RESUMO
Avoidance, a hallmark of anxiety-related psychopathology, often comes at a cost; avoiding threat may forgo the possibility of a reward. Theories predict that optimal approach-avoidance arbitration depends on threat-induced psychophysiological states, like freezing-related bradycardia. Here we used model-based fMRI analyses to investigate whether and how bradycardia states are linked to the neurocomputational underpinnings of approach-avoidance arbitration under varying reward and threat magnitudes. We show that bradycardia states are associated with increased threat-induced avoidance and more pronounced reward-threat value comparison (i.e., a stronger tendency to approach vs. avoid when expected reward outweighs threat). An amygdala-striatal-prefrontal circuit supports approach-avoidance arbitration under threat, with specific involvement of the amygdala and dorsal anterior cingulate (dACC) in integrating reward-threat value and bradycardia states. These findings highlight the role of human freezing states in value-based decision making, relevant for optimal threat coping. They point to a specific role for amygdala/dACC in state-value integration under threat.
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Imageamento por Ressonância Magnética , Humanos , Masculino , Adulto , Feminino , Adulto Jovem , Bradicardia/fisiopatologia , Aprendizagem da Esquiva/fisiologia , Tonsila do Cerebelo/fisiologia , Recompensa , Giro do Cíngulo/fisiologia , Medo/fisiologia , Ansiedade/fisiopatologia , Frequência Cardíaca/fisiologia , Tomada de Decisões/fisiologiaRESUMO
When choosing between sooner-smaller and later-larger rewards (i.e., intertemporal choices), adults typically prefer later-larger rewards more often than children. Intertemporal choice preferences have been implicated in various impulsivity-related psychopathologies, making it important to understand the underlying mechanisms not only in terms of how reward magnitude and delay affect choice but also in terms of how these mechanisms develop across age. We administered an intertemporal choice paradigm to 60 children (8-11 years), 79 adolescents (14-16 years), and 60 young adults (18-23 years). The paradigm systematically varied amounts and delays of the available rewards, allowing us to identify mechanisms underlying age-related differences in patience. Compared with young adults, both children and adolescents made fewer later-larger choices. In terms of underlying mechanisms, variation in delays, absolute reward magnitudes, and relative amount differences affected choice in each age group, indicating that children showed sensitivity to the same choice-relevant factors as young adults. Sensitivity to both absolute reward magnitude and relative amount differences showed a further monotonic age-related increase, whereas no change in delay sensitivity occurred. Lastly, adolescents and young adults weakly displayed a present bias (i.e., overvaluing immediate vs. future rewards; nonsignificant and trend, respectively), whereas children showed a nonsignificant but opposite pattern, possibly indicating that specifically dealing with future rewards changed with age. These findings shed light on the underlying mechanisms that contribute to the development of patience. By decomposing overt choices, our results suggest that the age-related increase in patience may be driven specifically by stronger sensitivity to amount differences with age.
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Comportamento de Escolha , Desvalorização pelo Atraso , Adulto Jovem , Humanos , Criança , Adolescente , Recompensa , Comportamento Impulsivo , ViésRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0260952.].
RESUMO
Risk behavior has substantial consequences for health, well-being, and general behavior. The association between real-world risk behavior and risk behavior on experimental tasks is well documented, but their modeling is challenging for several reasons. First, many experimental risk tasks may end prematurely leading to censored observations. Second, certain outcome values can be more attractive than others. Third, a priori unknown groups of participants can react differently to certain risk-levels. Here, we propose the censored mixture model which models risk taking while dealing with censoring, attractiveness to certain outcomes, and unobserved individual risk preferences, next to experimental conditions.
