction). The current findings demonstrate the importance of incorporating vACC function into models of social cognition and provide new avenues for sharpening our understanding of the psychological significance of vACC function in social evaluation and related domains such as reward and affect.

Potential reward reduces the adverse impact of negative distractor stimuli

Knowledge about interactions between reward and negative processing is rudimentary. Here, we employed functional MRI to probe how potential reward signaled by advance cues alters aversive distractor processing during perception. Behaviorally, the influence of aversive stimuli on task performance was reduced during the reward compared to no-reward condition. In the brain, at the task phase, paralleling the observed behavioral pattern, we observed significant interactions in the anterior insula and dorsal anterior cingulate cortex, such that responses during the negative (vs neutral) condition were reduced during the reward compared to no-reward condition. Notably, negative distractor processing in the amygdala appeared to be independent of the reward manipulation. During the initial cue phase, we observed increased reward-related responses in the ventral striatum/accumbens, which were correlated with behavioral interference scores at the subsequent task phase, revealing that participants with increased reward-related responses exhibited a greater behavioral benefit of reward in reducing the adverse effect of negative images. Furthermore, during processing of reward (vs no-reward) cues, the ventral striatum exhibited stronger functional connectivity with fronto-parietal regions important for attentional control. Together, our findings contribute to the understanding of how potential reward influences attentional control and reduces negative distractor processing in the human brain.

Model-based and model-free pain avoidance learning

Background: While there is good evidence that reward learning is underpinned by two distinct decision control systems – a cognitive ‘model-based’ and a habitbased ‘model-free’ system, a comparable distinction for punishment avoidance has been much less clear. Methods: We implemented a pain avoidance task that placed differential emphasis on putative model-based and model-free processing, mirroring a paradigm and modelling approach recently developed for reward-based decision-making. Subjects performed a two-step decision-making task with probabilistic pain outcomes of different quantities. The delivery of outcomes was sometimes contingent on a rule signalled at the beginning of each trial, emulating a form of outcome devaluation. Results: The behavioural data showed that subjects tended to use a mixed strategy – favouring the simpler model-free learning strategy when outcomes did not depend on the rule, and favouring a model-based when they did. Furthermore, the data were well described by a dynamic transition model between the two controllers. When compared with data from a reward-based task (albeit tested in the context of the scanner), we observed that avoidance involved a significantly greater tendency for subjects to switch between model-free and model-based systems in the face of changes in uncertainty. Conclusion: Our study suggests a dual-system model of pain avoidance, similar to but possibly more dynamically flexible than reward-based decision-making.

Probing culture in the head: the neural correlates of relational models

Relational Models Theory or RMT proposes that there are four universal ways in which socio-economic relations can be organized. According to the RMT, each of its four relational models (Communal Sharing, Authority Ranking, Equality Matching, and Market Pricing) is associated with a distinct cognitive representation, with a cumulative pattern in which each relational model is a superset of the next lower model. This report for the first time uses a combination of cognitive and the social neuroscience to put this model to the test. RMT proposes that members of every culture use all four relational models, just in different proportions. It should therefore be possible to study their neural correlates in a mono-cultural sample. In this study, thirty-nine European-American students were imaged in a 3T Siemens Trio with a 24-channel head coil while rating the extent to which each relational model organized relationships with each of thirty-two acquaintances/friend/relatives in a boxcar design. FreeSurfer Functional Analysis Stream (FS-FAST) analyses revealed distinct patterns of activation for each of the relational models. The activations did not follow a cumulative hierarchical pattern, suggestive that this aspect of the RMT model should be revised.

Choose, rate or squeeze: Comparison of economic value functions elicited by different behavioral tasks

A standard view in neuroeconomics is that to make a choice, an agent first assigns subjective values to available options, and then compares them to select the best. In choice tasks, these cardinal values are typically inferred from the preference expressed by subjects between options presented in pairs. Alternatively, cardinal values can be directly elicited by asking subjects to place a cursor on an analog scale (rating task) or to exert a force on a power grip (effort task). These tasks can vary in many respects: they can notably be more or less costly and consequential. Here, we compared the value functions elicited by choice, rating and effort tasks on options composed of two monetary amounts: one for the subject (gain) and one for a charity (donation). Bayesian model selection showed that despite important differences between the three tasks, they all elicited a same value function, with similar weighting of gain and donation, but variable concavity. Moreover, value functions elicited by the different tasks could predict choices with equivalent accuracy. Our finding therefore suggests that comparable value functions can account for various motivated behaviors, beyond economic choice. Nevertheless, we report slight differences in the computational efficiency of parameter estimation that may guide the design of future studies.

