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Introduction: Deficits in emotion recognition and processing are characteristic for patients with schizophrenia [SCZ]. Methods: We targeted both emotion recognition and affective sharing, one in static and one in dynamic facial stimuli, during functional magnetic resonance imaging [fMRI] in 22 SCZ patients and 22 matched healthy controls [HC]. Current symptomatology and cognitive deficits were assessed as potential influencing factors. Results: Behaviorally, patients only showed a prolonged response time in age-discrimination trials. For emotion-processing trials, patients showed a difference in neural response, without an observable behavioral correlate. During emotion and age recognition in static stimuli, a reduced activation of the bilateral anterior cingulate cortex [ACC] and the right anterior insula [AI] emerged. In the affective sharing task, patients showed a reduced activation in the left and right caudate nucleus, right AI and inferior frontal gyrus [IFG], right cerebellum, and left thalamus, key areas of empathy. Discussion: We conclude that patients have deficits in complex visual information processing regardless of emotional content on a behavioral level and that these deficits coincide with aberrant neural activation patterns in emotion processing networks. The right AI as an integrator of these networks plays a key role in these aberrant neural activation patterns and, thus, is a promising candidate area for neurofeedback approaches.
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Hormonal changes in ovarian hormones like estradiol (E2) during the menstrual cycle affect emotional processes, including emotion recognition, memory, and regulation. So far, the neural underpinnings of the effect of E2 on emotional experience have been investigated using task-based functional magnetic resonance imaging (fMRI) and functional connectivity. In the present study, we examined whether the intrinsic network dynamics at rest (i.e., directed effective connectivity) related to emotion regulation are (1) modulated by E2 levels and (2) linked to behavioral emotion regulation ability. Hence, 29 naturally cycling women participated in two resting-state fMRI scans in their early follicular phase after being administered a placebo or an E2 valerate, respectively. Emotion regulation ability was assessed using a standard emotion regulation task in which participants were asked to down-regulate their emotions in response to negative images. The regions of two functionally predefined neural networks related to emotional down-regulation and reactivity were used to investigate effective connectivity at rest using spectral dynamic causal modelling. We found that E2, compared to placebo, resulted in changes in effective connectivity in both networks. In the regulation network, prefrontal regions showed distinct connectivity in the E2 compared to the placebo condition, while mixed results evolved in the emotional reactivity network. Stepwise regressions revealed that in the E2 condition a connection from the parietal to the prefrontal cortex predicted regulation ability. Our results demonstrate that E2 levels influence effective connectivity in networks underlying emotion regulation and emotional reactivity. Thus, E2 and its potential modification via hormonal administration may play a supporting role in the treatment of mental disorders that show a dysregulation of emotions.
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Regulação Emocional , Emoções , Estradiol , Imageamento por Ressonância Magnética , Rede Nervosa , Humanos , Feminino , Regulação Emocional/fisiologia , Regulação Emocional/efeitos dos fármacos , Estradiol/farmacologia , Estradiol/metabolismo , Adulto , Adulto Jovem , Emoções/efeitos dos fármacos , Emoções/fisiologia , Rede Nervosa/efeitos dos fármacos , Rede Nervosa/fisiologia , Rede Nervosa/diagnóstico por imagem , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , Ciclo Menstrual/efeitos dos fármacos , Ciclo Menstrual/fisiologia , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiologia , Fase Folicular/fisiologia , Fase Folicular/efeitos dos fármacos , Conectoma/métodosRESUMO
BACKGROUND: Sex differences exist in the prevalence and clinical manifestation of several mental disorders, suggesting that sex-specific brain phenotypes may play key roles. Previous research used machine learning models to classify sex from imaging data of the whole brain and studied the association of class probabilities with mental health, potentially overlooking regional specific characteristics. METHODS: We here investigated if a regionally constrained model of brain volumetric imaging data may provide estimates that are more sensitive to mental health than whole brain-based estimates. Given its known role in emotional processing and mood disorders, we focused on the limbic system. Using two different cohorts of healthy subjects, the Human Connectome Project and the Queensland Twin IMaging, we investigated sex differences and heritability of brain volumes of limbic structures compared to non-limbic structures, and subsequently applied regionally constrained machine learning models trained solely on limbic or non-limbic features. To investigate the biological underpinnings of such models, we assessed the heritability of the obtained sex class probability estimates, and we investigated the association with major depression diagnosis in an independent clinical sample. All analyses were performed both with and without controlling for estimated total intracranial volume (eTIV). RESULTS: Limbic structures show greater sex differences and are more heritable compared to non-limbic structures in both analyses, with and without eTIV control. Consequently, machine learning models performed well at classifying sex based solely on limbic structures and achieved performance as high as those on non-limbic or whole brain data, despite the much smaller number of features in the limbic system. The resulting class probabilities were heritable, suggesting potentially meaningful underlying biological information. Applied to an independent population with major depressive disorder, we found that depression is associated with male-female class probabilities, with largest effects obtained using the limbic model. This association was significant for models not controlling for eTIV whereas in those controlling for eTIV the associations did not pass significance correction. CONCLUSIONS: Overall, our results highlight the potential utility of regionally constrained models of brain sex to better understand the link between sex differences in the brain and mental disorders.
