The impact of exercise on food-related inhibitory control- do calories, time of day, and BMI matter? Evidence from an event-related potential (ERP) study.

A growing body of research suggests exercise improves inhibitory control functions. We tested if exercise-related inhibitory control benefits extend to food-related inhibitory control and differ by calorie content, time of day, and weight status. One hundred thirty-eight individuals were pseudo-randomly assigned to a morning or evening group. Each subject participated in two lab sessions where they completed questionnaires (rest session) or walked on a treadmill at 3.8mph (exercise session) for 45 min. After each session, participants completed both a high-calorie and low-calorie go/no-go task while N2 and P3 event-related potentials (ERP), both neural indicators of inhibitory control, were measured. Participants also rated food images for valence and arousal. While N2 and P3 difference amplitudes were larger to high-calorie than low-calorie foods, neither exercise nor time of day affected results. Individuals had faster response times after exercise without decreases in accuracy. Arousal and valence for high-calorie foods were lower after exercise and lower for all foods after morning compared to evening exercise. In a subset of individuals with obesity and normal-weight individuals, individuals with obesity had larger N2 difference amplitudes after morning exercise, while normal-weight individuals had larger P3 difference amplitudes to high-calorie foods after exercise. Results suggest moderate exercise did not affect food-related inhibitory control generally, although morning exercise may be beneficial in improving early recruitment of food-related inhibitory control in individuals with obesity. Moderate exercise, particularly in the morning, may also help manage increased attention allocated to food.

Does intensity matter? A randomized crossover study of the role of acute exercise intensity on cognitive performance and motor speed and accuracy.

There is a well-recognized, yet nuanced, positive relationship between acute physical activity and cognitive function. However, the precise impact of exercise intensity remains ambiguous. We tested learning and memory, working memory and processing speed, and motor speed and accuracy across three distinct exercise intensities. A sample of 207 participants (100 female) between 18 and 44 years (mean age: 22.5±3.7years) completed all study procedures. Utilizing a within-subjects, cross-over design, participants completed moderate (35% VO2 Max), vigorous (70% VO2 Max), and sedentary (no exercise) conditions. Cognitive and motor assessments, including the Paced Auditory Serial Addition Test (PASAT), Rey Auditory Verbal Learning Test (RAVLT), Typing Speed Test, and Ten Key Data Entry Task, were conducted approximately 60min post-exercise. There were no significant differences in primary cognitive or motor outcome measures across the three exercise intensities, even with the study being strongly powered. There was, however, a small difference on the fastest trial of the PASAT, where vigorous-intensity exercise yielded slightly better performance compared to both sedentary and moderate-intensity exercise. This effect was no longer significant when including VO2 Max or maximum heart rate as indicators of fitness. There were no interactions on outcome variables by exercise intensity when including biological sex in the models. Thus, a single bout of acute exercise, regardless of its intensity, did not alter cognitive and motor performance when measured approximately 1h post-exercise. Findings highlight the importance of large samples and suggest that the temporal dynamics post-exercise might play a pivotal role in cognitive outcomes.

Age-related differences in food-specific inhibitory control: Electrophysiological and behavioral evidence in healthy aging.

The number of older adults in the United States is estimated to nearly double from 52 million to 95 million by 2060. Approximately 80-85% of older adults are diagnosed with a chronic health condition. Many of these chronic health conditions are influenced by diet and physical activity, suggesting improved diet and eating behaviors could improve health-related outcomes. One factor that might improve dietary habits in older adults is food-related inhibitory control. We tested whether food-related inhibitory control, as measured via behavioral data (response time, accuracy) and scalp-recorded event-related potentials (ERP; N2 and P3 components), differed between younger and older adults over age 55. Fifty-nine older adults (31 females [52.5%], Mage = 64, SDage = 7.5) and 114 younger adults (82 females [71.9%], Mage = 20.8) completed two go/no-go tasks, one inhibiting to high-calorie stimuli and one inhibiting to low-calorie stimuli, while electroencephalogram (EEG) data were recorded. Older adults had slower overall response times than younger adults, but this was not specific to either food task. There was not a significant difference in accuracy between younger and older adults, but both groups' accuracy and response times were significantly better during the high-calorie task than the low-calorie task. For both the N2 and P3 ERP components, younger adults had larger no-go ERP amplitudes than older adults, but this effect was not food-specific, reflecting overall generalized lower inhibitory control processing in older adults. P3 amplitude for the younger adults demonstrated a specific food-related effect (greater P3 amplitude for high-calorie no-go than low-calorie no-go) that was not present for older adults. Findings support previous research demonstrating age-related differences in inhibitory control though those differences may not be specific to inhibiting towards food.