Subjective utility moderates bidirectional effects of conflicting motivations on pain perception

Minimizing pain and maximizing pleasure are conflicting motivations when pain and reward co-occur. Decisions to prioritize reward consumption or pain avoidance are assumed to lead to pain inhibition or facilitation, respectively. Such decisions are a function of the subjective utility of the stimuli involved, i.e. the relative value assigned to the stimuli to compare the potential outcomes of a decision. To test perceptual pain modulation by varying degrees of motivational conflicts and the role of subjective utility, we implemented a task in which healthy volunteers had to decide between accepting a reward at the cost of receiving a nociceptive electrocutaneous stimulus or rejecting both. Subjective utility of the stimuli was assessed by a matching task between the stimuli. Accepting reward coupled to a nociceptive stimulus resulted in decreased perceived intensity, while rejecting the reward to avoid pain resulted in increased perceived intensity, but in both cases only if a high motivational conflict was present. Subjective utility of the stimuli involved moderated these bidirectional perceptual effects: the more a person valued money over pain, the more perceived intensity increased or decreased. These findings demonstrate pain modulation when pain and reward are simultaneously present and highlight the importance of subjective utility for such modulation.

A neural link between generosity and happiness

Generous behaviour is known to increase happiness, which could thereby motivate generosity. In this study, we use functional magnetic resonance imaging and a public pledge for future generosity to investigate the brain mechanisms that link generous behaviour with increases in happiness. Participants promised to spend money over the next 4 weeks either on others (experimental group) or on themselves (control group). Here, we report that, compared to controls, participants in the experimental group make more generous choices in an independent decision-making task and show stronger increases in self-reported happiness. Generous decisions engage the temporo-parietal junction (TPJ) in the experimental more than in the control group and differentially modulate the connectivity between TPJ and ventral striatum. Importantly, striatal activity during generous decisions is directly related to changes in happiness. These results demonstrate that top–down control of striatal activity plays a fundamental role in linking commitment-induced generosity with happiness.

Generous behaviour increases happiness, but the neural underpinnings of this link are unknown. Here, authors show that promising to be generous changes the neural response in the temporo-parietal junction, and that the connection between this region and the ventral striatum was related to happiness.

How do self-interest and other-need interact in the brain to determine altruistic behavior?

Altruistic behavior, i.e., promoting the welfare of others at a cost to oneself, is subserved by the integration of various social, affective, and economic factors represented in extensive brain regions. However, it is unclear how different regions interact to process/integrate information regarding the helper's interest and recipient's need when deciding whether to behave altruistically. Here we combined an interactive game with functional Magnetic Resonance Imaging (fMRI) and transcranial direct current stimulation (tDCS) to characterize the neural network underlying the processing/integration of self-interest and other-need. At the behavioral level, high self-risk decreased helping behavior and high other-need increased helping behavior. At the neural level, activity in medial prefrontal cortex (MPFC) and right dorsolateral prefrontal cortex (rDLPFC) were positively associated with self-risk levels, and activity in right inferior parietal lobe (rIPL) and rDLPFC were negatively associated with other-need levels. Dynamic causal modeling further suggested that both MPFC and rIPL were extrinsically connected to rDLPFC; high self-risk enhanced the effective connectivity from MPFC to rDLPFC, and the modulatory effect of other-need on the connectivity from rIPL to rDLPFC positively correlated with the modulatory effect of other-need on individuals' helping rate. Two tDCS experiments provided causal evidence that rDLPFC affects both self-interest and other-need concerns, and rIPL selectively affects the other-need concerns. These findings suggest a crucial role of the MPFC-IPL-DLPFC network during altruistic decision-making, with rDLPFC as a central node for integrating and modulating motives regarding self-interest and other-need.

