Eating Disorder Symptomatology Among Young Adult Cigarette and E-Cigarette Users.

Objective: Tobacco use is elevated among individuals with eating disorders (EDs). Yet, further research is needed to understand associations between cigarette and e-cigarette use patterns and ED symptomatology. To gain a more comprehensive understanding of tobacco use and EDs, this study characterized ED symptomatology and tobacco use patterns, including exclusive cigarette use, e-cigarette use, dual use, and nonuse. Method: Young adults aged 18-24 years who self-reported exclusive cigarette, e-cigarette, dual, or nonuse (N = 2500) were recruited via Lucid, an online survey management company. Participants completed questionnaires assessing body dissatisfaction, global ED psychopathology, binge eating and self-induced vomiting frequency, and demographics. ED diagnostic groups included: anorexia nervosa (AN), bulimia spectrum eating disorders (BSED), atypical AN, and night eating syndrome (NES). Results: Multinomial logistic models revealed those with AN were more likely to be dual users, those with atypical AN were more likely to be exclusive e-cigarette users, and participants with a BSED or NES were more likely to be exclusive e-cigarette or dual users, compared to those without an ED. General linear models suggested body dissatisfaction and global ED psychopathology were higher among exclusive e-cigarette and dual users, while binge eating and self-induced vomiting frequencies were greater among all tobacco use groups compared to nonusers. Discussion: Our findings suggest young adults with ED symptomatology were more likely to be users of e-cigarettes exclusively or dual users. It will be necessary to examine how these associations manifest using longitudinal and clinical populations in future research.

Effects of 'Ice' flavoured e-cigarettes with synthetic cooling agent WS-23 or menthol on user-reported appeal and sensory attributes.

BACKGROUND: This clinical experiment tested the effects of exposure to e-cigarettes with WS-23 or menthol cooling additives on user appeal and sensory attributes, and, secondarily, whether WS-23 effects generalised across base characterising flavour, nicotine concentration, or nicotine/tobacco product use status. METHODS: In this within-participant double-blind experiment, adult tobacco/nicotine users administered standardised puffs of 18 different e-cigarette solutions in randomised sequences using a pod-style device. Each of three base characterising e-cigarette flavour solutions ('bold tobacco', 'mango,' 'wintergreen') in both 2% and 4% concentrations of nicotine benzoate salt were manipulated by adding either: (1) Menthol (0.5%), (2) WS-23 (0.75%) or (3) No cooling agent. After each administration, participants rated 3 appeal and 5 sensory attributes (0-100 scales). RESULTS: Participants (n=84; M(SD)=38.6 (13.6) years old) were either exclusive e-cigarette (25.0%), cigarette (36.9%) or dual (38.1%) users. WS-23 versus no coolant products produced higher liking, willingness to use again, smoothness, and coolness and lower disliking, bitterness, and harshness ratings (|B|difference range: 4.8 to 20.1; ps<0.005). Menthol (vs no coolant) increased willingness to use again and reduced harshness and coolness (ps<0.05). Flavours with WS-23 (vs menthol) were rated as smoother, cooler and less harsh (ps<0.05). Coolant effects did not differ by base flavour, nicotine concentration, or tobacco use status. CONCLUSIONS: Adding synthetic coolant WS-23 to e-cigarettes appears to make the vaping user experience more appealing, regardless of characterising base flavour. Regulatory agencies should be aware that the manufacturing process of adding synthetic coolants may increase the attractiveness of various e-cigarette products.Cite Now.

Sweet taste preference is associated with greater hypothalamic response to glucose and longitudinal weight gain.

