P300 and the stroop effect in overweight minority adolescents

Effects of 12 weeks of aerobic exercise combined with resistance training on neurocognitive performance in obese women

Background/Objectives

To the best of our knowledge, there have been no previous studies conducted on the long-term effects of an exercise intervention on deficits in inhibitory control in obese individuals. The aim of this study was thus to examine the effect of 12 weeks of a combination of aerobic and resistance exercise on behavioral and cognitive electrophysiological performance involving cognitive interference inhibition in obese individuals.

Methods

Thirty-two qualified healthy obese women were randomly divided into either an exercise group (EG, age: 34.76 ± 5.52 years old; BMI: 29.35 ± 3.52 kg/m²) or a control group (CG, age: 33.84 ± 7.05 years old; BMI: 29.61 ± 4.31 kg/m²). All participants performed the Stroop task, with electrophysiological signals being collected simultaneously before and after a 12-week intervention. The estimated V̇O₂max, muscular strength, and body fat percentage (measured with dual-energy X-ray absorptiometry) were also assessed within one week before and after the intervention. Participants in the EG group engaged in 30 min of moderate-intensity aerobic exercise combined with resistance exercise, 5 sessions per week for 12 weeks, while the participants in the CG group maintained their regular lifestyle without engaging in any type of exercise.

Results

The results revealed that although a 12-week exercise intervention did not enhance the behavioral indices [e.g., accuracy rates (ARs) and reaction times (RTs)] in the EG group, significantly shorter N2 and P3 latencies and greater P2 and P3 amplitudes were observed. Furthermore, the fat percentage distribution (e.g. total body fat %, trunk fat %, and leg fat %) and level of physical fitness (e.g. estimated V̇O₂max and muscular strength) in the EG group were significantly improved. The changes prior to and after the intervention in the P3 amplitude and trunk fat percentage were significantly negatively correlated in the EG group (r = −0.521, p = 0.039).

Conclusions

These findings suggested that 12 weeks of aerobic exercise combined with resistance exercise in obese women affects cognitive function broadly, but not specifically in terms of inhibitory control. The percentage of decreased trunk fat may play a potential facilitating role in inhibition processing in obesity.

The effects of poverty stereotype threat on inhibition ability in individuals from different income-level families

INTRODUCTION

Poverty is characterized by a scarcity of resources and a threat of certain stereotypes. However, the effects of stereotype threat are largely dependent on various factors, both negative and positive. Few psychophysiological studies have studied the effects of poverty stereotype threats on inhibition ability in wealth and impoverished individuals.

METHODS

To fill this gap in the literature, this study used the event-related potential (ERP) technique to explore the brain mechanisms associated with stereotype threat in 135 participants.

RESULTS

Behavioral results showed that the rich group (participants from higher-income families) had better inhibition ability than the impoverished group (participants from lower-income families), with significantly shorter reaction time and significantly greater accuracy for poverty-related stimuli when in the nonthreat condition. Additionally, poverty stereotype threat could improve performance of the impoverished group for poverty-related stimuli. The electrophysiological results showed significantly larger P3 mean amplitude and significantly longer P3 latency in the rich group than the impoverished group in the nonthreat condition. Although no significant between-group differences were found in the threat condition, the results show that the effect of poverty stereotype threat varies with different income-level persons, for both behavioral and P3 data.

CONCLUSION

These findings suggest that impoverished people have worse inhibition abilities. Further, poverty stereotype threat has different effects on people according to their income level and could help to explain irrational consumption behaviors in people.

Neurocognitive Inhibitory Control Ability Performance and Correlations with Biochemical Markers in Obese Women

Inhibitory control, the ability to suppress prepotent responses and resist irrelevant stimuli, is thought to play a critical role in the maintenance of obesity. However, electrophysiological performance related to different inhibitory control processes and their relationship with motor response inhibition and cognitive interference and potential biochemical mechanisms in middle-aged, obese women are as yet unclear. This work thus compared different neurocognitive Go/Nogo and Stroop task performance in healthy sedentary normal-weight and obese women, as well as their correlation with biochemical markers. Twenty-six healthy, sedentary obese women (obese group) and 26 age-matched (21–45 years old) normal-weight women (control group) were the participants, categorized by body mass index and percentage fat, as measured with dual-energy X-ray absorptiometry. They provided a fasting blood sample and performed two cognitive tasks (i.e., Go/Nogo and Stroop tasks) with concomitant electrophysiological recording. The N2 and P3 waveforms of event-related potential (ERP) were recorded. Although the between-group behavioral performance was comparable, the obese group relative to the control group showed significantly longer N2 latency and smaller P3 amplitude in the Stroop task and smaller N2 and P3 amplitudes in the Go/Nogo task. Significant inflammation response indices (e.g., CRP, leptin, adiponectin/leptin ratio) were observed in the obese group. The Nogo P3 amplitude was significantly correlated with the adiponectin/leptin ratio. These findings indicate that healthy obese women still exhibit deviant neurophysiological performance when performing Go/Nogo and Stroop tasks, where the adiponectin/leptin ratio could be one of the influencing factors for the deficit in neural processes of motor response inhibition.

