Neuronal Reward and Decision Signals: From Theories to Data

Cannabinoid-based Pharmacology for the Management of Substance Use Disorders

In the last two decades, the endocannabinoid system has emerged as a crucial modulator of motivation and emotional processing. Due to its widespread neuroanatomical distribution and characteristic retrograde signaling nature, cannabinoid type I receptors and their endogenous ligands finely orchestrate somatic and axon terminal activity of dopamine neurons. Owing to these unique features, this signaling system is a promising pharmacological target to ameliorate dopamine-mediated drug-seeking behaviors while circumventing the adverse side effects of, for instance, dopaminergic antagonists. Despite considerable preclinical efforts, an agreement on the efficacy of endocannabinoid-targeting compounds for treating drug substance use disorders in humans has not been reached. In the following chapter, we will summarize preclinical and clinical evidence addressing the therapeutic potential of cannabinoids and endocannabinoid-targeting compounds in substance use disorders. To bridge the gap between animal and clinical research, we capitalize on studies evaluating the impact of endocannabinoid-targeting compounds in relevant settings, such as the management of drug relapse. Finally, we discuss the therapeutic potential of novel cannabinoid compounds that hold promise for treating substance use disorders.

A pilot study on the effects of olfactory stimulation with white musk aromatic oil on psychophysiological activity: a crossover study

Studies on the compounds of aromatic oils and their effects on psychophysiological changes in humans are often conducted separately. To obtain better validation, a suitable protocol is needed that can be extrapolated to large-scale olfactory stimulation experiments. Unfortunately, this type of study is still rarely performed. In this situation, we propose a randomized crossover pilot study on olfactory stimulation with aromatic oils in relation to changes in psychophysiological activity by focusing on white musk aromatic oil due to its popularity in the community. Chemical profiling by TDU-GC-MS (thermal desorption gas chromatography/mass spectrometry) was performed to understand the compounds of the aromatic oils presented. To understand the changes in the participants' impressions and mood states, POMS 2 (Profile of Mood States 2nd Edition) and VAS (Visual analogue scale) were performed in addition to physiological evaluation by using EEG (electroencephalogram), ECG (electrocardiogram) and salivary amylase measurements. The proposed pilot study showed "gorgeous", "sweet", and "like" impression toward white musk aromatic oil under VAS evaluation. Mood evaluation under POMS 2 variables such as Fatigue-Inertia (FI), Tension-anxiety (TA) and TMD (total mood disturbance) were significantly decreased under white musk aromatic oil inhalation. Under current protocol, we can also see the changes in autonomic activity and brain activity during olfactory stimulation. This pilot study could be the first step towards a larger sample size experiment on olfactory stimulation. This experiment has been registered to UMIN Clinical Trials Registry with register ID : UMIN000051972 on 24/08/2023.

The human reward system encodes the subjective value of ideas during creative thinking

Creative thinking involves the evaluation of one's ideas in order to select the best one, but the cognitive and neural mechanisms underlying this evaluation remain unclear. Using a combination of creativity and rating tasks, this study demonstrates that individuals attribute subjective values to their ideas, as a relative balance of their originality and adequacy. This relative balance depends on individual preferences and predicts individuals' creative abilities. Using functional Magnetic Resonance Imaging, we find that the Default Mode and the Executive Control Networks respectively encode the originality and adequacy of ideas, and that the human reward system encodes their subjective value. Interestingly, the relative functional connectivity of the Default Mode and Executive Control Networks with the human reward system correlates with the relative balance of adequacy and originality in individuals' preferences. These results add valuation to the incomplete behavioral and neural accounts of creativity, offering perspectives on the influence of individual preferences on creative abilities.

Mice born to mothers fed a diet high in omega-6 fatty acids and low in omega-3 fatty acids during pregnancy exhibit various behavioral changes including impaired social behaviors and enhanced recognition memory

BACKGROUND

Modern dietary trends have led to an increase in foods that are relatively high in n-6 polyunsaturated fatty acids (PUFAs) and low in n-3 PUFAs. We previously reported that the offspring of mother mice that consumed a diet high in n-6 linoleic acid (LA) and low in n-3 α-linolenic acid (ALA), hereinafter called the LAhigh/ALAlow diet, exhibit behavioral abnormalities related to anxiety and feeding.

OBJECTIVE

We currently lack a comprehensive overview of the behavioral abnormalities in these offspring, which was investigated in this study.

METHODS

C57BL/6J virgin female mice at 11 weeks of age were fed either a control diet or the LAhigh/ALAlow diet, mated at 13 weeks of age, and maintained on their respective diet throughout gestation. At birth, the lactating mothers' diet was replaced with standard lab chow. After weaning, the offspring continued to receive standard lab chow, and both male and female offspring at 1-63 weeks of age were analyzed using a comprehensive behavioral test battery (n = 6-14 offspring/group and offspring in each group were derived from at least 3 independent litters).

RESULTS

Both male and female offspring exposed in utero to the LAhigh/ALAlow diet exhibited impaired social behaviors including the lower number of contacts with novel mice in the social interaction test (diet, F(1,15) = 9.807, P = 0.007, two-way analysis of variance (ANOVA)) and also showed enhanced recognition memory in the object location test (diet, F(1,36) = 6.779, P = 0.013, two-way ANOVA) compared to offspring exposed in utero to the control diet. In addition, compared to sex-matched controls, female offspring displayed hyperactivity in the open field test (F(1,36) = 6.097, P = 0.018, simple main effect analysis).

CONCLUSIONS

The maternal balance between dietary n-6 and n-3 PUFAs during pregnancy can have significant effects on the offspring's behaviors, lasting well into adulthood.

A cluster-randomised controlled feasibility trial evaluating the Cognitive Occupation-Based programme for people with Multiple Sclerosis (COB-MS)

INTRODUCTION

There is a high prevalence of cognitive difficulties in MS, but despite this, there are few programmes targeting cognition that focus on the ability to function well in everyday life. The Cognitive Occupation-Based programme for people with Multiple Sclerosis (COB-MS), an occupation-focused cognitive intervention, was developed to address this. It addresses both the functional difficulties and the wide-ranging symptoms that present in MS.

OBJECTIVE

Here we report on the results of a cluster-randomised controlled feasibility trial (ISRCTN11462710; registered 4th September 2019) evaluating the COB-MS in terms of feasibility and initial efficacy as a cognitive intervention for people with MS.

METHOD

The eight-session COB-MS intervention was delivered remotely by occupational therapists to participants with MS in the intervention group. Following the end of the trial the COB-MS was delivered to the wait-list control group. Data was collected from people with MS experiencing cognitive difficulties at baseline, post-intervention, 12-weeks, and 6-month follow-up. The primary outcome measure was the Goal Attainment Scaling at 12 weeks. Data was also collected in the domains of cognition, quality of life, and mood.

RESULTS

One hundred and eighteen people with MS and cognitive difficulties were randomised to either usual care (n = 60) or COB-MS intervention (n = 58). Ninety-four participants were retained at 6-month follow-up. The COB-MS was found to be feasible, including trial procedures and protocol. Data indicates that the COB-MS is accepted by participants and had positive impacts on daily life. Those allocated to the COB-MS group had a significant improvement in the primary outcome compared to the control condition. Progression criteria set for the feasibility trial have been met therefore further testing of the COB-MS at a definitive trial is supported by the results.

CONCLUSION

The results provide a strong basis for a pathway to a future definitive trial of COB-MS, with respect to both feasibility and preliminary, clinical efficacy.

TRIAL REGISTRATION

ISRCTN11462710 Date of registration: 4th September 2019.

