RESUMO
Research has pointed to difficulties in emotion regulation as a risk factor for perpetrating intimate partner violence against women (IPVAW). While efforts have been made to understand the brain mechanisms underlying emotion regulation strategies such as reappraisal, little is known about the intrinsic neural dynamics supporting this strategy in male perpetrators. Resting-state functional magnetic resonance imaging was used to characterise the network dynamics underlying reappraisal. Spectral dynamic causal modelling was performed to examine the effective connectivity (EC) within a predefined reappraisal-related brain network. 26 men convicted for an IPVAW crime [male perpetrators] were compared to 29 men convicted of other crimes [other offenders] and 29 men with no criminal records [non-offenders]. The ability to down-regulate emotions in response to IPVAW stimuli was used as a covariate to explore its association with male perpetrators' EC. The analysis revealed that (1) compared to non-offenders, both convicted groups exhibited increased EC within prefrontal areas, enhanced EC from prefrontal to temporoparietal regions and decreased EC in the opposite direction; (2) male perpetrators compared to other offenders showed increased EC from temporoparietal to prefrontal regions and, increased EC from the supplementary motor area to frontal areas; (3) connections involving dorsolateral prefrontal cortex were found to be potential predictors of the ability to down-regulate emotions. The study provides a deeper characterisation of the brain architecture of the processes that underlie IPVAW. This knowledge could inform the work of adaptive emotion regulation strategies in intervention programmes for male perpetrators in order to reduce the high recidivism rates.
Assuntos
Criminosos , Regulação Emocional , Violência por Parceiro Íntimo , Humanos , Masculino , Feminino , Emoções/fisiologia , Violência por Parceiro Íntimo/psicologia , EncéfaloRESUMO
Obesity in adolescence is associated with cognitive changes that lead to difficulties in shifting unhealthy habits in favour of alternative healthy behaviours, similar to addictive behaviours. An outstanding question is whether this shift in goal-directed behaviour is driven by over-exploitation or over-exploration of rewarding outcomes. Here, we addressed this question by comparing explore/exploit behaviour on the Iowa Gambling Task in 43 adolescents with excess weight against 38 adolescents with healthy weight. We computationally modelled both exploitation behaviour (e.g., reinforcement sensitivity and inverse decay parameters), and explorative behaviour (e.g., maximum directed exploration value). We found that overall, adolescents with excess weight displayed more behavioural exploration than their healthy-weight counterparts - specifically, demonstrating greater overall switching behaviour. Computational models revealed that this behaviour was driven by a higher maximum directed exploration value in the excess-weight group (U = 520.00, p = .005, BF10 = 5.11). Importantly, however, we found substantial evidence that groups did not differ in reinforcement sensitivity (U = 867.00, p = .641, BF10 = 0.30). Overall, our study demonstrates a preference for exploratory behaviour in adolescents with excess weight, independent of sensitivity to reward. This pattern could potentially underpin an intrinsic desire to explore energy-dense unhealthy foods - an as-yet untapped mechanism that could be targeted in future treatments of obesity in adolescents.