HIV/AIDS and an overweight body mass are associated with excessive intra-individual variability in response preparation

Factors other than HIV/AIDS may influence the cognitive function of patients living with this disease. The present study tested the influence of a common comorbid problem-an overweight body mass. It also examined intra-task variabilities in performance and brain activation as potentially more sensitive indicators of dysfunction than their mean levels. One-hundred seventy-eight participants were recruited and categorized by HIV-1 serostatus (-/+) and body mass (BMI < 26/≥ 26 kg/m2). They performed a simple time estimation task during which response time accuracy and electroencephalographic readiness potentials were recorded. A few hours later, they completed a battery of tests measuring balance and gait. The analyses revealed an advantage of variability over the mean in differentiating groups: the presence of HIV-1 and an overweight body mass were independently and additively associated with greater variability across trials in readiness potential amplitude and response accuracy. The analysis also showed that intra-task variability in the readiness potential, but not in response accuracy, was predictive of decrements in single and tandem leg balance and gait velocity. The present findings suggest that an elevated body mass is associated with, and may contribute to, problems in brain function and motor behavior experienced by patients in the current era. The findings recommend a careful consideration of the manner in which these problems are measured. When the problems are episodic and subtle, measures of central tendency may be less than ideal.

Executive and Reward-Related Function in Pediatric Obesity: A Meta-Analysis

OBJECTIVE

This study examined the effect of pediatric obesity on executive function and reward-related decision-making, cognitive processes that are relevant to obesogenic behaviors, and evaluated their association with sample (e.g., age, gender, intelligence, and socioeconomic status, SES) and study/task (e.g., categorical/continuous variable, food stimuli) characteristics.

METHODS

A random-effects meta-analysis was conducted using Hedge's g effect sizes of published studies from 1960 to 2016, limited to children younger than the age of 21 years without medical comorbidities. Analysis included estimation of heterogeneity (τ²), publication bias (funnel-plot symmetry and fail-safe N), and sensitivity analyses for sample and study/task characteristics.

RESULTS

Across 68 studies with 70 samples, obesity was associated with worse functioning overall (-0.24; 95CI: -0.30 to -0.19; p < 0.001) and for each component process (attention, switching, inhibition, interference, working memory, reward, delay of gratification: -0.19 to -0.38; p's < 0.017), except trait impulsivity (-0.06; 95CI: -0.18 to 0.07). Deficits increased with age and female composition of the sample for inhibition (p = 0.002). No other characteristics moderated effect of obesity.

CONCLUSIONS

Small-to-moderate negative associations with obesity were observed for executive and reward-related performance, but not on reported impulsivity in studies with children younger than the age of 21 years. These results were not moderated by IQ, SES, and study/task characteristics. Age and gender moderated association with inhibition, with a larger obesity-related deficit in older and predominantly female samples. These results suggest cognitive and demographic intervention targets for prevention and mitigation of obesogenic behavior.

Challenges in the Detection of Working Memory and Attention Decrements among Overweight Adolescent Girls

BACKGROUND

The present study is unique in employing unusually difficult attention and working memory tasks to reveal subtle cognitive decrements among overweight/obese adolescents. It evaluated novel measures of background electroencephalographic (EEG) activity during one of the tasks and tested correlations of these and other measures with psychological and psychiatric predictors of obesity maintenance or progression.

METHODS

Working memory and sustained attention tasks were presented to 158 female adolescents who were rated on dichotomous (body mass index percentile <85 vs. ≥85) and continuous (triceps skinfold thickness) measures of adiposity.

RESULTS

The results revealed a significant association between excess adiposity and performance errors during the working memory task. During the sustained attention task, overweight/obese adolescents exhibited more EEG frontal beta power as well as greater intraindividual variability in reaction time and beta power across task periods than their normal-weight peers. Secondary analyses showed that frontal beta power during the sustained attention task was positively correlated with anxiety, panic, borderline personality features, drug abuse, and loss of control over food intake.

CONCLUSIONS

The findings suggest that working memory and sustained attention decrements do exist among overweight/obese adolescent girls. The reliable detection of the decrements may depend on the difficulty of the tasks as well as the manner in which performance and brain activity are measured. Future studies should examine the relevance of these decrements to dietary education efforts and treatment response.