Memory and automatic processing of valuable information in younger and older adults

People often engage in the selective remembering of valuable or important information, whether strategic and/or automatic. We examined potential age-related differences in the automatic processing of value during encoding on later remembering by presenting participants with words paired with point values (range: 1-10 twice or 1-20) to remember for a later test. On the first three lists, participants were told that they would receive the points associated with each word if they recalled it on the test (their goal was to maximize their score). On the last three lists, we told participants that all words were worth the same number of points if recalled on the tests, thus making the point value paired with each word meaningless. Results revealed that selective memory may be impaired in older adults using procedures with larger value ranges. Additionally, we demonstrated that the automatic effects of value may have a greater effect on younger adults relative to older adults, but there may be instances where older adults also exhibit these automatic effects. Finally, strategic and automatic processes may not be related within each learner, suggesting that these processes may rely on different cognitive mechanisms. This indicates that these processes could be underpinned by distinct cognitive mechanisms: strategic processes might engage higher-level cognitive operations like imagery, while automatic processes appear to be more perceptually driven.

Decoding Salience: A Functional Magnetic Resonance Imaging Investigation of Reward and Contextual Unexpectedness in Memory Encoding and Retrieval

The present study investigated the neuromodulatory substrates of salience processing and its impact on memory encoding and behaviour, with a specific focus on two distinct types of salience: reward and contextual unexpectedness. 46 Participants performed a novel task paradigm modulating these two aspects independently and allowing for investigating their distinct and interactive effects on memory encoding while undergoing high-resolution fMRI. By using advanced image processing techniques tailored to examine midbrain and brainstem nuclei with high precision, our study additionally aimed to elucidate differential activation patterns in subcortical nuclei in response to reward-associated and contextually unexpected stimuli, including distinct pathways involving in particular dopaminergic modulation. We observed a differential involvement of the ventral striatum, substantia nigra (SN) and caudate nucleus, as well as a functional specialisation within the subregions of the cingulate cortex for the two salience types. Moreover, distinct subregions within the SN in processing salience could be identified. Dorsal areas preferentially processed salience related to stimulus processing (of both reward and contextual unexpectedness), and ventral areas were involved in salience-related memory encoding (for contextual unexpectedness only). These functional specialisations within SN are in line with different projection patterns of dorsal and ventral SN to brain areas supporting attention and memory, respectively. By disentangling stimulus processing and memory encoding related to two salience types, we hope to further consolidate our understanding of neuromodulatory structures' differential as well as interactive roles in modulating behavioural responses to salient events.

Navigating the unknown: Leveraging self-information and diversity in partially observable environments

Reinforcement learning algorithms often struggle to learn in partially observable environments, where different states of the environment may appear identical. However, not all partially observable environments pose the same level of difficulty for learning. This work introduces the concept of dissonance distance, a metric that can estimate the difficulty of learning in such environments. We demonstrate that self-information, such as internal oscillations or memory of previous actions, can increase the dissonance distance and make learning easier in partially observable environments. Additionally, sensory occlusion may occur after learning was completed, leading to a lack of sufficient information and catastrophic failure. To address this, we propose a spatially layered architecture (SLA) inspired by the brain, which trains multiple policies in parallel for the same task. SLA can change the amount of external information processed at each timestep, providing an adaptive approach to handle the changing information in the environment state-space. We evaluate the effectiveness of our SLA method showing learnability and robustness against realistic noise and occlusion in sensory inputs for the partially observable Continuous Mountain Car environment. We hypothesize that multi-policy approaches like SLA might explain the complex dopamine dynamics in the brain that cannot be explained with the state of the art scalar Temporal Difference error.

Unconscious will as a neurobehavioral mechanism against adversity

Incentive salience theory both explains the directional component of motivation (in terms of cue attraction or "wanting") and its energetic component, as a function of the strength of cue attraction. This theory characterizes cue- and reward-triggered approach behavior. But it does not tell us how behavior can show enhanced vigor under reward uncertainty, when cues are inconsistent or resources hidden. Reinforcement theory is also ineffective in explaining enhanced vigor in case reward expectation is low or nil. This paper provides a neurobehavioral interpretation of effort in situations of adversity (which always include some uncertainty about outcomes) that is complementary to the attribution of incentive salience to environmental cues. It is argued that manageable environmental challenges activate an unconscious process of self-determination to achieve "wanted" actions. This unconscious process is referred to as incentive effort, which involves the hypothalamo-pituitary-adrenal (HPA) axis, noradrenaline, as well as striatal dopamine. Concretely, HPA-induced dopamine release would have the function to make effort-or effortful actions-"wanted" in a challenging context, in which the environmental cues are poorly predictive of reward-i.e., unattractive. Stress would only emerge in the presence of unmanageable challenges. It is hypothesized that incentive effort is the core psychological basis of will-and is, for this reason, termed "willing."

The Use of Extrinsic Performance Feedback and Reward to Enhance Upper Limb Motor Behavior and Recovery Post-Stroke: A Scoping Review

BACKGROUND

During post-stroke motor rehabilitation, patients often receive feedback from therapists or via rehabilitation technologies. Research suggests that feedback may benefit motor performance, skill acquisition, and action selection. However, there is no consensus on how extrinsic feedback should be implemented during stroke rehabilitation to best leverage specific neurobehavioral mechanisms to optimize recovery.

OBJECTIVE

To identify the existing evidence and research gaps regarding the effects of extrinsic feedback on upper extremity motor function in stroke survivors, and to map the evidence onto neurobehavioral concepts of motor performance, motor learning, and action selection.

METHODS

The MEDLINE, PsychInfo, EMBASE, and CINHAL databases were searched for relevant articles. A sequential screening process and data extraction were performed by 2 independent reviewers, and the results were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews guidelines.

RESULTS

A total of 29 studies were identified that met the criteria for inclusion. Beneficial effects of feedback were reported for clinical outcomes of rehabilitation interventions as well as motor performance, motor learning, and action selection post-stroke. Three studies showed that the addition of rewarding elements to positive performance feedback benefited learning or recovery.

CONCLUSIONS

Extrinsic feedback has the potential to improve outcomes of stroke rehabilitation through effects on motor performance, motor learning, or action selection. To understand how these specific neurobehavioral processes contribute to recovery, clinical trials should include more granular behavioral measures. Rewarding feedback may be particularly beneficial, but more research is needed regarding the specific implementation of feedback.

Play-mirth theory: a cognitive appraisal theory of humor

This work aims to introduce a general theory of humor elicitation and appreciation, the play-mirth theory, which is based on the cognitive appraisal perspective. Two experiments test the theory's central hypothesis: that is, to experience humor, one must interpret (a) a stimulus as a playful turn and (b) the turn as consistent with their motives. In the first experiment, 104 undergraduate students rated the appraisal determinants of successful and failed humor experiences that they recalled. In the second experiment, appraisals of playful turn (i.e., present or absent), situational state (i.e., motive-inconsistent/motive-consistent), and motivational state (punishment/reward) were manipulated. Overall, 150 undergraduate students were exposed to the manipulated stimuli and answered a structured questionnaire. The findings provide the first experimental evidence that two appraisals (i.e., playful turn and motive-consistency) do elicit humor. Play-mirth hypothesis sufficiently differentiates humorous from nonhumorous experiences as well as mirth from other positive emotions such as joy, and relief.

Disruption of network hierarchy pattern in bulimia nervosa reveals brain information integration disorder

The human brain works as a hierarchical organization that is a continuous axis spanning sensorimotor cortex to transmodal cortex (referring to cortex that integrates multimodal sensory information and participates in complex cognitive functions). Previous studies have demonstrated abnormalities in several specific networks that may account for their multiple behavioral deficits in patients with bulimia nervosa (BN), but whether and how the network hierarchical organization changes in BN remain unknown. This study aimed to investigate alterations of the hierarchy organization in BN network and their clinical relevance. Connectome gradient analyses were applied to depict the network hierarchy patterns of fifty-nine patients with BN and thirty-nine healthy controls (HCs). Then, we evaluated the network- and voxel-level gradient alterations of BN by comparing gradient values in each network and each voxel between patients with BN and HCs. Finally, the association between altered gradient values and clinical variables was explored. In the principal gradient, patients with BN exhibited reduced gradient values in dorsal attention network and increased gradient values in subcortical regions compared to HCs. In the secondary gradient, patients with BN showed decreased gradient values in ventral attention network and increased gradient values in limbic network. Regionally, the areas with altered principal or secondary gradient values in BN group were mainly located in transmodal networks, i.e., the default-mode and frontoparietal network. In BN group, the principal gradient values of right inferior frontal gyrus were negatively associated with external eating behavior. This study revealed the disordered network hierarchy patterns in patients with BN, which suggested a disturbance of brain information integration from attention network and subcortical regions to transmodal networks in these patients. These findings may provide insight into the neurobiological underpinnings of BN.