The hypothalamus has an abundant expression of sweet taste receptors that play a role in glucose sensing and energy homeostasis. Evidence suggests that liking "sweets" can be associated with weight gain, but the relationship between sweet taste preference and hypothalamic regulation of appetite is unknown. This study tested the hypothesis that sweet taste preference is associated with increased hypothalamic activation in response to glucose (a purported neural marker for weight gain risk) and greater longitudinal increases in body mass index (BMI). Fifty-four adults aged 18-35 years with a mean (± SD) BMI of 27.99 ± 5.32 kg/m2 completed the study. Height and weight were measured at baseline and 6-12 months later in a subset of 36 participants. Sweet taste preference was assessed via the Monell 2-series, forced-choice tracking procedure. Arterial spin labeling magnetic resonance imaging was performed before and after oral glucose ingestion to determine hypothalamic blood flow response to glucose. Linear models were used to examine relationships between sweet taste preference and the hypothalamic response to glucose and longitudinal changes in BMI, adjusting for age, sex, and baseline BMI. Sweet taste preference was positively associated with glucose-linked hypothalamic blood flow (beta = 0.017, p = 0.043), adjusted for age, sex and BMI. We also observed a positive association between sweet taste preference and longitudinal change in BMI (beta = 0.088, p = 0.015), adjusted for age, sex and baseline BMI. These findings suggest that heightened sweet taste preference is associated with glucose-linked hypothalamic activation and may be linked to increased susceptibility for weight gain.

The neural correlates of value representation: From single items to bundles.

One of the core questions in Neuro-economics is to determine where value is represented. To date, most studies have focused on simple options and identified the ventromedial prefrontal cortex (VMPFC) as the common value region. We report the findings of an fMRI study in which we asked participants to make pairwise comparisons involving options of varying complexity: single items (Control condition), bundles made of the same two single items (Scaling condition) and bundles made of two different single items (Bundling condition). We construct a measure of choice consistency to capture how coherent the choices of a participant are with one another. We also record brain activity while participants make these choices. We find that a common core of regions involving the left VMPFC, the left dorsolateral prefrontal cortex (DLPFC), regions associated with complex visual processing and the left cerebellum track value across all conditions. Also, regions in the DLPFC, the ventrolateral prefrontal cortex (VLPFC) and the cerebellum are differentially recruited across conditions. Last, variations in activity in VMPFC and DLPFC value-tracking regions are associated with variations in choice consistency. This suggests that value based decision-making recruits a core set of regions as well as specific regions based on task demands. Further, correlations between consistency and the magnitude of signal change with lateral portions of the PFC suggest the possibility that activity in these regions may play a causal role in decision quality.

Willingness to Use Commercial Nicotine Gums, Lozenges, and Gummies Among Nontobacco Using Adolescents in Southern California.

PURPOSE: New oral nicotine products (ONPs), often advertised as "tobacco-free" (i.e., pouches, gum, lozenges, gummies), come in nontobacco flavors appealing to adolescents. It is unknown how adolescent willingness to use ONPs differs by product type and flavor, and whether sociodemographic disparities exist. METHODS: Adolescent never tobacco product users (n = 1, 289) in ninth or 10th grade from 11 high schools in Southern California were surveyed in fall 2021 about ever and past 6-month use of ONPs and sociodemographic characteristics. Adolescents were randomized to view five different ONPs in either fruit or mint flavor, and asked to rate their willingness to use each product. Multivariable logistic random effect-repeated measures regression examined associations of product type, flavor, and sociodemographic characteristics with any willingness to use ONPs. RESULTS: Compared to traditional smokeless tobacco (willingness = 17.8%), adolescents reported greater willingness to use ONPs (gum, 28.2%; pouches, 21.1%; lozenge, 22.4%; gummies, 24.1%); adjusted odd ratios [aORs] 1.25-1.84; p-values<.001). Mint flavor (23.3%) compared to fruit flavor (21.4%), significantly increased odds of willingness to use across all ONPs (aOR [95%CI] = 1.15 [1.05, 1.26], p = .004). Younger adolescents (ninth, 24.2% vs. 10th grade, 21.4%) and LGBTQ+ (34.2%) versus heterosexual (19.7%) and cisgender (18.8%) adolescents were more willing to use these products. DISCUSSION: Adolescents reported greater willingness to use new ONPs compared to traditional smokeless tobacco. Adolescents who were younger (vs. older adolescents) or identified as LGBTQ+ (vs. heterosexual and cisgender) were more willing to use new ONPs. Efforts to monitor adolescents' willingness to use and actual use of these products are warranted.

Essential Role of Social Context and Self-Efficacy in Daily Paretic Arm/Hand Use After Stroke: An Ecological Momentary Assessment Study With Accelerometry.

