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The Adolescent Brain
Annals of the New York Academy of Sciences
Abstract
Adolescence is a developmental period characterized by suboptimal decisions and actions that are associated with an increased incidence of unintentional injuries, violence, substance abuse, unintended pregnancy, and sexually transmitted diseases. Traditional neurobiological and cognitive explanations for adolescent behavior have failed to account for the nonlinear changes in behavior observed during adolescence, relative to both childhood and adulthood. This review provides a biologically plausible model of the neural mechanisms underlying these nonlinear changes in behavior. We provide evidence from recent human brain imaging and animal studies that there is a heightened responsiveness to incentives and socioemotional contexts during this time, when impulse control is still relatively immature. These findings suggest differential development of bottom-up limbic systems, implicated in incentive and emotional processing, to top-down control systems during adolescence as compared to childhood and adulthood. This developmental pattern may be exacerbated in those adolescents prone to emotional reactivity, increasing the likelihood of poor outcomes.
... Adolescence is a period of marked social, biological, cognitive, and psychological change (Casey et al., 2008;Ernst et al., 2006), including an increased prevalence of risk-taking behaviors, which peak worldwide during late adolescence (Duell et al., 2018). Increased risk-taking may be due to the manner in which adolescents evaluate information and make decisions, particularly in rewarding or affectively salient contexts (Hartley & Somerville, 2015). ...
... Taken together, these patterns of behavioral maturation as well as activity patterns within the neural systems underlying them cohere with the dual systems model of adolescent development (Casey et al., 2008;Steinberg, 2008), which posits that adolescents are biased to respond vigorously to rewarding and novel experiences due to the more rapid maturation of the reward system, including associated incentive motivational or socioemotional processes, relative to the cognitive control system (Casey et al., 2008;Ernst et al., 2006;Steinberg, 2008). Specifically, adolescents' cognitive control abilities may not be equipped to regulate motivational drives, which may bias adolescents toward rewardrelated strivings and may predispose them to take risks when making behavioral decisions. ...
... Taken together, these patterns of behavioral maturation as well as activity patterns within the neural systems underlying them cohere with the dual systems model of adolescent development (Casey et al., 2008;Steinberg, 2008), which posits that adolescents are biased to respond vigorously to rewarding and novel experiences due to the more rapid maturation of the reward system, including associated incentive motivational or socioemotional processes, relative to the cognitive control system (Casey et al., 2008;Ernst et al., 2006;Steinberg, 2008). Specifically, adolescents' cognitive control abilities may not be equipped to regulate motivational drives, which may bias adolescents toward rewardrelated strivings and may predispose them to take risks when making behavioral decisions. ...
The dual systems model of adolescent development asserts that the neurobiological systems underlying reward/motivational processes and cognitive control mature at different rates, resulting in an “imbalance” during adolescence whereby adolescents are biased toward rewards but unable to exert sufficient executive control in risk-taking contexts. While a hypothesized imbalance between these systems is central to the dual systems model, few studies have investigated longitudinal trajectories within and between each system with age. Therefore, this validation study assessed the developmental trajectories of the reward and control systems, and directly quantified within-person differences between these systems using an accelerated longitudinal design, including up to five biennial assessments per participant. The sample included 166 predominately White individuals from middle-class to upper-middle-class backgrounds, aged 9–29 years, of which 54% were female at birth. Results indicate that both self-reported reward sensitivity and laboratory-based executive functions increase rapidly during early adolescence and plateau by early adulthood. Findings provide evidence for a unique period of developmental imbalance with heightened reward sensitivity relative to executive control present in early adolescence and imply that most adolescents demonstrate top-down regulatory control over incentive-reward motivation by mid-to-late adolescence. However, some individuals deviate from this mean-level trend, suggesting that individual differences in neurodevelopment must be considered as important determinants of decision-making in later adolescence. Further research into how developmental differences between reward and control systems relate to decision-making processes, including risk-taking tendencies, is an important future direction for this research.
... The corticolimbic system contributes to processing emotional salience and regulating emotional responses 17 , while the corticostriatal system is involved in motivated behavior, reward processing, learning, and habit formation 18 . These systems mature throughout development 19 and this is accompanied by significant changes in synaptic connectivity and myelination [20][21][22] . Critically, this development is asynchronous. ...
... Critically, this development is asynchronous. Limbic and striatal structures mature earlier than cortical structures, including the prefrontal cortex, resulting in heightened impulsivity during this period of developmental 'mismatch' 21,23,24 . Behaviorally, emotional regulation, motivation, and impulse control evolve throughout development with rapid changes in early life followed by gradual changes during adolescence [25][26][27][28][29] . ...
... This trajectory mirrors developmental changes observed in neuroanatomy. During adolescence and early adulthood, significant maturation occurs in the prefrontal cortex, a region critical for emotional regulation and impulse control [20][21][22] . This maturation involves synaptic pruning and increased white matter connectivity to refine neural circuits, leading to improved cognitive control and decreased impulsivity 22 . ...
A bstract
Individual differences in neural circuits underlying emotional regulation, motivation, and decision-making are implicated in many psychiatric illnesses. Interindividual variability in these circuits may manifest, at least in part, as individual differences in impulsivity at both normative and clinically significant levels. Impulsivity reflects a tendency towards rapid, unplanned reactions to internal or external stimuli without considering potential negative consequences coupled with difficulty inhibiting responses.
Here, we use multivariate brain-based predictive models to explore the neural bases of impulsivity across multiple behavioral scales, neuroanatomical features (cortical thickness, surface area, and gray matter volume), and sexes (females and males) in a large sample of youth from the Adolescent Brain Cognitive Development (ABCD) Study at baseline (n=9,099) and two-year follow-up (n=6,432).
Impulsivity is significantly associated with neuroanatomical variability, and these associations vary across behavioral scales and neuroanatomical features. Impulsivity broadly maps onto cortical thickness in dispersed regions (e.g., inferior frontal, lateral occipital, superior frontal, entorhinal), as well as surface area and gray matter volume in specific medial (e.g., parahippocampal, cingulate) and polar (e.g., frontal and temporal) territories. Importantly, while many relationships are stable across sexes and time points, others are sex-specific and dynamic.
These results highlight the complexity of the relationships between neuroanatomy and impulsivity across scales, features, sexes, and time points in youth. These findings suggest that neuroanatomy, in combination with other biological and environmental factors, reflects a key driver of individual differences in impulsivity in youth. As such, neuroanatomical markers may help identify youth at increased risk for developing impulsivity-related illnesses. Furthermore, this work emphasizes the importance of adopting a multidimensional and sex-specific approach in neuroimaging and behavioral research.
... [4][5][6][7][8][9] Adolescents are more prone to impulsive behavior and risk-taking due to delayed prefrontal cortex development and heightened limbic activity. [10][11][12][13] This neurodevelopmental imbalance increases susceptibility to peer influence and early alcohol use, raising the risk of problematic use and dependence. 7,10 Globally, alcohol use among adolescents is widespread, with estimates suggesting that over 22% of individuals aged 15-19 years consumed alcohol in 2019. 1 Early initiation of alcohol use is strongly associated with increased risks of injury, risky sexual behavior, mental health challenges, and poor academic and social outcomes. ...
... [10][11][12][13] This neurodevelopmental imbalance increases susceptibility to peer influence and early alcohol use, raising the risk of problematic use and dependence. 7,10 Globally, alcohol use among adolescents is widespread, with estimates suggesting that over 22% of individuals aged 15-19 years consumed alcohol in 2019. 1 Early initiation of alcohol use is strongly associated with increased risks of injury, risky sexual behavior, mental health challenges, and poor academic and social outcomes. 1,[14][15][16] For adolescents, whose brains are still maturing, alcohol use can lead to long-term cognitive impairments, emotional dysregulation, and behavioral difficulties. ...
Background
Adolescents and young adults in sub-Saharan Africa face a growing burden of alcohol use and related disorders, driven by a convergence of biological vulnerability, socio-environmental pressures, and weak regulatory systems. Rising digital media exposure and socio-economic disparities further exacerbate risky drinking behaviors.
Objective
This review synthesizes current evidence on the prevalence, risk factors, health and social impacts, and intervention strategies related to alcohol use among adolescents and young people in sub-Saharan Africa.
Methods
A narrative review approach was employed, drawing on peer-reviewed articles and global reports published between 2000 and 2024. Studies were identified through searches in databases including PubMed, Scopus, Google Scholar, and Web of Science, using defined inclusion criteria focused on youth aged 10–24 years.
Findings
Alcohol use and alcohol use disorders (AUD) among youth are influenced by a complex interplay of genetic, psychological, familial, social, and digital factors. Consequences include increased risks of mental illness, HIV infection, gender-based violence, poor educational outcomes, and long-term health complications. Despite these harms, interventions remain fragmented and under-resourced across much of the region. Promising interventions include school-based programs, community engagement, digital media regulation, and integration of alcohol services into mental and sexual health platforms.
Conclusion
Tackling adolescent alcohol misuse in sub-Saharan Africa requires urgent, multisectoral action. Policies must be evidence-based, culturally responsive, and supported by robust surveillance, regulation, and youth-centered programming to prevent long-term public health and socio-economic consequences.
