Granular retrosplenial cortex layer 2/3 generates high-frequency oscillations dynamically coupled with hippocampal rhythms across brain states

The granular retrosplenial cortex (gRSC) exhibits high-frequency oscillations (HFOs; ∼150 Hz), which can be driven by a hippocampus-subiculum pathway. How the cellular-synaptic and laminar organization of gRSC facilitates HFOs is unknown. Here, we probe gRSC HFO generation and coupling with hippocampal rhythms using focal optogenetics and silicon-probe recordings in behaving mice. ChR2-mediated excitation of CaMKII-expressing cells in L2/3 or L5 induces HFOs, but spontaneous HFOs are found only in L2/3, where HFO power is highest. HFOs couple to CA1 sharp wave-ripples (SPW-Rs) during rest and the descending phase of theta. gRSC HFO current sources and sinks are the same for events during both SPW-Rs and theta oscillations. Independent component analysis shows that high gamma (50-100 Hz) in CA1 stratum lacunosum moleculare is comodulated with HFO power. HFOs may thus facilitate interregional communication of a multisynaptic loop between the gRSC, hippocampus, and medial entorhinal cortex during distinct brain and behavioral states.

Dissociation and other trauma symptomatology are linked to imbalance in the competing neurobehavioral decision systems

Objective

Dissociation is a conscious state characterized by alterations in sensation and perception and is thought to arise from traumatic life experiences. Previous research has demonstrated that individuals with high levels of dissociation show impairments in cognitive-emotional processes. Therefore, using the Competing Neurobehavioral Decisions System (CNDS) theory, we used statistical modeling to examine whether dissociative experience and trauma symptoms are independently predicted by impulsivity, risk-seeking, affective state (i.e., anxiety, depression, stress, and negative affect), and trauma history.

Method

In this cross-sectional study design, data were collected via Amazon Mechanical Turk from a total of n = 557 English-speaking participants in the United States. Using Qualtrics, participants answered a series of self-reported questionnaires and completed several neurocognitive tasks. Three independent multiple linear regression models were conducted to assess whether impulsivity, risk seeking, affective state, and trauma history predict depersonalization, trauma symptoms, and PTSD symptoms.

Results

As hypothesized, we found that depersonalization and other trauma symptoms are associated with heightened impulsivity, increased risk-seeking, impaired affective states, and a history of traumatic experiences.

Conclusion

We demonstrate that an imbalanced CNDS (i.e., hyperimpulsive/hypoexecutive), as evidenced by decreased future valuation, increased risk seeking, and impaired affective states, predicts heightened depersonalization and other trauma and PTSD symptomatology. This is the first time that dissociation has been connected to delay discounting (i.e., the tendency to place more value on rewards received immediately compared to farther in the future). Interventions that positively impact areas of the CNDS, such as episodic future thinking or mindfulness meditation, may be a target to help decrease dissociative symptoms.

Assessing Human Spatial Navigation in a Virtual Space and its Sensitivity to Exercise

Spatial navigation (SN) is the ability to locomote through the environment, which requires an understanding of where one is located in time and space. This capacity is known to rely on the sequential firing of place cells within the hippocampus. SN is an important behavior to investigate as this process deteriorates with age, especially in neurodegenerative disorders. However, the investigation of SN is limited by the lack of sophisticated behavioral techniques to assess this hippocampal-dependent task. Therefore, the goal of this protocol was to develop a novel, real-world approach to studying SN in humans. Specifically, an active virtual SN task was developed using a cross-platform game engine. During the encoding phase, participants navigated their way through a virtual city to locate landmarks. During the remembering phase, participants remembered where these reward locations were and delivered items to these locations. Time to find each location was captured and episodic memory was assessed by a free recall phase, including aspects of place, order, item, and association. Movement behavior (x, y, and z coordinates) was assessed through an asset available in the game engine. Importantly, results from this task demonstrate that it accurately captures both spatial learning and memory abilities as well as episodic memory. Further, findings indicate that this task is sensitive to exercise, which improves hippocampal functioning. Overall, the findings suggest a novel way to track human hippocampal functioning over the course of time, with this behavior being sensitive to physical activity training paradigms.