OBJECTIVE: To determine the momentary effect of social-cognitive factors, in addition to motor capability, on post-stroke paretic arm/hand use in the natural environment. DESIGN: A 5-day observational study in which participants were sent 6 Ecological Momentary Assessment (EMA) prompts/day. SETTING: Participants' daily environment. PARTICIPANTS: Community-dwelling, chronic stroke survivors with right-dominant, mild-moderate upper extremity paresis (N=30). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Time duration of bimanual and unimanual paretic arm/hand use indexed by accelerometry; social-cognitive factors (social context, self-efficacy, mood) captured by EMA; motor capability of the paretic limb measured by Fugl-Meyer Upper Extremity Motor Assessment (FM). RESULTS: After accounting for participants' motor capability, we found that momentary social context (alone or not) and self-efficacy significantly predicted post-stroke paretic arm/hand use behavior in the natural environment. When participants were not alone, paretic arm/hand movement increased both with and without the less-paretic limb (bimanual and unimanual movements, P=.018 and P<.001, respectively). Importantly, participants were more likely to use their paretic arm/hand (unimanually) if they had greater self-efficacy for limb use (P=.042). EMA repeated-measures provide a real-time approach that captures the natural dynamic ebb and flow of social-cognitive factors and their effect on daily arm/hand use. We also observed that people with greater motor impairments (FM<50.6) increase unimanual paretic arm/hand movements when they are not alone, regardless of motor capability. CONCLUSIONS: In addition to motor capability, stroke survivors' momentary social context and self-efficacy play a role in paretic arm/hand use behavior. Our findings suggest the development of personalized rehabilitative interventions which target these factors to promote daily paretic arm/hand use. This study highlights the benefits of EMA to provide real-time information to unravel the complexities of the biopsychosocial (ie, motor capability and social-cognitive factors) interface in post-stroke upper extremity recovery.

Feasibility and acceptability of remote procedures to study tobacco product use and respiratory health: an observational study.

OBJECTIVE: Obtaining ecologically valid biological samples is critical for understanding respiratory effects of tobacco use, but can be burdensome. In two diverse samples, we examined feasibility and acceptability of studying pulmonary function and respiratory health entirely remotely. DESIGN: Observational feasibility and acceptability study. SETTING AND PARTICIPANTS: Adults age 18-25 (Biomedical Respiratory Effects Associated through Habitual Use of E-Cigarettes [BREATHE] Study) and 21-65 (Adult IQOS Respiratory [AIRS] Study) recruited from previous research studies and advertisements in Southern California, USA (BREATHE (AIRS): N=77 (N=31) completed baseline, n=64 (n=20) completed feasibility and acceptability measures). Shared inclusion criteria for the two studies were ownership of a smartphone, willingness to download applications and English fluency. In addition, BREATHE participants reported one of three tobacco use patterns. AIRS participants smoked daily and were willing to use a heated tobacco product. Exclusion criteria were medical contraindications. INTERVENTIONS: A 4-week study consisted of five virtual study visits, twice daily ecological momentary assessment diaries and spirometry assessments, and weekly Nasal Epithelial Lining Fluid and saliva collection. All study visits were conducted via video conference; study materials and biospecimens were exchanged via mail. Participants reported feasibility and acceptability of daily diaries, breath tests, biospecimen collection and shipments. MEASURES: Surveys assessed perceptions of timing and overall experience of daily diaries and breath tests, difficulty of and overall experience with biospecimen collection, and experience sending and receiving shipments. RESULTS: Most participants evaluated daily diaries and breath tests as manageable (62.5%-95.0%) and likeable (54.7%-70.0%). Breath tests were frequently described as 'interesting' (55.0%-57.8%) and 'easy' (25.0%-48.4%). Most participants reported that biospecimen collection was easy (50.0%-85.0%), and that shipments were easy to send (87.5%-95.0%), receive (95.3%-95.0%) and schedule (56.3%-60.0%). No participants received shipments in poor condition. CONCLUSIONS: Remote research procedures may be feasible and acceptable to facilitate tobacco research studies, potentially resulting in more diverse samples of participants and more generalisable research results.

Different Patterns of Neural Activity Characterize Motor Skill Performance During Acquisition and Retention.