The roles of valuation and reward processing in cognitive function and psychiatric disorders

In neuroeconomics, valuation refers to the process of assigning values to states and actions on the basis of the animal's current representation of the environment, while reward processing corresponds to processing the feedback received from the environment to update the values of states and actions. In this article, we review the brain circuits associated with valuation and reward processing and argue that these are fundamental processes critical to many cognitive functions. Specifically, we focus on the role of valuation and reward processing in attention, memory, decision making, and learning. Next, the extant neuroimaging literature on a number of psychiatric disorders is reviewed (i.e., addiction, pathological gambling, schizophrenia, and mood disorders), and an argument is made that associated deficits in cognitive functions can be explained in terms of abnormal valuation and reward processing. The review concludes with the impact of this framework in clinical settings and prescriptions for future research, in particular with regard to the conversions of qualitatively different valuation systems into a system of common currency.

Neuroanatomical Substrates for Risk Behavior

Individuals vary substantially in their tendency to take risks. In the past two decades, a large number of neuroimaging studies in humans have explored the neural mechanisms of several cognitive processes that contribute to risk taking. In this article, I focus on functional and structural MRI studies that investigated uncertainty processing, one of the main features of risk behavior. Using decision-making and learning paradigms, these studies implicated a network of brain areas, including posterior parietal cortex, anterior insula, anterior cingulate cortex, and ventrolateral prefrontal cortex, in various aspects of uncertainty processing. Individual differences in behavior under uncertainty are reflected in the function and structure of some of these areas and are integrated into value representations in ventromedial prefrontal cortex and ventral striatum, reinforcing the potential contribution of all of these brain structures to individual tendencies to take risks.

Aversive Counterconditioning Attenuates Reward Signaling in the Ventral Striatum

Appetitive conditioning refers to the process of learning cue-reward associations and is mediated by the mesocorticolimbic system. Appetitive conditioned responses are difficult to extinguish, especially for highly salient reward such as food and drugs. We investigate whether aversive counterconditioning can alter reward reinstatement in the ventral striatum in healthy volunteers using functional magnetic resonance imaging (fMRI). In the initial conditioning phase, two different stimuli were reinforced with a monetary reward. In the subsequent counterconditioning phase, one of these stimuli was paired with an aversive shock to the wrist. In the following extinction phase, none of the stimuli were reinforced. In the final reinstatement phase, reward was reinstated by informing the participants that the monetary gain could be doubled. Our fMRI data revealed that reward signaling in the ventral striatum and ventral tegmental area following reinstatement was smaller for the stimulus that was counterconditioned with an electrical shock, compared to the non-counterconditioned stimulus. A functional connectivity analysis showed that aversive counterconditioning strengthened striatal connectivity with the hippocampus and insula. These results suggest that reward signaling in the ventral striatum can be attenuated through aversive counterconditioning, possibly by concurrent retrieval of the aversive association through enhanced connectivity with hippocampus and insula.

Human mesostriatal response tracks motivational tendencies under naturalistic goal conflict

Goal conflict situations, involving the simultaneous presence of reward and punishment, occur commonly in real life, and reflect well-known individual differences in the behavioral tendency to approach or avoid. However, despite accumulating neural depiction of motivational processing, the investigation of naturalistic approach behavior and its interplay with individual tendencies is remarkably lacking. We developed a novel ecological interactive scenario which triggers motivational behavior under high or low goal conflict conditions. Fifty-five healthy subjects played the game during a functional magnetic resonance imaging scan. A machine-learning approach was applied to classify approach/avoidance behaviors during the game. To achieve an independent measure of individual tendencies, an integrative profile was composed from three established theoretical models. Results demonstrated that approach under high relative to low conflict involved increased activity in the ventral tegmental area (VTA), peri-aquaductal gray, ventral striatum (VS) and precuneus. Notably, only VS and VTA activations during high conflict discriminated between approach/avoidance personality profiles, suggesting that the relationship between individual personality and naturalistic motivational tendencies is uniquely associated with the mesostriatal pathway. VTA-VS further demonstrated stronger coupling during high vs low conflict. These findings are the first to unravel the multilevel relationship among personality profile, approach tendencies in naturalistic set-up and their underlying neural manifestation, thus enabling new avenues for investigating approach-related psychopathologies.