... Adolescence is a period of rapid physical, emotional, and cognitive change that significantly impacts emotional regulation (Brown & Larson, 2009;Casey et al., 2010). The heightened emotional responses common in this stage, such as anger, frustration, and anxiety, are often challenging for adolescents themselves as well as their families. ...
... As such, the role of family-based interventions in supporting adolescents through these challenges is increasingly recognized as essential for fostering resilience and promoting positive mental health (Luthar A major difficulty adolescents face is regulating intense emotions, particularly anger. This is mainly due to the developmental immaturity of the brain, especially the prefrontal cortex, which is crucial for impulse control and emotional regulation (Casey et al., 2010;Suardi Wekke et al., 2022). This neurobiological delay often results in heightened emotional reactivity, with anger frequently manifesting as a prominent issue. ...
Objective: This study examines the effectiveness of a family-centered emotion regulation intervention in reducing adolescent anger, enhancing psychological resilience, and improving family intimacy. Methods and Materials: A quasi-experimental pretest-posttest design with a three-month follow-up was conducted on 80 adolescents (aged 12–18 years), randomly assigned to an intervention group (n= 40) or a control group (n= 40). The intervention, conducted over 12 weeks, integrated Cognitive Behavioral Therapy (CBT), Emotion-Focused Therapy (EFT), and Parent-Child Interaction Therapy (PCIT) to improve emotional regulation skills in adolescents and enhance parental support. The State-Trait Anger Expression Inventory (STAXI-2), Connor-Davidson Resilience Scale (CD-RISC), and Family Intimacy Questionnaire (FIQ) were used to measure outcomes. Data were analyzed using repeated measures ANOVA and Bonferroni post-hoc tests. Findings: The intervention group showed significant improvements in Anger, Resilience and Family intimacy compared to the control group (p < 0.001). These effects were sustained at follow-up, confirming the long-term benefits of the intervention. Conclusion: A family-centered approach to emotion regulation significantly enhances adolescent psychological resilience, reduces anger, and strengthens family relationships. Integrating such interventions into school-based and community programs may provide sustainable support for adolescent mental health.
... Functional neuroimaging studies show that neural substrates underlying trust decisions-medial prefrontal cortex, temporoparietal junction, and insulaundergo substantial reorganization during adolescence (Fett et al., 2014;van den Bos et al., 2011). This developmental asynchrony between heightened socioemotional responsivity and cognitive control mechanisms that are still maturing makes adolescents vulnerable to contextual influences in trust decisions (Casey et al., 2008;Steinberg, 2008). ...
People rely on their impression of trustworthiness and competence that are formed while interacting with others. We report two studies that explore the interplay between trait perception, cognitive reflection, and trust reciprocity among adolescents across various contexts. Study 1 (N = 243, ages 13–15) used a correlational design to link cognitive reflection with trust preferences. Study 2 employed an experimental design to establish causality: sub‐study 2a (n = 113) and sub‐study 2b (n = 108) introduced time constraints and cognitive load to induce intuitive decision‐making. Our results show that adolescents prioritize competence in knowledge‐based and economic contexts, and warmth in communicative scenarios. Cognitive reflection attenuates preference for warmth, while preference for competence remains relatively stable. These findings underscore the role of cognitive and situational factors in trust dynamics.
... and behaviors associated with a heightened occurrence of accidents, violence, substance abuse, unintended pregnancies, and sexually transmitted infections characterize this developmental phase (Casey et al. 2008). Teenagers who are pessimistic often harbor pessimistic expectations for the future, lack faith in the possibility of favorable outcomes, and are susceptible to cognitive overload from negative thoughts and emotions. ...
Adolescence is a crucial time of identity formation, scholastic and social demands, future concerns, and relationship changes. Adolescents are especially susceptible to psychological issues like pessimism, which can hinder their progress and well‐being. Cognitive flexibility may help adolescents adjust to these challenges and improve subjective well‐being. Pessimism, cognitive flexibility, and subjective well‐being have been investigated cross‐sectionally, but their longitudinal association has not. This study examines cognitive flexibility's mediation function in the longitudinal association between pessimism and subjective well‐being in teenagers, taking into account their well‐being development and inadequacies. This study looked at how cognitive flexibility affects the link between pessimism and subjective well‐being. To address the limitations of cross‐sectional mediation analysis, the current study employed an autoregressive cross‐lagged panel model within a half‐longitudinal framework, which allows for a more accurate estimation of directional and temporal relationships among the variables. This model used two 3‐month‐apart data sets. Cognitive flexibility was found to mediate the relationship between pessimism and subjective well‐being (χ2 (3, N = 232) = 11.68, p < 0.001). These findings indicate that cognitive flexibility plays a significant mediating role in weakening the negative impact of pessimism on adolescents’ subjective well‐being, highlighting its importance as a protective cognitive factor during this critical developmental period.
... What initiates puberty is unclear, but neuronal (synaptic and astroglial) regulatory systems that use glutamate and gamma-aminobutyric acid (GABA) as neurotransmitters are involved [1,2]. ...
Epilepsy is one of the most common chronic neurological diseases in adolescents. The hormonal changes often lead to alterations in clinical presentation (including associated comorbidities) in childhood-onset epilepsies, and also the manifestation of a variety of new syndromes over time, while age-dependent syndromes may spontaneously go into permanent remission. Gender-specific hormonal changes influence the pharmacodynamic and pharmacokinetic profiles of antiseizure medications (ASM) and thus their range of effects and side effects. Finally, the specific psychosocial aspects of this age group have to be considered, and special programs to support coping strategies, personal responsibility and adherence to treatment have to be offered. This review highlights particularities of ASM treatment for adolescents with epilepsy. Differences to the recently published guidelines for adults are discussed.
... First, we examined the degree to which genetic associations with SA are mediated by impulsivity and exposure to PPEs in adolescence, as this developmental phase is characterized by particularly high levels of impulsivity (Casey et al., 2008) and is a key period for SA onset (Bolger et al., 1989;Nock et al., 2008Nock et al., , 2013. Yet, most studies on the IPT have been conducted in adults (Chu et al., 2017), and very few have included adolescent participants from racial and ethnic minority groups. ...
Background
Genetic risk factors, impulsivity, and exposure to painful and provocative events (PPEs) have each been linked with risk for suicide attempt (SA). However, the degree to which genetic associations with SA are mediated by dimensions of impulsivity and PPEs remains unexplored, particularly in early adolescence.
Methods
Participants were 6402 individuals (52.0% male, 48.0% female, 72.3% European ancestry, 27.7% African ancestry, mean age at baseline = 9.47 years, SD = 0.51 years) from the Adolescent Brain Cognitive Development (ABCD) Study. Genetic liability for SA was measured using polygenic scores and family history density scores. Multiple dimensions of impulsivity were assessed using self‐report measures and laboratory tasks, and potential PPEs included injuries, traumatic events, non‐suicidal self‐injury, and operations. A series of mediation models was specified to evaluate whether genetic associations with SA risk were mediated by impulsivity and PPE exposure. Separate models were tested in adolescents of European and African ancestry. Sex, age, socioeconomic factors, and depressive symptoms were included as covariates.
Results
Genetic liability for SA was largely unrelated to impulsivity, PPE exposure, and SA risk (|β| = 0.00–0.34). In addition, there was little support for the hypothesis that more impulsive individuals are more likely to experience PPEs, with the exception that urgency and low conscientiousness were significantly related to non‐suicidal self‐injury (|β| = 0.09–0.19). Several dimensions of impulsivity and two PPEs (non‐suicidal self‐injury and traumatic events) were related to increased risk for SA (|β| = 0.32–0.76).
Conclusions
Impulsivity and PPEs each contribute to risk for SA. However, there is little support for the hypothesis that genetic influences on SA are mediated by impulsivity and PPE exposure in early adolescence.
... In contrast, sex did not have the same effect. A possible explanation of these results is the development of the prefrontal cortex, which extends to young adulthood and is crucial for the development of higher cognitive functions (Arain et al., 2013;Casey et al., 2008;Diamond, 2009). Development involves synaptic pruning and myelination, which can result in a reduction of gray matter volume and cortical thinning. ...
Background & hypothesis: Self-disorders (SDs), central features of schizophrenia spectrum disorders, primarily affect the pre-reflective sense of self, the fundamental experience of existing as a conscious subject. This disruption also impacts reflective self-consciousness. This study aims to further explore the neural correlates of self-disorders in individuals with schizophrenia spectrum disorders by using a cognitive task designed to target approximate pre-reflective and reflective self-experience during fMRI. Study design: 27 individuals with schizophrenia spectrum disorders (patients, PT) and 32 healthy controls (HC) completed the cognitive task during 7 T fMRI scanning. The task involved a trait-judgment paradigm, where participants read three-word sentences (pronoun, verb, trait adjective) referencing themselves (self) or a well-known other (other), then provided a yes/no response upon reflection. SDs were examined with the Examination of Anomalous Self-Experience (EASE). Study results: For the pre-reflective component, the activity in the rostral posterior cingulate cortex was negatively correlated with the severity of SDs. For the reflective component, HC exhibited bilateral activations in the frontopolar cortex, the anterior part of the anterior cingulate cortex, and the pre-supplementary motor area, while PT showed activations in the left caudate nucleus, the anterior part of the anterior cingulate cortex, the right frontopolar cortex, and the left language area. Conclusions: At the pre-reflective level, abnormalities in the rostral posterior cingulate cortex are associated with SDs. For reflective self-experience, individuals with self-disorders appear to engage more in analytical thinking and deeper brain networks than HC, who rely more on interoceptive processes based on the frontopolar cortex.