Assuntos
Comportamento Exploratório , Sobrepeso , Humanos , Adolescente , Sobrepeso/psicologia , Obesidade , Aumento de Peso , Reforço PsicológicoRESUMO
Breastfeeding (BF) is the gold standard in infant nutrition; knowing how it influences brain connectivity would help understand the mechanisms involved, which would help close the nutritional gap between infant formulas and breast milk. We analyzed potential long-term differences depending on the diet with an experimental infant formula (EF), compared to a standard infant formula (SF) or breastfeeding (BF) during the first 18 months of life on children's hypothalamic functional connectivity (FC) assessed at 6 years old. A total of 62 children participating in the COGNIS randomized clinical trial (Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT02094547) were included in this study. They were randomized to receive an SF (n = 22) or a bioactive nutrient-enriched EF (n = 20). BF children were also included as a control study group (BF: n = 20). Brain function was evaluated using functional magnetic resonance imaging (fMRI) and mean glucose levels were collected through a 24-h continuous glucose monitoring (CGM) device at 6 years old. Furthermore, nutrient intake was also analyzed during the first 18 months of life and at 6 years old through 3-day dietary intake records. Groups fed with EF and BF showed lower FC between the medial hypothalamus (MH) and the anterior cingulate cortex (ACC) in comparison with SF-fed children. Moreover, the BF children group showed lower FC between the MH and the left putamen extending to the middle insula, and higher FC between the MH and the inferior frontal gyrus (IFG) compared to the EF-fed children group. These areas are key regions within the salience network, which is involved in processing salience stimuli, eating motivation, and hedonic-driven desire to consume food. Indeed, current higher connectivity found on the MH-IFG network in the BF group was associated with lower simple sugars acceptable macronutrient distribution ranges (AMDRs) at 6 months of age. Regarding linoleic acid intake at 12 months old, a negative association with this network (MH-IFG) only in the BF group was found. In addition, BF children showed lower mean glucose levels compared to SF-fed children at 6 years old. Our results may point out a possible relationship between diet during the first 18 months of life and inclined proclivity for hedonic eating later in life. Clinical trial registration: https://www.clinicaltrials.gov/, identifier NCT02094547.
RESUMO
Introduction: Little research has been carried out on the associations between several individual factors and hazardous alcohol use in women. The aim of this study was first, to study the relationship between reward sensitivity (RS) and alcohol use in both women with and without hazardous drinking separately. Second, to explore the potential mediating roles of the impulsivity and self-control traits in this relationship. Method: The study was analytical and cross-sectional and included 645 female participants (mean age = 19.14; standard deviation (SD)=1.60). All women were divided into two groups (286, 44.3%, with hazardous drinking, HDW; and 359, 55.7%, with light drinking, LDW). Correlation analyses were carried out to explore the associations between the variables, and parallel mediation analyses were performed to investigate the potential mediating roles of impulsivity and self-control in the RS-alcohol use associations in each group separately. Results: A significant association was observed between RS and alcohol use in HDW, contrary to that observed in their counterparts. In addition, both higher impulsivity and less self-control mediated the association between RS and alcohol use only in HDW. Conclusions: Impulsivity and self-control differently affect alcohol use under the condition of high reward sensitivity, only in HDW, suggesting alterations of the dual top-down and bottom-up mechanisms and a possible imbalance between the competing reflexive and impulsive brain systems. More research is needed regarding the individual factors that affect women's drinking to develop sensitive measures for the assessment of alcohol use and more efficient interventions for women.
Assuntos
Consumo de Bebidas Alcoólicas , Autocontrole , Adulto , Consumo de Bebidas Alcoólicas/epidemiologia , Estudos Transversais , Feminino , Humanos , Comportamento Impulsivo , Recompensa , Adulto JovemRESUMO
Intimate partner violence against women (IPVAW) is a serious and overwhelming public concern. Neuroimaging techniques have provided insights into the brain mechanisms underlying IPVAW perpetration. The purpose of this study is to examine the resting-state functional connectivity (rsFC) involving the process of social decision-making of male perpetrators. Twenty-six male perpetrators convicted for an IPVAW crime were compared to 29 men convicted for crimes other than IPVAW (other offenders) and 29 men with no criminal records (non-offenders) using a seed-based approach. Seeds were located in areas involved in reflective (prefrontal), impulsive (amygdala and striatum) and interoceptive (insula) processing. Then, as an exploratory analysis, the connectivity networks on male perpetrators were correlated with measures of executive functions and socioemotional self-report measures. Male perpetrators in comparison to other offenders and non-offenders, presented higher rsFC between prefrontal, limbic, brainstem, temporal and basal ganglia areas. Also male perpetrators showed higher rsFC between insula, default mode network and basal ganglia, while lower rsFC was found between prefrontal and motor areas and between amygdala, occipital and parietal areas. Exploratory correlations suggest that the specific rsFC in male perpetrators might be more related to socioemotional processes than to executive functions. These results showed that male perpetrators present a specific rsFC in brain systems that are essential for an adaptive social decision-making.