Humans Integrate Monetary and Liquid Incentives to Motivate Cognitive Task Performance

It is unequivocal that a wide variety of incentives can motivate behavior. However, few studies have explicitly examined whether and how different incentives are integrated in terms of their motivational influence. The current study examines the combined effects of monetary and liquid incentives on cognitive processing, and whether appetitive and aversive incentives have distinct influences. We introduce a novel task paradigm, in which participants perform cued task-switching for monetary rewards that vary parametrically across trials, with liquid incentives serving as post-trial performance feedback. Critically, the symbolic meaning of the liquid was held constant (indicating successful reward attainment), while liquid valence was blocked. In the first experiment, monetary rewards combined additively with appetitive liquid feedback to improve subject task performance. Aversive liquid feedback counteracted monetary reward effects in low monetary reward trials, particularly in a subset of participants who tended to avoid responding under these conditions. Self-report motivation ratings predicted behavioral performance above and beyond experimental effects. A follow-up experiment replicated the predictive power of motivation ratings even when only appetitive liquids were used, suggesting that ratings reflect idiosyncratic subjective values of, rather than categorical differences between, the liquid incentives. Together, the findings indicate an integrative relationship between primary and secondary incentives and potentially dissociable influences in modulating motivational value, while informing hypotheses regarding candidate neural mechanisms.

Delay discounting without decision-making: medial prefrontal cortex and amygdala activations reflect immediacy processing and correlate with impulsivity and anxious-depressive traits

Humans value rewards less when these are delivered in the future as opposed to immediately, a phenomenon referred to as delay discounting. While delay discounting has been studied during the anticipation of rewards and in the context of intertemporal decision-making, little is known about its neural correlates in the outcome phase (during reward delivery) and their relation to personality. Personality traits that have been associated with increased delay discounting include impulsivity and, potentially, anxious-depressive traits. Here we performed functional magnetic resonance imaging (fMRI) in 72 healthy participants while they carried out a monetary incentive delay (MID) task with a delay manipulation. In sixty percent of the experimental trials, participants won rewards that differed in magnitude (0.05€, 0.50€ or 1€) and delay until delivery (immediately, 10 days, or 100 days). A factor analysis on questionnaires yielded two factors reflecting Impulsivity and Anxiety/Depression, which we used to examine potential relationships between personality and delay discounting. When winning a reward, medial prefrontal cortex (mPFC) activation was higher for immediate compared to delayed rewards. Moreover, amygdala activation correlated with reward magnitude for immediate but not for delayed rewards. Amygdala activation to winning immediate rewards was higher in more impulsive participants, while mPFC activation to winning immediate rewards was higher in more anxious-depressed participants. Our results uncover neural correlates of delay discounting during reward delivery, and suggest that impulsivity and subclinical anxious-depressive traits are related to stronger neural responses for winning immediate relative to delayed rewards.

The good, the bad and the brain: Neural correlates of appetitive and aversive values underlying decision making

Approaching rewards and avoiding punishments could be considered as core principles governing behavior. Experiments from behavioral economics have shown that choices involving gains and losses follow different policy rules, suggesting that appetitive and aversive processes might rely on different brain systems. Here we contrast this hypothesis with recent neuroscience studies exploring the human brain from brainstem nuclei to cortical areas. Although some circuits show rigid specialization, many others appear to process both appetitive and aversive stimuli, in a flexible manner that depends on a context-wise subjective reference point. Moreover, appetitive and aversive aspects are often integrated into net values that are signaled with enhanced activity in 'positive regions', and suppressed activity in 'negative regions'. This dichotomy might explain why drugs or lesions can produce valence-specific effects, biasing decisions towards approaching a reward or avoiding a punishment.