Psychiatric disorders have different prevalence between sexes, with women being twice as likely to develop depression and anxiety across the lifespan. Previous studies have investigated sex differences in brain structure that might contribute to this prevalence but have mostly focused on a single-structure level, potentially overlooking the interplay between brain regions. Sex differences in structures responsible for emotional regulation (limbic system), affected in many psychiatric disorders, have been previously reported. Here, we apply a machine learning model to obtain an estimate of brain sex for each participant based on the volumes of multiple brain regions. Particularly, we compared the estimates obtained with a model based solely on limbic structures with those obtained with a non-limbic model (entire brain except limbic structures) and a whole brain model. To investigate the genetic determinants of the models, we assessed the heritability of the estimates between identical twins and fraternal twins. The estimates of all our models were heritable, suggesting a genetic component contributing to brain sex. Finally, to investigate the association with mental health, we compared brain sex estimates in healthy subjects and in a depressed population. We found an association between depression and brain sex in females for the limbic model, but not for the non-limbic model. No effect was found in males. Overall, our results highlight the potential utility of machine learning models of brain sex based on relevant structures to better understand the link between sex differences in the brain and mental disorders.
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Sistema Límbico , Transtornos Mentais , Fenótipo , Caracteres Sexuais , Humanos , Sistema Límbico/diagnóstico por imagem , Feminino , Masculino , Transtornos Mentais/genética , Transtornos Mentais/diagnóstico por imagem , Adulto , Aprendizado de Máquina , Transtorno Depressivo Maior/genética , Transtorno Depressivo Maior/diagnóstico por imagem , Adulto Jovem , Pessoa de Meia-IdadeRESUMO
Despite the evidence of altered emotion processing in oral contraceptive (OC) users, the impact of hormonal intrauterine devices (IUD) on emotional processing remains unexplored. Our study aimed to investigate how behavioural performance and event-related potentials (ERPs) linked with emotion reactivity and its regulation are associated with hormonal profiles of women using different types of hormonal contraception and naturally cycling women. Women using OCs (n = 25), hormonal IUDs (n = 33), and naturally cycling women in their early follicular (NCF, n = 33) or mid-luteal (NCL, n = 28) phase of the menstrual cycle were instructed to view emotional pictures (neutral, low and high negativity) and use cognitive reappraisal to up- or down-regulate negative emotions, while their electroencephalogram was recorded. Participants rated perceived negativity after each picture and their emotional arousal throughout the task. Saliva samples were collected to assess levels of 17ß-estradiol, progesterone, and testosterone. As expected, emotional arousal increased throughout the task and correlated positively with perceived negativity. Perceived negativity and the amplitudes of the middle (N2/P3) and later (LPP) latency ERP components increased with increasing stimuli negativity. Emotion regulation modulated perceived negativity and the amplitudes of very late ERP components (parietal and frontal LPP). Moreover, IUD-users showed a higher negative amplitude of the frontal N2 in comparison to all three other groups, with the most consistent differences during up-regulation. Finally, testosterone correlated positively with the N2 peak in IUD-users and NCL women. Overall, our findings suggest that IUD-use and testosterone might be related to altered preconscious processing during the emotion regulation task requiring attention to the stimulus. The study underscores the need for additional research into how different hormonal contraceptives are linked to socio-emotional functioning.