Motor performance and learning have distinct behavioral and neural signatures and can be uniquely modulated by various informational and motivational factors. Contemporary frameworks describe four different motor learning mechanisms mapped onto specific neural regions which are key for motor skill acquisition: error-based learning (cerebellum), reinforcement learning (basal ganglia), cognitive strategies (prefrontal cortex), and use-dependent learning (motor cortex). However, little is known about the neural circuits engaged during skill acquisition that are modulated specifically by practice-based performance improvement and those that predict recall performance. Based on previous work, we hypothesize that brain activity during practice in primary motor cortex and basal ganglia (1) is associated with trial-by-trial practice performance and (2) is predictive of immediate recall performance. Leveraging the contemporary framework, we use a well-known task paradigm that primarily relies upon cognitive strategy, reinforcement, and use-based learning mechanisms to test our hypotheses. Forty neurotypical young adults were asked to practice a pinch force tracking task. Participants received performance feedback after each trial during practice. We used whole brain analysis of functional magnetic resonance imaging (fMRI) and behavioral performance measures (i.e., time-on-target and self-efficacy) during the practice phase to determine which brain activation patterns are (1) associated with trial-by-trial tracking performance and (2) predictive of immediate no-feedback retention performance. We observed brain activations in the frontal orbital cortex, putamen, amygdala, and insula correlated with tracking performance improvement during practice. In contrast, a different set of performance-related activated regions were observed that were associated with immediate retention performance that included the primary motor cortex, superior frontal gyrus, somatosensory cortex, angular gyrus, and parietal gyrus. Our findings demonstrate that improved practice performance and recall of a sensorimotor skill are correlated with distinct neural activity patterns during acquisition, drawing on different motor learning mechanisms during encoding. While motor performance improvements depend on both cortical and subcortical regions, motor skill recall depends primarily on prefrontal and motor cortices. We discuss possible interpretations for why our hypothesis regarding basal ganglia activity and retention performance was not supported. Understanding the different neural mechanisms engaged in motor performance and learning may inform novel interventions to enhance motor skill learning.

FGF21 response to sucrose is associated with BMI and dorsal striatal signaling in humans.

OBJECTIVE: This study examined associations between BMI and dietary sugar intake with sucrose-induced fibroblast growth factor 21 (FGF21) and whether circulating FGF21 is associated with brain signaling following sucrose ingestion in humans. METHODS: A total of 68 adults (29 male; mean [SD), age 23.2 [3.8] years; BMI 27.1 [4.9] kg/m2 ) attended visits after a 12-hour fast. Plasma FGF21 was measured at baseline and at 15, 30, and 120 minutes after sucrose ingestion (75 g in 300 mL of water). Brain cerebral blood flow responses to sucrose were measured using arterial spin labeling magnetic resonance imaging. RESULTS: Higher circulating FGF21 levels were associated with reduced blood flow in the striatum in response to sucrose (ß = -7.63, p = 0.03). This association was greatest among persons with healthy weight (ß = -15.70, p = 0.007) and was attenuated in people with overweight (ß = -4.00, p = 0.63) and obesity (ß = -12.45, p = 0.13). BMI was positively associated with FGF21 levels in response to sucrose (ß = 0.53, p = 0.02). High versus low dietary sugar intake was associated with greater FGF21 responses to acute sucrose ingestion in individuals with healthy weight (ß = 8.51, p = 0.04) but not in individuals with overweight or obesity (p > 0.05). CONCLUSIONS: These correlative findings support evidence in animals showing that FGF21 acts on the brain to regulate sugar consumption through a negative feedback loop.

Changes in Social, Romantic, and General Life Satisfaction Over the Course of a Substance Use Disorder.