Testing the relationship between inhibitory control and soda consumption: An event-related potential (ERP) study.

The intake of sugar-sweetened beverages (SSB) may detrimentally influence health outcomes. Drinking less soda may help manage SSB consumption, as soft drinks are a top contributor to SSB intake. One cognitive factor that may influence soda consumption is inhibitory control, or the ability to withhold a dominant response in order to correctly respond to one's environment. Increased inhibitory control plays a role in decreasing consumption of high-calorie foods and strengthening inhibitory control may help individuals manage their food intake. However, neural response to soda beverages versus traditional non-sweetened beverages, such as water, and how it relates to soda consumption is unknown. In a sample of 116 healthy individuals (M = 20.56; SD = 2.08; 47.4% female), we measured soda consumption and tested event-related potential (ERP) measures of inhibitory control, including the N2 and P3 components, during soda-specific and neutral comparison go/no-go tasks. Female participants consumed less soda on average than males, and as participants got older, they consumed less soda. Participants showed faster response times and higher accuracy on the soda-specific go/no-go task compared to the neutral go/no-go task. ERP results indicated inhibitory control was greater when individuals withheld dominant responses to soda stimuli rather than neutral stimuli. Neither N2 no-go amplitude on the soda-specific go/no-go task nor P3 no-go amplitude on the soda-specific task predicted measures of soda intake. Results suggest greater inhibitory control resources are required when withholding responses to soda beverages compared to neutral stimuli, but inhibitory control ERPs did not predict day-to-day soda intake.

The relationship between acute stress and neurophysiological and behavioral measures of food-related inhibitory control: An event-related potential (ERP) study.

Stress influences many health-related behaviors including diet and nutrition intake, often resulting in increased calorie intake, fewer healthy eating behaviors, and poorer nutrition. Food intake is modulated by inhibitory control and has important implications for our physical, mental, and emotional health. Yet, little is known about the relationship between stress and food-related inhibitory control. We tested the influence of a short-term experimental stressor on behavioral and event-related potential (ERP; N2 and P3 components) measures of food-related inhibitory control. Ninety-seven healthy participants were randomly assigned to complete the Trier Social Stress Test (TSST) (n = 48, 27 females [52.9%]) or a neutral control condition (n = 49, 35 females [70%]) immediately followed by food-specific go/no-go and neutral go/no-go tasks while electroencephalogram (EEG) data were recorded. Stress levels were successfully manipulated, with heightened self-report and physiological measures (heart rate and systolic blood pressure) of the stress response in individuals who completed the TSST compared to control. As expected, the high calorie food-specific go/no-go task elicited larger N2 amplitude than the neutral task. N2 component amplitude was also significantly larger following the TSST relative to the control task. There were no significant between-group or task differences for P3 amplitude or behavioral measures. Findings suggest heightened N2 amplitude following psychological stress that is not specific to food or inhibition processes and may reflect heightened arousal following stress. Future research in individuals with overweight/obesity or experiencing chronic stress will further clarify the role of stress in food-related inhibitory control.

The impact of exercise intensity on neurophysiological indices of food-related inhibitory control and cognitive control: A randomized crossover event-related potential (ERP) study.

Food-related inhibitory control, the ability to withhold a dominant response towards highly palatable foods, influences dietary decisions. Food-related inhibitory control abilities may increase following a bout of aerobic exercise; however, the impact of exercise intensity on both food-related inhibitory control and broader cognitive control processes is currently unclear. We used a high-powered, within-subjects, crossover design to test how relative intensity of aerobic exercise influenced behavioral (response time, accuracy) and neural (N2 and P3 components of the scalp-recorded event-related potential [ERP]) measures of food-related inhibitory and cognitive control. Two hundred and ten participants completed three separate conditions separated by approximately one week in randomized order: two exercise conditions (35% VO2max or 70% VO2max) and seated rest. Directly following exercise or rest, participants completed a food-based go/no-go task and a flanker task while electroencephalogram data were recorded. Linear mixed models showed generally faster response times (RT) and improved accuracy following 70% VO2max exercise compared to rest, but not 35% VO2max; RTs and accuracy did not differ between 35% VO2max exercise and rest conditions. N2 and P3 amplitudes were larger following 70% VO2max exercise for the food-based go/no-go task compared to rest and 35% VO2max exercise. There were no differences between exercise conditions for N2 amplitude during the flanker task; however, P3 amplitude was more positive following 70% VO2max compared to rest, but not 35% VO2max exercise. Biological sex did not moderate exercise outcomes. Results suggest improved and more efficient food-related recruitment of later inhibitory control and cognitive control processes following 70% VO2max exercise.