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Assunção de Riscos , Humanos , PsicometriaRESUMO
Evaluations and value-based decisions are often accompanied by a feeling of confidence about whether or not the evaluation or decision is accurate. We argue that this feeling of confidence reflects the variation of an underlying value distribution and that this value distribution represents previously experienced values related to an object. Two preregistered experiments in which the variation of such value distributions was systematically varied provide causal evidence in favor of this hypothesis. A third preregistered experiment showed that, for natural food items with uncontrolled prior experiences, confidence in evaluations is again related to the variation of individuals' self-reported value distributions. Similarly, for choices between items, the variation of experienced values related to a choice pair influenced confidence in the perceived correctness of the choice. These findings converge with other domains of decision making showing that confidence tracks the variation of the underlying probability distribution of the evidence that a decision is based on, which in the case of value-based decisions, is informed by a value distribution reflecting priorly experienced values. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
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Comportamento de Escolha , Tomada de Decisões , Humanos , ProbabilidadeRESUMO
The endeavor to understand the human brain has seen more progress in the last few decades than in the previous two millennia. Still, our understanding of how the human brain relates to behavior in the real world and how this link is modulated by biological, social, and environmental factors is limited. To address this, we designed the Healthy Brain Study (HBS), an interdisciplinary, longitudinal, cohort study based on multidimensional, dynamic assessments in both the laboratory and the real world. Here, we describe the rationale and design of the currently ongoing HBS. The HBS is examining a population-based sample of 1,000 healthy participants (age 30-39) who are thoroughly studied across an entire year. Data are collected through cognitive, affective, behavioral, and physiological testing, neuroimaging, bio-sampling, questionnaires, ecological momentary assessment, and real-world assessments using wearable devices. These data will become an accessible resource for the scientific community enabling the next step in understanding the human brain and how it dynamically and individually operates in its bio-social context. An access procedure to the collected data and bio-samples is in place and published on https://www.healthybrainstudy.nl/en/data-and-methods/access. Trail registration: https://www.trialregister.nl/trial/7955.
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Encéfalo/fisiologia , Meio Social , Adulto , Afeto/fisiologia , Comportamento , Encéfalo/diagnóstico por imagem , COVID-19/diagnóstico , Cognição/fisiologia , Feminino , Humanos , Masculino , Neuroimagem , Sensação/fisiologia , Inquéritos e QuestionáriosRESUMO
The anticipation of threat facilitates innate defensive behaviours including freezing reactions. Freezing in humans is characterised by reductions in body sway and heart rate. Limited evidence suggests that individual differences in freezing reactions are associated with predictors of anxiety-related psychopathology including trait anxiety and hypothalamic-pituitary-adrenal (HPA) axis activity. However, previous human studies focused on acutely circulating cortisol levels, leaving the link between freezing and more stable, individual trait markers of HPA axis activity unclear. We investigated whether individual differences in anticipatory freezing reactions are predicted by accumulated hair cortisol concentrations (HCC) and trait anxiety, in a well-powered mixed sample of police recruits at the start of the police training, and age, sex and education matched controls (total N = 419, mean age = 24, Nwomen = 106, Npolice recruits = 337). Freezing-related reactions were assessed with posturographic and heart rate measurements during an active shooting task under threat of shock. The anticipation of threat of shock elicited the expected reductions in body sway and heart rate, indicative of human freezing. Individual differences in threat-related reductions in body sway, but not heart rate, were related to lower HCC and higher trait anxiety. The observed links between postural freezing and predictors of anxiety-related psychopathology suggest the potential value of defensive freezing as a somatic marker for individual differences in stress-vulnerability and resilience. DATA AVAILABILITY: The datasets analysed during the current study are available from the corresponding authors upon reasonable request.
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Ansiedade , Medo , Cabelo , Hidrocortisona , Adulto , Ansiedade/fisiopatologia , Medo/fisiologia , Medo/psicologia , Feminino , Cabelo/química , Humanos , Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisário/fisiologia , Masculino , Sistema Hipófise-Suprarrenal/fisiologia , Adulto JovemRESUMO
Successful responding to acutely threatening situations requires adequate approach-avoidance decisions. However, it is unclear how threat-induced states-like freezing-related bradycardia-impact the weighing of the potential outcomes of such value-based decisions. Insight into the underlying computations is essential, not only to improve our models of decision-making but also to improve interventions for maladaptive decisions, for instance in anxiety patients and first-responders who frequently have to make decisions under acute threat. Forty-two participants made passive and active approach-avoidance decisions under threat-of-shock when confronted with mixed outcome-prospects (i.e., varying money and shock amounts). Choice behavior was best predicted by a model including individual action-tendencies and bradycardia, beyond the subjective value of the outcome. Moreover, threat-related bradycardia (high-vs-low threat) interacted with subjective value, depending on the action-context (passive-vs-active). Specifically, in action-contexts incongruent with participants' intrinsic action-tendencies, stronger bradycardia related to diminished effects of subjective value on choice across participants. These findings illustrate the relevance of testing approach-avoidance decisions in relatively ecologically valid conditions of acute and primarily reinforced threat. These mechanistic insights into approach-avoidance conflict-resolution may inspire biofeedback-related techniques to optimize decision-making under threat. Critically, the findings demonstrate the relevance of incorporating internal psychophysiological states and external action-contexts into models of approach-avoidance decision-making.