Granular retrosplenial cortex layer 2/3 generates high-frequency oscillations coupled with hippocampal theta and gamma in online states or sharp-wave ripples in offline states

Neuronal oscillations support information transfer by temporally aligning the activity of anatomically distributed 'writer' and 'reader' cell assemblies. High-frequency oscillations (HFOs) such as hippocampal CA1 sharp-wave ripples (SWRs; 100-250 Hz) are sufficiently fast to initiate synaptic plasticity between assemblies and are required for memory consolidation. HFOs are observed in parietal and midline cortices including granular retrosplenial cortex (gRSC). In 'offline' brain states (e.g. quiet wakefulness) gRSC HFOs co-occur with CA1 SWRs, while in 'online' states (e.g. ambulation) HFOs persist with the emergence of theta oscillations. The mechanisms of gRSC HFO oscillations, specifically whether the gRSC can intrinsically generate HFOs, and which layers support HFOs across states, remain unclear. We addressed these issues in behaving mice using optogenetic excitation in individual layers of the gRSC and high density silicon-probe recordings across gRSC layers and hippocampus CA1. Optogenetically induced HFOs (iHFOs) could be elicited by depolarizing excitatory neurons with 100 ms half-sine wave pulses in layer 2/3 (L2/3) or layer 5 (L5) though L5 iHFOs were of lower power than in L2/3. Critically, spontaneous HFOs were only observed in L2/3 and never in L5. Intra-laminar monosynaptic connectivity between excitatory and inhibitory neurons was similar across layers, suggesting other factors restrict HFOs to L2/3. To compare HFOs in online versus offline states we analyzed, separately, HFOs that did or did not co-occur with CA1 SWRs. Using current-source density analysis we found uniform synaptic inputs to L2/3 during all gRSC HFOs, suggesting layer-specific inputs may dictate the localization of HFOs to L2/3. HFOs occurring without SWRs were aligned with the descending phase of both gRSC and CA1 theta oscillations and were coherent with CA1 high frequency gamma oscillations (50-80 Hz). These results demonstrate that gRSC can internally generate HFOs without rhythmic inputs and that HFOs occur exclusively in L2/3, coupled to distinct hippocampal oscillations in online versus offline states.

Hippocampal sharp wave-ripple dynamics in NREM sleep encode motivation for anticipated physical activity

Physical activity is an integral part of every mammal's daily life, and as a driver of Darwinian fitness, required coordinated evolution of the body and brain. The decision to engage in physical activity is driven either by survival needs or by motivation for the rewarding qualities of physical activity itself. Rodents exhibit innate and learned motivation for voluntary wheel running, and over time run longer and farther, reflecting increased incentive salience and motivation for this consummatory behavior. Dynamic coordination of neural and somatic physiology are necessary to ensure the ability to perform behaviors that are motivationally variable. Hippocampal sharp wave-ripples (SWRs) have evolved both cognitive and metabolic functions, which in modern mammals may facilitate body-brain coordination. To determine if SWRs encode aspects of exercise motivation we monitored hippocampal CA1 SWRs and running behaviors in adult mice, while manipulating the incentive salience of the running experience. During non-REM (NREM) sleep, the duration of SWRs before (but not after) running positively correlated with future running duration, and larger pyramidal cell assemblies were activated in longer SWRs, suggesting that the CA1 network encodes exercise motivation at the level of neuronal spiking dynamics. Inter-Ripple-intervals (IRI) before but not after running were negatively correlated with running duration, reflecting more SWR bursting, which increases with learning. In contrast, SWR rates before and after running were positively correlated with running duration, potentially reflecting a tuning of metabolic demand for that day's anticipated and actual energy expenditure rather than motivation. These results suggest a novel role for CA1 in exercise behaviors and specifically that cell assembly activity during SWRs encodes motivation for anticipated physical activity.

SIGNIFICANCE STATEMENT

Darwinian fitness is increased by body-brain coordination through internally generated motivation, though neural substrates are poorly understood. Specific hippocampal rhythms (i.e., CA1 SWRs), which have a well-established role in reward learning, action planning and memory consolidation, have also been shown to modulate systemic [glucose]. Using a mouse model of voluntary physical activity that requires body-brain coordination, we monitored SWR dynamics when animals were highly motivated and anticipated rewarding exercise (i.e., when body-brain coordination is of heightened importance). We found that during non-REM sleep before exercise, SWR dynamics (which reflect cognitive and metabolic functions) were correlated with future time spent exercising. This suggests that SWRs support cognitive and metabolic facets that motivate behavior by coordinating the body and brain.