Using generalizability theory and the ERP reliability analysis (ERA) toolbox for assessing test-retest reliability of ERP scores part 2: Application to food-based tasks and stimuli.

If an ERP score is to reflect a trait-like characteristic or indicate if an intervention had an effect over time, adequate internal consistency and test-retest reliability of that ERP score across multiple testing sessions must be established. The current paper is a companion paper to Clayson et al. (current issue) that applied generalizability theory formulas and the ERP Reliability Analysis (ERA) Toolbox to assess test-retest and internal consistency in a dataset of event-related brain potentials (ERPs) assessing food-related cognition. Although ERPs in response to food cues have been related to eating behaviors or assessed during a health intervention, the reliability of food-related ERPs generally has not been tested. Within the generalizability theory framework, we assessed the stability (cf., test-retest reliability) and equivalence (cf., internal consistency) of four commonly used food-related ERPs: the late positive potential (LPP), centro-parietal P3, N2, and fronto-central P3. 132 participants (92 female) completed two testing sessions held two weeks apart. During the sessions, participants completed a passive food viewing task, a high-calorie go/no-go task, and a low-calorie go/no-go task in a counterbalanced fashion. Coefficients of equivalence for all ERPs were excellent (>0.96). Coefficients of stability were moderate-to-low, with N2 scores on the low-calorie go/no-go task showing the highest test-retest reliability (>0.65) and fronto-central P3 scores on the high-calorie go/no-go task showing the lowest (0.48). Results suggest the ERPs in the current dataset have high internal consistency and would be reliable in detecting individual differences, but their test-retest reliability is limited. Reliability of these ERPs may be improved with changes in task stimuli, task instructions, and study procedures.

Using generalizability theory and the ERP Reliability Analysis (ERA) Toolbox for assessing test-retest reliability of ERP scores part 1: Algorithms, framework, and implementation.

The reliability of event-related brain potential (ERP) scores depends on study context and how those scores will be used, and reliability must be routinely evaluated. Many factors can influence ERP score reliability; generalizability (G) theory provides a multifaceted approach to estimating the internal consistency and temporal stability of scores that is well suited for ERPs. G theory's approach possesses a number of advantages over classical test theory that make it ideal for pinpointing sources of error in observed scores. The current primer outlines the G-theory approach to estimating internal consistency (coefficients of equivalence) and test-retest reliability (coefficients of stability). This approach is used to evaluate the reliability of ERP measurements. The primer outlines how to estimate reliability coefficients that consider the impact of the number of trials, events, occasions, and groups. The uses of two different G-theory reliability coefficients (i.e., generalizability and dependability) in ERP research are elaborated, and a dataset from the companion manuscript, which examines N2 amplitudes to Go/NoGo stimuli, is used as an example of the application of these coefficients to ERPs. The developed algorithms are implemented in the ERP Reliability Analysis (ERA) Toolbox, which is open-source software designed for estimating score reliability using G theory. The toolbox facilitates the application of G theory in an effort to simplify the study-by-study evaluation of ERP score reliability. The formulas provided in this primer should enable researchers to pinpoint the sources of measurement error in ERP scores from multiple recording sessions and subsequently plan studies that optimize score reliability.

Does inhibitory control training reduce weight and caloric intake in adults with overweight and obesity? A pre-registered, randomized controlled event-related potential (ERP) study.