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Dispositivos Intrauterinos , Levanogestrel , Feminino , Humanos , Levanogestrel/farmacologia , Ciclo Menstrual/fisiologia , Progesterona , TestosteronaRESUMO
Higher prevalence of depression in females might be associated with sex-specific cortisol levels. Evidence exists that cortisol levels differ between healthy females and males, however a sex-specific association in depression has not been systematically assessed. Thus, the current study quantifies the existing literature on different cortisol parameters, i.e., basal cortisol, hair cortisol, cortisol awakening response (CAR), and cortisol stress reactivity comparing depressed females and males as well as sex-specific comparisons with healthy controls. Following an extensive literature research, fifty original articles were included. Depressed females had significantly higher hair cortisol, higher CAR, and lower cortisol stress reactivity compared to depressed males. In comparison with sex-matched controls, female patients had significantly higher evening basal cortisol, higher CAR and lower cortisol stress reactivity, and male patients had significantly higher general, morning and evening basal cortisol. Overall, sex as a fundamental driver of cortisol levels in depression needs to be taken into account.
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Cabelo , Hidrocortisona , Caracteres Sexuais , Hidrocortisona/metabolismo , Humanos , Feminino , Masculino , Cabelo/química , Cabelo/metabolismo , Depressão/metabolismoRESUMO
Over the last decades, theoretical perspectives in the interdisciplinary field of the affective sciences have proliferated rather than converged due to differing assumptions about what human affective phenomena are and how they work. These metaphysical and mechanistic assumptions, shaped by academic context and values, have dictated affective constructs and operationalizations. However, an assumption about the purpose of affective phenomena can guide us to a common set of metaphysical and mechanistic assumptions. In this capstone paper, we home in on a nested teleological principle for human affective phenomena in order to synthesize metaphysical and mechanistic assumptions. Under this framework, human affective phenomena can collectively be considered algorithms that either adjust based on the human comfort zone (affective concerns) or monitor those adaptive processes (affective features). This teleologically-grounded framework offers a principled agenda and launchpad for both organizing existing perspectives and generating new ones. Ultimately, we hope the Human Affectome brings us a step closer to not only an integrated understanding of human affective phenomena, but an integrated field for affective research.
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Nível de Alerta , Emoções , HumanosRESUMO
Worldwide, over 150 million adolescent and adult women use oral contraceptives (OC). An association between OC-use and the emergence of symptoms of mental disorders has been suggested. This systematic review and meta-analysis provide an overview of published research regarding symptoms of mental disorders in association with OC-use, factoring the influence of OC types, age of first-use, duration of OC-intake, and previous diagnoses of mental disorders. A systematic literature search was conducted between June-July 2022. 22 studies were included. While most found no significant OC-use effects on mental symptoms, some hinted at OCs as a potential risk. The existing evidence regarding the potential link between progestin-only OC-use and an elevated risk of mental symptoms in comparison to combined OC-use remains inconclusive. However, due to emerging indications suggesting that the formulation of OC might play a role in mental health outcomes, this topic warrants further investigation. Moreover, indications of an increased risk for depressive symptoms in adolescent OC-users should be noted. Hence, while general population effects seem unlikely, they cannot be completely disregarded. The decision on OC-use should depend on the patient's medical history and should be re-evaluated regularly.