Assuntos
Mapeamento Encefálico , Violência por Parceiro Íntimo , Tonsila do Cerebelo , Gânglios da Base , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética , MasculinoRESUMO
Social mentalizing refers to the ability to understand the intentions, causes, emotions and beliefs of another person or the self and is crucial for interpersonal understanding. Disturbances in this process may lead to aggressive and violent behaviors. Literature has shown that male perpetrators convicted for intimate partner crime (IPVAW) present alterations in different measures related to social mentalizing, in particular, they present more irrational thoughts toward women and difficulties in emotional recognition and empathy processes. However, the brain mechanisms underlying this process are still unknown. The aim of this study is to examine the resting-state functional connectivity of the cerebellar Crus II area, as a core component of social mentalizing in male perpetrators, and to explore if this connectivity is associated with social mentalizing processes. To achieve these objectives, we compared the resting-state connectivity of 25 men convicted for an IPVAW crime (male perpetrators) with 29 men convicted for other crimes (other offenders) and 28 men with no criminal records (non-offenders) using a seed-based whole brain analysis. Subsequently, correlations were performed to explore the association between the significant connectivity networks and social mentalizing measures only in male perpetrators of IPVAW. Analyses showed that male perpetrators of IPVAW exhibit hyperconnectivity between Crus II and posterior areas of the default mode network, frontoparietal and limbic areas compared to other offenders and non-offenders. In addition, the greater connectivity found between the Crus II and the posterior default mode network was related to a greater number of distorted thoughts about women and less affective empathy in male perpetrators of IPVAW. These results show that connectivity between the cerebellum and the default mode network may underlie the social processes that are at the basis of intimate partner violence perpetration.
Assuntos
Criminosos , Violência por Parceiro Íntimo , Mentalização , Cerebelo , Emoções , Feminino , Humanos , MasculinoRESUMO
Alexithymia, difficulties in emotion regulation, and negative affect play an important role in adolescents who present pathological gambling. Therefore, the objectives of the present study were, firstly, to analyze the differences between alexithymia, difficulties in emotion regulation, and positive and negative affect in adolescents with and without risk of gambling problems. Secondly, the relationships between all the variables of the study in adolescents with and without risk of problem gambling were analyzed separately. Thirdly, we analyzed the mediating role of positive and negative affect in the relationship between alexithymia and dysfunctional emotion regulation strategies (ERS) in adolescents at risk of gambling problems. The sample was composed of 206 adolescents with ages ranging from 12 to 18 years (M = 15.52; SD = 1.43). They were divided into two groups according to the score obtained in the South Oaks Gambling Screen-Revised for Adolescents (SOGS-RA). Thus, 84 were included in the group without risk of gambling problems and 122 in the group at risk of gambling problems. The results obtained revealed higher scores in negative affect and pathological gambling in the group at risk of gambling problems. Likewise, positive relationships between alexithymia, maladaptive emotion regulation strategies (MERS), and affect were found. Mediation analyses showed that difficulties in identifying feelings were indirectly related to greater use of dysfunctional ERS through their relationship with negative affect in at-risk gamblers.