... Adolescents and college students are in a sensitive developmental period marked by continued maturation of brain regions involved in emotion regulation and social processing (Crone and Dahl 2012;Casey et al. 2008). Numerous cross-sectional studies have documented inverse associations between online social support and mental health symptoms, with higher support linked to lower levels of anxiety and depression (Chen et al. 2020), greater selfesteem and psychological well-being (Tao and Cheng 2018), and enhanced resilience (Yao et al. 2021). ...
Introduction
This cross‐temporal meta‐analysis examined 16‐year trends (2006–2022) in online social support among Chinese adolescents and college students, aiming to address an underexplored area in developmental and longitudinal research.
Methods
Analyses included 86 studies conducted in mainland China (N = 66,059; 41.68% male; Mage = 18.01 ± 2.4; data collected from 2006 to 2022). The Adolescent Online Social Support Questionnaire assessed informational, emotional, instrumental, and companionship support. Multilevel modeling evaluated associations with socioeconomic indicators (GDP, consumption, income), socio‐educational indicators (education funding), and social network indicators (internet penetration, per capita weekly internet usage hours), with stratified analyses by gender, urban–rural residence, and only‐child status.
Results
(1) Trends: Sustained increases in online social support were observed, with marked growth in informational and instrumental support, moderate increases in companionship, and stable emotional support. (2) Age disparities: College students showed faster increases in emotional and companionship support. (3) Gender patterns: Males showed consistent increases across all dimensions, while females experienced declines in emotional support. Gender differences favored males in instrumental and females in emotional support. (4) Demographics: Higher support levels were found among urban youth and only children. (5) Macro‐level correlates: Societal indicators were positively associated with informational, instrumental, and companionship support, but negatively associated with emotional support.
Conclusions
The findings underscore age‐specific developmental trajectories and highlight the role of socio‐technological transformation in shaping online social support. Future research should integrate standardized longitudinal cohorts with digital behavioral traces.
... Adolescence is a critical developmental period characterized by significant biological, psychological, and social transformations (1). This stage is particularly vulnerable to the emergence of mental health challenges, with anxiety disorders being among the most prevalent and debilitating conditions affecting adolescent well-being worldwide (2). ...
Introduction
Cultural factors and assessment methods significantly influence how anxiety symptoms are expressed and reported. However, few cross-cultural studies have employed culturally appropriate and validated tools, and even fewer have provided substantial comparisons across different groups with diverse cultural backgrounds. This study aimed to assess the measurement invariance of the GAD-7 scale across Chinese and Rwandese adolescents, enabling reliable cross-cultural comparisons.
Methods
This study included 2017 Chinese adolescents and 1813 Rwandan adolescents. Cronbach’s alpha, exploratory factor analysis (EFA), and multiple group confirmatory factor analysis (MGCFA) were used to assess the validity of the GAD-7 scale across the two groups. Measurement invariance testing was employed to investigate cross-cultural equivalence.
Results
The GAD-7 demonstrated good psychometric properties. CFA supported a one-factor model for the GAD-7 in both samples, though model fit indices varied. Measurement invariance testing confirmed configural and metric invariance but found partial scalar invariance. A latent mean comparison indicated a trend toward higher anxiety levels in Rwandan adolescents compared to Chinese adolescents, though the difference was not statistically significant (z = 0.02, d = 0.033, p = 0.98).
Discussion
The GAD-7 showed reliability in measuring generalized anxiety in both Chinese and Rwandese adolescents, confirming its cross-cultural construct validity. However, partial scalar invariance suggests that while the GAD-7 effectively detects anxiety symptoms, the severity of reported symptoms may not be directly comparable across cultures due to response patterns and possible linguistic factors. These findings highlight the importance of culturally sensitive instruments for accurate anxiety assessment and expand evidence on reliable symptom screening and treatment monitoring across diverse populations.
... In summary, an imbalance in prefrontal-subcortical circuits involved in urge/emotion regulation and cognitive control is particularly relevant to addictive behaviors, such as striatum, dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), insula, amygdala, etc. Consistent with this model, other neurobiological models or reviews similarly emphasize the important roles of altered neural features in prefrontal-subcortical circuits relevant to reward/emotion processing and cognitive control in developing and maintaining addictive behaviors or mental diseases (Antons, Brand, & Potenza, 2020;Bickel et al., 2018;Brand, 2022;Casey, Jones, & Hare, 2008;Dong & Potenza, 2014;Heatherton & Wagner, 2011;Kuss, Pontes, & Griffiths, 2018;McClure & Bickel, 2015;Weinstein, Livny, & Weizman, 2017). Accordingly, the current study focused on the neural alteration in prefrontal-subcortical circuits relevant to reward/emotion processing and regulation and cognitive control in IGD. ...
Background and aims
Based on the Interaction of Person-Affect-Cognition-Execution (I-PACE) model, this study aimed to identify dynamic reconfiguration of the basal ganglia network (BGN), limbic network (LN) and frontal-parietal network (FPN) in individuals with internet gaming disorder (IGD) during a real gaming situation. This approach overcomes the indirectness of experimental task situations in previous studies, providing direct evidence for the underlying neural basis of IGD.
Methods
Thirty gamers with IGD and 37 gamers with recreational game use (RGU) were scanned during online gaming and immediate deprivation. Two coefficients (recruitment and integration) were calculated using community structure, an emerging method, to represent individual functional segregation and integration of brain networks over time, respectively.
Results
The IGD group showed greater recruitment of BGN and LN after deprivation of gaming, and greater integration between the inferior frontal gyrus in the FPN and BGN and between the dorsolateral prefrontal cortex in the FPN and LN during deprivation. In contrast, the RGU group exhibited lower recruitment of BGN during deprivation than during gaming, stable recruitment of LN and stable integration between nodes in the FPN and BGN.
Conclusions
Gamers with RGU always maintain stable cognitive control and emotional regulation and could drop cravings/anticipation for continuing gaming after being interrupted gaming. However, gamers with IGD have stronger craving/anticipation and emotional responses after being interrupted gaming and insufficient control over cravings/anticipation and emotions. These findings help directly explain why gamers with IGD are addicted to gaming, despite having similar gaming experiences to those of gamers with RGU.
... The nucleus accumbens is involved in reward processing and emotional regulation (Levita et al. 2009;Klawonn and Malenka 2018). Adolescents differ markedly from adults in terms of neurodevelopmental trajectories, impulsivity and emotional reactivity (Casey et al. 2008;Dumontheil 2016). For example, previous research has shown that subcortical structures, including the amygdala and nucleus accumbens, mature earlier in development compared to cortical regions such as the prefrontal cortex, which is thought to continue developing into young adulthood. ...
Genome‐wide association studies (GWAS) have uncovered genetic variants associated with suicide attempt (SA) risk and regional brain volumes (RBVs). However, the extent of their genetic overlap remains unclear. To address this, we investigated whether the genetic architecture of SA and various RBVs (i.e., caudate nucleus, hippocampus, brainstem, ventral diencephalon, thalamus, globus pallidus, putamen, nucleus accumbens, amygdala and intracranial volume (ICV)) was shared. We leveraged GWAS summary statistics from the largest available datasets on SA (N = 958,896) and intracranial and subcortical RBVs (N = 74,898). Using linkage disequilibrium score regression, we estimated genome‐wide genetic correlations between SA and individual RBVs. GWAS‐pairwise analyses identified genomic segments associated with both SA and RBVs, followed by functional annotation. Additionally, we examined whether polygenic scores (PGS) for SA were associated with ICV and subcortical brain structure phenotypes in youth of European ancestry (N = 5276) in the Adolescent Brain Cognitive Development (ABCD) study. Linkage disequilibrium score regression results indicated a significant genetic correlation between SA and ICV (rG = −0.10, p‐value = 1.9 × 10–3). GWAS‐pairwise analyses and functional annotation revealed 10 genomic segments associated with SA and at least one RBV (thalamus, putamen and caudate nucleus). After adjusting for multiple tests, PGS association analysis indicated that a higher PGS for SA was significantly associated with a smaller volume of the right nucleus accumbens (b = −7.05, p = 0.018). Our findings highlight a negative genetic correlation between SA and ICV amongst adults and suggest different neural correlates associated with genetic risk for SA across developmental periods. This study advances our understanding of the shared genetic underpinnings of SA and brain structure, potentially informing future research and clinical interventions.
... This period is also a time when skills in regulating emotions are acquired. The fact that adolescents have complex and fluctuating emotional states causes them to use dysfunctional methods by experiencing inadequacy in emotion regulation skills (Casey et al., 2008). Due to the difficulties in coping with emotions, they tend towards more aggressive behaviors (Sullivan et al., 2010). ...
