Examining neural responses to anticipating or receiving monetary rewards and the development of binge eating in youth. A registered report using data from the Adolescent Brain Cognitive Development (ABCD) study.

Binge eating is characterized as eating a large amount of food and feeling a loss of control while eating. However, the neurobiological mechanisms associated with the onset and maintenance of binge eating are largely unknown. Recent neuroimaging work has suggested that increased responsivity within reward regions of the brain to the anticipation or receipt of rewards is related to binge eating; however, limited longitudinal data has precluded understanding of the role of reward responsivity in the development of binge eating. The current study used data from the Adolescent Brain and Cognitive Development® (ABCD) longitudinal study dataset to assess whether heightened neural responses to different phases of reward processing (reward anticipation and receipt) (1) differentiated individuals with binge eating from matched controls, and (2) predicted the onset of binge eating in an "at risk" sample. Consistent with hypotheses, heightened neural responsivity in the right caudate and bilateral VS during reward anticipation differentiated youth with and without binge eating. Moreover, greater VS response to reward anticipation predicted binge eating two years later. Neural responses to reward receipt also were consistent with hypotheses, such that heightened VS and OFC responses differentiated youth with and without binge eating and predicted the presence of binge eating two years later. Findings from the current study suggest that hypersensitivity to rewards may contribute to the development of binge eating during early adolescence.

TAG-ME again: A serious game for measuring working memory.

BrainTagger (demo version: researcher-demo.braintagger.com) is a suite of Target Acquisition Games for Measurement and Evaluation (TAG-ME). Here we introduce TAG-ME Again, a serious game modeled after the well-established N-Back task, to assess working memory ability across three difficulty levels corresponding to 1-, 2-, and 3-back conditions. We also report on two experiments aimed at assessing convergent validity with the N-Back task. Experiment 1 examined correlations with N-Back task performance in a sample of adults (n = 31, 18-54 years old) across three measures: reaction time; accuracy; a combined RT/accuracy metric. Significant correlations between game and task were found, with the strongest relationship being for the most difficult version of the task (3-Back). In Experiment 2 (n = 66 university students, 18-22 years old), we minimized differences between the task and the game by equating stimulus-response mappings and spatial processing demands. Significant correlations were found between game and task for both the 2-Back and 3-Back levels. We conclude that TAG-ME Again is a gamified task that has convergent validity with the N-Back Task.

Investigating Cortical Buffering Effects of Acute Moderate Intensity Exercise: A cTBS Study Targeting the Left Dorsolateral Prefrontal Cortex.

Background: The beneficial effects of both single-session bouts of aerobic exercise and therapeutic exercise interventions on the cortical regions associated with top-down attentional control [i.e., prefrontal cortex (PFC)] have been well documented. However, it remains unclear whether aerobic exercise can be used to buffer against suppressive influences on the dorsolateral PFC (dlPFC). Objective: The current study sought to determine whether a single session of moderate intensity aerobic exercise can offset the expected suppressive effects of continuous theta burst stimulation (cTBS) targeting the dorsolateral prefrontal cortex (dlPFC). Methods: Twenty-two right-handed participants (aged 19-30) completed a 20-minute movement-only control session [10% heart rate reserve (HRR)] and moderate intensity (50% HRR) exercise in a counterbalanced order. Following each exercise session, participants received active cTBS to the left dlPFC. Changes in executive functions were quantified using a Flanker paradigm employed at baseline, post-exercise and post-cTBS time points. Additionally, EEG was used to measure changes in event-related potential components related to inhibitory control (i.e., N2) and attentional control (i.e., P3) during the flanker task. Results: Behavioral results from the flanker task revealed a significant improvement in task performance following an acute bout of moderate intensity exercise. Furthermore, the effect of cTBS in both the movement-only control and moderate intensity conditions were non-significant. Similarly, EEG data from P3b and N2 ERP components revealed no changes to amplitude across time and condition. P3b latency data revealed a significant effect of time in both the moderate intensity and movement-only conditions, such that P3b latencies were significantly shorter across time points. Latency data within the N2 ERP component revealed no significant interactions or main effects. Conclusion: The findings of the current study provide tentative support for the hypothesis that both moderate and light intensity exercise promote cortical buffering against the suppressive effects of cTBS targeting the dlPFC. However, in the absence of a no-movement control, a lack of expected suppressive effects of cTBS cannot be ruled out.

