Using event-related potentials to characterize inhibitory control and self-monitoring across impulsive and compulsive phenotypes: a dimensional approach to OCD.

OBJECTIVE: "Subsyndromal" obsessive-compulsive disorder symptoms (OCDSs) are common and cause impaired psychosocial functioning. OCDSs are better captured by dimensional models of psychopathology, as opposed to categorical diagnoses. However, such dimensional approaches require a deep understanding of the underlying neurocognitive drivers and impulsive and compulsive traits (ie, neurocognitive phenotypes) across symptoms. This study investigated inhibitory control and self-monitoring across impulsivity, compulsivity, and their interaction in individuals (n = 40) experiencing mild-moderate OCDSs. METHODS: EEG recording concurrent with the stop-signal task was used to elicit event-related potentials (ERPs) indexing inhibitory control (ie, N2 and P3) and self-monitoring (ie, error-related negativity and correct-related negativity (CRN): negativity following erroneous or correct responses, respectively). RESULTS: During unsuccessful stopping, individuals high in both impulsivity and compulsivity displayed enhanced N2 amplitude, indicative of conflict between the urge to respond and need to stop (F(3, 33) = 1.48, P < .05, 95% Cl [-0.01, 0.001]). Individuals high in compulsivity and low in impulsivity showed reduced P3 amplitude, consistent with impairments in monitoring failed inhibitory control (F(3, 24) = 2.033, P < .05, 95% CI [-0.002, 0.045]). Following successful stopping, high compulsivity (independent of impulsivity) was associated with lower CRN amplitude, reflecting hypo-monitoring of correct responses (F(4, 32) = 4.76, P < .05, 95% CI [0.01, 0.02]), and with greater OCDS severity (F(3, 36) = 3.32, P < .05, 95% CI [0.03, 0.19]). CONCLUSION: The current findings provide evidence for differential, ERP-indexed inhibitory control and self-monitoring profiles across impulsive and compulsive phenotypes in OCDSs.

The Effects of Combined Physical and Cognitive Training on Inhibitory Control: A Systematic Review and Meta-Analysis.

While strong inhibitory control is critical for health and wellbeing, there are no broadly applicable effective behavioural interventions that enhance it. This meta-analysis examined the neurocognitive rationale for combined physical and cognitive training and synthesised the rapidly growing body of evidence examining combined paradigms to enhance inhibitory control. Across the research to date, there was a small positive effect (n studies = 16, n participants = 832) of combined training on improving inhibitory control. Sub-group analyses showed small-moderate positive effects when the physical component of the combined training was moderately intense, as opposed to low or vigorous intensities; moderate positive effects were found in older adults, as compared to adolescents and adults; and healthy individuals and those with vascular cognitive impairment, as compared to ADHD, ASD, mild cognitive impairment and cancer survivors. This is the first meta-analysis to provide evidence that combined physical, specifically when moderately intense, and cognitive training has the capacity to improve inhibitory control, particularly when delivered to healthy individuals and those experiencing age-related decline.

Parameters of visual processing abnormalities in adults with body image concerns.

Body dysmorphic disorder (BDD), at the extreme end of the body image concern (BIC) spectrum, is thought to be associated with a local (detail-focussed) visual processing bias. Given that the inversion of a stimulus disrupts holistic processing and demands detail-specific attention, this perceptual bias is characterised by superior processing of such inverted stimuli. This study examined the processing bias, via a body-inversion discrimination task, of 26 participants with non-clinical, high-BIC (Dysmophic Concern Questionnaire (DCQ) scores between 11-19) and 26 participants with low-BIC (DCQ scores between 0-4). This study also explored the impact of varying stimuli presentation durations and discrimination difficulties during the inversion task on visual processing. As hypothesised, compared to those with low-BIC, participants with high-BIC demonstrated superior accuracy when discriminating between images of inverted bodies, indicating a local processing bias. Also as hypothesised, this local processing bias selectively manifested only when stimuli were presented for longer durations and at higher discrimination difficulties, revealing the parameters of this, potentially conscious, processing tendency. Consistent with previous research, this study identified a local processing bias in those with high BIC, which may be a predisposing factor for developing BDD. In turn, identifying the parameters (stimulus exposure and stimulus complexity) in which the local bias manifests has implications for future interventions aiming to reverse this perceptual abnormality.

Effects of sports training & nutrition on bone mineral density in young Indian healthy females.

BACKGROUND & OBJECTIVES: Peak bone mass, a major determinant of osteoporosis is influenced by genetic, nutritional, lifestyle and hormonal factors. This study was designed to evaluate the impact of sports training on dietary intake and bone mineral and metabolic parameters in young healthy Indian females. METHODS: Healthy female college going students (N=186, sportswomen, 90; controls 96) in the age group of 18-21 yr, residing in New Delhi (India) were evaluated for anthropometry, biochemistry (serum total and ionic calcium, phosphorus, total alkaline phosphatase, 25-hydroxyvitamin D & parathyroid hormone), diet, physical activity and lifestyle. Bone mineral density (BMD) at hip, forearm and lumbar spine were studied using central DXA. RESULTS: Sports related physical activity (3 vs. 0 h/day, P < 0.001) and direct sunlight exposure (120 vs. 30 min/day, P < 0.001) were significantly higher in sportswomen than in controls with sedentary lifestyle. Significantly higher intake of all macronutrients (energy, protein, carbohydrates and fat) and dietary calcium was noted in the diets of sportswomen. Mean serum 25(OH)D levels were significantly higher (53.0 ± 18.9 vs. 12.9 ± 7.7 nmol/l; P < 0.001) while PTH (35.3 ± 17.6 vs. 51.7 ± 44.9 pg/ml; P < 0.001) and ALP levels (194.0 ± 51.0 vs. 222.1 ± 51.4 IU/l; P<0.001) were significantly lower in sportswomen when compared to controls. No significant difference was found in ionized calcium and inorganic phosphorus in the two groups. Significantly higher (P < 0.001) total BMD and BMD at all sites except femur neck were found in sportswomen than controls (P < 0.001). INTERPRETATION & CONCLUSIONS: Physical activity, optimal nutrition and adequate sun exposure are vital for attaining peak bone mass.