The increase in aggressive behavior during adolescence has led to both research on aggression and the identification of various types of aggression by considering aggression as a multidimensional structure. One of these is relational aggression. In this context, this study aims to examine the mediating role of forgiveness in the relationship between high school students' emotion regulation difficulties and relational aggression. The relational screening method and basic mediation model were used in the study. The study group of the research consists of 1012 students attending public high schools in the center of Eskişehir in the 2021-2022 academic year. The study used the Relational Aggression in Friendship Relationships Scale Adolescent Form, the Difficulty in Emotion Regulation Scale, and the Forgiveness Scale for Adolescents. According to the study's findings, adolescents' forgiveness is directly and negatively predicted by difficulties in emotion regulation. Relational aggression is directly and negatively predicted by forgiveness. The total effect of difficulties in emotion regulation on relational aggression was .19. When the mediator variable, forgiveness, is included in the model, the total effect decreases to .17, which is significant. The indirect effect of forgiveness on adolescents' difficulty in emotion regulation and relational aggression was found to be significant. The partial mediating role of forgiveness was found to be significant, but its effect level was low. In conclusion, all these findings indicate that high school students' difficulty in emotion regulation is a risk factor for relational aggression, while forgiveness is a protective factor.
... While the literature on coping mechanisms among youth as a collective group is well established, with research spanning decades (Edlynn et al., 2008;Gaylord-Harden et al., 2009;Grant et al., 2014;McConnell et al., 2014), there is a paucity of studies examining contemporary coping strategies among non-adjudicated adolescent Black males (ages 15-17). Adolescents aged 15-17 occupy a critical developmental period characterized by increasing autonomy and heightened sensitivity to social and threat-related cues (Casey et al., 2008;Steinberg, 2014). Moreover, at this age, they engage more independently with physical and digital environments, facing risks like community violence and online harassment (Finkelhor et al., 2015;Turner et al., 2016), while often lacking access to support systems (Zimmerman & Posick, 2016), necessitating a closer examination of their coping patterns. ...
Young Black males (YBM), ages 15–17, experience disproportionately high rates of firearm violence and related structural disadvantages, shaping both their psychological and practical responses to violence-related stressors. These intersecting exposures influence their coping strategies, mental health, help-seeking behaviors, and broader social functioning. Generational shifts in how young males conceptualize identity, mental health, help-seeking, and masculinity, combined with increasing exposure to firearm violence, underscore the need for a closer examination of contemporary coping strategies. This qualitative study applies Thorne’s Interpretive Description (ID) to explore coping patterns among YBM navigating violence exposure in physical and online environments. Drawing from two focus groups of 33 YBM (M = 15.8, SD = 1.19) from a Midwest high school, we conducted a thematic analysis grounded in the interpretive description tradition. Integrating the Phenomenological Variant of Ecological Systems Theory (PVEST) and the Transactional Model of Stress and Coping (TMSC), we examined how structural and interpersonal factors shape YBM agency and coping responses. Four coping patterns emerged: (1) Problem-Focused Adaptive, (2) Problem-Focused Maladaptive, (3) Emotion-Focused Adaptive, and (4) Emotion-Focused Maladaptive. The findings underscore the dynamic interaction between environmental stressors, available resources, and cognitive appraisals, indicating that for Black adolescent males, coping strategies are neither static nor inherently adaptive or maladaptive.
... Adolescence is a period of metamorphosis from childhood to adulthood, marked by significant physical, psychosocial, and emotional changes. Increasing curiosity, a sense of growth, idealism, impulsivity, stress reactivity, a lack of self-regulation, limited decision-making skills, and a decrease in emotional stability are all characteristics of adolescence [1][2][3][4][5][6]. Adolescents are particularly vulnerable to various environmental, interpersonal, and cultural influences [7][8][9][10]. ...
This study explores adolescents' perceptions of their Internet usage: the patterns of Internet use and
the extent of Internet addiction. We collected data from 386 adolescents across two pre-university colleges in Bangalore City using a cross-sectional survey design. A semi-structured proforma captured socio-demographic details, Internet use patterns, and scores from Young’s Internet Addiction Test. The findings revealed a high prevalence of Internet addiction at 71.6%, attributed to factors such as widespread Internet access, the availability of smartphones, and increased engagement in online leisure activities, particularly exacerbated during the COVID-19 pandemic. These results underscore the critical need for initiatives promoting balanced Internet use to support adolescents' overall well-being.Given the limited Indian research on adolescent Internet use and addiction, especially following the COVID-19 pandemic, we believe this manuscript will provide valuable insights and contribute to addressing this critical public health issue.
... This trajectory aligns with the expected downward slope of the age-crime curve post-peak, suggesting that our older participants, who started closer to the peak offending age, were traversing the descending portion of the curve during our study period. The initial higher risk in older youth followed by a steeper decline may reflect a combination of factors including biological and psychosocial maturity (Casey et al., 2008;Monahan et al., 2009;Steinberg et al., 2015). Our explicit modelling of the time-varying effects of age challenges the conventional view of risk factors as either static or dynamic and suggests that traditionally "static" factors like age may indeed have time-varying effects. ...
... Given the rapid brain remodeling and changes in social and lifestyle habits during adolescence, it is not surprising that this period is associated with increased vulnerability to mental health issues like anxiety and depression. [161][162][163][164]. [165][166][167]. ...
The current discovery that the gut microbiome, which contains roughly 100 trillion microbes, affects health and disease has catalyzed a boom in multidisciplinary research efforts focused on understanding this relationship. Also, it is commonly demonstrated that the gut and the CNS are closely related in a bidirectional pathway. A balanced gut microbiome is essential for regular brain activities and emotional responses. On the other hand, the CNS regulates the majority of GI physiology. Any disruption in this bidirectional pathway led to a progression of health problems in both directions, neurological and gastrointestinal diseases. In this review, we hope to shed light on the complicated connections of the microbiome-gut-brain axis and the critical roles of gut microbiome in the early development of the brain in order to get a deeper knowledge of microbiome-mediated pathological conditions and management options through rebalancing of gut microbiome.
... They also exhibited a greater extent of altruism in their decisions than expected per current developmental theories by being willing to enroll in Phase 1 clinical trials to benefit others, even with the potential for toxicity [29]. Nonetheless, adolescents may lack social or emotional maturity, causing them to be prone to risk-taking or easily influenced by their current emotional state, which may widely fluctuate day-to-day or with new developments in their medical disease [30,31]. If the peer influence and emotional arousal can be minimized, older adolescents (above 14 years of age) exhibit similar maturity levels as adults [32]. ...
Advance care planning (ACP) involves longitudinal communication between the patient and physician to explore the patient’s wishes and goals while relaying accurate diagnostic and prognostic information to support informed and shared medical decision-making. In pediatrics, it also uniquely involves the parents or legal guardians as the primary medical decision-makers. ACP ideally leads to the implementation of advanced directives (ADs) and can be a difficult concept to discuss with pediatric patients and families with refractory oncologic disease, given the distinctive burdens that accompany this population. Many obstacles can delay the initiation of these conversations with these families, although existing literature supports beginning ACP conversations at the time of initial diagnosis and treatment. Parents or legal guardians often serve as the sole decision maker for pediatric patients but there has also been a shift in the literature to include children/adolescents in conversations regarding ADs and other aspects of end-of-life (EOL) care, an essential aspect of patient-centered ACP. This guidance is unfortunately not often translated into clinical practice. In this review, we aim to define and discuss the current status, obstacles, and benefits surrounding early initiation of ACP conversations with children or adolescents with advanced cancer and their families. We also discuss how physicians and the medical team, including pediatric palliative care, can increase the degree of pediatric patient involvement in ACP and EOL discussions, as developmentally appropriate, and mitigate delays in discussing ACP with these families and patients.
... Erikson's psychosocial theory (Erikson, 1968) highlights identity development, while Arnett's (2004) Emerging Adulthood Theory describes this stage as one of self-exploration and transition. Neurologically, the prefrontal cortex, essential for impulse control and decision-making, continues to mature, influencing emotional regulation (Casey et al., 2008). While personality remains relatively stable, it evolves under social and environmental influences. ...
Personality and emotional regulation are interrelated psychological constructs that significantly impact mental
well-being, decision-making, and interpersonal relationships (Gross, 2015). Young adulthood (18-25) is a critical
developmental stage marked by identity formation, cognitive maturation, and emotional self-regulation, where
individuals navigate academic, career, and social challenges that shape their emotional coping strategies (Arnett,
2000). This study examines the correlation between multiple domains of personality and emotional regulation in
young adults using the Five-Factor Model (FFM) as a framework (McCrae & Costa, 1999). Traits such as
neuroticism, conscientiousness, extraversion, openness, and agreeableness influence the selection and
effectiveness of emotional regulation strategies (John & Srivastava, 1999). Adaptive strategies, such as cognitive
reappraisal and problem-solving, are often associated with higher conscientiousness and agreeableness (Gross &
John, 2003) while maladaptive strategies, including emotional suppression and rumination, are frequently linked to
neuroticism (Aldao et al., 2010). Neurological evidence supports these associations, with heightened amygdala
activity in neurotic individuals contributing to increased emotional reactivity, while greater prefrontal cortex
engagement in conscientious individuals facilitates better emotional control (Peña-Gómez et al., 2011; Scheffel et
al., 2019). While extensive research on personality and emotional regulation exists in Western contexts, there is a
gap in understanding this relationship in India, where collectivist values, familial interdependence, and societal
expectations influence emotional regulation differently (Markus & Kitayama, 1991). Unlike Western cultures that
prioritize self-expression, Indian social norms often encourage emotional suppression and social harmony, shaping
unique coping mechanisms. Given the rising mental health concerns among Indian young adults, including stress,
anxiety, and emotional dysregulation (National Mental Health Survey of India, 2016) understanding these
dynamics within India's socio-cultural framework is essential. Through this study, which integrates academic
research with clinical observations from internships and work at Your Cozie Couch, we aim to provide insights into
how personality traits shape emotional regulatory patterns in Indian young adults. The findings contribute to a
deeper understanding of psychological resilience, stress management, and the development of culturally tailored
mental health interventions.