The Bilingual Advantage in Children's Executive Functioning Is Not Related to Language Status: A Meta-Analytic Review.

There is considerable debate about whether bilingual children have an advantage in executive functioning relative to monolingual children. In the current meta-analysis, we addressed this debate by comprehensively reviewing the available evidence. We synthesized data from published studies and unpublished data sets, which equated to 1,194 effect sizes from 10,937 bilingual and 12,477 monolingual participants between the ages of 3 and 17 years. Bilingual language status had a small overall effect on children's executive functioning (g = .08, 95% confidence interval = [.01, .14]). However, the effect of language status on children's executive functioning was indistinguishable from zero (g = -.04) after we adjusted for publication bias. Further, no significant effects were apparent within the executive-attention domain, in which the effects of language status have been hypothesized to be most pronounced (g = .06, 95% confidence interval = [-.02, .14]). Taken together, available evidence suggests that the bilingual advantage in children's executive functioning is small, variable, and potentially not attributable to the effect of language status.

Adolescent obesity and dietary decision making-a brain-health perspective.

Adolescence represents a key period of brain development underpinned by the ongoing maturation of the prefrontal cortex-a brain region involved in the regulation of behaviour and cognition. Given the high prevalence of obesity in adolescents worldwide, this Review examines neurobiological and neurocognitive evidence describing the adolescent propensity to consume calorie-dense foods, and the neurodevelopmental mechanisms that heighten the adverse impact of these foods on brain function. The excessive consumption of calorie-dense food can undermine self-regulatory processes through effects on brain function and behavioural control. These changes could introduce enduring maladaptive eating behaviours that underlie adult obesity and related metabolic syndromes. Better understanding of links between adolescence, dietary decision making, and brain function is essential for clinicians to develop effective intervention strategies and for reducing long-term health-care costs associated with obesity.

Quantifying Cortical Resilience in Experimental, Clinical, and Epidemiological Studies: A Conceptually Grounded Method Using Noninvasive Brain Stimulation.

OBJECTIVE: Cortical resilience can be defined as the ability of the cortex of the human brain to rebound efficiently from perturbation. This concept is important in both research and clinical practice contexts. However, no direct measure of cortical resilience exists. Inhibitory variants of repetitive transcranial magnetic stimulation, such as continuous theta burst stimulation, provide a standardized method for inducing a perturbation; when coupled with the assessment of recovery rate from the perturbation, such a paradigm might provide a standardized measure of cortical resilience. This article describes a standardized method for quantifying cortical resilience using theta burst stimulation protocols. METHODS: A descriptive overview of a method for assessing cortical resilience is presented. Links are drawn between critical facets of the resilience construct and the protocol described. RESULTS: The Cortical Challenge and Recovery Test (CCaRT) method makes use of existing stimulation parameters and cognitive testing paradigms to provide a flexible and conceptually meaningful measure of cortical resilience. CONCLUSIONS: The CCaRT paradigm is potentially useful in research and contexts where cortical resilience is to be measured. The CCaRT paradigm has applicability to epidemiological studies and laboratory experimentation as well as diagnostic practice and clinical trial outcome measures.

The Prefrontal Cortex and Obesity: A Health Neuroscience Perspective.

In the modern obesogenic environment, limiting calorie-dense food consumption is partially dependent on the capacity of individuals to override visceral reactions to hyperpalatable and rewarding food cues. In the current review, we employ a health neuroscience framework to outline: (i) how individual variations in prefrontal cortical structure and functionality, and by extension, executive functions, may predispose an individual to the overconsumption of appetitive calorie-dense foods via differences in dietary self-regulation; (ii) how obesity may result in changes to cortical structure and functionality; and (iii) how the relationship between the structure and function of the prefrontal cortex and obesity may be best described as reciprocal in nature.