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Aprendizagem da Esquiva/fisiologia , Tomada de Decisões/fisiologia , Congelamento , Hipocampo/fisiologia , Adolescente , Adulto , Ansiedade , Sistema Nervoso Autônomo , Biorretroalimentação Psicológica , Bradicardia , Comportamento de Escolha , Conflito Psicológico , Emoções , Feminino , Humanos , Aprendizagem , Masculino , Negociação , Psicofisiologia , Reforço Psicológico , Sensibilidade e Especificidade , Adulto JovemRESUMO
Social anxiety and psychopathy have conceptually been linked to nearly opposite emotional, behavioral and endocrinological endophenotypes, representing social fearfulness and fearlessness, respectively. Although such a dimensional view has theoretical and practical implications, no study has directly compared social anxiety and psychopathy in terms of emotional experiences, relevant hormones (i.e. cortisol, testosterone) and behavioral tendencies (i.e. social approach-avoidance). Therefore, the present study examined 1) whether self-reported social anxiety and psychopathic traits are indeed anticorrelated, and 2) whether social anxiety, psychopathic traits, cortisol, testosterone and their interplay are differentially linked to social approach-avoidance tendencies. In a well-powered study, a sample of 196 healthy female participants, we assessed self-reported emotional and behavioral tendencies of social fear (i.e. social anxiety and social avoidance) and psychopathic traits (i.e. Factor I [interpersonal-affective deficit] and Factor II [impulsive behavior]). Furthermore, hormone levels were assessed, and approach-avoidance tendencies towards emotional (angry, happy) facial expressions were measured by means of a joystick reaction time task. Results confirmed that self-reported emotional tendencies of social anxiety and psychopathy Factor I (interpersonal-affective deficit) correlated negatively, but self-reported behavioral tendencies (social avoidance and psychopathy Factor II [impulsive behavior]) correlated positively. Furthermore, Structural Equation Modelling demonstrated that participants with higher social anxiety and higher cortisol levels showed an avoidance tendency towards happy faces, while participants with higher psychopathic traits showed an approach tendency towards angry faces. In sum, the notion that social anxiety and psychopathic traits are opposing ends of one dimension was supported only in terms of self-reported emotional experiences, but a comparable relationship with regard to behavioral and endocrinological aspects is debatable. The current findings stress the necessity to study emotional, endocrinological and behavioral factors in unison in order to better understand the shared and distinctive mechanisms of social anxiety and psychopathic traits.
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Transtorno da Personalidade Antissocial/psicologia , Ansiedade/psicologia , Medo , Hidrocortisona/metabolismo , Adolescente , Adulto , Aprendizagem da Esquiva , Feminino , Fibrinogênio , Humanos , Protrombina , Autorrelato , Testosterona , Adulto JovemRESUMO
Adolescents with a family history (FH+) of substance use disorder (SUD) are at a greater risk for SUD, suggested to be partly due to the transmission of behavioral impulsivity. We used a delay discounting task to compare impulsivity in decision-making and its associated brain functioning among FH+ and FH - minority adolescents. Participants chose between Smaller Sooner (SS) and Larger Later (LL) rewards. The SS was available immediately (Now trials) or in the future (Not-Now trials), allowing for greater differentiation between impulsive decisions. The FH+ group showed greater impatience by responding SS more frequently than the FH - group, only on the Now trials, and even when the relative reward differences (RRD) increased. Surprisingly, there were no differences in brain activity between the groups. Combined, the groups showed greater reward activity during the Now vs. Not-Now trials in medial prefrontal/anterior cingulate, posterior cingulate, precuneus, and inferior frontal gyrus (i.e., an immediacy effect). As the RRD increased activation in the reward network decreased, including the striatum, possibly reflecting easy decision-making. These results indicate that risk for SUD, seen behaviorally among FH+ adolescents, may not yet be associated with discernable brain changes, suggesting that early intervention has the potential to reduce this risk.