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Anticoncepcionais Orais , Transtornos Mentais , Adulto , Adolescente , Humanos , Feminino , Anticoncepcionais Orais/efeitos adversos , AnticoncepçãoRESUMO
BACKGROUND: Transcranial direct current stimulation (tDCS) can influence brain network activity and associated cognitive and behavioural functions. In addition to the extensive variety in stimulation parameters, numerous biological factors drive these effects, however these are yet poorly understood. Here, we investigate one of the major biological factors by focusing on sex-dependent effects of tDCS on a challenging cognitive control task (adaptive paced auditory serial addition task [PASAT]) in healthy humans. METHODS: This sex-specific re-analysis was performed on data of 163 subjects who underwent a 2-week cognitive control training (6 sessions in total). Subjects received either verum (anodal/cathodal) or sham tDCS. Electrodes were placed over the left or right dorsolateral prefrontal cortex and the respective contralateral deltoid muscle. Cognitive control was measured as performance in the PASAT and was analysed in respect to stimulation conditions (sham, anodal, cathodal) and sex. RESULTS: Regardless of stimulation condition, performance gains between the sexes were higher in females compared to males (p = 0.0038). Female's performance during anodal tDCS exceeded male's (p = 0.0070), yet no effects were found for cathodal or sham tDCS. Moreover, in females we found a superior effect for anodal tDCS over sham stimulation (fanodal: p = 0.0354; fcathodal: p = 0.6181), but no such effect in males (manodal: p = 0.6882; mcathodal: p = 0.4822). CONCLUSIONS: This study highlights the relevance of biological sex for the effects of tDCS on cognitive training. Thus, an increased attention to biological sex is advisable in future brain stimulation research to highlight and in consequence better understand potentially underlying sex-specific mechanisms. Considering biological sex will further advance customisation and individualisation of tDCS interventions. Trial registration ClinicalTrials.gov, NCT04108663.
In previous studies, brain stimulation techniques like transcranial direct current stimulation (tDCS) have been shown to support cognitive trainings. However, these effects are rather small and vary between people. A key factor of variability is the biological sex. Hence, in this study we were interested in whether the effects of tDCS differ between females and males. To answer this research question, we analysed the data of 163 human subjects who underwent a 2-week cognitive control training program, which incorporates a challenging cognitive task (the adaptive paced auditory serial addition task [PASAT]). During the PASAT, subjects have to solve a stressful calculation exercise. Concurrently to solving this task, the subjects received either real (further divided into anodal [= enhancing] and cathodal [= inhibiting]) or placebo tDCS. We found that females had greater performance gains in the task than males, regardless of the type of tDCS they received. Furthermore, females performed particularly well when they received anodal tDCS, but there were no significant effects for cathodal or placebo tDCS. For males, we did not find any significant benefits of tDCS. These findings highlight the importance of considering biological sex in future brain stimulation research and suggest that biological sex is an important component to consider when studying the effects of tDCS. By paying more attention to this factor, researchers can better understand how tDCS works and develop more effective and personalised interventions.
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Estimulação Transcraniana por Corrente Contínua , Feminino , Humanos , Masculino , Fatores Biológicos , Treino Cognitivo , Estimulação Transcraniana por Corrente Contínua/métodosRESUMO
Background: Controllability is a measure of the brain's ability to orchestrate neural activity which can be quantified in terms of properties of the brain's network connectivity. Evidence from the literature suggests that aging can exert a general effect on whole-brain controllability. Mounting evidence, on the other hand, suggests that parenthood and motherhood in particular lead to long-lasting changes in brain architecture that effectively slow down brain aging. We hypothesize that parenthood might preserve brain controllability properties from aging. Methods: In a sample of 814 healthy individuals (aged 33.9 ± 12.7 years, 522 females), we estimate whole-brain controllability and compare the aging effects in subjects with vs. those without children. We use diffusion tensor imaging (DTI) to estimate the brain structural connectome. The level of brain control is then calculated from the connectomic properties of the brain structure. Specifically, we measure the network control over many low-energy state transitions (average controllability) and the network control over difficult-to-reach states (modal controllability). Results and conclusion: In nulliparous females, whole-brain average controllability increases, and modal controllability decreases with age, a trend that we do not observe in parous females. Statistical comparison of the controllability metrics shows that modal controllability is higher and average controllability is lower in parous females compared to nulliparous females. In men, we observed the same trend, but the difference between nulliparous and parous males do not reach statistical significance. Our results provide strong evidence that parenthood contradicts aging effects on brain controllability and the effect is stronger in mothers.