Tibial nerve stimulation in the management of primary sexual dysfunction in patients with multiple sclerosis: a pilot randomized control trial

INTRODUCTION

Sexual dysfunction (SD) is a common symptom that affects 40-90% of patients with multiple sclerosis (MS). Previous studies have highlighted the negative impact of sexual dysfunction in the mental health status and overall quality of life in patients with MS.

METHODS

The aim of this study was to examine the effects of transcutaneous tibial nerve stimulation (TTNS) in the primary SD symptoms in patients with MS. A total of 40 participants were randomized (1:1 ratio) to either TTNS or Sham group and received three 20 min sessions over the course of two months. Pre and post intervention SD was evaluated using the Multiple Sclerosis Intimacy Questionnaire (MISQ-15).

RESULTS

Statistically significant improvements in the aspects of primary sexual dysfunction were observed in the TTNS group pre-post intervention (specifically erectile function (for males)/vaginal lubrication (for females) (p < .001), orgasm quality and satisfaction for both male and female patients (p < .001), sexual desire (p < .05) and bladder related symptomatology (p < .005). In the sham group pre-post intervention, the only observed improvement was in the sexual desire aspect (p < .05). Post intervention the groups significantly differed erectile function/vaginal lubrication and orgasm quality and satisfaction (p < .05).

CONCLUSIONS

Our findings underline the efficacy of TTNS in improving primary SD symptoms as well as bladder problems in both male and female patients with MS. TTNS demonstrated significant improvement in the following domains: erectile function, vaginal lubrication, orgasm quality, satisfaction, bladder-related symptoms, and sexual desire.

Imaging of impulse control disorders in Parkinson's disease

Impulse control disorders (ICD) are frequent and cumbersome behavioral disorders in patients with Parkinson's disease (PD). Understanding their pathophysiological underpinnings is crucial. Molecular imaging using positron emission tomography (PET) and single-photon emission computed tomography (SPECT) clearly indicates preexisting vulnerability and abnormal sensitization of the pre- and postsynaptic dopaminergic system. Functional magnetic resonance imaging (fMRI) studies reveal abnormal connectivity within the reward system involving the ventral striatum and orbitofrontal cortex. These alterations pinpoint the dysfunction of reinforcement learning in ICD, which is biased toward the overvaluation of reward and underestimation of risk, and the deficit in inhibitory control mechanisms related to abnormal connectivity within and between the limbic and the associative and motor networks.

Dysregulation of dopamine neurotransmission in drug addicts: implications for criminal behavior and corrective interventions

Drug addiction often correlates with criminal behavior. When investigating criminal behavior among individuals grappling with drug addiction, it becomes crucial to scrutinize the influence of dopamine. Substances such as heroin, morphine, methamphetamine and other drugs can cause abnormal dopamine secretion when people are addicted to them, which promotes changes in the brain's reward circuit and emotional balance, thereby increasing susceptibility to criminal behavior. The pivotal role of dopamine within the reward pathway and its regulatory function in emotional processes exert profound influence on behavior following drug simulation. These influences are primarily manifested by three distinct attributes: a singular criminal motive and objective, lack of moral sense, and impulsive decision-making processes. Drawing upon the distinctive dopaminergic dynamics inherent in individuals afflicted by drug addiction, this study advocates for targeted corrective interventions. The preventive paradigm encompasses the cultivation of supportive community environments, the establishment of comprehensive databases, and providing legal education and protection, among other initiatives. In terms of treatment, along with judicial sanctions and protections, exercise regimens and psychotherapeutic interventions are advocated. The corrective endeavor necessitates a synergistic integration of community-based and legalistic frameworks. The objective is to furnish guiding principles for tackling criminal behavior precipitated by aberrant dopamine secretion, underpinned by a scientifically informed approach.

Neural reward system reflects individual value comparison strategy in cost-benefit decisions

A core assumption in decision neuroscience is that individuals decide between options by comparing option-specific subjective reward values. Psychological accounts challenge this view and suggest that decisions are better explained by comparisons between choice attributes than by comparisons between option-specific values, casting doubts on the interpretation of activation in the neural reward system as subjective value signals. Here, we provide neuroimaging and pharmacological evidence that value-related neural activity follows the value comparison strategy employed by an individual on the psychological level. Neural model comparisons reveal that activation in the striatum, rather than generally reflecting attribute-wise or option-wise value comparisons, reflects the value comparison strategy that provides the best explanation for an individual's choice behavior. Strikingly, manipulating activation in the dopaminergic reward system reveals that dopamine antagonism counteracts the engagement in an individual's dominant value comparison strategy. Together, our findings provide evidence for the biological plausibility of psychological accounts of decision making and emphasize the importance of neural model comparisons to prevent misinterpretations of brain activation.

Dynamic overrepresentation of accumbal cues in food- and opioid-seeking rats after prenatal THC exposure

The increasing prevalence of cannabis use during pregnancy has raised medical concerns, primarily related to Δ9-tetrahydrocannabinol (THC), which readily crosses the placenta and affects fetal brain development. Previous research has identified dopaminergic alterations related to maternal THC consumption. However, the consequences that prenatal cannabis exposure (PCE) has on striatum-based processing during reward pursuit have not been determined. Here, we characterize PCE rats during food or opioid-maintained reward seeking. We find that the supramotivational phenotype of PCE rats is independent of value-based processing and is instead related to augmented reinforcing efficiency of opioid rewards. Our findings reveal that prenatal THC exposure leads to increased cue-evoked dopamine responses and an overrepresentation of effort-driven striatal encoding patterns. Recapitulating clinical findings, drug-related PCE adaptations were more pronounced in males, who showed increased vulnerability for relapse. Collectively, these findings indicate that prenatal THC exposure in male rats engenders a pronounced neurodevelopmental susceptibility to addiction-like disorders.

Molecular and Environmental Determinants of Addictive Substances

Knowledge about determinants of addiction in people taking addictive substances is poor and needs to be supplemented. The novelty of this paper consists in the analysis of innovative aspects of current research about relationships between determinants of addiction in Polish patients taking addictive substances and rare available data regarding the relationships between these factors from studies from recent years from other environments, mainly in Europe, and on the development of genetic determinants of physiological responses. We try to explain the role of the microelements Mn, Fe, Cu, Co, Zn, Cr, Ni, Tl, Se, Al, B, Mo, V, Sn, Sb, Ag, Sr, and Ba, the toxic metals Cd, Hg, As, and Pb, and the rare earth elements Sc, La, Ce, Pr, Eu, Gd, and Nd as factors that may shape the development of addiction to addictive substances or drugs. The interactions between factors (gene polymorphism, especially ANKK1 (TaqI A), ANKK1 (Taq1 A-CT), DRD2 (TaqI B, DRD2 Taq1 B-GA, DRD2 Taq1 B-AA, DRD2-141C Ins/Del), and OPRM1 (A118G)) in patients addicted to addictive substances and consumption of vegetables, consumption of dairy products, exposure to harmful factors, and their relationships with physiological responses, which confirm the importance of internal factors as determinants of addiction, are analyzed, taking into account gender and region. The innovation of this review is to show that the homozygous TT mutant of the ANKK1 TaqI A polymorphism rs 1800497 may be a factor in increased risk of opioid dependence. We identify a variation in the functioning of the immune system in addicted patients from different environments as a result of the interaction of polymorphisms.