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Desvalorização pelo Atraso , Transtornos Relacionados ao Uso de Substâncias , Adolescente , Criança , Imagem de Tensor de Difusão , Feminino , Humanos , Comportamento Impulsivo , Imageamento por Ressonância Magnética , Masculino , RecompensaRESUMO
Excessive avoidance behaviour is a cardinal symptom of anxiety disorders. Avoidance is not only associated with the benefits of avoiding threats, but also with the costs of missing out on rewards upon exploration. Psychological and psychophysiological mechanisms contributing to these costly avoidance decisions in prospect of mixed outcomes remain unclear. We developed a novel Fearful Avoidance Task (FAT) that resembles characteristics of real-life approach-avoidance conflicts, enabling to disentangle reward and threat effects. Using the FAT, we investigated individual differences in avoidance behaviour and anticipatory psychophysiological states (i.e. startle reflex and skin conductance) in a relatively large sample of 343 (78 females) participants. Avoidance under acute threat of shock depends on a trade-off between perceived reward and threat. Both increased startle and skin conductance in the absence of threat of shock emerged as predictors of increased avoidance (potentially indicative of fear generalization). Increased avoidance was also associated with female sex and trait anxiety, dependent on reward and threat levels. Our findings highlight distinct possible predictors of heightened avoidance and add to mechanistic understanding of how individual propensity for costly avoidance may emerge. Distinct avoidance typologies based on differential reward and threat sensitivities may have different mechanistic origins and thereby could benefit from different treatment strategies.
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Individualidade , Psicofisiologia , Aprendizagem da Esquiva , Medo , Feminino , Humanos , Reflexo de SobressaltoRESUMO
Previous studies suggest that cues predicting the outcome of attentional shifts provide a measure of anticipatory alcohol-related attentional bias that is correlated with risky drinking and has high reliability. However, this is complicated by potential contributions of visual features of cues to reliability, unrelated to their predictive value. Further, little is known of the sensitivity of the bias to variations in cue-outcome mapping manipulations, limiting our theoretical and methodological knowledge: Does the bias robustly follow varying cue-outcome mappings, or are there automatic cue-related associative processes involved? The current studies aimed to address these issues. Participants performed variations of the cued Visual Probe Task (cVPT) in which cues were non-predictive; in which there were multiple cue pairs, used simultaneously and serially; and in which the cue-outcome mapping was reversed. The major findings were, first, that previously found reliability cannot be attributed to aspects of the cues not related to outcome-prediction; second, that reliability of the bias does not survive deviations from a simple, consistent cue-outcome mapping; third, that all predictive versions of the task showed a bias towards alcohol; fourth, that the bias did not simply follow awareness of the cue-outcome mapping; and finally, that only in the case of simultaneous multiple cue pairs, an association with risky drinking was replicated. The results provide support for the reliability of the anticipatory attentional bias for alcohol, suggest that relatively persistent associative processes underlie the bias in the alcohol context, and provide a foundation for future work using the cVPT.
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Viés de Atenção , Bebidas , Sinais (Psicologia) , Etanol , Estimulação Luminosa/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos TestesRESUMO
The current study focused on the degree to which decision context (deliberative vs. affective) differentially impacted the use of available information about uncertainty (i.e., probability, positive and negative outcome magnitudes, expected value, and variance/risk) when older adults were faced with decisions under risk. In addition, we examined whether individual differences in general mental ability and executive function moderated the associations between age and information use. Participants (N = 96) completed a neuropsychological assessment and the hot (affective) and cold (deliberative) versions of an explicit risk task. Our results did not find a significant Age × Hot/Cold Condition interaction on overall risk-taking. However, we found that older adults were less likely to use the full decision information available regardless of the decision context. This finding suggested more global age differences in information use. Moreover, older adults were less likely to make expected-value sensitive decisions, regardless of the hot/cold context. Finally, we found that low performance on measures of executive functioning, but not general mental ability, appears to be a risk factor for lower information use. This pattern appears in middle age and progressively becomes stronger in older age. The current work provides evidence that common underlying decision processes may operate in risk tasks deemed either affective or deliberative. It further suggests that underlying mechanisms such as information use may be paramount, relative to differences in the affective context. Additionally, individual differences in neuropsychological function may act as a moderator in the tendency to use available information across affective context. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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Envelhecimento/psicologia , Tomada de Decisões/fisiologia , Função Executiva/fisiologia , Individualidade , Testes Neuropsicológicos/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Assunção de Riscos , Adulto JovemRESUMO
Visual Probe Tasks (VPTs) have been extensively used to measure spatial attentional biases, but as usually analysed, VPTs do not consider trial-to-trial carryover effects of probe location: Does responding to a probe on, e.g., the location of a threat cue affect the bias on the subsequent trial? The aim of the current study was to confirm whether this kind of carryover exists, using a novel task version, the diagonalized VPT, designed to focus on such trial-to-trial interactions. Two versions of the task were performed by a sample of college students. In one version cues were coloured squares; in the other, cues were threat-related and neutral images. Both versions included partially random positive or negative response feedback and varying Cue-Probe Intervals (200 or 600â¯ms). Carryover effects were found in both versions. Responding to a probe at the location of a cue of a given colour induced an attentional bias on the subsequent trial in the direction of that colour. Responding to a threat-related cue induced an attentional bias towards threat on the subsequent trial. The results provide evidence that trial-to-trial carryover effects on spatial attentional bias indeed exist. A methodological implication is that previous probe location could be considered in analyses or re-analyses of spatial visual attention tasks.