Examining neurobehavioral differences that support success in recovery from alcohol and other substance use disorders

OBJECTIVE

Substance use disorders (SUDs) are brain disorders associated with impairments resulting from the recurrent use of alcohol, drugs, or both. Though recovery is possible, SUDs are chronic, relapsing-remitting disorders, with estimates of SUD relapse at 40-60%. Currently, we know little about the mechanisms underlying successful recovery processes and whether substance-specific mechanisms exist. The current study sought to examine delay discounting (a measure of future valuation), executive skills, abstinence duration, and health behaviors in a population of individuals in recovery from alcohol, stimulants, opioids, and other substances.

METHODS

In this observational study, we utilized a cohort of individuals (n = 238) from the International Quit and Recovery Registry, an online registry for those in recovery from SUDs around the world. We assessed delay discounting through a neurobehavioral task, and assessed abstinence duration, executive skills, and engagement in positive health behaviors through self-report measures.

RESULTS

We found that delay discounting, executive skills, and engagement in positive health behaviors were similar among individuals in recovery from different substances. Abstinence duration was associated with delay discounting and engagement in health behaviors. Additionally, executive skills and engagement in health behaviors were positively associated.

CONCLUSION

These findings suggest that common behavioral mechanisms support recovery from misuse of various substances. As both delay discounting and executive skills are dependent upon executive brain centers, such as the prefrontal cortex, strategies that target executive functioning, such as episodic future thinking, meditation, or exercise, may be efficient strategies for optimizing recovery from SUDs.

Effects of a Neuroscience-Based Mindfulness Meditation Program on Psychological Health: Pilot Randomized Controlled Trial

BACKGROUND

Mindfulness and meditation have a rich historical tradition, and a growing scientific base of evidence supports their use in creating positive psychological and neuroplastic changes for practitioners. Although meditation can be taught in various ways, the scientific community has yet to systematically study the impact of different types of meditation on neuropsychological outcomes, especially as it pertains to digital implementation. Therefore, it is critical that the instruction of mindfulness be evidence based because meditation is being used in both scientific and clinical settings.

OBJECTIVE

This study investigated the use of teacher cueing and the integration of neuroscience education into a meditation program. Compassion cueing was chosen as the element of experimental manipulation because traditional lineages of Buddhist meditation teach compassion for self and others as one of the primary outcomes of meditation. We hypothesized that participants receiving compassion cueing would have enhanced neuropsychological outcomes compared with those receiving functional cueing and that gains in neuroscience knowledge would relate to positive neuropsychological outcomes.

METHODS

Participants (n=89) were randomized to receive either functional cueing (control group) or compassion cueing (experimental group) and engaged with five 10-minute meditation sessions a week for 4 weeks. All intervention sessions were administered through digital presentation. All participants completed ecological momentary assessments before and after the daily intervention, as well as pre- and postintervention questionnaires.

RESULTS

Participants demonstrated significant benefits over time, including increased mindfulness and self-compassion, decreased depression, and gains in neuroscience content (all P<.001); however, no significant between-group differences were found. Daily scores from each day of the intervention showed a statistically significant shift from active toward settled. Importantly, long-term increases in mindfulness were positively correlated to changes in compassion (r=0.326; P=.009) and self-compassion (r=0.424; P<.001) and negatively correlated to changes in anxiety (r=-0.266; P=.03) and depression (r=-0.271; P=.03). Finally, the acute effects of meditation were significantly correlated to the longitudinal outcomes (with a small-to-medium effect size), especially those relevant to mindfulness.

CONCLUSIONS

We developed a novel neuroscience-based education-meditation program that enhanced self-regulation as evidenced by improved mindfulness, self-compassion, and mood state. Our findings demonstrate the behavioral importance of engaging with mindfulness meditation and reinforce the idea that the benefits of meditation are independent of teacher cueing behavior. Future studies will need to investigate the brain-based changes underlying these meditation-induced outcomes.