Background: The pandemic has highlighted the importance of social connection for health and well-being. Satisfaction across domains of life is associated with substance use outcomes, such as risk of relapse and mortality. Previous work has delineated the relationship between substance use and social connections, yet there is a lack of research exploring the relationship between substance use and satisfaction with domains of life over time. Methods: We retrospectively assessed satisfaction with social life, romantic life, and general life across five phases of substance use among 339 adults, of whom 289 identify as formerly having a problem with substance use, and a comparison group of 50 who report no history of problematic drug use. We compared those whose primary drug of choice was alcohol, marijuana, methamphetamine, non-prescription opioids, and prescription opioids. Results: Those who used prescription opioids reported a larger drop in satisfaction in social life, romantic life, and general life during the course of substance use than those who used other drugs. However, we report no significant differences in current satisfaction, social well-being, or quality of life between people in recovery and people with no history of problematic substance use. Conclusions: These findings-alongside neuropsychological work on the opioid system and sociality-paint a picture that those who formerly used prescription opioids may experience lower satisfaction across life domains during the course of their substance use than those who used other substances. However, people in prolonged recovery-regardless of their drug of choice-all show similar levels of satisfaction compared to people with no history of problematic substance use.

Brain responses to glucose ingestion are greater in children than adults and are associated with overweight and obesity.

OBJECTIVE: This study investigated whether brain regions involved in the regulation of food intake respond differently to glucose ingestion in children and adults and the relationship between brain responses and weight status. METHODS: Data included 87 children (ages 7-11 years) and 94 adults (ages 18-35 years) from two cohorts. Healthy weight, overweight, and obesity were defined by Centers for Disease Control and Prevention criteria. Brain responses to glucose were determined by measuring cerebral blood flow using arterial spin labeling magnetic resonance imaging in brain regions involved in the regulation of eating behavior. RESULTS: Children showed significantly larger increases in brain responses to glucose than adults in the dorsal striatum (p < 0.01), insula (p < 0.01), hippocampus (p < 0.01), and dorsal-lateral prefrontal cortex (p < 0.01). Responses to glucose in the dorsal striatum (odds ratio [OR] = 1.52, 95% CI 1.05-2.20; p = 0.03), hippocampus (OR = 1.51, 95% CI: 1.02-2.22; p = 0.04), insula (OR = 1.64, 95% CI: 1.11-2.42; p = 0.01), and orbitofrontal cortex (OR = 1.63 95% CI: 1.12-2.39; p = 0.01) were positively associated with overweight or obesity, independent of age group. CONCLUSIONS: Children have greater brain responses to glucose ingestion than adults in regions involved in eating behavior, and these responses are associated with weight status.

Obesity and Sex-Related Associations With Differential Effects of Sucralose vs Sucrose on Appetite and Reward Processing: A Randomized Crossover Trial.