Keywords: personality, emotions, emotional regulation, traits, coping strategies, cognition, five factor model
... Conversely, students with a negative perception of school climate are more likely to report diminished learning motivation, decreased interpersonal engagement, and heightened psychological distress [4,5]. Adolescence is marked by a tendency to interpret surroundings through a more emotional and less rational lens [6,7]. This renders adolescents' schemas, attitudes, and evaluations of external environments subject to their emotional states [8]. ...
Background
A positive school climate benefits adolescents in multiple developmental dimensions. However, theoretical frameworks suggest that detrimental parenting practices can trigger adolescents’ negative emotional states, which may skew their perceptions of school climate. Although self-consciousness, a critical intrapersonal trait, may mitigate these adverse effects, limited research has empirically explored its moderating role in the context where negative parenting influences adolescents’ mental health and school-related outcomes. Thereby, this study investigates how parental negative control influences adolescents’ perceived school climate via depression, with self-consciousness moderating the link between parental negative control and depression.
Methods
A short-term longitudinal design was employed, with the data collected from a sample of Chinese adolescents (NT1 = 733, NT2=711). Self-reports were used to measure parental negative control, depressive symptoms, self-consciousness, and perceived school climate. Structural equation modeling was conducted to assess the mediating effect of depression and the moderating effect of self-consciousness.
Results
The findings show that depression mediates the relationship between parental negative control and perceived school climate. Adolescents experiencing higher levels of negative control reported more depressive symptoms, which were associated with lower perceptions of school climate. Self-consciousness moderates the link between parental negative control and depression, with adolescents exhibiting higher self-consciousness showing less vulnerability to the adverse effects of negative control.
Conclusions
This study reveals the detrimental impact of parental negative control and depression on adolescents’ perceived school climate while highlighting the protective role of self-consciousness. Interventions can target families engaged in maladaptive parenting practices and adolescents with psychopathological symptoms, focusing on enhancing family dynamics and adolescents’ self-processes.
... In South Korea, the youth suicide rate is significantly higher than the average among member countries of the Organization for Economic Cooperation and Development (OECD) [3]. This heightened vulnerability is attributed to adolescents' developmental transitions and increased emotional sensitivity [4]. Adolescents who feel trapped in their environment-such as at school or home-may perceive suicide as their only escape, increasing the likelihood of suicide attempts [5]. ...
Purpose: This study aimed to systematically evaluate school-based suicide prevention programs for adolescents, focusing on their impact on suicide attempts, knowledge and attitudes about suicide, and help-seeking behaviors. Methods: A systematic review was conducted following PRISMA guidelines. Databases searched included PubMed, Cochrane Library, EMBASE, PsycINFO, CINAHL, KMBASE, KoreaMed, and ScienceON. Randomized controlled trials of school-based interventions for middle and high school students were included. The Risk of Bias 2.0 tool was used to assess study quality. Results: Out of 1,738 screened records, eight studies met the inclusion criteria. SOS (Signs of Suicide) and SEYLE (Saving and Empowering Young Lives in Europe) programs significantly reduced suicide attempts by 40% and 55%, respectively. Sources of Strength improved help-seeking behavior (ES=0.62, p <.001), though results were inconsistent across interventions. All programs enhanced knowledge and attitudes about suicide, but methodological limitations, such as variability in implementation and reporting, affected reliability. Conclusion: School-based suicide prevention programs effectively reduce suicide attempts and improve awareness but show mixed results for help-seeking behaviors. Standardized, scalable interventions and rigorous evaluations are needed to enhance their impact.
... In contrast, the limbic system, which includes structures such as the amygdala and the nucleus accumbens, matures at a faster rate than the prefrontal cortex. This asynchrony leads to heightened emotional reactivity and increased sensitivity to the brain's reward system, promoting the pursuit of novel and risky experiences, hallmark behaviors of adolescence (Casey et al., 2008;Steinberg, 2008;Tottenham & Galván, 2016). ...
Unsatisfactory sleep is a worldwide concern, as evidenced by the high prevalence of insomnia symptoms and diagnosis in the general population, and an issue that has also risen among adolescents. These circumstances are a cause of worry due to, among other factors, the observed bidirectional association of sleep disturbances and the risk of substance use disorder development. In this regard, across the globe, several reports indicate that substance consumption is at an all-time high, with alcohol, nicotine, and cannabis leading the charts. Additionally, the age of onset has dropped, with reports suggesting that first contact is usually during adolescence. Although the nature of the link between poor sleep and substance use disorder development is still not fully understood, it is possible that an overactive orexinergic system could play a role, as it has been observed that treatment with orexinergic antagonists improves insomnia symptoms and that postmortem studies show an increase in orexin immunoreactive neurons in sections obtained from habitual opioid consumers. We further argue that it is during adolescence that this maladaptive loop can be established, priming for the development of substance use disorders.
... Furthermore, research shows that suicidal thoughts and behaviours (STB) 1 are prevalent amongst university students (Mortier et al. 2018;Kiekens et al. 2019Kiekens et al. , 2023. STB frequently emerge during adolescence, a period characterised by vulnerability and significant development (Başgöze et al. 2021;Casey et al. 2008). Given the potential for STB to affect academic performance and overall satisfaction with the university experience, universities have a vested interest in promoting and safeguarding student wellbeing (Baik et al. 2019). ...
Suicide is a significant public health issue and a leading cause of death amongst those aged 15 to 29, making it particularly relevant in the university context, where many students fall within this age range. Universities are motivated to promote student wellbeing, as it is closely linked to academic achievement and overall satisfaction with the university experience. University chaplains play a vital role on campuses, providing spiritual care to the entire university community. Whilst their contributions to suicide prevention are acknowledged, there is a notable lack of explicit research in this area. This paper presents the results of an online multimethod questionnaire on the self-reported contributions of university chaplains to suicide prevention, involving 50 participants working in 16 different countries. The findings indicate that university chaplains self-report contributing to all three levels of the suicide prevention framework: prevention, intervention, and postvention, with prevention being the area where they feel they contribute most. This paper also explores the wellbeing practices of university chaplains, key elements of university chaplaincy, and various aspects of the professionalisation of university chaplaincy.
... are not yet fully matured, which may hinder their ability to cope with emotions and stress (Casey, Jones, and Hare 2008). Studies show that adolescents with depression exhibit weaker effective connectivity between the DMN and SAN, possibly reflecting abnormalities in emotion regulation and self-awareness (Willinger et al. 2024). ...
Background and Aims
Adolescent major depressive disorder (MDD) is prevalent globally but often goes unnoticed due to differences in symptoms compared to adult criteria. Analyzing the brain from a network perspective provides new insights into higher‐level brain functions and its pathophysiology. This study aimed to investigate changes in the topological organization of functional networks in adolescents with first‐episode, treatment‐naïve MDD.
Method
The study included 23 adolescents with depression and 27 matched healthy controls (HCs). Resting‐state functional MRI (rs‐fMRI) was conducted, and whole‐brain functional networks were constructed. Graph theory analysis was used to evaluate network topological properties. A machine‐learning multivariate diagnostic model was developed using network metrics associated with depression severity.
Results
Both the MDD and HC groups displayed small‐world topology, with male MDD patients showing reduced global clustering efficiency (Cp). The nodal Cp (NCp) and local efficiency (NLE) in the bilateral pallidum were significantly positively correlated with depression severity. In contrast, nodal efficiency (NE) in the left medial orbital superior frontal gyri (ORBsupmed) showed a negative correlation with disease severity. A machine‐learning multivariate model using regional network topological features produced an AUROC of 0.71 (95% CI: 0.54–0.92) and an F1 score of 0.65, successfully differentiating adolescent MDD from HCs.
Conclusion
Our findings suggest disruptions in small‐world topology in both global and local brain networks in adolescent depression. These abnormal nodal properties may serve as novel neural markers of the disorder.
Background
The endocannabinoid signaling system regulates stress and is implicated in depression, with altered circulating endocannabinoid concentrations frequently reported in adults with depression compared to without. Maternal depression is a well-established predictor of depressive symptoms in youth. However, few studies have examined the relationship between circulating endocannabinoids and susceptibility to psychiatric disorders during adolescence, a high-risk period for symptom onset. This study examines associations among adolescent depressive symptoms, maternal depressive symptoms, and circulating endocannabinoids in a heterogenous community sample of adolescents.