Acutely enhancing affective state and social connection following an online dance intervention during the COVID-19 social isolation crisis

The COVID-19 pandemic has forced many throughout the world to isolate themselves from their respective communities to stop the spread of disease. Although this form of distancing can prevent the contraction of a virus, it results in social isolation and physical inactivity. Consequently, our communities have become heavily reliant on digital solutions to foster social connection and increase physical activity when forced to isolate. Dance is a multidimensional form of physical activity that includes sensory, motor, cognitive, rhythmic, creative, and social elements. Long-term, interventional studies in dance have shown positive effects on both mental and social health; however, little has been done to examine the acute effects and no studies to date have explored the relationship between the affective state and social outcomes of dance. We examined the hypothesis that online dance is associated with improvements in affective state and social connection during a time of social isolation, namely, the COVID-19 crisis. Healthy adults (age ≥ 18; n = 47) engaged in a single session of 60 min of self-selected online dance, completing a series of validated self-reported questionnaires before and after class. We found that online dance was associated with improvements in affective state as measured by increased positive affect and self-esteem and decreased negative affect and depressive symptoms. Additionally, online dance was associated with improvements in social and community connectedness. Further, we found that those who experienced the largest increases in self-esteem and decreases in negative affect demonstrated the largest gains in social connectivity. Although in-person dance classes may be optimal for formalized dance training, online dance instruction offers an accessible platform that can provide mental and social health benefits during the COVID-19 social isolation crisis. We conclude that through online dance, individuals can experience a connection between the body, mind, and community.

Development and validation of the multidimensional impacts of movement scale (MIMS) for yoga, weightlifting, and running

Background

Movement is an essential element in maintaining overall well-being, producing both physical and mental health benefits. Yoga is a mindful movement practice, with traditional yogic texts providing a framework, called the Koshas, that delineates how an intentional movement practice may impact multidimensional aspects of an individual. To date, no self-report measure examines the multifaceted ways that movement affects the individual at a physical and psychological level. Therefore, we developed the Multidimensional Impacts of Movement Scale (MIMS) by aligning ancient yogic traditions with current neuroscientific concepts.

Methods

MIMS was developed based on the five categories of the Koshas; 9 questions per Kosha resulted in 45 total questions. Participants (n = 103) self-identified as having yoga, running, or weightlifting as their primary movement practice, engaging in this practice at least 30 min per session, once a week, for the past 3 months. Participants engaged in their usual movement practice and then (within 2 h of their workout session) completed the MIMS along with a series of previously validated questionnaires. After a period of 2 weeks, participants completed their normal movement practice once again and took the MIMS a second time to assess test-retest reliability and Cronbach's alpha. Validity testing included convergent and divergent validity testing through Pearson's product-moment correlations and confirmatory factor analysis.

Results

One-hundred and three participants completed all study measures. Test-retest reliability demonstrated stability over time (r = 0.737, p < 0.001). Cronbach's alpha was between 0.775 and 0.840 for each of the factors, p < 0.001. MIMS was sensitive to confirmatory and discriminatory validity testing. Validity was also demonstrated through confirmatory factor analysis (i.e., Chi Square, Comparative Fit Index, Root Mean Square Error of Approximation).

Conclusion

MIMS is a valid and reliable tool to measure the multidimensional impacts of movement. The tool provides information about the effects of movement on a range of physical and psychological elements including subscales representing the body, energy, mind, intuition, and contentment. Physical activities that include aspects of mindfulness may demonstrate the most robust effects on the MIMS.

Dispositional mindfulness and its relationship to exercise motivation and experience

Mindfulness is the psychological state of staying attuned to the present moment, without ruminating on past or future events, and allowing thoughts, feelings, or sensations to arise without judgment or attachment. Previous work has shown that heightened dispositional mindfulness is associated with the awareness of the importance of exercise, exercise self-efficacy, exercise motivation, and self-reported exercise level. However, more methodologically rigorous studies are needed to understand the relationship between mindfulness and the psychological mechanisms related to exercise motivation, including the identification of why individuals are motivated to engage in exercise, the subjective experience of exercise, and the propensity for exercise dependence and addiction. In this cross-sectional investigation, we utilized the framework of the Self-Determination Theory to examine the hypothesis that heightened dispositional mindfulness (as measured by the Mindful Attention Awareness Scale) would be associated with increased levels of exercise motivation that were derived by higher levels of autonomous self-regulation. Individuals were recruited from urban areas who self-reported either low (exercising 2 or fewer times per week for 20 min or less; n = 78) or moderate (exercising 1 or 2 times per week for 20 min or more; n = 127) levels of exercise engagement. As hypothesized, heightened dispositional mindfulness was significantly associated with heightened levels of exercise self-determination as measured by the Behavioral Regulations in Exercise Questionnaire, with this effect being driven by negative associations with amotivation, external regulation, and introjected regulation. Additionally, we found that heightened dispositional mindfulness was associated with lower levels of psychological distress upon exercise and decreased exercise dependence/addiction. Overall, increased dispositional mindfulness may support a healthy relationship with exercise. These findings have implications for the utility of mindfulness interventions to support the regulation of exercise behaviors in service of enhancing exercise motivation and engagement.