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The amygdala contains androgen receptors and is involved in various affective and social functions. An interaction between testosterone and the amygdala's functioning is likely. We investigated the amygdala's resting-state functional connectivity (rsFC) network in association with testosterone in 94 healthy young adult women and men (final data available for analysis from 42 women and 39 men). Across the whole sample, testosterone was positively associated with the rsFC between the right amygdala and the right middle occipital gyrus, and it further predicted lower agreeableness scores. Significant sex differences appeared for testosterone and the functional connectivity between the right amygdala and the right superior frontal gyrus (SFG), showing higher testosterone levels with lower connectivity in women. Sex further predicted the openness and agreeableness scores. Our results show that testosterone modulates the rsFC between brain areas involved in affective processing and executive functions. The data indicate that the cognitive control of the amygdala via the frontal cortex is dependent on the testosterone levels in a sex-specific manner. Testosterone seems to express sex-specific patterns (1) in networks processing affect and cognition, and (2) in the frontal down-regulation of the amygdala. The sex-specific coupling between the amygdala and the frontal cortex in interaction with the hormone levels may drive sex-specific differences in a variety of behavioral phenomena that are further associated with psychiatric illnesses that show sex-specific prevalence rates.
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The increasing use of machine learning approaches on neuroimaging data comes with the important concern of confounding variables which might lead to biased predictions and in turn spurious conclusions about the relationship between the features and the target. A prominent example is the brain size difference between women and men. This difference in total intracranial volume (TIV) can cause bias when employing machine learning approaches for the investigation of sex differences in brain morphology. A TIV-biased model will not capture qualitative sex differences in brain organization but rather learn to classify an individual's sex based on brain size differences, thus leading to spurious and misleading conclusions, for example when comparing brain morphology between cisgender- and transgender individuals. In this study, TIV bias in sex classification models applied to cis- and transgender individuals was systematically investigated by controlling for TIV either through featurewise confound removal or by matching the training samples for TIV. Our results provide strong evidence that models not biased by TIV can classify the sex of both cis- and transgender individuals with high accuracy, highlighting the importance of appropriate modeling to avoid bias in automated decision making.
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Pessoas Transgênero , Humanos , Feminino , Masculino , Tamanho do Órgão , Viés , Encéfalo/diagnóstico por imagem , Aprendizado de MáquinaRESUMO
Objectives: To correctly recognize and respond to your counterpart's emotion is essential for a successful get-together. To ensure this, emotional processes and inhibitory control are linked and interact with each other. However, this interaction can be altered in several mental disorders. In a group of psychosomatic patients, we investigated possible differences in the response inhibition between neutral and emotional stimuli and whether a psychosomatic inpatient and day-hospital patient treatment influences response inhibition profiles. Methods: One hundred and one patients, diagnosed with different psychiatric diagnoses (77 women, 41.43 ± 13.13 years), completed an emotional stop-signal task (ESST) and an impulsive behavior scale upon admission in an inpatient and day-hospital patient treatment on a psychosomatic ward (T0) and at discharge (T1). Patients with depressive disorders completed the test again after 1 year (follow-up measurement T2, n = 22). Emotional stimuli were angry and neutral faces. Stop-signal reaction time (SSRT) and stop-signal delay (SSD) were calculated as the main behavioral parameters. Results: We found a significantly higher SSRT for neutral than angry faces at both admission (8.538 ms, p < 0.001) and discharge (11.142 ms, p < 0.001), with a matching higher SSD for angry than neutral faces at both timepoints (T0: 8.360 ms, p < 0.001, T1: (6.950 ms, p < 0.001). The SSRT for angry faces significantly decreased after treatment (-8.485 ms, p = 0.0110). For neutral faces, the decrease failed to reach significance (-5.881 ms, p = 0.250). A significant decrease in SSRT for neutral faces in patients with depressive disorders was found 1 year after discharge compared with admission (-19.040 ms, p = 0.0380). Conclusion: Our data demonstrate a decreased response inhibition for neutral compared with emotional stimuli and an improved response inhibition for angry faces after discharge in a psychosomatic inpatient and day-hospital patient cohort. Additionally, patients with depressive disorders displayed a significantly better response inhibition for neutral faces 1 year after discharge compared with the baseline measurement. With this study, we provide more evidence for altered emotional response inhibition in different mental disorders and a hint that psychosomatic inpatient and day-hospital patient treatment may help to normalize it, even if the effects remained small and it needs further research to prove causality.