Assuntos
Regulação Emocional , Jogo de Azar , Adolescente , Sintomas Afetivos/psicologia , Criança , Emoções , Jogo de Azar/psicologia , HumanosRESUMO
RATIONALE: Endocannabinoids are well poised to regulate crosstalk between energy sensing of hunger and satiety and reward-driven motivation. OBJECTIVES: Here, we aimed to unravel associations between plasma endocannabinoids and brain connectivity in homeostatic and reward circuits across hunger and satiety states. METHODS: Fifteen participants (7 females) underwent two counter-balanced resting-state functional magnetic resonance imaging scans, one after overnight fasting and one after consumption of a standardized filling meal (satiety). Before each scan, we drew blood to measure plasma endocannabinoid concentrations (anandamide [AEA], anandamide-derived POEA, and 2-arachidonoylglycerol [2-AG]), analyzed with liquid chromatography tandem mass spectrometry. RESULTS: We found that AEA levels were associated with increased connectivity between the lateral hypothalamus and the ventral striatum during satiety. Furthermore, fasting AEA levels correlated with connectivity between the ventral striatum and the anterior cingulate cortex and the insula. CONCLUSIONS: Altogether, results suggest that peripheral AEA concentrations are sensitive to homeostatic changes and linked to neural communication in reward and salience networks. Findings may have significant implications for understanding normal and abnormal interactions between homeostatic input and reward valuation.
Assuntos
Mapeamento Encefálico , Endocanabinoides , Encéfalo , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , RecompensaRESUMO
This study aimed to explore, on one side, the differences between a group of athletes exercising outdoor (OG) and another group exercising indoor (IG) in stress and awareness, and, on the other side, between-group differences in the fMRI activations during the visualization of natural environment images versus urban images. In addition, we aimed to analyze the associations between the resulting task-related brain activations and stress and attention-awareness in each group separately. All the participants (N = 49; OG = 21, 11 females, mean age = 40, SD = 6.49; and IG = 25, 11 females, mean age = 40; 6.19) underwent an fMRI scan and completed the Perceived Stress Scale and the Mindful Attention Awareness Scale. Besides, we collected a sample of hair cortisol. Participants viewed three types of images: water nature, green nature and urban images. Two-sample t-test with corrected p=0.001 values were carried out. Further correlational analyses were performed to estimate the associations between task-related brain activations and our pyscho-emotional measures in each group. Fisher tests were used to explore for potential between-group differences in the correlational indexes. In OG, compared to IG, we found a higher activation of the middle occipital cortex and a cluster comprising the supplementary motor area (SMA), the premotor cortex and the pre-SMA while viewing green nature images versus urban images. In OG, more than in IG, the higher activation of the left SMA cluster negatively correlated with perceived stress, while in the IG, more than in OG, the higher premotor cortex activation was positively related to the total score on MAAS. No significant association was found with the hair cortisol levels. Exercising outdoor would relate to better psycho-emotional outcomes, also for athletes. On the other side, the exposition to green nature led to higher activation of brain areas related to motor planning, but also to emotion regulation and emotional response.
Assuntos
Imageamento por Ressonância Magnética , Córtex Motor , Adulto , Atenção/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Feminino , Humanos , Hidrocortisona , MasculinoRESUMO
Recent studies have shown that maternal supplementation with folate and long-chain polyunsaturated fatty acids (LC-PUFAs) during pregnancy may affect children's brain development. We aimed at examining the potential long-term effect of maternal supplementation with fish oil (FO) and/or 5-methyl-tetrahydrofolate (5-MTHF) on the brain functionality of offspring at the age of 9.5-10 years. The current study was conducted as a follow-up of the Spanish participants belonging to the Nutraceuticals for a Healthier Life (NUHEAL) project; 57 children were divided into groups according to mother's supplementation and assessed through functional magnetic resonance imaging (fMRI) scanning and neurodevelopment testing. Independent component analysis and double regression methods were implemented to investigate plausible associations. Children born to mothers supplemented with FO (FO and FO + 5-MTHF groups, n = 33) showed weaker functional connectivity in the default mode (DM) (angular gyrus), the sensorimotor (SM) (motor and somatosensory cortices) and the fronto-parietal (FP) (angular gyrus) networks compared to the No-FO group (placebo and 5-MTHF groups, n = 24) (PFWE < 0.05). Furthermore, no differences were found regarding the neuropsychological tests, except for a trend of better results in an object recall (memory) test. Considering the No-FO group, the aforementioned networks were associated negatively with attention and speed-processing functions. Mother's FO supplementation during pregnancy seems to be able to shape resting-state network functioning in their children at school age and appears to produce long-term effects on children´s cognitive processing.