Reproducibility and sources of interindividual variability in the responsiveness to prefrontal continuous theta burst stimulation (cTBS).

Despite the increasing use of continuous theta burst (cTBS) protocols targeting the prefrontal cortex in clinical and research settings, very little is known regarding the interindividual factors that influence the magnitude and duration of cTBS aftereffects. The few existing studies have predominantly focussed on motor and corticospinal excitability, and the applicability of such findings to prefrontal modulation remains unclear. The current investigation aggregated published data from our laboratory to (1) assess the reproducibility of the effects of cTBS targeting the left dorsolateral prefrontal cortex (dlPFC) on executive function task performance, and (2) determine which factors are associated with individual differences in cTBS responsivity. Data from 76 healthy young adult female participants aged 19-26 (M = 20.6; SD = 1.6) were included in the analyses. Significant attenuations in executive function task performance from baseline were observed following active cTBS. However, these effects were not totally universal in that cTBS-induced attenuation of executive functions was observed in 61.8% of participants (i.e., responders). In addition, baseline task performance was a significant predictor of the magnitude of the cTBS-induced change in task performance in that cTBS effect was larger for individuals with higher baseline executive control abilities than those with lower abilities. Together, these data provide a quantitative estimate of the degree to which healthy participants may vary in the responsiveness to prefrontal cTBS, and potential moderating factors.

The neurocognitive mechanisms underlying food cravings and snack food consumption. A combined continuous theta burst stimulation (cTBS) and EEG study.

Regulation of food cravings is thought to be critical for modulating eating behavior, yet we do not fully understand the mechanisms by which cognitive control operates in the eating context. The current study combined rTMS and EEG paradigms to examine the causal role of the left dorsolateral prefrontal cortex (dlPFC) in modulating visceral and behavioral responses to high calorie foods, and the mediational mechanisms underlying this relation. 28 right-handed female participants received both active and sham continuous theta burst stimulation (cTBS; a rTMS variant used to decrease cortical activity) targeting the left dlPFC in a counterbalanced order. Prior to and following each stimulation session participants completed a flanker and food-cue presentation (high and low calorie food) task. Following cTBS participants had the opportunity to consume both high and low calorie foods during a taste test. Findings revealed a reliable effect of cTBS on food consumption, such that participants selectively ingested significantly more calories from appetitive calorie dense snack foods following active relative to sham cTBS; this effect did not translate to control (low calorie) food consumption. In addition, attenuation of dlPFC activity resulted in the significant increase in N2 amplitude and P3b latency to incongruent flanker trials, and the selective significant increase in the P3a amplitude to and P3a amplitude bias for high calorie food stimuli. Results from the parallel mediation analysis revealed that only the indirect effect of flanker task performance was significant; the indirect effects of stimulation induced changes in the P3 bias for high calorie foods, the urge to consume high calorie foods, and the general liking ratings for high calorie foods were not significant. These findings confirm the causal role of the left dlPFC in the modulation of calorie dense food consumption via inhibitory control capacity.

Effects of left dlPFC modulation on social cognitive processes following food sampling.

BACKGROUND: The dorsolateral prefrontal cortex (dlPFC) plays a central role in the inhibition of eating, but also the modulation of conscious thought processes that might precede, accompany or follow initial food tasting. The latter might be particularly important to the extent that post-tasting cognitions may drive prolonged eating beyond the satiety point. However, we know very little about the effect of the dlPFC on conation following initial food sampling. This investigation compared the effects of dlPFC attenuation using repetitive transcranial magnetic stimulation (rTMS) on social cognition following (Study 1) and prior to (Study 2) a food consumption opportunity. METHODS: In Study 1, participants (N = 21; Mage = 21 years) were randomized to active or sham continuous theta-burst stimulation (cTBS; an inhibitory variant of rTMS) targeting the left dlPFC followed by an interference task. Participants subsequently completed measures of attitudes, norms and perceived control following a mock taste test. In Study 2, a second sample of right handed participants (N = 37; Mage = 21 years) were assigned to active or sham cTBS, followed by an interference task and two measures of attitudes (implicit and explicit), both assessed prior to the same taste test paradigm. RESULTS: In Study 1, findings revealed a reliable effect of cTBS on post-tasting attitudes (t(1,19) = 3.055, p = .007; d = 1.34), such that attitudes towards calorie dense snack foods were significantly more positive following active stimulation than following sham stimulation. Similar effects were found for social norms (t(1,19) = 3.024, p = .007, d = 1.31) and perceived control (t(1,20) = 19.247, p < .001, d = 0.50). In Study 2, no effects of cTBS were observed on pre-consumption attitudes, despite reliable effects on interference scores and subsequent consumption. CONCLUSIONS: The left dlPFC may selectively modulate facilitative social cognition following initial food sampling (but not pre-consumption).