Methods
This study reports on 77 adolescents (M ± SD = 13.36 ± 2.19 years, 51.9% female; 41.6% White Non-Hispanic, 41.6% Black Non-Hispanic, 5.2% Hispanic, 9.0% biracial) and their biological mothers. Depressive symptoms were measured in mothers and adolescents using the Beck Depression Inventory and Children’s Depression Inventory, respectively. Adolescent plasma concentrations of the endocannabinoids N-arachidonoylethanolamine (anandamide, AEA) and 2-arachidonoylglycerol (2-AG) were quantified using liquid chromatography-tandem mass spectrometry.
Results
Over half (58.4%) of adolescents and 15.6% of mothers exceeded clinically significant depression cut-offs. Maternal and adolescent depressive symptoms were not significantly associated (R² = 0.120, p = 0.053). However, maternal (but not adolescent) depressive symptoms were positively associated with adolescent AEA concentrations, adjusting for covariates (R² = 0.332, p < 0.001). This association was moderated by adolescent depressive symptoms (p = 0.004; B=-0.2557), particularly when maternal symptoms were low. Adolescent or maternal symptoms were not significantly associated with adolescent 2-AG concentrations (R² = 0.097, p = 0.670 and R² = 0.098, p = 0.611, respectively).
Conclusion
Higher AEA concentrations may serve as a monitoring marker of familial susceptibility for depression during adolescence, including among adolescents with subthreshold symptoms. These results suggest the endocannabinoid system as a potential target for identifying risk and developing interventions during adolescence.
Sleep plays a critical role in learning and cognitive function, fundamentally shaping how the brain processes, stores and retains information. Different sleep stages support memory formation and consolidation, with distinct neural mechanisms aiding the transfer and strengthening of learned material. Sleep deprivation impacts cognitive performance well beyond memory, affecting abilities ranging from basic attention to complex decision-making. Neuroimaging and cognitive testing reveal how sleep loss impairs brain function, leading to measurable deficits that manifest in real-world consequences across various professional contexts, from medical errors to workplace accidents. Adolescents face particular vulnerability to sleep disruption due to their developing brains and shifting circadian rhythms. The relationship between sleep and cognition is bidirectional: mental strain can impair sleep quality, while inadequate sleep undermines cognitive performance. These findings carry significant implications for public health and workplace policies, highlighting the necessity of adequate sleep for optimal cognitive function and safety.
Using as a model the primary accounts of the visionary experience of Joseph Smith (founder of The Church of Jesus Christ of Latter-day Saints), this article argues that multiple narratives of the same experience, religious or not, reveal how the mind processes memory over time. To that end, the article points to parallels shown in the retrieval of the 9/11 events and mobilizes the disciplines of neuroscience, psychology, and history to explain memory processes and illustrate how decompartmentalization between academic disciplines provides a better understanding of those processes. Beyond Smith and religion, the article concludes with the proposition that one’s reaction toward a version of a retrieved memory is influenced more by a subjective interpretation of and rapport with events, experiences, or narratives than by an entirely rational and objective understanding of the inherently unstable nature of memory.
Peer problems are a pervasive issue for children with ADHD, but less is known about the role of peers in the development of executive functioning (EF). We examined the predictive relation between childhood peer preference (i.e., the extent to which one is liked vs. disliked by peers) and the development of various EF skills (response inhibition, working memory, and global EF) from childhood to early adulthood within a diverse female sample enriched for ADHD. We sampled 140 girls diagnosed with ADHD in childhood and 88 neurotypical comparison girls, matched for age and race. Girls were 6–12 years old at baseline and followed for three additional waves across 16 years. Peer preference was assessed via sociometric interviews in childhood; EF data were collected at all waves via neuropsychological tests. Through multilevel modeling, we evaluated relations between childhood peer preference and the development of each EF skill from childhood to early adulthood, adjusting for ADHD diagnostic status, verbal IQ, and socioeconomic status. We found that lower peer preference in childhood (a) was associated with poorer global EF across development and (b) predicted significantly less improvement in response inhibition from childhood to adulthood. Childhood ADHD diagnostic status was also related to lower global EF and response inhibition across development, but unlike peer preference, ADHD was not predictive of differences in EF growth. Secondary analyses revealed that peer rejection, not acceptance, drove these core findings. Findings highlight the influence of childhood peer preference on EF development, particularly response inhibition. We discuss intervention implications.
Postnatal brain development is characterised by dynamic macrostructural changes, including cortical thinning and cortical flattening during childhood and adolescence. These macro-structural changes are parallel with developmental changes in brain neurochemistry, probed in the human brain using Magnetic Resonance Spectroscopy (MRS). This includes neurotransmitters such glutamate and gamma-aminobutyric acid (GABA), as well as building blocks of neuronal and associated tissue such as N-acetyl aspartate (NAA), and those involved in metabolism such as creatine (Cr). While previous research has linked MRS-measured neuro-metabolite levels to bulk tissue composition (e.g., gray matter, white matter, and cerebrospinal fluid), the relationship between neurochemistry and more granular macrostructural metrics, such as cortical thickness, area, volume, and local gyrification, remains unexplored. This study investigates the association between MRS-measured neuro-metabolite levels in the posterior parietal cortex (PPC) and PPC-voxel cortical macrostructural metrics in a developmental cohort of 86 individuals aged 5–35 years. We also examine whether PPC metabolite concentrations associate with whole-brain structural metrics to determine whether associations are region-specific or more broadly generalisable. Our findings reveal significant positive associations between PPC cortical thickness, volume, local gyrification index (LGI) and Glx (glutamate + glutamine) levels, likely because differences in cortical microstructure , including dendritic arbour complexity, contributes to variation in both cortical macrostructure and Glx activity across development. Additionally, PPC Glx:GABA+ ratio negatively associated with subcortical gray matter volume, while PPC total NAA positively associated with cerebral white matter volume, suggesting a link between regional neurochemistry and broader brain structure. These results highlight the importance of accounting for macrostructural and broader brain structural characteristics when interpreting the neuroanatomical correlates of MRS-measured metabolites, beyond controlling for bulk tissue composition. This approach is particularly crucial when comparing neuro-metabolite levels across groups with known structural differences, such as developmental cohorts or individuals with neurodevelopmental conditions.
Key points
Posterior parietal cortex (PPC) Glx levels are positively associated with PPC cortical thickness and local gyrification index, likely because differences in cortical microstructure, including dendritic arbour complexity, contributes to both cortical macrostructure and neuro-metabolic traits across development.
The PPC Glx:GABA+ ratio is negatively associated with subcortical gray matter volume, while PPC total NAA is positively associated with cerebral white matter volume, suggesting a link between regional neurochemistry and broader brain structure.
These findings emphasise the importance of considering more detailed macrostructural characteristics, as well as bulk tissue composition (white matter, gray matter, cerebral spinal fluid), when interpreting MRS-measured metabolite differences.
Today, most children with end-stage renal disease and after kidney transplantation reach adulthood, even with complex underlying diseases. As a result, nephrologists in internal medicine are increasingly encountering patients with clinical pictures that used to play only a minor role in the past.
The aim of this article is to provide an overview of the transition currently taking place in German nephrology and to offer perspectives for improving the process.
Based on current literature and transition initiatives in German nephrology, the current situation of transition in Germany is analyzed and compared with the requirements of the AWMF (“Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften”) S3 guideline “Health care transition from pediatric to adult care”.
The transition from pediatric to internal nephrology marks a vulnerable phase for patients, in which problems in therapy cooperation occur with above-average frequency. Based on the AWMF S3 guideline, the transition in nephrology is defined as an interdisciplinary challenge based on the special features of pediatric–nephrology patients, barriers are identified and options for action are presented.
In Germany, different local transition models are practiced in nephrology, not all of which meet the requirements of the guideline. A harmonization of the procedure is necessary. However, this requires appropriate funding for transition.
Today, most children with end-stage renal disease and after kidney transplantation reach adulthood, even with complex underlying diseases. As a result, nephrologists in internal medicine are increasingly encountering patients with clinical pictures that used to play only a minor role in the past.
The aim of this article is to provide an overview of the transition currently taking place in German nephrology and to offer perspectives for improving the process.
Based on current literature and transition initiatives in German nephrology, the current situation of transition in Germany is analyzed and compared with the requirements of the AWMF (“Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften”) S3 guideline “Health care transition from pediatric to adult care”.
The transition from pediatric to internal nephrology marks a vulnerable phase for patients, in which problems in therapy cooperation occur with above-average frequency. Based on the AWMF S3 guideline, the transition in nephrology is defined as an interdisciplinary challenge based on the special features of pediatric–nephrology patients, barriers are identified and options for action are presented.
In Germany, different local transition models are practiced in nephrology, not all of which meet the requirements of the guideline. A harmonization of the procedure is necessary. However, this requires appropriate funding for transition.
Significant changes in developmental, cognitive, linguistic, affective, and behavioural domains characterise the continuous process of neuropsychological development from birth to adolescence. This chapter focusues on the stages of neuropsychological development from birth to adolescence outlined in Jean Piaget's Cognitive Development Theory (1936), as well as major contributions in the field by Lev Vygotsky and Alexander Luria. In addition, it describes how some well-known neuropsychological disorders, such as attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and intellectual disabilities, including Down syndrome can be diagnosed using the milestones of typical child development found in the Cognitive Development Theory. The chapter discusses important factors to consider when deciding whether interventions would be suitable for children with cognitive difficulties.