Assuntos
Encéfalo/crescimento & desenvolvimento , Desenvolvimento Infantil/efeitos dos fármacos , Suplementos Nutricionais , Óleos de Peixe/administração & dosagem , Fenômenos Fisiológicos da Nutrição Materna/efeitos dos fármacos , Tetra-Hidrofolatos/administração & dosagem , Adulto , Encéfalo/diagnóstico por imagem , Criança , Feminino , Seguimentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Exposição Materna , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/crescimento & desenvolvimento , Gravidez , Análise de Componente Principal , Análise de Regressão , Descanso/fisiologiaRESUMO
OBJECTIVE: The amygdala is importantly involved in stress and obesity, but its role on weight change and diet-related stress remains unexplored among adolescents with excess weight. We aimed to examine the functional connectivity of the Central and Basolateral amygdala nuclei (CeA and BLA) among adolescents, and to explore the longitudinal association between brain connectivity measures and diet-related cortisol and weight loss in adolescents with excess weight. METHODS: We compared resting-state functional connectivity between adolescents with excess (EW, N = 34; Age = 16.44 ± 1.66) and normal weight (NW, N = 36; Age = 16.50 ± 1.40) using a seed-based (CeA and BLA) whole-brain approach. Then, in a subset of 30 adolescents with EW, followed-up after 3-months of dietary/lifestyle intervention, we explored for interactions between connectivity in the CeA/BLA networks and weight loss. Regression analyses were performed to explore the relationship between accumulated cortisol and weight loss, and to test the potential effect of the amygdala networks on such association. RESULTS: In EW compared with NW, the CeA regions showed higher functional connectivity with anterior portions, and lower connectivity with posterior portions of the cingulate cortex, while the left BLA regions showed lower connectivity with the dorsal caudate and angular gyrus. In addition, higher connectivity between the left CeA-midbrain network was negatively associated with weight loss. Hair cortisol significantly predicted weight change (p = 0.012). However, this association was no longer significant (p = 0.164) when considering the CeA-midbrain network in the model as an additional predictor. CONCLUSIONS: Adolescents with EW showed functional connectivity alterations within the BLA/CeA networks. The CeA-midbrain network might constitute an important brain pathway regulating weight change.
Assuntos
Tonsila do Cerebelo/fisiopatologia , Hidrocortisona/análise , Sobrepeso/dietoterapia , Estresse Fisiológico , Redução de Peso , Adolescente , Tonsila do Cerebelo/diagnóstico por imagem , Dieta , Feminino , Cabelo/química , Humanos , MasculinoRESUMO
College students are particularly vulnerable to risky alcohol use, which increases their likelihood of developing an alcohol use disorder in the future. As such, preventing and reducing alcohol use among college students should be a priority for health and social policies. This work was aimed to show that brief group-delivered MI is as effective as brief-group CBT at reducing alcohol use in college students. Eighty-nine college students (69 females; mean age = 21.01, SD = 2.85) with risky alcohol use, as measured by the AUDIT-C, were assigned to two groups, receiving three sessions of either brief group-delivered MI or CBT (bMI/bCBT). Alcohol use was assessed 3 and 6 months after the interventions, and analyzed according to an Intention-to-treat design. Changes in alcohol use at both points (relative to baseline) as well as post-intervention scores of intention to continue treatment and satisfaction with the psychologist were compared across groups, using one-sided Bayesian t-tests. Alcohol use decreased in both groups at the 3- and 6-months measurement points (relative to baseline). However, using bCBT superiority as an alternative hypothesis and the absence of such superiority as a point-null hypothesis, the Bayes factors supported the null at both the 3- and the 6-months follow-up (BF01 = 7.13, and BF01 = 5.22 respectively). Furthermore, the intention to continue treatment was substantially higher in the bMI group (BF10 = 9.77). These results are considerably robust to changes in analyses' priors. This study suggests that bCBT is not more effective than bMI at reducing alcohol use in our college student group (in which females are overrepresented). Additionally, bMI showed higher intention to continue treatment scores. The comparable results of brief and group-delivered CBT and MI interventions in alcohol use reduction allows clinicians to select treatments based on their own skills or preferences without any detriment to efficacy.