Importance: Nonnutritive sweeteners (NNSs) are used as an alternative to nutritive sweeteners to quench desire for sweets while reducing caloric intake. However, studies have shown mixed results concerning the effects of NNSs on appetite, and the associations between sex and obesity with reward and appetitive responses to NNS compared with nutritive sugar are unknown. Objective: To examine neural reactivity to different types of high-calorie food cues (ie, sweet and savory), metabolic responses, and eating behavior following consumption of sucralose (NNS) vs sucrose (nutritive sugar) among healthy young adults. Design, Setting, and Participants: In a randomized, within-participant, crossover trial including 3 separate visits, participants underwent a functional magnetic resonance imaging task measuring blood oxygen level-dependent signal in response to visual cues. For each study visit, participants arrived at the Dornsife Cognitive Neuroimaging Center of University of Southern California at approximately 8:00 am after a 12-hour overnight fast. Blood was sampled at baseline and 10, 35, and 120 minutes after participants received a drink containing sucrose, sucralose, or water to measure plasma glucose, insulin, glucagon-like peptide(7-36), acyl-ghrelin, total peptide YY, and leptin. Participants were then presented with an ad libitum meal. Participants were right-handed, nonsmokers, weight-stable for at least 3 months before the study visits, nondieters, not taking medication, and with no history of eating disorders, illicit drug use, or medical diagnoses. Data analysis was performed from March 2020 to March 2021. Interventions: Participants ingested 300-mL drinks containing either sucrose (75 g), sucralose (individually sweetness matched), or water (as a control). Main Outcomes and Measures: Primary outcomes of interest were the effects of body mass index (BMI) status and sex on blood oxygen level-dependent signal to high-calorie food cues, endocrine, and feeding responses following sucralose vs sucrose consumption. Secondary outcomes included neural, endocrine, and feeding responses following sucrose vs water and sucralose vs water (control) consumption, and cue-induced appetite ratings following sucralose vs sucrose (and vs water). Results: A total of 76 participants were randomized, but 2 dropped out, leaving 74 adults (43 women [58%]; mean [SD] age, 23.40 [3.96] years; BMI range, 19.18-40.27) who completed the study. In this crossover design, 73 participants each received water (drink 1) and sucrose (drink 2), and 72 participants received water (drink 1), sucrose (drink 2), and sucralose (drink 3). Sucrose vs sucralose was associated with greater production of circulating glucose, insulin, and glucagon-like peptide-1 and suppression of acyl-ghrelin, but no differences were found for peptide YY or leptin. BMI status by drink interactions were observed in the medial frontal cortex (MFC; P for interaction < .001) and orbitofrontal cortex (OFC; P for interaction = .002). Individuals with obesity (MFC, ß, 0.60; 95% CI, 0.38 to 0.83; P < .001; OFC, ß, 0.27; 95% CI, 0.11 to 0.43; P = .002), but not those with overweight (MFC, ß, 0.02; 95% CI, -0.19 to 0.23; P = .87; OFC, ß, -0.06; 95% CI, -0.21 to 0.09; P = .41) or healthy weight (MFC, ß, -0.13; 95% CI, -0.34 to 0.07; P = .21; OFC, ß, -0.08; 95% CI, -0.23 to 0.06; P = .16), exhibited greater responsivity in the MFC and OFC to savory food cues after sucralose vs sucrose. Sex by drink interactions were observed in the MFC (P for interaction = .03) and OFC (P for interaction = .03) after consumption of sucralose vs sucrose. Female participants had greater MFC and OFC responses to food cues (MFC high-calorie vs low-calorie cues, ß, 0.21; 95% CI, 0.05 to 0.37; P = .01; MFC sweet vs nonfood cues, ß, 0.22; 95% CI, 0.02 to 0.42; P = .03; OFC food vs nonfood cues, ß, 0.12; 95% CI, 0.02 to 0.22; P = .03; and OFC sweet vs nonfood cues, ß, 0.15; 95% CI, 0.03 to 0.27; P = .01), but male participants' responses did not differ (MFC high-calorie vs low-calorie cues, ß, 0.01; 95% CI, -0.19 to 0.21; P = .90; MFC sweet vs nonfood cues, ß, -0.04; 95% CI, -0.26 to 0.18; P = .69; OFC food vs nonfood cues, ß, -0.08; 95% CI, -0.24 to 0.08; P = .32; OFC sweet vs nonfood cues, ß, -0.11; 95% CI, -0.31 to 0.09; P = .31). A sex by drink interaction on total calories consumed during the buffet meal was observed (P for interaction = .03). Female participants consumed greater total calories (ß, 1.73; 95% CI, 0.38 to 3.08; P = .01), whereas caloric intake did not differ in male participants (ß, 0.68; 95% CI, -0.99 to 2.35; P = .42) after sucralose vs sucrose ingestion. Conclusions and Relevance: These findings suggest that female individuals and those with obesity may be particularly sensitive to disparate neural responsivity elicited by sucralose compared with sucrose consumption. Trial Registration: ClinicalTrials.gov Identifier: NCT02945475.

Validating Habitual and Goal-Directed Decision-Making Performance Online in Healthy Older Adults.

Everyday decision-making is supported by a dual-system of control comprised of parallel goal-directed and habitual systems. Over the past decade, the two-stage Markov decision task has become popularized for its ability to dissociate between goal-directed and habitual decision-making. While a handful of studies have implemented decision-making tasks online, only one study has validated the task by comparing in-person and web-based performance on the two-stage task in children and young adults. To date, no study has validated the dissociation of goal-directed and habitual behaviors in older adults online. Here, we implemented and validated a web-based version of the two-stage Markov task using parameter simulation and recovery and compared behavioral results from online and in-person participation on the two-stage task in both young and healthy older adults. We found no differences in estimated free parameters between online and in-person participation on the two-stage task. Further, we replicate previous findings that young adults are more goal-directed than older adults both in-person and online. Overall, this work demonstrates that the implementation and use of the two-stage Markov decision task for remote participation is feasible in the older adult demographic, which would allow for the study of decision-making with larger and more diverse samples.