Examining the Effect of Increased Aerobic Exercise in Moderately Fit Adults on Psychological State and Cognitive Function

Regular physical exercise can decrease the risk for obesity, diabetes, and cardiovascular disease, increase life expectancy, and promote psychological health and neurocognitive functioning. Cross-sectional studies show that cardiorespiratory fitness level (VO2 max) is associated with enhanced brain health, including improved mood state and heightened cognitive performance. Interventional studies are consistent with these cross-sectional studies, but most have focused on low-fit populations. Few such studies have asked if increasing levels of physical activity in moderately fit people can significantly enhance mood, motivation, and cognition. Therefore, the current study investigated the effects of increasing aerobic exercise in moderately fit individuals on psychological state and cognitive performance. We randomly assigned moderately fit healthy adults, 25-59 years of age, who were engaged in one or two aerobic exercise sessions per week to either maintain their exercise regimen (n = 41) or increase their exercise regimen (i.e., 4-7 aerobic workouts per week; n = 39) for a duration of 3 months. Both before and after the intervention, we assessed aerobic capacity using a modified cardiorespiratory fitness test, and hippocampal functioning via various neuropsychological assessments including a spatial navigation task and the Mnemonic Similarity Task as well as self-reported measures including the Positive and Negative Affect Scale, Beck Anxiety Inventory, State-Trait Anxiety Inventory, Perceived Stress Scale, Rumination Scale, Eating Disorders Examination, Eating Attitudes Test, Body Attitudes Test, and Behavioral Regulation of Exercise Questionnaire. Consistent with our initial working hypotheses, we found that increasing exercise significantly decreased measures of negative affect, including fear, sadness, guilt, and hostility, as well as improved body image. Further, we found that the total number of workouts was significantly associated with improved spatial navigation abilities and body image as well as reduced anxiety, general negative affect, fear, sadness, hostility, rumination, and disordered eating. In addition, increases in fitness levels were significantly associated with improved episodic memory and exercise motivation as well as decreased stress and disordered eating. Our findings are some of the first to indicate that in middle-aged moderately-fit adults, continuing to increase exercise levels in an already ongoing fitness regimen is associated with additional benefits for both psychological and cognitive health.

The phenotype of recovery II: The association between delay discounting, self-reported quality of life, and remission status among individuals in recovery from substance use disorders

Quality of life (QOL) and delay discounting (preference for smaller, immediate rewards) are significantly associated with substance use status, severity, and treatment outcomes. Associations between delay discounting and QOL among individuals in recovery from substance use have not been investigated. In this 2-study investigation, using data collected from The International Quit & Recovery Registry, we examined the association between QOL, discounting rates, and remission status among individuals in recovery from SUD. Study 1 (N = 166) investigated the relationship between delay discounting and QOL among individuals in recovery from SUD. Study 2 (N = 282) aimed to validate and extend the results of Study 1 by assessing the association between the remission status, delay discounting, and QOL among individuals in recovery from alcohol use disorder (AUD). In both studies, delay discounting was a significant predictor of QOL domains of physical health, psychological, and environment even after controlling for age, gender, race, ethnicity, education, and days since last use. In Study 2, a mediation analysis using Hayes's methods revealed that the association between the remission status and QOL domains of physical health, psychological and environment were partially mediated by the discounting rates. The current study expands the generality of delay discounting and indicates that discounting rates predict QOL and remission status among individuals in recovery from substance use disorders. This finding corroborates the recent characterizations of delay discounting as a candidate behavioral marker of addiction and may help identify subgroups that require special treatment or unique interventions to overcome their addiction. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Changes in temporal discounting, hedonic hunger, and food addiction during recovery from substance misuse