Assuntos
Consumo de Álcool na Faculdade , Consumo de Bebidas Alcoólicas/prevenção & controle , Terapia Cognitivo-Comportamental , Entrevista Motivacional , Adolescente , Feminino , Humanos , Masculino , Psicoterapia de Grupo , Resultado do Tratamento , Adulto JovemRESUMO
OBJECTIVE: Adolescents with excess weight are particularly sensitive to stress, which may contribute to the presence of emotional eating behaviors. It is proposed that this may be due to alterations in the connectivity between hypothalamic networks and regions of the "emotional nervous system," involved in the regulation of energy balance and stress processing. However, this remains to be clarified in adolescents with excess weight. METHOD: We investigated whole-brain differences in the functional connectivity of the medial and lateral hypothalamus (MH and LH) between adolescents with excess weight (EW, n = 53; mean age = 14.64 years, SD = 1.78) and normal weight (NW, n = 51; mean age = 15.29 years, SD = 1.75) using seed-based resting-state analyses. Then, in a subset of 22 adolescents with EW (mean age = 15.75 years, SD = 1.70) and 32 with NW (mean age = 15.27, SD = 2.03), we explored for group interactions between the MH/LH networks and stress response in the Trier Social Stress Task (TSST) and emotional eating, assessed with the Dutch Eating Behavior Questionnaire (DEB-Q). RESULTS: Compared to NW, EW showed higher functional connectivity in the LH-orbitofrontal cortex, ventral striatum, anterior insula, and in the MH-middle temporal cortex networks. EW also showed lower connectivity in the LH-cerebellum, and in the MH-middle prefrontal, pre-, and postcentral gyri networks. In EW, higher connectivity of the LH-nucleus accumbens and LH-midbrain networks were associated with stress response. Higher connectivity in the LH-midbrain was also associated with a greater presence of emotional eating behaviors in EW. CONCLUSION: Adolescents with EW showed functional connectivity alterations within both MH/LH networks. Alterations in the LH network were linked with higher levels of stress response and emotional-driven eating patterns.
Assuntos
Mapeamento Encefálico , Emoções , Comportamento Alimentar , Hipotálamo/fisiopatologia , Vias Neurais/fisiologia , Sobrepeso/patologia , Adolescente , Estudos de Casos e Controles , Feminino , Humanos , Hipotálamo/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/diagnóstico por imagemRESUMO
INTRODUCTION: There is an outstanding need to identify predictors of driving under the influence of alcohol (DUI) among young adults, particularly women. Impulsivity, or the tendency to act without thinking, is a predictor of DUI, but the specific facets of impulsivity that predict DUI and their interaction with sex differences remain unclear. We aimed to investigate sex differences in the link between impulsivity facets and DUI. Moreover, we sought to replicate previous findings regarding sex differences on impulsivity, and associations between impulsivity facets and DUI. METHOD: A total of 506 university students participated in the study (males, n = 128; females, n = 378). Participants completed measures of impulsivity (UPPS-P short version), alcohol use (AUDIT-C), frequency of DUI episodes and related perception of risk. The UPPS-P assesses five facets of impulsivity: sensation seeking, (lack of) premeditation and perseverance and positive and negative urgency. RESULTS: Men showed higher sensation seeking and lack of perseverance, alcohol use and DUI frequency and lower risk perception than women. DUI frequency was negatively associated with perception of risk and positively associated with alcohol use and the five impulsivity facets. After controlling for alcohol use and risk perception, only lack of premeditation was associated with DUI frequency in the whole sample. Sensation seeking was positively associated with DUI frequency only in women. DISCUSSION: The link between lack of premeditation and DUI suggest that pre-drinking planning strategies can contribute to prevent risky driving. In women, specific links between sensation seeking and DUI suggest the need for personality-tailored prevention strategies.