A cognitive intervention that may reduce weight and caloric intake is inhibitory control training (ICT; having individuals repeatedly withhold dominant responses to unhealthy food images). We conducted a randomized controlled trial where 100 individuals with overweight or obesity were assigned to complete a generic (n = 48) or food-specific ICT (n = 52) training four times per week for four weeks. Weight and caloric intake were obtained at baseline, four-weeks, and 12-weeks. Participants also completed high-calorie and neutral go/no-go tasks while N2 event-related potential (ERP) data, a neural indicator of inhibitory control, was measured at all visits. Results from mixed model analyses indicate that neither weight, caloric intake, nor N2 ERP component amplitude towards high-calorie foods changed at post-testing or at the 12-week follow up. Regression analyses suggest that individuals with smaller N2 difference amplitudes to food may show greater weight loss and reductions in caloric intake after a generic ICT, while individuals with larger N2 difference amplitudes to food may show greater weight loss and reductions in caloric intake after a food-specific ICT. Overall, multiple food-specific or generic ICT sessions over the course of a four-week period do not affect overall weight loss, caloric intake, or N2 ERP amplitude.

To play or not to play? The relationship between active video game play and electrophysiological indices of food-related inhibitory control in adolescents.

Sedentary behaviors, such as computer use and sedentary video games, are barriers to physical activity, contribute to overweight and obesity among adolescents, and can adversely affect eating behaviors. Active video games may increase daily physical activity levels among adolescents and improve food-related inhibitory control. We compared the effects of acute bouts of active and sedentary video gaming on event-related potential (ERP) indices of food-related inhibitory control, energy expenditure, and ad libitum eating. In a within-subjects design, 59 adolescent participants (49% female, Mage  = 13.29 ± 1.15) completed two separate counterbalanced, 60-min long video gaming sessions separated by seven days. Immediately after, participants completed two go/no-go tasks with high- and low-calorie images and N2 and P3 ERP amplitudes were measured. Participants also completed a Stroop task and were given high- and low-calorie snacks to consume ad libitum. Results indicated that active relative to sedentary video games significantly increased energy expenditure on multiple measures (e.g., METs, heart rate, kcals burned) and participants consumed more calories after the active compared to the sedentary video game session. N2 amplitudes were larger when participants inhibited to high- compared to low-calorie foods, suggesting that high-calorie foods necessitate increased the recruitment of inhibitory control resources; however, there were non-significant differences for the N2 or P3 amplitudes, accuracy or response times, and Stroop performance between active versus sedentary video game sessions. Overall, sixty minutes of active video gaming increased energy expenditure and food consumption but did not significantly alter neural or behavioral measures of inhibitory control to food stimuli.

The relationship between exercise intensity and neurophysiological responses to food stimuli in women: A randomized crossover event-related potential (ERP) study.

We tested the effect of different intensities of acute exercise on hunger, and post-exercise energy intake, and neurophysiological measures of attention towards food- and non-food stimuli in women. In a within-subjects crossover design, forty-two women completed no exercise, moderate-intensity exercise, and vigorous-intensity exercise sessions separated by one week, in a counterbalanced fashion. At each session, participants completed a passive viewing task of food (high- and low-calorie) and non-food pictures while electroencephalogram (EEG) data were recorded. The early posterior negativity (EPN), P3, and late positive potential (LPP) components of the event-related potential (ERP) measured neurophysiological responses. Subjective ratings of hunger were measured before and immediately after each condition using a visual analog scale (VAS) and food intake was measured using an ad libitum snack buffet offered at the end of each condition. Results indicated that hunger levels increased as time passed for all sessions. EPN amplitude was larger to non-food compared to food images; P3 amplitude was larger to food than non-food stimuli. LPP amplitude did not differ by high-calorie, low-calorie, or non-food images. Notably, there were no significant main effects or interactions of any ERP component amplitude as a function of exercise intensity. Food intake also did not differ by rest or moderate or vigorous exercise, although subjective arousal ratings to the images were higher after moderate and vigorous exercise compared to rest. Food images also had higher arousal and valence ratings than non-food images overall. Findings indicate that, in this sample, acute moderate and vigorous exercise compared to rest did not disproportionately affect neurophysiological measures of attention to food or non-food stimuli, caloric intake, or hunger.

Does type of active workstation matter? A randomized comparison of cognitive and typing performance between rest, cycling, and treadmill active workstations.