Substance use disorders (SUDs) and obesity are both chronic, relapsing, remitting disorders that arise from a heightened preference for immediate-focused rewards (i.e., steep temporal discounting). During recovery from SUDs, overweight and obese outcomes are common as individuals may replace drug rewards for food rewards. However, little has been done to investigate the neuropsychological processes underlying food reward and addiction in individuals recovering from SUDs. Using data collected from the International Quit and Recovery Registry and Amazon Mechanical Turk, we aimed to elucidate the factors that influence the attraction to palatable foods in a population in recovery from substance misuse (n = 114) as well as a population with no history of substance misuse (n = 97). We hypothesized that individuals in recovery from substance misuse would have steeper temporal discounting, an increased drive for palatable foods (i.e., hedonic hunger), and greater food addiction symptoms than non-substance users. Contrary to our hypotheses, we found that individuals in recovery from SUDs show improved outcomes in temporal discounting, hedonic hunger, and food addiction symptoms. Moreover, recovery status and temporal discounting significantly predicted these outcomes. Our findings suggest that the enhanced executive control processes needed for successful SUD recovery may transfer to other reward-related processes such as food reward and consumption. Interventions targeted at improving executive function including episodic future thinking, meditation, or exercise, may be excellent ways to support a successful recovery and improve other reward-related processes, including food consumption, to decrease the risk of overweight or obese outcomes during recovery.

The phenotype of recovery VI: The association between life-history strategies, delay discounting, and maladaptive health and financial behaviors among individuals in recovery from alcohol use disorders

BACKGROUND

The life-history theory is a well-established framework that predicts behaviors and explains how and why organisms allocate effort and resources to different life goals. Delay discounting (DD) is associated with risky behaviors and has been suggested as a candidate behavioral marker of addiction. Thus, we investigated the relationship between DD, life-history strategies, and engagement in risky behaviors among individuals in recovery from alcohol use disorder (AUD).

METHODS

Data from 110 individuals in recovery from addiction from The International Quit & Recovery Registry, an ongoing online registry designed to understand recovery phenotype, were included in the analysis. The association between life-history strategies, DD, engagement in risky behaviors, and remission status were assessed.

RESULTS

Life-history strategy scores were significantly associated with DD rates and finance, health, and personal development behaviors after controlling for age, sex, race, ethnicity, years of education, marital status, smoking status, and history of other substance use. Remission status was significantly associated with life-history strategy, DD, drug use, fitness, health, and safe driving after controlling for age, sex, race, years of education, marital status, and smoking status. In addition, a mediation analysis using Hayes' methods revealed that the discounting rates partially mediated the association between remission status and life-history strategy scores.

CONCLUSIONS

Life-history strategies and remission status are both significantly associated with DD and various health and finance behaviors among individuals in recovery from AUD. This finding supports the characterizations of DD as a candidate behavioral marker of addiction that could help differentiate subgroups needing special attention or specific interventions to improve the outcomes of their recovery. Future longitudinal studies are warranted to understand the relationships between changes in life-history strategies, DD, maladaptive health behaviors, and remission status over time.

Temporal discounting as a candidate behavioral marker of obesity

Although obesity is a result of processes operating at multiple levels, most forms result from decision-making behavior. The aim of this review was to examine the candidacy of temporal discounting (TD) (i.e. the reduction in the value of a reinforcer as a function of the delay to its receipt) as a behavioral marker of obesity. For this purpose, we assessed whether TD has the ability to: identify risk for obesity development, diagnose obesity, track obesity progression, predict treatment prognosis/outcomes, and measure treatment effectiveness. Three databases (Pubmed, PsycINFO, and Web of Science) were searched using a combination of terms related to TD and obesity. A total of 153 papers were reviewed. Several areas show strong evidence of TD's predictive utility as a behavioral marker of obesity (e.g., distinguishing obese from non obese). However, other areas have limited and/or mixed evidence (e.g., predicting weight change). Given the positive relationship for TD in the majority of domains examined, further consideration for TD as a behavioral marker of obesity is warranted.