Exploring gender differences in the relations between passion, grit and flow

The current study sought to explore the association between passion, grit and flow and study possible differences between the genders in a sample of 529 adults in Norway. There were 323 females and 204 males. Passion was measured with the passion scale, Grit with the Grit-S scale, and flow with the General Flow Proneness scale. Results indicate that males score significantly higher on passion and flow, whereas females score higher on grit. Additionally, there were significant correlations between these constructs which differed between the sexes. Both passion and grit have been demonstrated to have a positive relationship with flow. To investigate which factor that has the strongest association with flow. We performed a multiple regression analysis. The results suggested that a model with passion and grit explained 33 % of the variation in Flow for the whole sample. Grit had the strongest relationship with flow while controlling for passion (β = 0.44). Passion had a significant and positive relationship with Flow while controlling for grit (β = 0.26). We further investigated the relative importance of passion and grit in predicting flow. Grit (lgm =0.67) was approximately twice as important as passion (lgm = 0.32) in predicting flow. These findings suggest that grit is a more critical factor in achieving flow, offering theoretical insights into how these constructs contribute to life satisfaction, well-being, learning, and achievement.

Amplifying Cognitive Functions in Amateur Esports Athletes: The Impact of Short-Term Virtual Reality Training on Reaction Time, Motor Time, and Eye-Hand Coordination

OBJECTIVES

Electronic sports (esports) have grown into a major competitive field in today's digital landscape, attracting the interest of established companies and evolving into a fast-growing industry. Cognitive function, including reaction time, motor time, and eye-hand coordination, plays a crucial role in e-athlete performance. This study aims to examine the impact of VR training on these cognitive functions in amateur e-athletes.

METHODS

The study involved 66 amateur e-athletes (45 men and 21 women, aged 19-41, with a mean age of 23.96 ± 3.90 years) who reported active, non-professional involvement in esports. Participants were randomly assigned to an experimental group (E) (n = 32) and a control group (C) (n = 34), with initial comparisons confirming no significant differences in daily gaming habits, esports experience, or age between groups. The E group completed 15-minute daily training sessions using the VR game Beat Saber over eight consecutive days.

RESULTS

The results demonstrated that VR training significantly improved eye-hand coordination in the experimental group, although there were no notable effects on reaction time or motor time.

CONCLUSIONS

These findings suggest that VR training may be an effective method to enhance certain cognitive functions, specifically eye-hand coordination, among amateur e-athletes. This could offer a valuable approach for performance improvement in this rapidly growing field.

A generic self-learning emotional framework for machines

In nature, intelligent living beings have developed emotions to modulate their behavior as a fundamental evolutionary advantage. However, researchers seeking to endow machines with this advantage lack a clear theory from cognitive neuroscience describing emotional elicitation from first principles, namely, from raw observations to specific affects. As a result, they often rely on case-specific solutions and arbitrary or hard-coded models that fail to generalize well to other agents and tasks. Here we propose that emotions correspond to distinct temporal patterns perceived in crucial values for living beings in their environment (like recent rewards, expected future rewards or anticipated world states) and introduce a fully self-learning emotional framework for Artificial Intelligence agents convincingly associating them with documented natural emotions. Applied in a case study, an artificial neural network trained on unlabeled agent's experiences successfully learned and identified eight basic emotional patterns that are situationally coherent and reproduce natural emotional dynamics. Validation through an emotional attribution survey, where human observers rated their pleasure-arousal-dominance dimensions, showed high statistical agreement, distinguishability, and strong alignment with experimental psychology accounts. We believe that the framework's generality and cross-disciplinary language defined, grounded on first principles from Reinforcement Learning, may lay the foundations for further research and applications, leading us toward emotional machines that think and act more like us.

The subjective value of social context in people who use cannabis

Disordered cannabis use is linked to social problems, which could be explained by a subjective devaluation of nondrug social contexts and/or an overvaluation of cannabis-paired options relative to nondrug alternatives. To examine these hypotheses, measures to assess the subjective value of social- and/or cannabis-paired contexts were collected in people who use cannabis (n = 85) and controls (n = 98) using crowdsourcing methods. Measures included a cued concurrent choice task that presented two images (cannabis, social, social cannabis, and neutral images) paired with monetary options, hypothetical purchase tasks that included access to social parties with and without a cannabis "open bar," and the Social Anhedonia Scale (SAS). Little evidence was found to suggest that the cannabis group undervalued social contexts. People who used cannabis demonstrated a preference for social- versus neutral-cued options, and no preference for cannabis- versus social cannabis-cued options on the choice task. In addition, social party demand and SAS scores did not differ between groups. In contrast, we observed evidence for an overvaluation of cannabis context in people who use cannabis, including preference for social cannabis- versus social-cued options, and more disadvantageous choices for cannabis-cued options on the choice task, as well as more intense and inelastic demand for the social cannabis party compared to the social party. These results suggest that social problems associated with cannabis use could be at least partially explained by an overvaluation of cannabis-paired options, rather than devaluation of nondrug social-paired options, in the value calculations underlying drug use decisions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Passion and grit in individuals with high levels of growth mindset are different than in individuals who have low growth mindset

The main aim of the study was to investigate whether passion and grit varied in individuals with distinct levels of growth mindset. From an original sample of 1548 participants in the age 13 to 77 years, two groups with the 5 % highest scoring and the 5 % lowest scoring on growth mindset, respectively, were compared on their scores in passion and grit. Participants completed as a measure of Mindset the Theories of intelligence Scale (TIS). Grit-S scale was used to assess grit and to assess passion the eight item Passion Scale was used. Findings displayed that the growth mindset group with low scoring had significantly lower score in passion and grit than the growth mindset group with high scoring, indicating that adults with low growth mindset shows lower levels of passion and grit related to their peers with a high-level score. These results may probable be significant for better understanding of the relationship between these constructs positively related to life satisfaction, well-being, achievement, and learning. Additionally, acquiring a better picture of what indicate individuals with different levels of growth mindset can increase our comprehension of how to increase motivation, pursue long-term goals and maintain effort in different groups. It can be argued that growth mindset should be all encompassing in our society. Both in schools, sports, working life and within the walls of the family.

Adaptive circuits for action and value information in rodent operant learning

Operant learning is a behavioral paradigm where animals learn to associate their actions with consequences, adapting their behavior accordingly. This review delves into the neural circuits that underpin operant learning in rodents, emphasizing the dynamic interplay between neural pathways, synaptic plasticity, and gene expression changes. We explore the cortico-basal ganglia circuits, highlighting the pivotal role of dopamine in modulating these pathways to reinforce behaviors that yield positive outcomes. We include insights from recent studies, which reveals the intricate roles of midbrain dopamine neurons in integrating action initiation and reward feedback, thereby enhancing movement-related activities in the dorsal striatum. Additionally, we discuss the molecular diversity of striatal neurons and their specific roles in reinforcement learning. The review also covers advances in transcriptome analysis techniques, such as single-cell RNA sequencing, which have provided deeper insights into the gene expression profiles associated with different neuronal populations during operant learning.

Vagus nerve stimulation for stroke rehabilitation: Neural substrates, neuromodulatory effects and therapeutic implications

Paired vagus nerve stimulation (VNS) has emerged as a promising strategy to potentiate recovery after neurological injury. This approach, which combines short bursts of electrical stimulation of the vagus nerve with rehabilitation exercises, received approval from the US Food and Drug Aministration in 2021 as the first neuromodulation-based therapy for chronic stroke. Because this treatment is increasingly implemented in clinical practice, there is a need to take stock of what we know about this approach and what we have yet to learn. Here, we provide a survey on the foundational basis of VNS therapy for stroke and offer insight into the mechanisms that underlie potentiated recovery, focusing on the principles of neuromodulatory reinforcement. We discuss the current state of observations regarding synaptic reorganization in motor networks that are enhanced by VNS, and we propose other prospective loci of neuromodulation that should be evaluated in the future. Finally, we highlight the future opportunities and challenges to be faced as this approach is increasingly translated to clinical use. Collectively, a clearer understanding of the mechanistic basis of VNS therapy may reveal ways to maximize its benefits.