Active workstations are associated with improved health outcomes, but differences in cognitive and typing outcomes between the types of active workstations are unclear. We addressed two main questions: (1) Are there differences in cognitive and typing performance between seated and active workstations? (2) Are there differences in cognitive and typing performance between cycling and treadmill workstations, specifically? Participants included 137 healthy young adults (74 female, mean age = 20.8 years) who completed two sessions. At session one (baseline), all participants completed cognitive and typing tests including the Rey-Auditory Verbal Learning Test, Paced Auditory Serial Addition Test, a typing test, and a flanker task while sitting at rest. At session two, participants were randomized to an active workstation group (treadmill or cycling desk) during which they performed the tests listed above in a randomized fashion, using alternate versions when available. Participants showed significantly better attention and cognitive control scores during the active session as compared to the seated session, but worse verbal memory scores during the active session. Participants were faster and more accurate at typing during the active session relative to the seated session. There were no significant differences between cycling or treadmill workstations on any cognitive or typing outcomes. Improvements during active sessions may be influenced by practice effects, although alternate forms were used when possible. We conclude that active workstations do not seem to largely impact cognitive abilities, with the exception of a slight decrease in verbal memory performance. Findings suggest active workstations, whether walking or cycling, are useful to improve physical activity, particularly when completing tasks that do not require verbal memory recall.

The Association Between Experimentally Induced Stress, Performance Monitoring, and Response Inhibition: An Event-Related Potential (ERP) Analysis.

Psychological stress is increasingly associated with alterations in performance and affect. Yet, the relationship between experimentally induced psychological stress and neural indices of performance monitoring and error processing, as well as response inhibition, are unclear. Using scalp-recorded event-related potentials (ERPs), we tested the relationship between experimental stress, using the Trier Social Stress Test (TSST), and the error-related negativity (ERN), error positivity (Pe), and N2 ERP components. A final sample of 71 undergraduate students were randomly assigned to go through the TSST (n = 36; 18 female) or a brief mindfulness relaxation exercise (n = 35; 16 female) immediately followed by a go/no-go task while electroencephalogram (EEG) data were collected. Salivary cortisol, heart rate, and blood pressure confirmed increased physiological stress in the TSST group relative to control. Reaction times, accuracy, and post-error slowing did not differ by stress group. Two-group (TSST, control) by 2-trial type (correct, incorrect for ERN/Pe; go correct, no-go correct for N2) repeated measures ANOVAs for the ERN, Pe, and N2 showed the expected main effects of trial type; neither the ERN nor the N2 ERP components showed interactions with the stress manipulation. In contrast, the Pe component showed a significant Group by Trial interaction, with reduced Pe amplitude following the stress condition relative to control. Pe amplitude did not, however, correlate with cortisol reactivity. Findings suggest a reduction in Pe amplitude following experimental stress that may be associated with reduced error awareness or attention to errors following the TSST. Given the variability in the extant literature on the relationship between experimentally induced stress and neurophysiological reflections of performance monitoring, we provide another point of data and conclude that better understanding of moderating variables is needed followed by high-powered replication studies to get at the nuance that is not yet understood in the relationship between induced stress and performance monitoring/response inhibition processes.

Dimensions of anxiety and depression and neurophysiological indicators of error-monitoring: Relationship with delta and theta oscillatory power and error-related negativity amplitude.

Error-monitoring processes may be affected by transdiagnostic dimensions of psychopathology symptoms including trait anxiety, worry, and severity of depressive symptoms. We tested the relationship between continuous measures of anxiety and depressive symptomology and neural correlates of error-monitoring as measured by time-frequency domain delta and theta oscillatory power and time-domain error-related negativity (ERN) amplitude extracted from the electroencephalogram (EEG). Secondary analyses tested for diagnostic group differences in error-related neural responses in individuals with generalized anxiety disorder (GAD), major depressive disorder (MDD), and comorbid psychiatric disorders. About 178 participants (104 female, M[SD]age  = 21.7[4.6]) with a wide range of psychopathology symptoms completed a modified version of the Eriksen flanker task and symptom questionnaires. Residualized difference values between correct and error trials for delta/theta power and error/correct ERN amplitude were used as dependent variables. Linear regression analyses adjusted for age, sex, and task accuracy showed nonsignificant associations of symptom dimension measures with error-related residualized delta/theta power or residualized ERN amplitude. Subset analyses on those with confirmed psychopathology diagnoses also did not predict residualized error-related delta/theta power nor residualized ERN amplitude (nGAD  = 14, nMDD  = 28, nComorbid  = 19, nControl  = 85). Taken in the context of the previous literature, results suggest a heterogeneous relationship between depressive and anxiety symptom dimensions and neurophysiological indices of error-monitoring.