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BACKGROUND: Emotion regulation theories and the negative urgency concept assume that negative mood increases binge eating. Negative emotions are considered as a trigger for binge eating, while binge eating itself is regarded as an impulsive behavior and should thus be increased within the negative urgency concept. Anger might be a specific negative emotion triggering binge eating in patients with binge eating disorder (BED). We investigated how inhibitory control as one main factor of impulsivity is influenced by anger stimuli in patients with BED and two control groups. METHODS: We compared patients with BED (N = 20) with normal-weight healthy control participants (NW-CG, N = 20) and BMI-matched overweight and obese control participants (BMI-CG, N = 18). We used the emotional Stop Signal task (eSST) to investigate inhibitory control, where we presented angry facial expressions in comparison with neutral facial expressions as emotional stimuli. RESULTS: All participants showed decreased inhibitory control in the angry versus neutral condition, i.e., a faster Stop Signal Reaction Time and a lower percentage of correct reactions. However, no significant group differences emerged in terms of performance. Performance in the eSST did not correlate with negative urgency, disorder- or emotion-related characteristics. CONCLUSIONS: The current pilot study does not deliver evidence for decreased inhibitory control towards angry stimuli in patients with BED, as we detected a general and not disorder-related effect in all participants that might represent the conjunction of inhibitory control and anger. A direct mood induction technique might have led to different results. Further research in healthy and clinical groups is needed.
Several theories suggest that binge eating episodes are often appearing in negative mood and anger is one specific emotion that might commonly trigger binge eating. The aim of this study was to investigate inhibitory control under anger in patients with binge eating disorder (BED). Inhibitory control is a specific component of impulsivity and further studies suggest that inhibitory control deficits are related to binge eating. We compared patients with BED with normal-weight participants and overweight or obese participants as control groups in a specific inhibitory control task, where faces with angry or neutral expressions were presented and participants should stop, i.e. inhibit their reactions. All participants had more inhibitory control deficits when they viewed angry faces in comparison with neutral expressions, and patients with BED did not differ from the participants of the two control groups. Thus, all participants react on anger with increased impulsivity indicating that patients with BED seem to have no specific deficit in this regard. As this was a pilot study, further studies should investigate the interplay of several emotions and impulsivity in healthy and clinical groups.
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Stress is an important factor in the development, triggering, and maintenance of psychotic symptoms. Still, little is known about the neural correlates of cognitively regulating stressful events in schizophrenia. The current study aimed at investigating the cognitive down-regulation of negative, stressful reactions during a neuroimaging psychosocial stress paradigm (non-regulated stress versus cognitively regulated stress). In a randomized, repeated-measures within-subject design, we assessed subjective reactions and neural activation in schizophrenia patients (SZP) and matched healthy controls in a neuroimaging psychosocial stress paradigm. In general, SZP exhibited an increased anticipation of stress compared to controls (p = 0.020). During non-regulated stress, SZP showed increased negative affect (p = 0.033) and stronger activation of the left parietal operculum/posterior insula (p < 0.001) and right inferior frontal gyrus/anterior insula (p = 0.005) than controls. Contrarily, stress regulation compared to non-regulated stress led to increased subjective reactions in controls (p = 0.003) but less deactivation in SZP in the ventral anterior cingulate cortex (p = 0.027). Our data demonstrate stronger reactions to and anticipation of stress in patients and difficulties with cognitive stress regulation in both groups. Considering the strong association between mental health and stress, the investigation of cognitive regulation in individuals vulnerable to stress, including SZP, has crucial implications for improving stress intervention trainings.
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In cost-benefit decision-making, women and men often show different trade-offs. However, surprisingly little is known about sex differences in instrumental tasks, where physical effort is exerted to gain rewards. To this end, we tested 81 individuals (47 women) with an effort allocation task, where participants had to repeatedly press a button to collect food and money tokens. We analyzed the motivational phases of invigoration and effort maintenance with varying reward magnitude, difficulty, and reward type. Whereas women and men did not differ in invigoration, we found that women showed higher effort maintenance as well as higher subjective wanting and exertion ratings for small rewards compared with men. Notably, men increased their effort more than women for higher rewards to match women's levels of performance. Crucially, we found no sex differences depending on reward type or difficulty, indicating that sex differences were specific to the encoding of the magnitude of benefits, not costs. To summarize, women exerted higher physical effort for small rewards, which corresponded with an elevated subjective value in women compared with men. Therefore, sex differences in perceived reward magnitude may contribute to differential behavioral preferences highlighting the potential of cost-benefit decision-making to provide insights about potential mechanisms.