Independent operations of appetitive and aversive conditioning systems lead to simultaneous production of conflicting memories in an insect

Pavlovian conditioning is a ubiquitous form of associative learning that enables animals to remember appetitive and aversive experiences. Animals possess appetitive and aversive conditioning systems that memorize and retrieve appetitive and aversive experiences. Here, we addressed a question of whether integration of competing appetitive and aversive information takes place during the encoding of the experience or during memory retrieval. We developed novel experimental procedures to address this question using crickets (Gryllus bimaculatus), which allowed selective blockade of the expression of appetitive and aversive memories by injecting octopamine and dopamine receptor antagonists. We conditioned an odour (conditioned stimulus 1, CS1) with water and then with sodium chloride solution. At 24 h after conditioning, crickets retained both appetitive and aversive memories, and the memories were integrated to produce a conditioned response (CR). Importantly, when a visual pattern (CS2) was conditioned with CS1, appetitive and aversive memories formed simultaneously. This indicates that appetitive and aversive second-order conditionings are achieved at the same time. The memories were integrated for producing a conditioned response. We conclude that appetitive and aversive conditioning systems operate independently to form parallel appetitive and aversive memories, which compete to produce learned behaviour in crickets.

Neural Hyperresponsivity During the Anticipation of Tangible Social and Nonsocial Rewards in Autism Spectrum Disorder: A Concurrent Neuroimaging and Facial Electromyography Study

BACKGROUND

Atypical anticipation of social reward has been shown to lie at the core of the social challenges faced by individuals with autism spectrum disorder (ASD). However, previous research has yielded inconsistent results and has often overlooked crucial characteristics of stimuli. Here, we investigated ASD reward processing using social and nonsocial tangible stimuli, carefully matched on several key dimensions.

METHODS

We examined the anticipation and consumption of social (interpersonal touch) and nonsocial (flavored milk) rewards in 25 high-functioning individuals with ASD and 25 neurotypical adult individuals. In addition to subjective ratings of wanting and liking, we measured physical energetic expenditure to obtain the rewards, brain activity with neuroimaging, and facial reactions through electromyography on a trial-by-trial basis.

RESULTS

Participants with ASD did not exhibit reduced motivation for social or nonsocial rewards; their subjective ratings, motivated efforts, and facial reactions were comparable to those of neurotypical participants. However, anticipation of higher-value rewards increased neural activation in lateral parietal cortices, sensorimotor regions, and the orbitofrontal cortex. Moreover, participants with ASD exhibited hyperconnectivity between frontal medial regions and occipital regions and the thalamus.

CONCLUSIONS

Individuals with ASD who experienced rewards with tangible characteristics, whether social or nonsocial, displayed typical subjective and objective motivational and hedonic responses. Notably, the observed hyperactivations in sensory and attentional nodes during anticipation suggest atypical sensory overprocessing of forthcoming rewards rather than decreased reward value. While these atypicalities may not have manifested in observable behavior here, they could impact real-life social interactions that require nuanced predictions, potentially leading to the misperception of reduced interest in rewarding social stimuli in ASD.

Neural Responses to Auditory Food Stimuli Following Cognitive Behavioral Therapy for Binge-Eating Disorder

OBJECTIVE

Adults with binge-eating disorder (BED), compared with those without BED, demonstrate higher blood-oxygen-level-dependent (BOLD) response to food cues in reward-related regions of the brain. It is not known whether cognitive behavioral therapy (CBT) can reverse this reward system hyperactivation. This randomized controlled trial (RCT) assessed changes in BOLD response to binge-eating cues following CBT versus wait-list control (WLC).

METHOD

Females with BED (N = 40) were randomized to CBT or WLC. Participants completed assessments at baseline and 16 weeks including measures of eating and appetite and functional magnetic resonance imaging (fMRI) to measure BOLD response while listening to personalized scripts of binge-eating and neutral-relaxing cues. Data were analyzed using general linear models with mixed effects.

RESULTS

Overall retention rate was 87.5%. CBT achieved significantly greater reductions in binge-eating episodes than WLC (mean ± standard error decline of 14.6 ± 2.7 vs. 5.7 ± 2.8 episodes in the past 28 days, respectively; p = 0.03). CBT and WLC did not differ significantly in changes in neural responses to binge-eating stimuli during the fMRI sessions. Compared with WLC, CBT had significantly greater improvements in reward-based eating drive, disinhibition, and hunger as assessed by questionnaires (ps < 0.05).

DISCUSSION

CBT was effective in reducing binge eating, but, contrary to our hypothesis, CBT did not improve BOLD response to auditory binge-eating stimuli in reward regions of the brain. Further studies are needed to assess mechanisms underlying improvements with CBT for BED.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03604172.

Physical activity promotes brain development through serotonin during early childhood

Early childhood serves as a critical period for neural development and skill acquisition when children are extremely susceptible to the external environment and experience. As a crucial experiential stimulus, physical activity is believed to produce a series of positive effects on brain development, such as cognitive function, social-emotional abilities, and psychological well-being. The World Health Organization recommends that children engage in sufficient daily physical activity, which has already been strongly advocated in the practice of preschool education. However, the mechanisms by which physical activity promotes brain development are still unclear. The role of neurotransmitters, especially serotonin, in promoting brain development through physical activity has received increasing attention. Physical activity has been shown to stimulate the secretion of serotonin by increasing the bioavailability of free tryptophan and enriching the diversity of gut microbiota. Due to its important role in modulating neuronal proliferation, differentiation, synaptic morphogenesis, and synaptic transmission, serotonin can regulate children's explicit cognitive and social interaction behavior in the early stages of life. Therefore, we hypothesized that serotonin emerges as a pivotal transmitter that mediates the relationship between physical activity and brain development during early childhood. Further systematic reviews and meta-analyses are needed to specifically explore whether the type, intensity, dosage, duration, and degree of voluntariness of PA may affect the role of serotonin in the relationship between physical activity and brain function. This review not only helps us understand the impact of exercise on development but also provides a solid theoretical basis for increasing physical activity during early childhood.

Chronic Cocaine Use and Parkinson's Disease: An Interpretative Model

Over the years, the growing "epidemic" spread of cocaine use represents a crucial public health and social problem worldwide. According to the 2023 World Drug Report, 0.4% of the world's population aged 15 to 64 report using cocaine; this number corresponds to approximately 24.6 million cocaine users worldwide and approximately 1 million subjects with cocaine use disorder (CUD). While we specifically know the short-term side effects induced by cocaine, unfortunately, we currently do not have exhaustive information about the medium/long-term side effects of the substance on the body. The scientific literature progressively highlights that the chronic use of cocaine is related to an increase in cardio- and cerebrovascular risk and probably to a greater incidence of psychomotor symptoms and neurodegenerative processes. Several studies have highlighted an increased risk of antipsychotic-induced extrapyramidal symptoms (EPSs) in patients with psychotic spectrum disorders comorbid with psychostimulant abuse. EPSs include movement dysfunction such as dystonia, akathisia, tardive dyskinesia, and characteristic symptoms of Parkinsonism such as rigidity, bradykinesia, and tremor. In the present paper, we propose a model of interpretation of the neurobiological mechanisms underlying the hypothesized increased vulnerability in chronic cocaine abusers to neurodegenerative disorders with psychomotor symptoms. Specifically, we supposed that the chronic administration of cocaine produces significant neurobiological changes, causing a complex dysregulation of various neurotransmitter systems, mainly affecting subcortical structures and the dopaminergic pathways. We believe that a better understanding of these cellular and molecular mechanisms involved in cocaine-induced neuropsychotoxicity may have helpful clinical implications and provide targets for therapeutic intervention.