The effects of theta burst stimulation (TBS) targeting the prefrontal cortex on executive functioning: A systematic review and meta-analysis.

Theta burst stimulation (TBS) is a highly efficient repetitive transcranial magnetic stimulation (rTMS) variant employed in experimental and clinical treatment paradigms. Despite widespread usage of TBS targeting the prefrontal cortex (PFC), there has been no systematic review of the evidence linking TBS protocols to changes in task performance on common measures of prefrontal function in general, and executive functions specifically. A systematic review of the literature was conducted using PsycINFO, PubMed, Web of Science and Scopus databases to identify articles examining the effects of TBS targeting the PFC on executive function task performance. Both the up-regulating (intermittent theta burst stimulation; iTBS) and down-regulating (continuous theta burst stimulation; cTBS) variants of TBS were considered. 32 (29 cTBS; 8 iTBS) studies met the inclusion criteria. Participants (n = 759; 51.41% female) were primarily young adults (Mage = 26), with one study examining the effects of cTBS and iTBS in older adults. Results from individual studies were converted to Hedge's g and random-effects models were used to estimate the overall effect size for each protocol. Age, biological sex, and control methodology were examined as potential moderators of the cTBS effect on executive function test performance. Findings indicated a- reliable attentuating effect of cTBS on executive function task performance (g = -.244, Z = -5.920, p < .001); this effect was relatively uniform across included studies (Q= 24.178, p = .838, I2 = 0). Although no significant moderators of the cTBS effect were identified, laterality sub analyses indicated that the magnitude of the effect was significantly higher (Mdiff = .213, Zdiff = 2.546, p = .011) for left-sided (g = -.358, Z = -5.816, p < .001) relative to right-sided (g = -.145, Z = -2.552, p = .011) PFC stimulation. A systematic review of iTBS studies revealed variability in reliability of effects though most were in the theorized direction. TBS protocols appear to be effective in modulating prefrontal cortical excitability in previously theorized directions.

The neurocognitive consequences of sleep restriction: A meta-analytic review.

The current meta-analytic review evaluated the effects of experimentally manipulated sleep restriction on neurocognitive functioning. Random-effects models were employed to estimate the overall effect size and the differential effect size across cognitive domains. Age, time of day, age-adjusted sleep deficit, cumulative days of restricted sleep, sleep latency, subjective sleepiness, and biological sex were examined as potential moderators of the effect. Based on a sample of 61 studies, from 71 different populations, findings revealed a significant negative effect of sleep restriction on cognitive processing across cognitive domains (g=-0.383, p<0.001). This effect held for executive functioning (g=-0.324, p<0.001), sustained attention (g=-0.409, p<0.001), and long-term memory (g=-0.192, p=0.002). There was insufficient evidence to detect an effect within the domains of attention, multitask, impulsive decision-making or intelligence. Age group, time of day, cumulative days of restricted sleep, sleep latency, subjective sleepiness, and biological sex were all significant moderators of the overall effect. In conclusion, the current meta-analysis is the first comprehensive review to provide evidence that short-term sleep restriction significantly impairs waking neurocognitive functioning.

Effects of Moderate Exercise on Cortical Resilience: A Transcranial Magnetic Stimulation Study Targeting the Dorsolateral Prefrontal Cortex.