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Tomada de Decisões , Motivação , Masculino , Humanos , Feminino , Recompensa , Análise Custo-BenefícioRESUMO
Females and males differ in stress reactivity, coping, and the prevalence rates of stress-related disorders. According to a neurocognitive framework of stress coping, the functional connectivity between the amygdala and frontal regions (including the dorsolateral prefrontal cortex (dlPFC), ventral anterior cingulate cortex (vACC), and medial prefrontal cortex (mPFC)) plays a key role in how people deal with stress. In the current study, we investigated the effects of sex and stressor type in a within-subject counterbalanced design on the resting-state functional connectivity (rsFC) of the amygdala and these frontal regions in 77 healthy participants (40 females). Both stressor types led to changes in subjective ratings, with decreasing positive affect and increasing negative affect and anger. Females showed higher amygdala-vACC and amygdala-mPFC rsFC for social exclusion than for achievement stress, and compared to males. Whereas a higher amygdala-vACC rsFC indicates the activation of emotion processing and coping, a higher amygdala-mPFC rsFC indicates feelings of reward and social gain, highlighting the positive effects of social affiliation. Thus, for females, feeling socially affiliated might be more fundamental than for males. Our data indicate interactions of sex and stressor in amygdala-frontal coupling, which translationally contributes to a better understanding of the sex differences in prevalence rates and stress coping.
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INTRODUCTION: Sex differences in stress reactions are often reported in the literature. However, the sex-dependent interplay of different facets of stress is still not fully understood. Particularly in neuroimaging research, studies on large samples combining different indicators of stress remain scarce. MATERIALS AND METHODS: In a functional magnetic resonance imaging study, a sample of 140 healthy participants (67 females using oral contraceptives) underwent a standardized stress induction protocol, the ScanSTRESS. During the experiment, salivary cortisol and subjective ratings were obtained at multiple time points and heart rate was recorded. RESULTS: Sex differences emerged in different facets of the stress response:Women reacted with enhanced subjective feelings of stress and increases in heart rate, while men showed more pronounced neural activation in stress-related brain regions such as the inferior frontal gyrus and insula. Subjective feelings of stress and (para) hippocampal activity were negatively related in women,whereas a slightly positive association was observed in men. DISCUSSION: These results provide further insight in the sex-specific stress response patterns. Moreover, they emphasize the role of the hippocampus in the regulation of the stress response. This paves the way for the identification of sex-dependent vulnerability factors that can, in the future, be implemented in the prevention and treatment of stress-related disorders.
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Encéfalo , Emoções , Humanos , Masculino , Feminino , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Córtex Pré-Frontal , Imageamento por Ressonância Magnética/métodos , Hidrocortisona , Estresse PsicológicoRESUMO
BACKGROUND: Sexual orientation in humans represents a multilevel construct that is grounded in both neurobiological and environmental factors. OBJECTIVE: Here, we bring to bear a machine learning approach to predict sexual orientation from gray matter volumes (GMVs) or resting-state functional connectivity (RSFC) in a cohort of 45 heterosexual and 41 homosexual participants. METHODS: In both brain assessments, we used penalized logistic regression models and nonparametric permutation. RESULTS: We found an average accuracy of 62% (±6.72) for predicting sexual orientation based on GMV and an average predictive accuracy of 92% (±9.89) using RSFC. Regions in the precentral gyrus, precuneus and the prefrontal cortex were significantly informative for distinguishing heterosexual from homosexual participants in both the GMV and RSFC settings. CONCLUSIONS: These results indicate that, aside from self-reports, RSFC offers neurobiological information valuable for highly accurate prediction of sexual orientation. We demonstrate for the first time that sexual orientation is reflected in specific patterns of RSFC, which enable personalized, brain-based predictions of this highly complex human trait. While these results are preliminary, our neurobiologically based prediction framework illustrates the great value and potential of RSFC for revealing biologically meaningful and generalizable predictive patterns in the human brain.