Neuronal Activity in the Gustatory Cortex during Economic Choice

An economic choice entails computing and comparing the values of individual offers. Offer values are represented in the orbitofrontal cortex (OFC)-an area that participates in value comparison-but it is unknown where offer values are computed in the first place. One possibility is that this computation takes place in OFC. Alternatively, offer values might be computed upstream of OFC. For choices between edible goods, a primary candidate is the gustatory region of the anterior insula (gustatory cortex, GC). Here we recorded from the GC of male rhesus monkeys choosing between different juice types. As a population, neurons in GC represented the flavor, the quantity, and the subjective value of the juice chosen by the animal. These variables were represented by distinct groups of cells and with different time courses. Specifically, chosen value signals emerged shortly after offer presentation, while neurons encoding the chosen juice and the chosen quantity peaked after juice delivery. Surprisingly, neurons in GC did not represent individual offer values in a systematic way. In a computational sense, the variables encoded in GC follow the process of value comparison. Thus our results argue against the hypothesis that offer values are computed in GC. At the same time, signals representing the subjective value of the expected reward indicate that responses in GC are not purely sensory. Thus neuronal responses in GC appear consummatory in nature.

Different mechanisms of contextual inference govern associatively learned and sensory-evoked postural responses

Human standing balance relies on the continuous monitoring and integration of sensory signals to infer our body's motion and orientation within the environment. However, when sensory information is no longer contextually relevant to balancing the body (e.g., when sensory and motor signals are incongruent), sensory-evoked balance responses are rapidly suppressed, much earlier than any conscious perception of changes in balance control. Here, we used a robotic balance simulator to assess whether associatively learned postural responses are similarly modulated by sensorimotor incongruence and contextual relevance to postural control. Twenty-nine participants in three groups were classically conditioned to generate postural responses to whole-body perturbations when presented with an initially neutral sound cue. During catch and extinction trials, participants received only the auditory stimulus but in different sensorimotor states corresponding to their group: 1) during normal active balance, 2) while immobilized, and 3) throughout periods where the computer subtly removed active control over balance. In the balancing and immobilized states, conditioned responses were either evoked or suppressed, respectively, according to the (in)ability to control movement. Following the immobilized state, conditioned responses were renewed when balance was restored, indicating that conditioning was retained but only expressed when contextually relevant. In contrast, conditioned responses persisted in the computer-controlled state even though there was no causal relationship between motor and sensory signals. These findings suggest that mechanisms responsible for sensory-evoked and conditioned postural responses do not share a single, central contextual inference and assessment of their relevance to postural control, and may instead operate in parallel.

The Role of the Human Cerebellum for Learning from and Processing of External Feedback in Non-Motor Learning: A Systematic Review

This review aimed to systematically identify and comprehensively review the role of the cerebellum in performance monitoring, focusing on learning from and on processing of external feedback in non-motor learning. While 1078 articles were screened for eligibility, ultimately 36 studies were included in which external feedback was delivered in cognitive tasks and which referenced the cerebellum. These included studies in patient populations with cerebellar damage and studies in healthy subjects applying neuroimaging. Learning performance in patients with different cerebellar diseases was heterogeneous, with only about half of all patients showing alterations. One patient study using EEG demonstrated that damage to the cerebellum was associated with altered neural processing of external feedback. Studies assessing brain activity with task-based fMRI or PET and one resting-state functional imaging study that investigated connectivity changes following feedback-based learning in healthy participants revealed involvement particularly of lateral and posterior cerebellar regions in processing of and learning from external feedback. Cerebellar involvement was found at different stages, e.g., during feedback anticipation and following the onset of the feedback stimuli, substantiating the cerebellum's relevance for different aspects of performance monitoring such as feedback prediction. Future research will need to further elucidate precisely how, where, and when the cerebellum modulates the prediction and processing of external feedback information, which cerebellar subregions are particularly relevant, and to what extent cerebellar diseases alter these processes.

Why creatives don't find the oddball odd: Neural and psychological evidence for atypical salience processing

Creativity has previously been linked with various attentional phenomena, including unfocused or broad attention. Although this has typically been interpreted through an executive functioning framework, such phenomena may also arise from atypical incentive salience processing. Across two studies, we examine this hypothesis both neurally and psychologically. First we examine the relationship between figural creativity and event-related potentials during an audio-visual oddball task, finding that rater creativity of drawings is associated with a diminished P300 response at midline electrodes, while abstractness and elaborateness of the drawings is associated with an altered distribution of the P300 over posterior electrodes. These findings support the notion that creativity may involve an atypical attribution of salience to prominent information. We further explore the incentive salience hypothesis by examining relationships between creativity and a psychological indicator of incentive salience captured by participants' ratings of enjoyment (liking) and their motivation to pursue (wanting) diverse real world rewards, as well as their positive spontaneous thoughts about those rewards. Here we find enhanced motivation to pursue activities as well as a reduced relationship between the overall tendency to enjoy rewards and the tendency to pursue them. Collectively, these findings indicate that creativity may be associated with atypical allocation of attentional and motivational resources to novel and rewarding information, potentially allowing more types of information access to attentional resources and motivating more diverse behaviors. We discuss the possibility that salience attribution in creatives may be less dependent on task-relevance or hedonic pleasure, and suggest that atypical salience attribution may represent a trait-like feature of creativity.

Diffusion Magnetic Resonance Imaging and Human Reward System Research: A Bibliometric Analysis and Visualisation of Current Research Trends

Background

The human reward system has been extensively studied using neuroimaging. This bibliometric analysis aimed to determine the global trend in diffusion magnetic resonance imaging (dMRI) and human reward research in terms of the number of documents, the most active countries and their collaborating countries, the top journals and institutions, the most prominent authors and most cited articles, and research hotspots.

Methods

The research datasets were acquired from the Scopus database. The search terms used were 'reward' AND 'human' AND 'diffusion imaging' OR 'diffusion tensor imaging' OR 'diffusion MRI' OR 'diffusion-weighted imaging' OR 'tractography' in the abstract, article title and keywords. A total of 336 publications were analysed using Harzing's Publish or Perish and VOSviewer software.

Results

The results revealed an upward trend in the number of publications with the highest number of articles in 2020 and 2022. Most publications were limited to countries, authors, and institutions in the USA, China and Europe. Bracht, Coenen, Wiest, Federspiel and Feng were among the top authors from Switzerland, Germany and the UK. Neuroimage, Neuroimage Clinical, Frontiers in Human Neuroscience, Human Brain Mapping, and the Journal of Neuroscience were the top journals. Among the top articles, six were reviews and four were original articles, while the top keywords in human reward research were 'diffusion MRI', 'adolescence', 'depression' and 'reward-related brain areas'.

Conclusion

These findings may serve as researchers' references to find collaborative authors, relevant journals, cooperative countries/institutions, and hot topics related to dMRI and reward research.

Non-invasive stimulation of the human striatum disrupts reinforcement learning of motor skills

Reinforcement feedback can improve motor learning, but the underlying brain mechanisms remain underexplored. In particular, the causal contribution of specific patterns of oscillatory activity within the human striatum is unknown. To address this question, we exploited a recently developed non-invasive deep brain stimulation technique called transcranial temporal interference stimulation (tTIS) during reinforcement motor learning with concurrent neuroimaging, in a randomized, sham-controlled, double-blind study. Striatal tTIS applied at 80 Hz, but not at 20 Hz, abolished the benefits of reinforcement on motor learning. This effect was related to a selective modulation of neural activity within the striatum. Moreover, 80 Hz, but not 20 Hz, tTIS increased the neuromodulatory influence of the striatum on frontal areas involved in reinforcement motor learning. These results show that tTIS can non-invasively and selectively modulate a striatal mechanism involved in reinforcement learning, expanding our tools for the study of causal relationships between deep brain structures and human behaviour.