Effects of addiction science on conceived freewill and responsibility.

Although there is speculation that medicalization of addiction undermines conceived agency, only relatively modest effects have been reported. Research participants generally have ideas about addiction that are informed both by personal experience and by media, and their views may not be wholly updated in response to study-information. Here we examine the potential impact of addiction science theories on perceived volition and responsibility by considering the issues in the context of a hypothetical new drug, "Z." Participants (N = 662) were provided one of three functional accounts that each corresponded to a prominent theory within addiction science: incentive-sensitization, impaired self-control, and habit-system dominance. For half of participants, additional neuroscience mechanism information was included with the functional account. Across explanations, the inclusion of mechanism information was associated with significantly less perceived volition and marginal reduction in blame, For several measures, there was a significant or marginally significant interaction between which addiction explanation was used and whether mechanism information was included, with mechanism generally having the largest impact given the impaired self-control explanation of addiction and little evidence of impact given the incentive-sensitization explanation of addiction. Taken together, these results suggest robust effects of addiction science on judgments of agency when presented in the context of a novel addiction. It is unclear whether a sustained scientific consensus around an existing theory could produce a similar impact on how people understand real addictive behavior.

A Novel Combination of Accelerometry and Ecological Momentary Assessment for Post-Stroke Paretic Arm/Hand Use: Feasibility and Validity.

Use of the paretic arm and hand is a key indicator of recovery and reintegration after stroke. A sound methodology is essential to comprehensively identify the possible factors impacting daily arm/hand use behavior. We combined ecological momentary assessment (EMA), a prompt methodology capturing real-time psycho-contextual factors, with accelerometry to investigate arm/hand behavior in the natural environment. Our aims were to determine (1) feasibility and (2) measurement validity of the combined methodology. We monitored 30 right-dominant, mild-moderately motor impaired chronic stroke survivors over 5 days (6 EMA prompts/day with accelerometers on each wrist). We observed high adherence for accelerometer wearing time (80.3%), EMA prompt response (84.6%), and generally positive user feedback upon exit interview. The customized prompt schedule and the self-triggered prompt option may have improved adherence. There was no evidence of EMA response bias nor immediate measurement reactivity. An unexpected small but significant increase in paretic arm/hand use was observed over days (12-14 min), which may be the accumulated effect of prompting that provided a reminder to choose the paretic limb. Further research that uses this combined methodology is needed to develop targeted interventions that effectively change behavior and enable reintegration post-stroke.

Obesity and Dietary Added Sugar Interact to Affect Postprandial GLP-1 and Its Relationship to Striatal Responses to Food Cues and Feeding Behavior.

It has been hypothesized that the incretin hormone, glucagon-like peptide-1 (GLP-1), decreases overeating by influencing mesolimbic brain regions that process food-cues, including the dorsal striatum. We previously showed that habitual added sugar intake was associated with lower glucose-induced circulating GLP-1 and a greater striatal response to high calorie food cues in lean individuals. Less is known about how dietary added sugar and obesity may interact to affect postprandial GLP-1 and its relationship to striatal responses to food cues and feeding behavior. The current study aimed to expand upon previous research by assessing how circulating GLP-1 and striatal food cue reactivity are affected by acute glucose consumption in participants with varied BMIs and amounts of habitual consumption of added sugar. This analysis included 72 participants from the Brain Response to Sugar Study who completed two study visits where they consumed either plain water or 75g glucose dissolved in water (order randomized; both drinks were flavored with non-caloric cherry flavoring) and underwent repeated blood sampling, a functional magnetic resonance imaging (fMRI) based food-cue task, and an ad-libitum buffet meal. Correlations between circulating GLP-1 levels, striatal food-cue reactivity, and food intake were assessed, and interactions between obesity and added sugar on GLP-1 and striatal responses were examined. An interaction between BMI and dietary added sugar was associated with reduced post-glucose GLP-1 secretion. Participants who were obese and consumed high levels of added sugar had the smallest increase in plasma GLP-1 levels. Glucose-induced GLP-1 secretion was correlated with lower dorsal striatal reactivity to high-calorie versus low-calorie food-cues, driven by an increase in reactivity to low calorie food-cues. The increase in dorsal striatal reactivity to low calorie food-cues was negatively correlated with sugar consumed at the buffet. These findings suggest that an interaction between obesity and dietary added sugar intake is associated with additive reductions in postprandial GLP-1 secretion. Additionally, the results suggest that changes to dorsal striatal food cue reactivity through a combination of dietary added sugar and obesity may affect food consumption.