Effects of marijuana use on prefrontal and parietal volumes and cognition in emerging adults

RATIONALE

Chronic marijuana (MJ) use among adolescents has been associated with structural and functional abnormalities, particularly in developing regions responsible for higher order cognition.

OBJECTIVES

This study investigated prefrontal (PFC) and parietal volumes and executive function in emerging adult MJ users and explored potential gender differences.

METHODS

Participants (ages 18-25) were 27 MJ users and 32 controls without neurologic or psychiatric disorders or heavy other drug use. A series of multiple regressions examined whether group status, past year MJ use, and their interactions with gender predicted ROI volumes. Post hoc analyses consisted of brain-behavior correlations between volumes and cognitive variables and Fisher's z tests to assess group differences.

RESULTS

MJ users demonstrated significantly smaller medial orbitofrontal (mOFC; p = 0.004, FDR p = 0.024) and inferior parietal volumes (p = 0.04, FDR p = 0.12); follow-up regressions found that increased past year MJ use did not significantly dose-dependently predict smaller mOFC volume in a sub-sample of individuals with at least one past year MJ use. There were no significant gender interactions. There was a significant brain-behavior difference by group, such that smaller mOFC volumes were associated with poorer complex attention for MJ users (p < 0.05).

CONCLUSIONS

Smaller mOFC volumes among MJ users suggest disruption of typical neurodevelopmental processes associated with regular MJ use for both genders. These results highlight the need for longitudinal, multi-modal imaging studies providing clearer information on timing of neurodevelopmental processes and neurocognitive impacts of youth MJ initiation.

Visual illusions and inattention: Their association with adiposity among adolescent girls

The Delboeuf concentric circle illusion is frequently invoked as an explanation for the hypothesized association between dinner plate size and overeating. We examined its association with adiposity among 162 girls, aged 14-18 years. We also examined the association of adiposity with neural and behavioral responses during a separate visual discrimination task. The analysis showed that girls with a body mass index percentile ≥ 85, or with greater triceps skinfold thickness, exhibited less sensitivity to the Delboeuf illusion than girls with normal adiposity. The excess adiposity group also exhibited significantly smaller electroencephalographic responses and more errors during the separate visual discrimination task. In combination, the findings from the two tasks suggest that girls with an elevated body mass are less sensitive to visual cues in their environment. The implications of these findings for weight loss education should be considered.

Who gains? Genetic and neurophysiological correlates of BMI gain upon college entry in women

The present investigation examined P3 event-related electroencephalographic potentials and a short and selected list of addiction-related candidate gene single nucleotide polymorphisms (SNPs) within 84 female students, aged 18-20 yrs. The students were assigned to groups defined by the presence versus absence of a positive body mass index (BMI) change from the pre-college physical exam to the current day. Analyses revealed significantly greater P3 latencies and reduced P3 amplitudes during a response inhibition task among students who exhibited a BMI gain. BMI gain was also significantly associated with a ANKK1 SNP previously implicated in substance dependence risk. In logistic regression analyses, P3 latencies at the frontal electrode and this ANKK1 genotype correctly classified 71.1% of the students into the BMI groups. The present findings suggest that heritable indicators of impaired response inhibition can differentiate students who may be on a path toward an overweight or obese body mass.

Increased marijuana use and gender predict poorer cognitive functioning in adolescents and emerging adults

This study sought to characterize neuropsychological functioning in MJ-using adolescents and emerging adults (ages 18-26) and to investigate whether gender moderated these effects. Data were collected from 59 teens and emerging adults including MJ users (n = 23, 56% female) and controls (n = 35, 50% female) aged 18-26 (M = 21 years). Exclusionary criteria included independent Axis I disorders (besides SUD), and medical and neurologic disorders. After controlling for reading ability, gender, subclinical depressive symptoms, body mass index, and alcohol and other drug use, increased MJ use was associated with slower psychomotor speed/sequencing ability (p < .01), less efficient sustained attention (p < .05), and increased cognitive inhibition errors (p < .03). Gender significantly moderated the effects of MJ on psychomotor speed/sequencing ability (p < .003) in that males had a more robust negative relationship. The current study demonstrated that MJ exposure was associated with poorer psychomotor speed, sustained attention and cognitive inhibition in a dose-dependent manner in young adults, findings that are consistent with other samples of adolescent MJ users. Male MJ users demonstrated greater cognitive slowing than females. Future studies need to examine the neural substrates underlying with these cognitive deficits and whether cognitive rehabilitation or exercise interventions may serve as a viable treatments of cognitive deficits in emerging adult MJ users.