Differential patterns of amygdala and ventral striatum activation predict gender-specific changes in sexual risk behavior

Although the initiation of sexual behavior is common among adolescents and young adults, some individuals express this behavior in a manner that significantly increases their risk for negative outcomes including sexually transmitted infections. Based on accumulating evidence, we have hypothesized that increased sexual risk behavior reflects, in part, an imbalance between neural circuits mediating approach and avoidance in particular as manifest by relatively increased ventral striatum (VS) activity and relatively decreased amygdala activity. Here, we test our hypothesis using data from seventy 18- to 22-year-old university students participating in the Duke Neurogenetics Study. We found a significant three-way interaction between amygdala activation, VS activation, and gender predicting changes in the number of sexual partners over time. Although relatively increased VS activation predicted greater increases in sexual partners for both men and women, the effect in men was contingent on the presence of relatively decreased amygdala activation and the effect in women was contingent on the presence of relatively increased amygdala activation. These findings suggest unique gender differences in how complex interactions between neural circuit function contributing to approach and avoidance may be expressed as sexual risk behavior in young adults. As such, our findings have the potential to inform the development of novel, gender-specific strategies that may be more effective at curtailing sexual risk behavior.

Normative development of ventral striatal resting state connectivity in humans

Incentives play a crucial role in guiding behavior throughout our lives, but perhaps no more so than during the early years of life. The ventral striatum is a critical piece of an incentive-based learning circuit, sharing robust anatomical connections with subcortical (e.g., amygdala, hippocampus) and cortical structures (e.g., medial prefrontal cortex (mPFC), insula) that collectively support incentive valuation and learning. Resting-state functional connectivity (rsFC) is a powerful method that provides insight into the development of the functional architecture of these connections involved in incentive-based learning. We employed a seed-based correlation approach to investigate ventral striatal rsFC in a cross-sectional sample of typically developing individuals between the ages of 4.5 and 23-years old (n=66). Ventral striatal rsFC with the mPFC showed regionally specific linear age-related changes in connectivity that were associated with age-related increases in circulating testosterone levels. Further, ventral striatal connectivity with the posterior hippocampus and posterior insula demonstrated quadratic age-related changes characterized by negative connectivity in adolescence. Finally, across this age range, the ventral striatum demonstrated positive coupling with the amygdala beginning during childhood and remaining consistently positive across age. In sum, our findings suggest that normative ventral striatal rsFC development is dynamic and characterized by early establishment of connectivity with medial prefrontal and limbic structures supporting incentive-based learning, as well as substantial functional reorganization with later developing regions during transitions into and out of adolescence.

Attenuated Neural Processing of Risk in Young Adults at Risk for Stimulant Dependence

Objective

Approximately 10% of young adults report non-medical use of stimulants (cocaine, amphetamine, methylphenidate), which puts them at risk for the development of dependence. This fMRI study investigates whether subjects at early stages of stimulant use show altered decision making processing.

Methods

158 occasional stimulants users (OSU) and 50 comparison subjects (CS) performed a “risky gains” decision making task during which they could select safe options (cash in 20 cents) or gamble them for double or nothing in two consecutive gambles (win or lose 40 or 80 cents, “risky decisions”). The primary analysis focused on risky versus safe decisions. Three secondary analyses were conducted: First, a robust regression examined the effect of lifetime exposure to stimulants and marijuana; second, subgroups of OSU with >1000 (n = 42), or <50 lifetime marijuana uses (n = 32), were compared to CS with <50 lifetime uses (n = 46) to examine potential marijuana effects; third, brain activation associated with behavioral adjustment following monetary losses was probed.

Results

There were no behavioral differences between groups. OSU showed attenuated activation across risky and safe decisions in prefrontal cortex, insula, and dorsal striatum, exhibited lower anterior cingulate cortex (ACC) and dorsal striatum activation for risky decisions and greater inferior frontal gyrus activation for safe decisions. Those OSU with relatively more stimulant use showed greater dorsal ACC and posterior insula attenuation. In comparison, greater lifetime marijuana use was associated with less neural differentiation between risky and safe decisions. OSU who chose more safe responses after losses exhibited similarities with CS relative to those preferring risky options.

Discussion

Individuals at risk for the development of stimulant use disorders presented less differentiated neural processing of risky and safe options. Specifically, OSU show attenuated brain response in regions critical for performance monitoring, reward processing and interoceptive awareness. Marijuana had additive effects by diminishing neural risk differentiation.