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Viés de Atenção/fisiologia , Percepção de Cores/fisiologia , Estimulação Luminosa/métodos , Desempenho Psicomotor/fisiologia , Comportamento Espacial/fisiologia , Adolescente , Adulto , Sinais (Psicologia) , Feminino , Humanos , Masculino , Adulto JovemRESUMO
This study evaluated the aspects of complex decisions influenced by peers, and components of peer involvement influential to adolescents' risky decisions. Participants (N = 140) aged 13-25 completed the Columbia Card Task (CCT), a risky choice task, isolating deliberation-reliant and affect-reliant decisions while alone, while a friend monitors choices, and while a friend is merely present. There is no condition in which a nonfriend peer is present. Results demonstrated the risk-increasing peer effect occurred in the youngest participants in the cold CCT and middle-late adolescents in the hot CCT, whereas other ages and contexts showed a risk-decreasing peer effect. Mere presence was not sufficient to influence risky behavior. These boundaries in age, decision, and peer involvement constrain prevailing models of adolescent peer influence.
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Comportamento do Adolescente/fisiologia , Comportamento de Escolha/fisiologia , Desenvolvimento Humano/fisiologia , Influência dos Pares , Assunção de Riscos , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Given the long-lasting detrimental effects of internalizing symptoms, there is great need for detecting early risk markers. One promising marker is freezing behavior. Whereas initial freezing reactions are essential for coping with threat, prolonged freezing has been associated with internalizing psychopathology. However, it remains unknown whether early life alterations in freezing reactions predict changes in internalizing symptoms during adolescent development. In a longitudinal study (N = 116), we tested prospectively whether observed freezing in infancy predicted the development of internalizing symptoms from childhood through late adolescence (until age 17). Both longer and absent infant freezing behavior during a standard challenge (robot-confrontation task) were associated with internalizing symptoms in adolescence. Specifically, absent infant freezing predicted a relative increase in internalizing symptoms consistently across development from relatively low symptom levels in childhood to relatively high levels in late adolescence. Longer infant freezing also predicted a relative increase in internalizing symptoms, but only up until early adolescence. This latter effect was moderated by peer stress and was followed by a later decrease in internalizing symptoms. The findings suggest that early deviations in defensive freezing responses signal risk for internalizing symptoms and may constitute important markers in future stress vulnerability and resilience studies.
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Adaptação Psicológica/fisiologia , Desenvolvimento do Adolescente/fisiologia , Medo/psicologia , Estresse Psicológico/psicologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Grupo Associado , Polimorfismo Genético/genética , Estudos Prospectivos , Proteínas da Membrana Plasmática de Transporte de Serotonina/genéticaRESUMO
We are often presented with choices that differ in their more immediate versus future consequences. Interestingly, in everyday-life, ambiguity about the exact timing of such consequences frequently occurs, yet it remains unknown whether and how time-ambiguity influences decisions and their underlying neural correlates. We developed a novel intertemporal fMRI choice task in which participants make choices between sooner-smaller (SS) versus later-larger (LL) monetary rewards with systematically varying levels of time-ambiguity. Across trials, delay information of the SS, the LL, or both rewards was either exact (e.g., in 5 weeks), of low ambiguity (4 week range: e.g., in 3-7 weeks), or of high ambiguity (8 week range: e.g., in 1-9 weeks). Choice behavior showed that the majority of participants preferred options with exact delays over those with ambiguous delays, indicating time-ambiguity aversion. Consistent with these results, the ventromedial prefrontal cortex showed decreased activation during ambiguous versus exact trials. In contrast, intraparietal sulcus activation increased during ambiguous versus exact trials. Furthermore, exploratory analyses suggest that more time-ambiguity averse participants show more insula and dorsolateral prefrontal cortex activation during subjective value (SV)-coding of ambiguous versus exact trials. Lastly, the best-fitting computational choice models indicate that ambiguity impacts the SV of options via time perception or via an additive ambiguity-related penalty term. Together, these results provide the first behavioral and neural signatures of time-ambiguity, pointing towards a unique profile that is distinct from impatience. Since time-ambiguity is ubiquitous in real-life, it likely contributes to shortsighted decisions above and beyond delay-discounting.