A registered report of error-related negativity and reward positivity as biomarkers of depression: P-Curving the evidence.

Performance-monitoring event-related brain potentials (ERPs), such as the error-related negativity (ERN) and reward positivity (RewP), are advocated as biomarkers of depression symptoms and risk. However, a recent meta-analysis indicated effect size heterogeneity in the ERN and RewP literatures. Hence, advocating these ERPs as biomarkers of depression might be premature or possibly misguided due to the selective reporting of significant analyses on the part of researchers (e.g., p-hacking or omission of non-significant findings). The present study quantified the degree of selective reporting and the evidential value for a true relationship between depression and ERN and RewP using a p-curve analysis. We predicted that the ERN and RewP literatures would fail to show evidential value for a relationship between each ERP and depression. Contrary to expectations, both literatures showed evidential value, albeit weak. The statistical power of the included ERN studies was between 20% and 25%, and the statistical power of the RewP was around 27%. Taken together, these findings provide support for a relationship between these ERPs and depression, which strengthens claims that these ERPs represent candidate biomarkers of depression symptoms and risk. In light of the evidence for these relationships being weak, some recommendations moving forward include conducting a priori power analyses, increasing sample sizes to improve statistical power, assessing the internal consistency of ERP scores, and carefully planning statistical approaches to maximize power.

White matter integrity disparities between normal-weight and overweight/obese adolescents: an automated fiber quantification tractography study.

Obese adults have been shown to have poorer white brain matter integrity relative to normal-weight peers, but few studies have tested whether white matter integrity is compromised in overweight and obese adolescents. Also, it is unclear if age interacts with body mass to affect white matter integrity in adolescents. We used Automated Fiber Quantification, a tractography method, to compare fractional anisotropy between normal-weight and overweight/obese adolescents in the corpus callosum, corticospinal tract, cingulum, inferior fronto-occipital fasciculus, and uncinate fasciculus. Further, we tested whether any differences were moderated by age. Forty-seven normal-weight and forty overweight/obese adolescents were scanned using a diffusion tensor imaging (DTI) scan sequence. Overweight/obese compared to normal-weight adolescents had decreased white matter integrity in the superior frontal corpus callosum, left and right uncinate fasciculi, left inferior fronto-occipital fasciculus, and left corticospinal tract, which may be related to heightened reward processing. Overweight/obese compared to normal-weight adolescents had increased white matter integrity in the orbital and anterior frontal corpus callosum, right inferior fronto-occipital fasciculus, left cingulum, and left corticospinal tract, which may be related to heightened attentional processing. As age increased, six tracts showed poorer white matter integrity as body mass index percentile (BMI%) increased, but three tracts showed greater white matter integrity as BMI% increased. Future research examining associations between white matter integrity and neural indices of food-related reward and attention are needed to clarify the functional significance of white matter integrity discrepancies between normal-weight and overweight/obese adolescents.

Differentiating electrophysiological indices of internal and external performance monitoring: Relationship with perfectionism and locus of control.

The impact of individual differences on performance monitoring and psychopathology is a question of active debate. Personality traits associated with psychopathology may be related to poor internal performance monitoring (as measured by the error-related negativity [ERN]) but intact external performance monitoring (as measured by the reward positivity [RewP]), suggesting that there are underlying neural differences between internal and external performance monitoring processes. We tested the relationships between individual difference measures of perfectionism, locus of control, and ERN, error-positivity (Pe), and RewP component difference amplitude in a healthy undergraduate sample. A total of 128 participants (69 female, M(SD)age = 20.6(2.0) years) completed two tasks: a modified version of the Eriksen Flanker and a doors gambling task along with the Frost Multidimensional Perfectionism scale, the Rotter Locus of Control scale, and the Levenson Multidimensional Locus of Control scale to quantify perfectionism and locus of control traits, respectively. Linear regressions adjusting for age and gender showed that neither ΔERN nor ΔRewP amplitude were significantly moderated by perfectionism or locus of control scores. Findings suggest that, in psychiatrically-healthy individuals, there is not a strong link between perfectionism, locus of control, and ERN or RewP amplitude. Future research on individual difference measures in people with psychopathology may provide further insight into how these personality traits affect performance monitoring.