Time-scale invariant contingency yields one-shot reinforcement learning despite extremely long delays to reinforcement

Reinforcement learning inspires much theorizing in neuroscience, cognitive science, machine learning, and AI. A central question concerns the conditions that produce the perception of a contingency between an action and reinforcement-the assignment-of-credit problem. Contemporary models of associative and reinforcement learning do not leverage the temporal metrics (measured intervals). Our information-theoretic approach formalizes contingency by time-scale invariant temporal mutual information. It predicts that learning may proceed rapidly even with extremely long action-reinforcer delays. We show that rats can learn an action after a single reinforcement, even with a 16-min delay between the action and reinforcement (15-fold longer than any delay previously shown to support such learning). By leveraging metric temporal information, our solution obviates the need for windows of associability, exponentially decaying eligibility traces, microstimuli, or distributions over Bayesian belief states. Its three equations have no free parameters; they predict one-shot learning without iterative simulation.

Beta activity in human anterior cingulate cortex mediates reward biases

The rewards that we get from our choices and actions can have a major influence on our future behavior. Understanding how reward biasing of behavior is implemented in the brain is important for many reasons, including the fact that diminution in reward biasing is a hallmark of clinical depression. We hypothesized that reward biasing is mediated by the anterior cingulate cortex (ACC), a cortical hub region associated with the integration of reward and executive control and with the etiology of depression. To test this hypothesis, we recorded neural activity during a biased judgment task in patients undergoing intracranial monitoring for either epilepsy or major depressive disorder. We found that beta (12-30 Hz) oscillations in the ACC predicted both associated reward and the size of the choice bias, and also tracked reward receipt, thereby predicting bias on future trials. We found reduced magnitude of bias in depressed patients, in whom the beta-specific effects were correspondingly reduced. Our findings suggest that ACC beta oscillations may orchestrate the learning of reward information to guide adaptive choice, and, more broadly, suggest a potential biomarker for anhedonia and point to future development of interventions to enhance reward impact for therapeutic benefit.

Common neural dysfunction of economic decision-making across psychiatric conditions

Adaptive decision-making, which is often impaired in various psychiatric conditions, is essential for well-being. Recent evidence has indicated that decision-making capacity in multiple tasks could be accounted for by latent dimensions, enlightening the question of whether there is a common disruption of brain networks in economic decision-making across psychiatric conditions. Here, we addressed the issue by combining activation/lesion network mapping analyses with a transdiagnostic brain imaging meta-analysis. Our findings indicate that there were transdiagnostic alterations in the thalamus and ventral striatum during the decision or outcome stage of decision-making. The identified regions represent key nodes in a large-scale network, which is composed of multiple heterogeneous brain regions and plays a causal role in motivational functioning. The findings suggest that disturbances in the network associated with emotion- and reward-related processing play a key role in dysfunctions of decision-making observed in various psychiatric conditions. This study provides the first meta-analytic evidence of common neural alterations linked to deficits in economic decision-making.

Repeated binge-like eating episodes in female rats alter adenosine A2A and dopamine D2 receptor genes regulation in the brain reward system

OBJECTIVE

Binge-eating disorder is an eating disorder characterized by recurrent binge-eating episodes, during which individuals consume excessive amounts of highly palatable food (HPF) in a short time. This study investigates the intricate relationship between repeated binge-eating episode and the transcriptional regulation of two key genes, adenosine A2A receptor (A2AAR) and dopamine D2 receptor (D2R), in selected brain regions of rats.

METHOD

Binge-like eating behavior on HPF was induced through the combination of food restrictions and frustration stress (15 min exposure to HPF without access to it) in female rats, compared to control rats subjected to only restriction or only stress or none of these two conditions. After chronic binge-eating episodes, nucleic acids were extracted from different brain regions, and gene expression levels were assessed through real-time quantitative PCR. The methylation pattern on genes' promoters was investigated using pyrosequencing.

RESULTS

The analysis revealed A2AAR upregulation in the amygdala and in the ventral tegmental area (VTA), and D2R downregulation in the nucleus accumbens in binge-eating rats. Concurrently, site-specific DNA methylation alterations at gene promoters were identified in the VTA for A2AAR and in the amygdala and caudate putamen for D2R.

DISCUSSION

The alterations on A2AAR and D2R genes regulation highlight the significance of epigenetic mechanisms in the etiology of binge-eating behavior, and underscore the potential for targeted therapeutic interventions, to prevent the development of this maladaptive feeding behavior. These findings provide valuable insights for future research in the field of eating disorders.

PUBLIC SIGNIFICANCE

Using an animal model with face, construct, and predictive validity, in which cycles of food restriction and frustration stress evoke binge-eating behavior, we highlight the significance of epigenetic mechanisms on adenosine A2A receptor (A2AAR) and dopamine D2 receptor (D2R) genes regulation. They could represent new potential targets for the pharmacological management of eating disorders characterized by this maladaptive feeding behavior.

Behavioral Activation and Brain Network Changes in Depression

Behavioral activation (BA) is a well-established method of evidence-based treatment for depression. There are clear links between the neural mechanisms underlying reward processing and BA treatment for depressive symptoms, including anhedonia; however, integrated interpretations of these two domains are lacking. Here we examine brain imaging studies involving BA treatments to investigate how changes in brain networks, including the reward networks, mediate the therapeutic effects of BA, and whether brain circuits are predictors of BA treatment responses. Increased activation of the prefrontal and subcortical regions associated with reward processing has been reported after BA treatment. Activation of these regions improves anhedonia. Conversely, some studies have found decreased activation of prefrontal regions after BA treatment in response to cognitive control stimuli in sad contexts, which indicates that the therapeutic mechanism of BA may involve disengagement from negative or sad contexts. Furthermore, the decrease in resting-state functional connectivity of the default-mode network after BA treatment appears to facilitate the ability to counteract depressive rumination, thereby promoting enjoyable and valuable activities. Conflicting results suggest that an intact neural response to rewards or defective reward functioning is predictive of the efficacy of BA treatments. Increasing the benefits of BA treatments requires identification of the unique individual characteristics determining which of these conflicting findings are relevant for the personalized treatment of each individual with depression.

Falling into the trap: A study of the cognitive neural mechanisms of immediate rewards impact on consumer attitudes toward forwarding perk advertisements

In the context of digital marketing, consumers often express aversion to perk advertisements yet find it challenging to resist the temptation and forward it, resulting in inconsistent attitudes and behaviors. This study, based on the Associative Propositional Evaluation model and the Confirmation Bias theory, utilizes event-related potential experiments to identify the interactive impacts of immediate rewards and information diagnosticity in advertisements on consumer attitude change in specific contexts. The research findings indicate that when rewards were present, information diagnosticity positively influences attitude change and the willingness to forward. However, when rewards were absent, the impact of information diagnosticity on attitude change and the willingness to forward is not significant, and neuroscientific evidence supports these findings. Theoretically, this study extends the research perspective on attitude change in online advertising contexts and broadens the application of the Associative Propositional Evaluation model in the field of consumer attitude change towards advertisements. In practice, this research holds significant guiding value for constraining platform manipulation of consumer cognitive behaviors, guiding the healthy development of platform economics, and promoting digital technology ethics.

Bilingualism Predicts Affective Theory of Mind in Autistic Adults

PURPOSE

This study examined the impact of bilingualism on affective theory of mind (ToM) and social prioritization (SP) among autistic adults compared to neurotypical comparison participants.

METHOD

Fifty-two (25 autistic, 27 neurotypical) adult participants (ages 21-35 years) with varying second language (L2) experience, ranging from monolingual to bilingual, completed an affective ToM task. A subset of this sample also completed a dynamic eye-tracking task designed to capture differences in time spent looking at social aspects of a scene (SP). Four language groups were compared on task performance (monolingual autism and neurotypical, bilingual autism and neurotypical), followed by analyses examining the contribution of L2 experience, autism characteristics, and social face prioritization on affective ToM, controlling for verbal IQ. Finally, we conducted an analysis to identify the contribution of SP on affective ToM when moderated by autism status and L2 experience, controlling for verbal IQ.