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Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Desvalorização pelo Atraso/fisiologia , Percepção do Tempo/fisiologia , Adulto , Humanos , Imageamento por Ressonância Magnética , MasculinoRESUMO
Adolescence is characterized by considerable changes in cognitive and socio-emotional skills. There are considerable differences between adolescents with regards to the development of these skills. However, most studies examine adolescents' average functioning, without taking into account this heterogeneity. The current study applies network analysis in order to examine heterogeneity of cognitive and socio-emotional functioning in adolescents on-track or delayed in their school progression. Data was collected at two time-points for on-track (n = 320) and delayed (n = 69) adolescents (Mage = 13.30 years, SDage = 0.77). Repeated measures ANOVA showed no significant differences between the groups in cognitive and socio-emotional functioning (p's > 0.05). Network analysis revealed that executive functions play a key role in the network of cognitive, social, and emotional functioning. This is especially the case in the delayed group where executive functions are even more central, both at T1 (inhibition and shifting) and T2 (shifting). Subsequent community analysis revealed three profiles in both groups: a well-adapted and well-balanced group, a group with high levels of need for arousal and risk-taking, and a group with regulation problems. Compared to on-track adolescents, delayed adolescents showed even higher levels of risk-taking in the second profile and higher levels of executive function problems in the third profile at T1. These differences were leveled out at T2, indicating adolescents in the delayed group catch up with their peers. This study highlights the intricate balance between cognitive, social and emotional functioning in adolescents in relation to school performance and provides preliminary evidence of the importance of taking individual differences within groups into account.
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Freezing behavior, a commonly observed defensive stress response, shows relatively high stability over time in animals. Given the relevance of freezing for stress-coping and human psychopathology, it is relevant to know whether freezing behavior is also stable in humans, particularly during adolescence, when most affective symptoms develop. In a prospective longitudinal study, we investigated freezing-like behavior in response to social threat in 75 adolescents at age 14, repeated 3 years later at age 17. We used a well-established method combining electrocardiography (ECG; heart rate) and posturography (body sway) in response to emotional picture-viewing of angry, happy, and neutral faces. We hypothesized that individual differences in freezing-like behavior in response to social threat-operationalized by contrasting angry vs. neutral faces-would be relatively stable over time. Our results indeed showed relative stability between ages 14 and 17 in individual differences in freezing-like behavior in heart rate (r = 0.82), as well as in combined heart rate and body sway measures (r = 0.65). These effects were not specific for the angry vs. neutral contrast; they were also visible in other emotion contrasts. Exploratory analysis in males and females separately showed stability in body sway specifically for angry vs. neutral faces only in females. Together, these results suggest moderate to strong stability in human freezing-like behavior in response to social threat from mid to late adolescence (with exception for the body sway measure in males). This relative stability was not specific for threat-induction and may reflect a general stability that is particularly strong for heart rate. The fact that this relative stability was found over a relatively long time range of 3 years is promising for studies aiming to use freezing-like behavior as a marker for internalizing symptoms in adolescent development.
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The Hypothalamic-Pituitary-Adrenal (HPA)-axis plays an important role in the expression of defensive freezing. Adaptive freezing reactivity, characterized by an immediate increase in acute stress and timely termination upon threat offset or need to act, is essential for adequate stress coping. Blunted HPA-axis activity in animals is associated with blunted freezing reactivity and internalizing symptoms. Despite their potential relevance, it remains unknown whether these mechanisms apply to humans and human psychopathology. Using a well-established method combining electrocardiography and posturography, we assessed freezing before, immediately after, and one hour after a stress induction in 92 human adolescents. In line with animal models, human adolescents showed stress-induced freezing, as quantified by relative reductions in heart rate and body sway after, as compared to before, stress. Moreover, relatively lower basal cortisol was associated with reduced stress-induced freezing reactivity (i.e., less immediate freezing and less recovery). Path analyses showed that decreased freezing recovery in individuals with reduced cortisol levels was associated with increased levels of internalizing symptoms. These findings suggest that reduced freezing recovery may be a promising marker for the etiology of internalizing symptoms.