Anticipatory anxiety disrupts neural valuation during risky choice

Incidental negative emotions unrelated to the current task, such as background anxiety, can strongly influence decisions. This is most evident in psychiatric disorders associated with generalized emotional disturbances. However, the neural mechanisms by which incidental emotions may affect choices remain poorly understood. Here we study the effects of incidental anxiety on human risky decision making, focusing on both behavioral preferences and their underlying neural processes. Although observable choices remained stable across affective contexts with high and low incidental anxiety, we found a clear change in neural valuation signals: during high incidental anxiety, activity in ventromedial prefrontal cortex and ventral striatum showed a marked reduction in (1) neural coding of the expected subjective value (ESV) of risky options, (2) prediction of observed choices, (3) functional coupling with other areas of the valuation system, and (4) baseline activity. At the same time, activity in the anterior insula showed an increase in coding the negative ESV of risky lotteries, and this neural activity predicted whether the risky lotteries would be rejected. This pattern of results suggests that incidental anxiety can shift the focus of neural valuation from possible positive consequences to anticipated negative consequences of choice options. Moreover, our findings show that these changes in neural value coding can occur in the absence of changes in overt behavior. This suggest a possible pathway by which background anxiety may lead to the development of chronic reward desensitization and a maladaptive focus on negative cognitions, as prevalent in affective and anxiety disorders.

Relative valuation of pain in human orbitofrontal cortex

The valuation of health-related states, including pain, is a critical issue in clinical practice, health economics, and pain neuroscience. Surprisingly the monetary value people associate with pain is highly context-dependent, with participants willing to pay more to avoid medium-level pain when presented in a context of low-intensity, rather than high-intensity, pain. Here, we ask whether context impacts upon the neural representation of pain itself, or alternatively the transformation of pain into valuation-driven behavior. While undergoing fMRI, human participants declared how much money they would be willing to pay to avoid repeated instances of painful cutaneous electrical stimuli delivered to the foot. We also implemented a contextual manipulation that involved presenting medium-level painful stimuli in blocks with either low- or high-level stimuli. We found no evidence of context-dependent activity within a conventional "pain matrix," where pain-evoked activity reflected absolute stimulus intensity. By contrast, in right lateral orbitofrontal cortex, a strong contextual dependency was evident, and here activity tracked the contextual rank of the pain. The findings are in keeping with an architecture where an absolute pain valuation system and a rank-dependent system interact to influence willing to pay to avoid pain, with context impacting value-based behavior high in a processing hierarchy. This segregated processing hints that distinct neural representations reflect sensory aspects of pain and components that are less directly nociceptive whose integration also guides pain-related actions. A dominance of the latter might account for puzzling phenomena seen in somatization disorders where perceived pain is a dominant driver of behavior.

Pain: a distributed brain information network?

Understanding how pain is processed in the brain has been an enduring puzzle, because there doesn't appear to be a single "pain cortex" that directly codes the subjective perception of pain. An emerging concept is that, instead, pain might emerge from the coordinated activity of an integrated brain network. In support of this view, Woo and colleagues present evidence that distinct brain networks support the subjective changes in pain that result from nociceptive input and self-directed cognitive modulation. This evidence for the sensitivity of distinct neural subsystems to different aspects of pain opens up the way to more formal computational network theories of pain.

Functional connectivity with ventromedial prefrontal cortex reflects subjective value for social rewards

According to many studies, the ventromedial prefrontal cortex (VMPFC) encodes the subjective value of disparate rewards on a common scale. Yet, a host of other reward factors-likely represented outside of VMPFC-must be integrated to construct such signals for valuation. Using functional magnetic resonance imaging (fMRI), we tested whether the interactions between posterior VMPFC and functionally connected brain regions predict subjective value. During fMRI scanning, participants rated the attractiveness of unfamiliar faces. We found that activation in dorsal anterior cingulate cortex, anterior VMPFC and caudate increased with higher attractiveness ratings. Using data from a post-scan task in which participants spent money to view attractive faces, we quantified each individual's subjective value for attractiveness. We found that connectivity between posterior VMPFC and regions frequently modulated by social information-including the temporal-parietal junction (TPJ) and middle temporal gyrus-was correlated with individual differences in subjective value. Crucially, these additional regions explained unique variation in subjective value beyond that extracted from value regions alone. These findings indicate not only that posterior VMPFC interacts with additional brain regions during valuation, but also that these additional regions carry information employed to construct the subjective value for social reward.