OBJECTIVE: The beneficial effects of exercise on the brain regions that support cognitive control and memory are well documented. However, examination of the capacity of acute exercise to promote cortical resilience-the ability to recover from temporary pertubation-has been largely unexplored. The present study sought to determine whether single session of moderate-intensity aerobic exercise can accelerate recovery of inhibitory control centers in the dorsolateral prefrontal cortex after transient perturbation via continuous theta burst stimulation (cTBS). METHODS: In a within-participants experimental design, 28 female participants aged 18 to 26 years (mean [standard deviation] = 20.32 [1.79] years) completed a session each of moderate-intensity and very light-intensity exercise, in a randomized order. Before each exercise session, participants received active cTBS to the left dorsolateral prefrontal cortex. A Stroop task was used to quantify both the initial perturbation and subsequent recovery effects on inhibitory control. RESULTS: Results revealed a significant exercise condition (moderate-intensity exercise, very light-intensity exercise) by time (prestimulation, poststimulation, postexercise) interaction (F(2,52) = 5.93, p = .005, d = 0.38). Specifically, the proportion of the cTBS-induced decrement in inhibition restored at 40 minutes postexercise was significantly higher after a bout of moderate-intensity exercise (101.26%) compared with very light-intensity exercise (18.36%; t(27) = -2.17, p = .039, d = -.57, 95% confidence interval = -161.40 to -4.40). CONCLUSION: These findings support the hypothesis that exercise promotes cortical resilience, specifically in relation to the brain regions that support inhibitory control. The resilience-promoting effects of exercise have empirical and theoretical implications for how we conceptualize the neuroprotective effects of exercise.

Effects of Noninvasive Brain Stimulation on Food Cravings and Consumption: A Meta-Analytic Review.

OBJECTIVE: The primary aim of this review was to evaluate the effectiveness of noninvasive brain stimulation to the dorsolateral prefrontal cortex (dlPFC) for modulating appetitive food cravings and consumption in laboratory (via meta-analysis) and therapeutic (via systematic review) contexts. METHODS: Keyword searches of electronic databases (PubMed, Scopus, Web of Science, PsychoInfo, and EMBASE) and searches of previous quantitative reviews were used to identify studies (experimental [single-session] or randomized trials [multi-session]) that examined the effects of neuromodulation to the dlPFC on food cravings (n = 9) and/or consumption (n = 7). Random-effects models were employed to estimate the overall and method-specific (repetitive transcranial magnetic stimulation [rTMS] and transcranial direct current stimulation [tDCS]) effect sizes. Age and body mass index were examined as potential moderators. Two studies involving multisession therapeutic stimulation were considered in a separate systematic review. RESULTS: Findings revealed a moderate-sized effect of modulation on cravings across studies (g, -0.516; p = .037); this effect was subject to significant heterogeneity (Q, 33.086; p < .001). Although no statistically significant moderators were identified, the stimulation effect on cravings was statistically significant for rTMS (g, -0.834; p = .008) but not tDCS (g, -0.252; p = .37). There was not sufficient evidence to support a causal effect of neuromodulation and consumption in experimental studies; therapeutic studies reported mixed findings. CONCLUSIONS: Stimulation of the dlPFC modulates cravings for appetitive foods in single-session laboratory paradigms; when estimated separately, the effect size is only significant for rTMS protocols. Effects on consumption in laboratory contexts were not reliable across studies, but this may reflect methodological variability in delivery of stimulation and assessment of eating behavior. Additional single- and multi-session studies assessing eating behavior outcomes are needed.

An exploration of exercise-induced cognitive enhancement and transfer effects to dietary self-control.