Methodological reporting behavior, sample sizes, and statistical power in studies of event-related potentials: Barriers to reproducibility and replicability.

Methodological reporting guidelines for studies of ERPs were updated in Psychophysiology in 2014. These guidelines facilitate the communication of key methodological parameters (e.g., preprocessing steps). Failing to report key parameters represents a barrier to replication efforts, and difficulty with replicability increases in the presence of small sample sizes and low statistical power. We assessed whether guidelines are followed and estimated the average sample size and power in recent research. Reporting behavior, sample sizes, and statistical designs were coded for 150 randomly sampled articles from five high-impact journals that frequently published ERP research from 2011 to 2017. An average of 63% of guidelines were reported, and reporting behavior was similar across journals, suggesting that gaps in reporting is a shortcoming of the field rather than any specific journal. Publication of the guidelines article had no impact on reporting behavior, suggesting that editors and peer reviewers are not enforcing these recommendations. The average sample size per group was 21. Statistical power was conservatively estimated as .72-.98 for a large effect size, .35-.73 for a medium effect, and .10-.18 for a small effect. These findings indicate that failing to report key guidelines is ubiquitous and that ERP studies are primarily powered to detect large effects. Such low power and insufficient following of reporting guidelines represent substantial barriers to replication efforts. The methodological transparency and replicability of studies can be improved by the open sharing of processing code and experimental tasks and by a priori sample size calculations to ensure adequately powered studies.

Quantifying evidential value and selective reporting in recent and 10-year past psychophysiological literature: A pre-registered P-curve analysis.

Selective reporting (i.e., only reporting significant findings as opposed to all analyses or results) is a questionable research practice that undermines the integrity of published research. Psychophysiology research may be susceptible to selective reporting, given the high number of decision points and methodological complexity in analyses of psychophysiology data. We aimed to assess the presence of selective reporting and evidential value (i.e., that significant results are due to true underlying effects) in recent and past psychophysiological research by utilizing p-curve analyses. Study protocols and methods were pre-registered on the Open Science Framework (OSF). P-values and the associated test statistics were extracted from articles in the most recent issue (as of January 2018) and 10-year previous counterpart issue of three major psychophysiology journals: Psychophysiology, International Journal of Psychophysiology, and Journal of Psychophysiology. Using the p-curve application, 10 primary p-curves were conducted: all recent articles, all past articles, recent articles split by journal, past articles split by journal, recent cognitive electrophysiology articles, and past cognitive electrophysiology articles. Evidential value and generally adequate average power (≥78% average power) were present in all p-curves, except those that only included articles from the Journal of Psychophysiology because of the small number of articles published in the journal. Findings provide some positive news and indicate that, generally, results were not selectively reported, and selective reporting may not be a primary issue for this sample of psychophysiological research. Future p-curve analyses examining sub-disciplines of psychophysiology are recommended.

Quantifying the presence of evidential value and selective reporting in food-related inhibitory control training: a p-curve analysis.

Meta-analyses suggest inhibitory control training (ICT) may be effective for reducing food intake. However, psychological research has come under scrutiny for lack of reliability. Selective reporting (only reporting significant results) is one factor contributing to the lack of reliability in published research. Therefore, estimates of food-related ICT effects may be inaccurate. We conducted p-curve analyses to assess the presence of selective reporting, evidential value, average effect size, and power in the food-related ICT literature. Extracted p-values were selected from articles included in food-related ICT meta-analyses and an updated literature search. Four p-curve analyses resulted in 'U'-shaped distributions, suggesting evidence for both a true underlying effect and selective reporting in the food-related ICT literature. Robust analyses suggested the evidence for an underlying effect was primarily driven by the smallest p-value. The average effect size from included studies was small (d = 0.04 to 0.25). Average power to detect this effect was also small (7% to 18%). Results suggest no clear support for or against a true effect for food-related ICT. Low average effect size and power across studies suggests estimated effects are likely inflated in published literature. Higher-powered, pre-registered, longitudinal food-related ICT studies are needed to test for the presence and magnitude of ICT effects.