The present study aimed to investigate changes in facial information processing that occur with age. To achieve this, we compared the performance of 73 children aged between 3 and 12 years old, divided into three age groups (3 - 5 years, 6 - 8 years, and 9 - 12 years), and 30 adults in tasks involving perception and recall of facial identity and expression. The results indicate that there is an increase in both perception and memory with age, which stabilizes between 9 and 12 years old, at which point children would achieve similar results to adults. Furthermore, it is observed that holistic/configurational processing improves as age increases. When comparing emotions, happiness was found to be the easiest emotion to recognize at all ages, while anger was the least well-recognized. Despite the age-related improvement, the results of this study indicate that school-aged children recognize emotions of fear and neutral faces better than adults.
Exposure to early socioeconomic disadvantage impacts the development of working memory, a component of executive functions underlying engagement in risky behaviors including substance misuse. Given that working memory develops across adolescence, coinciding with increases in the onset and rapid escalation of substance use and other risky behaviors, interventions designed to improve working memory may have promise for supporting behavioral health for youth from low-resource areas. However most working memory programs have been developed for adults from higher-resource contexts and may not be feasible for youth from socioeconomically distressed communities. The current study (n = 23) uses a mixed methods approach to evaluate the implementation potential and preliminary effectiveness of a computer-based working memory training program among youth ages 12 to 16 from a very low-resource community. Participants (48% female; 100% Black) were administered tests of working memory before and after completing a working memory program or a control computer program. Results suggest youth in the active condition found the intervention to be acceptable, appropriate and enjoyable and evidenced statistically significant increases in working memory. No improvement was seen among youth in the comparison condition. Findings suggest preliminary support for implementation of this program in an impoverished urban setting.
The Best Possible Self intervention (BPS) has demonstrated efficacy in promoting well-being in various populations, yet its impact in adolescence is under-researched. Our study investigated the feasibility and efficacy of the BPS in early adolescence (11–15 years) to promote positive affect and reduce negative affect. We conducted a randomized controlled online trial (N = 200, Mage = 14.01 years, SD = 1.19, 78.5 % female). Participants were assigned to the BPS group (n = 59), a writing control group (n = 68), or a non-writing control group (n = 73). Affect (PANAS-C-SF) was measured immediately before and after the intervention. The BPS demonstrated feasibility in our sample and significantly increased positive affect post-intervention compared to both control groups, suggesting a mood-boosting effect. The BPS did not significantly reduce negative affect post-intervention relative to the control groups. Our findings provide initial evidence that the BPS is a feasible and effective intervention for enhancing positive affect in early adolescence. Future research should explore its long-term effects, repeated administration, and potential for implementation in group settings to maximize its impact.
Objectives: Adverse childhood experiences (ACEs) pose a significant public health concern, negatively impacting children’s physical and mental health. This study examines the association between ACEs and the co-occurrence of somatization and post-traumatic stress symptoms (PTSSs) among Chinese college students. Additionally, it explores the roles of both internal (psychological resilience) and external (social support) protective factors in this relationship. Methods: A sample of 701 students were analyzed using the Adverse Childhood Experiences International Questionnaire, the Somatization subscale from the Symptom Checklist-90, the PTSD Checklist from the DSM-5, the Connor–Davidson Resilience Scale, and the Multidimensional Scale of Perceived Social Support. A four-level outcome variable was created based on measures of somatization and PTSSs: no symptoms, somatization-only, post-traumatic stress symptoms-only (PTSSs-only), and co-occurring symptoms. Data analysis was conducted using multiple logistic regression. Results: Among Chinese college students, the prevalence of ACEs was 62.9%, while the prevalence of co-occurring somatization and PTSSs was 13.7%. The results of the multiple logistic regression analysis indicated a positive association between ACEs and the co-occurrence of somatization and PTSSs compared to no symptoms (OR = 2.28, p < 0.001). Furthermore, social support (OR = 0.26, p < 0.001) and psychological resilience (OR = 0.48, p = 0.049) were negatively associated with the co-occurrence. Conclusions: ACEs are risk factors for the co-occurrence of somatization and PTSSs among college students, while social support and psychological resilience serve as effective protective factors against this risk.
Teenagers use social media platforms as a part of their daily routine, being a source positive and negative impacts on their well-being. This study assessed the psychological effect of using digital devices in adolescents and with cross-sectional research design. Three hundred participants from different schools and colleges filled up structured questionnaires that assessed the symptoms of anxiety, signs of depression, and self-esteem. The results revealed that more time on social networking was quite strongly related to anxiety-depression and lowering self-esteem. Moreover, the differences in psychological changes were found across the different social media platforms, which indicates that certain characteristics of the platforms and the interactions with other users may influence the mental health risks. To ensure the participant’s rights and their privacy were respected, strict ethical measures were observed. These extend the need to address digital literacy and to design programs that can change the negative behaviours of the youths in the usage of the internet.
Seminal studies in animal neuroscience demonstrate that frontostriatal circuits exhibit a ventral–dorsal functional gradient to integrate neural functions related to reward processing and cognitive control. Prominent neurodevelopmental models posit that heightened reward seeking and risk taking during adolescence result from maturational imbalances between frontostriatal neural systems underlying reward processing and cognitive control. The present study investigated whether the development of ventral (VS) and dorsal (DS) striatal resting-state connectivity (rsFC) networks along this proposed functional gradient relates to putative imbalances between reward and executive systems posited by a dual neural systems theory of adolescent development. One hundred sixty-three participants aged 11–25 years (54% female, 90% white) underwent resting scans at baseline and biennially thereafter, yielding 339 scans across four assessment waves. We observed developmental increases in VS rsFC with brain areas implicated in reward processing (e.g., subgenual cingulate gyrus and medial orbitofrontal cortex) and concurrent decreases with areas implicated in executive function (EF; e.g., ventrolateral and dorsolateral prefrontal cortices). DS rsFC exhibited the opposite pattern. More rapid developmental increases in VS rsFC with reward areas were associated with developmental improvements in reward-based decision-making, whereas increases in DS rsFC with EF areas were associated with improved EF, though each network exhibited some crossover in function. Collectively, these findings suggest that typical adolescent neurodevelopment is characterized by a divergence in ventral and dorsal frontostriatal connectivity that may relate to developmental improvements in affective decision-making and EF.
Adolescence (ages 10-24) is characterized by cognitive, behavioural and social development. Childhood environments are typically centred on home and care settings, whereas adolescents increasingly engage with peer and community environments. These changing environments confer risks of experiencing specific adversities at different ages. Despite the unique characteristics of adversities in adolescence and potential associations with lifespan outcomes, few frameworks exist to systematize adversities in adolescents. Here we review current research and propose an approach specific to this developmental period: the adverse adolescent experiences (AAEs) framework. Building on existing models (for example, the adverse childhood experiences framework), the AAEs focus on potentially traumatizing experiences during adolescence. The framework builds on Bronfenbrenner's ecological systems theory to conceptualize adversities at intrapersonal, interpersonal, community and societal levels. We argue that this approach can enhance our understanding of adolescent adversity, facilitate the study of its potential effects, and guide prevention and intervention efforts.
Background:
Observational studies suggest that alcohol consumption increases the risk of traumatic brain injury (TBI); however, the causality of this association remains unclear.
Objectives:
This study aimed to identify which drinking pattern is the primary factor influencing TBI.
Method:
Two-sample Mendelian randomization (MR) was used to assess whether drinking patterns (alcohol consumption, abuse, and intake frequency) are causally associated with TBI risk.
Results:
MR analysis revealed causal effects of alcohol intake frequency [odds ratio (OR) 0.806, 95% confidence interval (CI): 0.665-0.978, p = 0.028, beta: -0.215, se: 0.098], alcohol drinks per week (OR 1.772, 95% CI: 1.140-2.753, p = 0.011, beta: 0.572, se: 0.225), and alcohol abuse (OR 1.095, 95% CI: 1.006-1.192, p = 0.035, beta: 0.091, se: 0.043) on TBI. Additionally, no causal effect of alcohol consumption (OR 0.730, 95% CI: 0.264-2.025, p = 0.546, beta: -0.314, se: 0.520) or average monthly alcohol intake (OR 1.138, 95% CI: 0.805-1.609, p = 0.463, beta: 0.130, se: 0.177) on TBI was observed. Similarly, the effects of TBI on alcohol intake were statistically non-significant.
Conclusion:
Drinking patterns, including alcohol intake frequency and abuse, influence TBI, whereas TBI rarely influences drinking patterns.
Problem: Priority health-risk behaviors, which contribute to the leading causes of morbidity and mortality among youth and adults, often are established during childhood and adolescence, extend into adulthood, are interrelated, and are preventable.
Reporting Period Covered: October 2004--January 2006.
Description of the System: The Youth Risk Behavior Surveillance System (YRBSS) monitors six categories of priority health-risk behaviors among youth and young adults, including behaviors that contribute to unintentional injuries and violence; tobacco use; alcohol and other drug use; sexual behaviors that contribute to unintended pregnancy and sexually transmitted diseases (STDs), including human immunodeficiency virus (HIV) infections; unhealthy dietary behaviors; and physical inactivity. In addition, the YRBSS monitors general health status and the prevalence of overweight and asthma. YRBSS includes a national school-based survey conducted by CDC and state and local school-based surveys conducted by state and local education and health agencies. This report summarizes results from the national survey, 40 state surveys, and 21 local surveys conducted among students in grades 9--12 during October 2004--January 2006.