Assuntos
Dirigir sob a Influência/psicologia , Dirigir sob a Influência/estatística & dados numéricos , Comportamento Impulsivo/fisiologia , Assunção de Riscos , Fatores Sexuais , Adolescente , Adulto , Consumo de Bebidas Alcoólicas/epidemiologia , Dirigir sob a Influência/prevenção & controle , Feminino , Humanos , Masculino , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND/OBJECTIVES: Accumulation of visceral adiposity can disrupt the brain's sensitivity to interoceptive feedback, which is coded in the insula. This study aimed to test the link between visceral fat and the functional connectivity of two insulae regions relevant for eating behavior: the middle-dorsal insula (mIns), which codes homeostatic changes, and the rostral insula (rIns), which codes stable representations of food properties. We also assessed the impact of visceral adiposity-associated insulae networks on food craving. SUBJECTS/METHODS: Seventy-five adults ranging in weight status (normal and excess weight) underwent resting-state functional magnetic resonance imaging (fMRI) and subjective food craving measures. We examined the association between visceral fat and seed-based functional connectivity of the mIns and the rIns, controlling for BMI, age, and sex, using multiple regressions in SPM8. We also tested if visceral fat mediated the association between insulae connectivity and food craving. RESULTS: Higher visceral adiposity was associated with decreased connectivity between the mIns and a cluster involving the hypothalamus and the bed nucleus of the stria terminalis. Decreased connectivity in this network was associated with greater food craving, a relation mediated by visceral adiposity. Visceral adiposity was also associated with increased connectivity between the mIns and the middle frontal gyri and the right intraparietal cortex, and between the rIns and the right amygdala. CONCLUSIONS: Accumulation of visceral adiposity is linked to disrupted functional connectivity within the mIns and rIns networks. Furthermore, the link between the mIns network and food craving is mediated by visceral fat. Findings suggest that visceral fat disrupts insula coding of bodily homeostatic signals, which may boost externally driven food cravings.
Assuntos
Córtex Cerebral/fisiopatologia , Fissura/fisiologia , Obesidade Abdominal/epidemiologia , Obesidade Abdominal/fisiopatologia , Adulto , Índice de Massa Corporal , Córtex Cerebral/diagnóstico por imagem , Feminino , Humanos , Fome/fisiologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The food addiction model proposes that obesity overlaps with addiction in terms of neurobiological alterations in the striatum and related clinical manifestations (i.e., craving and persistence of unhealthy habits). Therefore, we aimed to examine the functional connectivity of the striatum in excess-weight versus normal-weight subjects and to determine the extent of the association between striatum connectivity and individual differences in food craving and changes in body mass index (BMI). METHODS: Forty-two excess-weight participants (BMI > 25) and 39 normal-weight participants enrolled in the study. Functional connectivity in the ventral and dorsal striatum was indicated by seed-based analyses on resting-state data. Food craving was indicated with subjective ratings of visual cues of high-calorie food. Changes in BMI between baseline and 12 weeks follow-up were assessed in 28 excess-weight participants. Measures of connectivity in the ventral striatum and dorsal striatum were compared between groups and correlated with craving and BMI change. RESULTS: Participants with excess weight displayed increased functional connectivity between the ventral striatum and the medial prefrontal and parietal cortices and between the dorsal striatum and the somatosensory cortex. Dorsal striatum connectivity correlated with food craving and predicted BMI gains. CONCLUSIONS: Obesity is linked to alterations in the functional connectivity of dorsal striatal networks relevant to food craving and weight gain. These neural alterations are associated with habit learning and thus compatible with the food addiction model of obesity.