The primary objective of this study was to examine the effects of aerobic exercise on executive function, specifically inhibitory control, and the transfer to self-control in the dietary domain. It was hypothesized that exercise would enhance inhibitory control, and that this enhancement would facilitate self-control in a laboratory taste test paradigm. Using a crossover design, 51 participants completed counterbalanced sessions of both moderate exercise (experimental condition) and minimal effort walking (control condition) using a treadmill; the intersession interval was 7days. Prior to each exercise bout participants completed a Stroop task. Following each bout participants completed a second Stoop task, as well as a bogus taste test involving three appetitive calorie dense snack foods and two control foods; the amount of each food type consumed during the taste test was covertly measured. Results revealed that moderate exercise significantly improved performance on the Stroop task, and also reduced food consumption during the taste test for appetitive calorie dense snack foods; there was no exercise effect on control food consumption. Exercise-induced gains in Stroop performance mediated the effects of moderate exercise on appetitive snack food consumption. Together these findings provide evidence that a bout of a moderate aerobic exercise can enhance inhibitory control, and support for cross-domain transfer effects to dietary self-control.

The effects of continuous theta burst stimulation to the left dorsolateral prefrontal cortex on executive function, food cravings, and snack food consumption.

OBJECTIVES: Prior research has demonstrated that executive function (EF) strength is positively associated with dietary self-control. As such, the differential operation of the brain centers underlying EFs (i.e., dorsolateral prefrontal cortex [DLPFC]) may explain controlled aspects of dietary self-control. The present study was designed to examine the causal relationship between DLPFC function and two aspects of dietary self-control: visceral cravings and actual consumptive behaviors. METHODS: The research was conducted using a within-participant design. A sample of 21 healthy female young adults aged 19 to 26 years (mean [M; standard deviation] = 21.10 [1.86] years) received both active and sham continuous theta burst stimulation (cTBS) to the left DLPFC. Before and after each session, subjective food cravings were assessed using the Food Craving Questionnaire-State. After each stimulation session, participants competed three measures of EF (Stroop, Go/No-Go, and Stop-Signal) and a bogus taste test. RESULTS: Participants reported larger increases in snack food cravings after active stimulation (M = 9.98% change, standard error [SE] = 0.45) than after sham stimulation (M = -3.46, SE = 0.39, p = .012) on the reinforcement anticipation dimension of Food Craving Questionnaire-State. Likewise, participants consumed significantly more snack foods after active stimulation (M = 70.62 grams, SE = 5.17) than after sham stimulation (M = 61.33, SE = 3.56, p = .006). Finally, performance on the Stroop task was reduced more after active (M = 71.56 milliseconds, SE = 25.18) than after sham stimulation (M = 20.16, SE = 13.32, p = .033); reduction in Stroop performance mediated the effect of active stimulation on increased appetitive food consumption. CONCLUSION: These results support the contention that EF strength, as modulated by DLPFC activity, is causally associated with effective dietary self-control.

The effects of acute aerobic activity on cognition and cross-domain transfer to eating behavior.

Prior studies have demonstrated that a single session of aerobic exercise can enhance cognitive functioning; specifically, the inhibition facet of executive function (EF). Additionally, previous research has demonstrated that inhibitory abilities are essential for effective dietary self-control. However, it is currently unknown whether exercise induced enhancements in EF also facilitate self-control in the dietary domain. The present study sought to determine whether a single session of aerobic exercise enhances EF, and whether there is a transfer effect to dietary self-control. Thirty four undergraduate students were randomly assigned to one of three exercise conditions: (1) minimal exercise; (2) moderate intensity exercise (30% heart rate reserve); (3) vigorous intensity exercise (50% heart rate reserve). After the exercise bout, participants completed three standardized EF tasks followed by a bogus taste test for three appetitive snack foods (milk chocolate and potato chips) and two control foods (dark chocolate and crackers). The amount of food consumed during the taste test was covertly measured. The results revealed a significant main effect of treatment condition on the Stroop task performance, but not Go-NoGo (GNG) and Stop Signal task performance. Findings with respect to food consumption revealed that EF moderated the treatment effect, such that those with larger exercise effects on Stroop performance in the moderate intensity exercise condition consumed more control foods (but not less appetitive foods). These findings support the contention that a single bout of aerobic exercise enhances EF, and may have transfer effects to the dietary domain, but that such effects may be indirect in nature.