A novel model of obesity prediction: Neurobehaviors as targets for treatment

Obesity is a worldwide epidemic that is on the rise, with approximately 30% of the world population classified as either overweight or obese. The United States has some of the highest rates of obesity, and in most countries in the world, obesity now poses more of a serious health concern than malnutrition. Obesity is a chronic, relapsing disorder that is both preventable and treatable; however, traditional interventions that target eating less and exercising more have low success rates, especially in the long term. Therefore, identifying the neurobehaviors that predict obesity is important to help identify targets to decrease BMI and improve obesity outcomes. Using the Competing Neurobehavioral Decisions System (CNDS) Theory, we hypothesized that individuals with obesity compared to individuals without obesity would display neurobehaviors marked by a hyperactive impulsive system and a hypoactive executive system. To test this hypothesis, we collected data from a battery of self-reported measures and neurocognitive assessments through Amazon Mechanical Turk from n = 178 obese (BMI ≥ 30) and n = 198 nonobese controls who were weight stable for the past 3 months. We found that compared to the nonobese control group, individuals with obesity showed heightened delay discounting (a marker of CNDS imbalance), impaired motivation, poor self-image, decreased affective state, and impaired executive function. Using a Bayesian network approach, we established a neurobehavioral model that predicts obesity with 64.4% accuracy and indicates an imbalance between impulsive and executive neural systems. Results from our study suggest that interventions targeting neurobehaviors may be integral to help improve obesity outcomes. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The phenotype of recovery V: Does delay discounting predict the perceived risk of relapse among individuals in recovery from alcohol and drug use disorders

BACKGROUND

Substance use recovery is a dynamic process. Relapse, often part of the recovery process, is a persistent problem for individuals seeking freedom from their harmful substance use and has become a focus of research on the improvement of recovery outcomes. Delay discounting is associated with substance use disorder severity, both its negative outcomes and the propensity to relapse. However, the association between delay discounting and perceived risk of relapse as measured by the Alcohol Warning of Relapse Questionnaire has not previously been examined in a population of individuals in long-term recovery from substance misuse.

METHODS

In this study, using data collected from the International Quit and Recovery Registry, we investigated the association between delay discounting, self-reported time in recovery, and perceived risk of relapse. Data from 193 individuals self-reporting to be in recovery from harmful substance use were included in the study.

RESULTS

Delay discounting rates were significantly negatively associated with length of recovery (p = 0.036) and positively with perceived risk of relapse (p = 0.027) even after controlling for age, gender, education, marital status, ethnicity, race, primary substance, and length in the registry. Moreover, a mediation analysis using Hayes' methods revealed that the association between the length of recovery and perceived relapse risk was partially mediated by delay discounting, accounting for 21.2% of the effect.

CONCLUSIONS

Our finding supports previous characterizations of delay discounting as a candidate behavioral marker of substance misuse and may help to identify individuals at higher perceived risk of relapse in an extended recovery population.

Dance on the Brain: Enhancing Intra- and Inter-Brain Synchrony

Dance has traditionally been viewed from a Eurocentric perspective as a mode of self-expression that involves the human body moving through space, performed for the purposes of art, and viewed by an audience. In this Hypothesis and Theory article, we synthesize findings from anthropology, sociology, psychology, dance pedagogy, and neuroscience to propose The Synchronicity Hypothesis of Dance, which states that humans dance to enhance both intra- and inter-brain synchrony. We outline a neurocentric definition of dance, which suggests that dance involves neurobehavioral processes in seven distinct areas including sensory, motor, cognitive, social, emotional, rhythmic, and creative. We explore The Synchronicity Hypothesis of Dance through several avenues. First, we examine evolutionary theories of dance, which suggest that dance drives interpersonal coordination. Second, we examine fundamental movement patterns, which emerge throughout development and are omnipresent across cultures of the world. Third, we examine how each of the seven neurobehaviors increases intra- and inter-brain synchrony. Fourth, we examine the neuroimaging literature on dance to identify the brain regions most involved in and affected by dance. The findings presented here support our hypothesis that we engage in dance for the purpose of intrinsic reward, which as a result of dance-induced increases in neural synchrony, leads to enhanced interpersonal coordination. This hypothesis suggests that dance may be helpful to repattern oscillatory activity, leading to clinical improvements in autism spectrum disorder and other disorders with oscillatory activity impairments. Finally, we offer suggestions for future directions and discuss the idea that our consciousness can be redefined not just as an individual process but as a shared experience that we can positively influence by dancing together.