Present-state dependency in valuation of the future.

Ainslie's target article provides a map of distinct mechanisms relevant to self-control, potentially providing needed precision to the field. He also breaks new ground in characterizing the symbiotic relationship between suppression and resolve. In this commentary, I argue that one behaviorism-based feature of his framework, present-state independence, is unjustified and unnecessary for the broader claims of the theory.

Associations Between Exposure to Gestational Diabetes Mellitus In Utero and Daily Energy Intake, Brain Responses to Food Cues, and Adiposity in Children.

OBJECTIVE: Children exposed to gestational diabetes mellitus (GDM) or maternal obesity in utero have an increased propensity to develop obesity. Little is known about the mechanisms underlying this phenomenon. We aimed to examine relationships between exposure to GDM or maternal obesity and daily energy intake (EI), brain responses to food cues within reward regions, and adiposity in children. RESEARCH DESIGN AND METHODS: Participants were 159 children ages 7-11 years. Repeated 24-h recalls were conducted to assess mean daily EI. A subset of children (n = 102) completed a food cue task in the MRI scanner. A priori regions of interest included the orbital frontal cortex (OFC), insula, amygdala, ventral striatum, and dorsal striatum. Adiposity measurements, BMI z-scores, percent body fat, waist-to-height ratio (WtHR), and waist-to-hip ratio (WHR) were assessed. RESULTS: Exposure to GDM was associated with greater daily EI, and children exposed to GDM diagnosed before 26 weeks gestation had greater OFC food cue reactivity. Children exposed to GDM also had larger WHR. Results remained significant after adjusting for child's age and sex, maternal education and race/ethnicity, maternal prepregnancy BMI, and child's physical activity levels. Furthermore, children who consumed more daily calories had greater WHR, and the relationship between GDM exposure and WHR was attenuated after adjustment for daily EI. Prepregnancy BMI was not significantly related to daily EI or food cue reactivity in reward regions. However, prepregnancy BMI was significantly related to all adiposity measurements; results remained significant for BMI z-scores, WtHR, and WHR after controlling for child's age and sex, maternal education and race/ethnicity, maternal GDM exposure, and child's physical activity levels. CONCLUSIONS: Exposure to GDM in utero, in particular before 26 weeks gestation, is associated with increased EI, enhanced OFC food cue reactivity, and increased WHR. Future study with longitudinal follow-up is merited to assess potential pathways of daily EI and food cue reactivity in reward regions on the associations between GDM exposure and childhood adiposity.

The Early Impact of Social Distancing Measures on Drug Use.

BACKGROUND AND OBJECTIVES: Social distancing policies have been widely adopted in response to the COVID-19 pandemic. High levels of social connection are positively associated with beneficial health outcomes, while social isolation is associated with poor long-term health outcomes including reduced life expectancy. The present study evaluates the impact of social distancing measures during the early period of COVID-19 on substance use behaviors among those in the United States. Methods: We used an internet-based survey with participants (n = 157; 86 male) reporting a history of problems related to drug use. We relied on ANOVA and logistic regression techniques to assess the associations between social connection and substance use. Results: People with more severe drug use problems reported feeling more socially isolated during social distancing. Those who primarily use alcohol reported higher global feelings of social connection than those who primarily use opioids. During social distancing, participants reported an increase in alcohol and cigarette consumption, and a decrease in cocaine use. Lastly, those who reported using drugs for social reasons were less likely to have decreased substance use during social distancing. Conclusions: The current study provides evidence that social distancing guidelines have impacted both substance use behaviors and feelings of social and physical connection. Further, there are differential impacts based on drug of choice. These results advance delineation of the connection between sociality and drug use.