Functional Magnetic Resonance Imaging (fMRI) demonstrates that the subliminal presentation of arousing stimuli can activate subcortical brain regions independently of consciousness-generating top-down cortical modulation loops. Delineating these processes may elucidate mechanisms for arousal, aberration in which may underlie some psychiatric conditions. Here we are the first to review and discuss four Activation Likelihood Estimation (ALE) meta-analyses of fMRI studies using subliminal paradigms. We find a maximum of 9 out of 12 studies using subliminal presentation of faces contributing to activation of the amygdala, and also a significantly high number of studies reporting activation in the bilateral anterior cingulate, bilateral insular cortex, hippocampus and primary visual cortex. Subliminal faces are the strongest modality, whereas lexical stimuli are the weakest. Meta-analyses independent of studies using Regions of Interest (ROI) revealed no biasing effect. Core neuronal arousal in the brain, which may be at first independent of conscious processing, potentially involves a network incorporating primary visual areas, somatosensory, implicit memory and conflict monitoring regions. These data could provide candidate brain regions for the study of psychiatric disorders associated with aberrant automatic emotional processing.
Objectives: To investigate the effectiveness of Body Project groups delivered virtually (vBP) by peer educators for prevention of eating disorders. Method: In a randomized controlled trial vBP groups (N = 149) were compared with a placebo (expressive writing, EW: N = 148) over 24-month follow-up and to a waitlist control condition (N = 146) over 6-month follow-up among females (15–20 years old) with body image concerns. The primary outcome was incidence of eating disorder onset over 2-year follow-up measured by blinded diagnostic interviews. Waitlist participants were offered the vBP after 6 months. Results: The incidence of eating disorders onset over 24 months follow up were 3 in vBP (2.0%) and 13 in EW (8.8%), a significant difference; Hazard Ratio (Experiment B) = 0.26, 95% confidence interval (CI) [0.075, 0.92], p = .037. Incidence of eating disorder onset in vBP participants was 77% less than in EW participants. The vBP participants generally showed significantly greater reduction in eating disorder symptoms, clinical impairment, body dissatisfaction, and internalization of thin ideal compared with the waitlist participants at postintervention and 6-month follow-up, and in eating disorder symptoms, restraint, body dissatisfaction, and internalization of thin ideal compared with the EW participants at postintervention, and 6-, 12-, 18-, or 24-months follow-up. EW participants reported significantly greater reduction in clinical impairment and body dissatisfaction at postintervention compared with the waitlist participants. Conclusions: The present reduction in the incidence of eating disorders is notable given that the intervention was implemented virtually, rather than in-person. The vBP might be a viable option for future evaluation of scalable prevention of eating disorders.
Previous neuroimaging studies demonstrated sex and also sexual orientation related structural and functional differences in the human brain. Genetic information and effects of sex hormones are assumed to contribute to the male/female differentiation of the brain, and similar effects could play a role in processes influencing human's sexual orientation. However, questions about the origin and development of a person's sexual orientation remain unanswered, and research on sexual orientation related neurobiological characteristics is still very limited. To contribute to a better understanding of the neurobiology of sexual orientation, we used magnetic resonance imaging (MRI) in order to compare regional cortical thickness (Cth) and subcortical volumes of homosexual men (hoM), heterosexual men (heM) and heterosexual women (heW). hoM (and heW) had thinner cortices primarily in visual areas and smaller thalamus volumes than heM, in which hoM and heW did not differ. Our results support previous studies, which suggest cerebral differences between hoM and heM in regions, where sex differences have been reported, which are frequently proposed to underlie biological mechanisms. Thus, our results contribute to a better understanding of the neurobiology of sexual orientation.
Genome-wide association studies have shown a strong association of single-nucleotide polymorphisms (SNPs) in the near vicinity of the TMEM18 gene. The effects of the TMEM18-associated variants are more readily observed in children. TMEM18 encodes a 3TM protein, which locates to the nuclear membrane. The functional context of TMEM18 and the effects of its associated variants are as of yet undetermined. To further explore the effects of near-TMEM18 variants, we have genotyped two TMEM18-associated SNPs, rs6548238 and rs4854344, in a cohort of 2352 Greek children (Healthy Growth Study). Included in this study are data on anthropomorphic traits body weight, BMI z-score and waist circumference. Also included are dietary energy and macronutrient intake as measured via 24-h recall interviews. Major alleles of rs6548238 and rs4854344 were significantly associated with an increased risk of obesity (odds ratio¼1.489 (1.161-1.910) and 1.494 (1.165-1.917), respectively), and positively correlated to body weight (P¼0.017, P¼0.010) and waist circumference (P¼0.003, P¼0.003). An association to energy and macronutrient intake was not observed in this cohort. We also correlated food intake and body weight in a food choice model in rats to Tmem18 expression in central regions involved in feeding behavior. We observed a strong positive correlation between TMEM18 expression and body weight in the prefrontal cortex (PFC) (r¼0.5694, P¼0.0003) indicating a potential role for TMEM18 in higher functions related to feeding involving the PFC. Keywords: obesity; TMEM18; FTO INTRODUCTION Genome-wide association (GWA) studies have led to the identification of several loci in the human genome containing genetic variants conferring an increased risk of developing overweight and obesity. 1-2 One such gene to be associated with a higher BMI, the fat mass and obesity-associated gene (FTO) was identified by Frayling et al in 2007. 3 FTO has since been shown to be involved in regulation of feeding behavior via homeostatic hypothalamic pathways, 4-6 and its obesityassociated variants to confer gain-of-function by increasing gene transcription. 7 The most recent meta analyses of GWA studies on obesity, which included genetic information from 249 796 individuals, identified variants at a total of 32 genetic loci affecting the development of BMI. 2 Single-nucleotide polymorphisms (SNPs) in the FTO gene, followed by SNPs in the proximity of TMEM18 and MC4R, have consistently given the strongest associations to obesity in large-scale GWA studies. TMEM18-associated SNPs were first found to be associated with a higher BMI in 2009 by the GIANT consortium, 1 and this was confirmed in the same year by an independent group. 8 Results from child cohorts have shown stronger effects of near-TMEM18 SNPs to obesity, compared with adults. Zhao et al 9 found near-TMEM18 SNPs to confer the strongest effect on pediatric BMI out of 25 studied obesity-associated variants in a cohort of 6078
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.