Reinforcer Pathology: Implications for Substance Abuse Intervention

The rate at which individuals discount future rewards (i.e., discounting rate) is strongly associated with their propensity for substance abuse as well as myriad other negative health behaviors. An excessive preference for immediately available rewards suggests a shortened time horizon in which immediate rewards are overvalued and future, potentially negative consequences are undervalued. This review outlines Reinforcer Pathology Theory (i.e., the interaction between excessive preference for immediately available rewards and the overvaluation of a particular commodity that offers brief, intense reinforcement), its neurobiological/behavioral underpinnings, and its implications for treating substance use disorders. In doing so, the current review provides an overview of a variety of ways in which interventions have been used to manipulate aspects of reinforcer pathology in an individual, including narrative theory, framing manipulations, and neuromodulation (e.g., working memory training, TMS) which may serve as promising avenues for the modulation of the temporal window and/or valuation of reinforcers.

Excessive discounting of delayed reinforcers as a trans-disease process: Update on the state of the science

Delay discounting, or the process by which reinforcers lose value with delay to their receipt, has been identified as a trans-disease process underlying addiction, other disorders, and maladaptive health behaviors. Delay discounting has been identified as an endophenotype for multiple psychiatric disorders including substance use disorder, ADHD, and major depressive disorder, with this endophenotype being linked to deficits in dopaminergic and serotonergic neurotransmission. In addition, neuroanatomical and neurophysiological deficits in areas of the executive and impulsive systems have been associated with both steeper discounting and substance use disorders. Delay discounting constitutes a novel target for interventions to change health behaviors. A new theory, termed reinforcer pathology, has been developed uniting these findings and setting the stage for future research.

The Effects of Acute Exercise on Mood, Cognition, Neurophysiology, and Neurochemical Pathways: A Review

A significant body of work has investigated the effects of acute exercise, defined as a single bout of physical activity, on mood and cognitive functions in humans. Several excellent recent reviews have summarized these findings; however, the neurobiological basis of these results has received less attention. In this review, we will first briefly summarize the cognitive and behavioral changes that occur with acute exercise in humans. We will then review the results from both human and animal model studies documenting the wide range of neurophysiological and neurochemical alterations that occur after a single bout of exercise. Finally, we will discuss the strengths, weaknesses, and missing elements in the current literature, as well as offer an acute exercise standardization protocol and provide possible goals for future research.

The medial prefrontal cortex and nucleus accumbens mediate the motivation for voluntary wheel running in the rat

Voluntary wheel running in rats provides a preclinical model of exercise motivation in humans. We hypothesized that rats run because this activity has positive incentive salience in both the acquisition and habitual stages of wheel running and that gender differences might be present. Additionally, we sought to determine which forebrain regions are essential for the motivational processes underlying wheel running in rats. The motivation for voluntary wheel running in male and female Sprague-Dawley rats was investigated during the acquisition (Days 1-7) and habitual phases (after Day 21) of running using conditioned place preference (CPP) and the reinstatement (rebound) response after forced abstinence, respectively. Both genders displayed a strong CPP for the acquisition phase and a strong rebound response to wheel deprivation during the habitual phase, suggesting that both phases of wheel running are rewarding for both sexes. Female rats showed a 1.5 times greater rebound response than males to wheel deprivation in the habitual phase of running, while during the acquisition phase, no gender differences in CPP were found. We transiently inactivated the medial prefrontal cortex (mPFC) or the nucleus accumbens (NA), hypothesizing that because these regions are involved in the acquisition and reinstatement of self-administration of both natural and pharmacological stimuli, they might also serve a role in the motivation to wheel run. Inactivation of either structure decreased the rebound response in the habitual phase of running, demonstrating that these structures are involved in the motivation for this behavior.

Prism adaptation for spatial neglect after stroke: translational practice gaps

Spatial neglect increases hospital morbidity and costs in around 50% of the 795,000 people per year in the USA who survive stroke, and an urgent need exists to reduce the care burden of this condition. However, effective acute treatment for neglect has been elusive. In this article, we review 48 studies of a treatment of intense neuroscience interest: prism adaptation training. Due to its effects on spatial motor 'aiming', prism adaptation training may act to reduce neglect-related disability. However, research failed, first, to suggest methods to identify the 50-75% of patients who respond to treatment; second, to measure short-term and long-term outcomes in both mechanism-specific and functionally valid ways; third, to confirm treatment utility during the critical first 8 weeks poststroke; and last, to base treatment protocols on systematic dose-response data. Thus, considerable investment in prism adaptation research has not yet touched the fundamentals needed for clinical implementation. We suggest improved standards and better spatial motor models for further research, so as to clarify when, how and for whom prism adaptation should be applied.