RESULTS

The monolingual autism group performed significantly worse than the other three groups (bilingual autism, monolingual neurotypical, and bilingual neurotypical) on the affective ToM task; however, there were no significant differences between the bilingual autism group compared to the monolingual and bilingual neurotypical groups. For autistic individuals, affective ToM capabilities were positively associated with both verbal IQ and L2 experience but did not relate to autism characteristics or SP during eye tracking. Neurotypical participants showed greater SP during the eye-tracking task, and SP did not relate to L2 or autism characteristics for autistic individuals. SP and verbal IQ predicted affective ToM performance across autism and neurotypical groups, but this relationship was moderated by L2 experience; SP more strongly predicted affective ToM performance among participants with lower L2 experience (e.g., monolingual) and had less of an impact for those with higher L2 experience.

CONCLUSION

This study provides support for a bilingual advantage in affective ToM for autistic individuals.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25696083.

Convergence of oxytocin and dopamine signalling in neuronal circuits: Insights into the neurobiology of social interactions across species

Social behaviour is essential for animal survival, and the hypothalamic neuropeptide oxytocin (OXT) critically impacts bonding, parenting, and decision-making. Dopamine (DA), is released by ventral tegmental area (VTA) dopaminergic neurons, regulating social cues in the mesolimbic system. Despite extensive exploration of OXT and DA roles in social behaviour independently, limited studies investigate their interplay. This narrative review integrates insights from human and animal studies, particularly rodents, emphasising recent research on pharmacological manipulations of OXT or DA systems in social behaviour. Additionally, we review studies correlating social behaviour with blood/cerebral OXT and DA levels. Behavioural facets include sociability, cooperation, pair bonding and parental care. In addition, we provide insights into OXT-DA interplay in animal models of social stress, autism, and schizophrenia. Emphasis is placed on the complex relationship between the OXT and DA systems and their collective influence on social behaviour across physiological and pathological conditions. Understanding OXT and DA imbalance is fundamental for unravelling the neurobiological underpinnings of social interaction and reward processing deficits observed in psychiatric conditions.

Appetitive conditioning with pornographic stimuli elicits stronger activation in reward regions than monetary and gaming-related stimuli

Appetitive conditioning plays an important role in the development and maintenance of pornography-use and gaming disorders. It is assumed that primary and secondary reinforcers are involved in these processes. Despite the common use of pornography and gaming in the general population appetitive conditioning processes in this context are still not well studied. This study aims to compare appetitive conditioning processes using primary (pornographic) and secondary (monetary and gaming-related) rewards as unconditioned stimuli (UCS) in the general population. Additionally, it investigates the conditioning processes with gaming-related stimuli as this type of UCS was not used in previous studies. Thirty-one subjects participated in a differential conditioning procedure in which four geometric symbols were paired with either pornographic, monetary, or gaming-related rewards or with nothing to become conditioned stimuli (CS + porn, CS + game, CS + money, and CS-) in an functional magnetic resonance imaging study. We observed elevated arousal and valence ratings as well as skin conductance responses for each CS+ condition compared to the CS-. On the neural level, we found activations during the presentation of the CS + porn in the bilateral nucleus accumbens, right medial orbitofrontal cortex, and the right ventral anterior cingulate cortex compared to the CS-, but no significant activations during CS + money and CS + game compared to the CS-. These results indicate that different processes emerge depending on whether primary and secondary rewards are presented separately or together in the same experimental paradigm. Additionally, monetary and gaming-related stimuli seem to have a lower appetitive value than pornographic rewards.

Novel genome-wide associations for effort valuation and psychopathology in children and adults

The Research Domain Criteria (RDoC) initiative was established by the US National Institute of Mental Health as a multilevel, disorder-agnostic framework for analysis of human psychopathology through designated domains and constructs, including the "Positive Valence Systems" domain focused on reward-related behavior. This study investigates the reward valuation subconstruct of "effort" and its association with genetic markers, functional neurobiological pathways, and polygenic risk scores for psychopathology in 1215 children aged 6-12 and their parents (n = 1044). All participants completed the effort expenditure for rewards task (EEfRT), which assesses "effort" according to two quantitative measures: hard-task choice and reward sensitivity. Genetic association analyses were undertaken in MAGMA, utilizing EEfRT outcome variables as genome-wide association studies phenotypes to compute SNP and gene-level associations. Genome-wide association analyses found two distinct genetic loci that were significantly associated with measures of reward sensitivity and a separate genetic locus associated with hard task choice. Gene-set enrichment analysis yielded significant associations between "effort" and multiple gene sets involved in reward processing-related pathways, including dopamine receptor signaling, limbic system and forebrain development, and biological response to cocaine. These results serve to establish "effort" as a relevant construct for understanding reward-related behavior at the genetic level and support the RDoC framework for assessing disorder-agnostic psychopathology.

Dynamic Overrepresentation of Accumbal Cues in Food- and Opioid-Seeking Rats after Prenatal THC Exposure

The increasing prevalence of cannabis use during pregnancy has raised significant medical concerns, primarily related to the presence of Δ9-tetrahydrocannabinol (THC), which readily crosses the placenta and impacts fetal brain development. Previous research has identified midbrain dopaminergic neuronal alterations related to maternal THC consumption. However, the enduring consequences that prenatal cannabis exposure (PCE) has on striatum-based processing during voluntary reward pursuit have not been specifically determined. Here, we characterize PCE rats during food (palatable pellets) or opioid (remifentanyl)-maintained reward seeking. We find that the supra motivational phenotype of PCE rats is independent of value-based processing and is instead related to augmented reinforcing efficiency of opioid rewards. Our findings reveal that in utero THC exposure leads to increased cue-evoked dopamine release responses and an overrepresentation of cue-aligned, effort-driven striatal patterns of encoding. Recapitulating findings in humans, drug-related neurobiological adaptations of PCE were more pronounced in males, who similarly showed increased vulnerability for relapse. Collectively, these findings indicate that prenatal THC exposure in male rats engenders a pronounced neurodevelopmental susceptibility to addiction-like disorders later in life.

A dopamine mechanism for reward maximization

Individual survival and evolutionary selection require biological organisms to maximize reward. Economic choice theories define the necessary and sufficient conditions, and neuronal signals of decision variables provide mechanistic explanations. Reinforcement learning (RL) formalisms use predictions, actions, and policies to maximize reward. Midbrain dopamine neurons code reward prediction errors (RPE) of subjective reward value suitable for RL. Electrical and optogenetic self-stimulation experiments demonstrate that monkeys and rodents repeat behaviors that result in dopamine excitation. Dopamine excitations reflect positive RPEs that increase reward predictions via RL; against increasing predictions, obtaining similar dopamine RPE signals again requires better rewards than before. The positive RPEs drive predictions higher again and thus advance a recursive reward-RPE-prediction iteration toward better and better rewards. Agents also avoid dopamine inhibitions that lower reward prediction via RL, which allows smaller rewards than before to elicit positive dopamine RPE signals and resume the iteration toward better rewards. In this way, dopamine RPE signals serve a causal mechanism that attracts agents via RL to the best rewards. The mechanism improves daily life and benefits evolutionary selection but may also induce restlessness and greed.

Dopamine Pharmacodynamics: New Insights

Dopamine is a key neurotransmitter involved in physiological processes such as motor control, motivation, reward, cognitive function, and maternal and reproductive behaviors. Therefore, dysfunctions of the dopaminergic system are related to a plethora of human diseases. Dopamine, via different circuitries implicated in compulsive behavior, reward, and habit formation, also represents a key player in substance use disorder and the formation and perpetuation of mechanisms leading to addiction. Here, we propose dopamine as a model not only of neurotransmission but also of neuromodulation capable of modifying neuronal architecture. Abuse of substances like methamphetamine, cocaine, and alcohol and their consumption over time can induce changes in neuronal activities. These modifications lead to synaptic plasticity and finally to morphological and functional changes, starting from maladaptive neuro-modulation and ending in neurodegeneration.