Results: In the United States, 71% of all deaths among persons aged 10--24 years result from four causes: motor-vehicle crashes, other unintentional injuries, homicide, and suicide. Results from the 2005 national Youth Risk Behavior Survey (YRBS) indicated that, during the 30 days preceding the survey, many high school students engaged in behaviors that increased their likelihood of death from these four causes: 9.9% had driven a car or other vehicle when they had been drinking alcohol; 18.5% had carried a weapon; 43.3% had drunk alcohol; and 20.2% had used marijuana. In addition, during the 12 months preceding the survey, 35.9% of high school students had been in a physical fight and 8.4% had attempted suicide. Substantial morbidity and social problems among youth also result from unintended pregnancies and STDs, including HIV infection. During 2005, a total of 46.8% of high school students had ever had sexual intercourse; 37.2% of sexually active high school students had not used a condom at last sexual intercourse; and 2.1% had ever injected an illegal drug. Among adults aged >25 years, 61% of all deaths result from two causes: cardiovascular disease and cancer. Results from the 2005 national YRBS indicated that risk behaviors associated with these two causes of death were initiated during adolescence. During 2005, a total of 23.0% of high school students had smoked cigarettes during the 30 days preceding the survey; 79.9% had not eaten >5 times/day of fruits and vegetables during the 7 days preceding the survey; 67.0% did not attend physical education classes daily; and 13.1% were overweight.
Interpretation: Since 1991, the prevalence of many health-risk behaviors among high school students nationwide has decreased. However, many high school students continue to engage in behaviors that place them at risk for the leading causes of mortality and morbidity. The prevalence of many health-risk behaviors varies across cities and states.
Public Health Action: YRBS data are used to measure progress toward achieving 15 national health objectives for Healthy People 2010 and three of the 10 leading health indicators, to assess trends in priority health-risk behaviors among high school students, and to evaluate the impact of broad school and community interventions at the national, state, and local levels. More effective school health programs and other policy and programmatic interventions are needed to reduce risk and improve health outcomes among youth.
A major focus of developmental researchers has concerned the isolation of the mechanisms behind age-related improvements in cognition. Working memory capacity, metacognitive abilities, strategies, and knowledge base have all been touted as important causative agents in children’s thinking (e.g., Bjorklund, 1990; Schneider & Pressley, 1989). Meanwhile, although inhibition processes enjoyed a role in early theories of cognition and development (Luria, 1961; Underwood, 1957), inhibition has been neglected, in part, because it has not appeared to be compatible with the computer metaphor of cognition (Bjork, 1989; Dempster, this volume). Currently, the developmental significance of inhibitory processing is garnering renewed support from such diverse areas as memory development (Bjorklund & Harnishfeger, 1990), object permanence in infancy (Diamond, 1988), and discourse processing in the aged (Hasher & Zacks, 1989). It is time to reexamine inhibition as a central mechanism in accounts of cognitive development.
This study examines important developmental differences in patterns of activation in the prefrontal cortex during performance of a Go-No-Go paradigm using functional magnetic resonance imaging (fMRI). Eighteen subjects (9 children and 9 adults) were scanned using gradient echo, echo planar imaging during performance of a response inhibition task. The results suggest four general findings. First, the location of activation in the prefrontal cortex was not different between children and adults, which is similar to our earlier pediatric fMRI results of prefrontal activation during a working memory task (Casey et al., 1995). Second, the volume of activation was significantly greater for children relative to adults. These differences in volume of activation were observed predominantly in the dorsal and lateral prefrontal cortices. Third, although inhibitory processes have typically been associated with more ventral or orbital frontal regions, the current study revealed activation that was distributed across both dorsolateral and orbitofrontal cortices. Finally, consistent with animal and human lesion studies, activity in orbital frontal and anterior cingulate cortices correlated with behavioral performance (i.e., number of false alarms). These results further demonstrate the utility of this methodology in studying pediatric populations.
"The reward cascade" is the release of serotonin, which in turn at the hypothalamus stimulates enkephalin, which in turn inhibits gamma-aminobutyric acid (GABA) at the substantia nigra, which in turn fine tunes the amount of dopamine (DA) released at the nucleus accumbens or "reward site." When DA is released into the synapse, it stimulates a number of DA receptors which results in increased feelings of well-being and stress reduction. It is suggested that when there is a dysfunction in the brain reward cascade, especially in the DA system causing a hypodopaminergic trait, the brain of that person requires a DA fix to feel good. This trait leads to multiple drug-seeking behavior. This is so because alcohol, cocaine, heroin, marijuana, nicotine, and glucose all cause activation and neuronal release of brain DA, which could heal the abnormal cravings. The lack of D₂ receptors causes individuals to have a high risk of multiple addictive, impulsive and compulsive behavioral propensities, such as severe alcoholism, cocaine, heroin, marijuana and nicotine use, glucose bingeing, pathological gambling, sex addiction, attention deficit hyperactivity disorder (ADHD), Tourette's syndrome, autism, chronic violence, posttraumatic stress disorder (PTSD), schizoid/avoidant cluster, conduct disorder, and antisocial behavior. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Cognitive control has been described and referred to over the years by different terminology including "controlled processing", "central executive" and "attentional bias". We present behavioral and neuroimaging experimental investigations of this psychological construct reflecting top-down control in overriding inappropriate thoughts, actions, and emotions. The ability to override competing actions and emotions is a key component of cognitive and social functioning and at the core of a child's development. We show in a series of behavioral and imaging studies that the development of frontostriatal and frontoamygdala circuitry may underlie mature cognitive and affective control.
The influence of differences in knowledge base on children's memory performance is reviewed. It is proposed that age differences in semantic memory affect the ease with which information in permanent memory can be activated, which in turn influences the amount of mental effort available for other cognitive operations. Having detailed knowledge about a set of items can influence memory performance by (a) increasing the accessibility of specific items (item-specific effects), (b) the relatively effortless activation of relations among sets of items (nonstrategic organization), or (c) facilitating the use of deliberate memory strategies. Concerning the latter, children are not expected to use sophisticated mnemonics until processing of individual items requires sufficiently little mental effort. As items and relations among items in children's semantic memories become more elaboratively represented and easily activated, processing efficiency increases and deliberate strategies are more apt to be used.
Piaget's cognitive-developmental variable is conceptualized as a quantitative construct, the central processor M. The set measure of M, i.e., the maximum number of discrete “chunks” of information or schemes that M can control or integrate in a single act, is assumed to grow in an all-or-none manner as a function of age in normal subjects. The M measure is taken as the quantitative characteristic of each developmental stage. M values for the Piagetian stages were inferred from Piagetian data and postulated as experimental hypotheses.A new compound-stimuli visual information (CSVI) type of task was designed for testing quantitatively the M construct. The stochastic model used for these predictions in the CSVI task is the Bose-Einstein occupancy model of combinatorial analysis.Successful results from two different series of studies with 5-, 7-, 9- and 11-year-olds are reported. In addition, the manifestation at the performance level of the “hidden parameter” M is shown to be mediated by a number of moderator variables such as Witkin's cognitive style, attentional learning-sets, etc.
Risk-taking behavior is a major cause of morbidity and mortality in adolescence. In the context of decision theory and motivated (goal-directed) behavior, risk-taking reflects a pattern of decision-making that favors the selection of courses of action with uncertain and possibly harmful consequences. We present a triadic, neuroscience systems-based model of adolescent decision-making.
We review the functional role and neurodevelopmental findings of three key structures in the control of motivated behavior, i.e. amygdala, nucleus accumbens, and medial/ventral prefrontal cortex. We adopt a cognitive neuroscience approach to motivated behavior that uses a temporal fragmentation of a generic motivated action. Predictions about the relative contributions of the triadic nodes to the three stages of a motivated action during adolescence are proposed.
The propensity during adolescence for reward/novelty seeking in the face of uncertainty or potential harm might be explained by a strong reward system (nucleus accumbens), a weak harm-avoidant system (amygdala), and/or an inefficient supervisory system (medial/ventral prefrontal cortex). Perturbations in these systems may contribute to the expression of psychopathology, illustrated here with depression and anxiety.
A triadic model, integrated in a temporally organized map of motivated behavior, can provide a helpful framework that suggests specific hypotheses of neural bases of typical and atypical adolescent behavior.
Localized amygdalar lesions in humans produce deficits in the recognition of fearful facial expressions. We used functional neuroimaging to test two hypotheses: (i) that the amygdala and some of its functionally connected structures mediate specific neural responses to fearful expressions; (ii) that the early visual processing of emotional faces can be influenced by amygdalar activity. Normal subjects were scanned using PET while they performed a gender discrimination task involving static grey-scale images of faces expressing varying degrees of fear or happiness. In support of the first hypothesis, enhanced activity in the left amygdala, left pulvinar, left anterior insula and bilateral anterior cingulate gyri was observed during the processing of fearful faces. Evidence consistent with the second hypothesis was obtained by a demonstration that amygdalar responses predict expression-specific neural activity in extrastriate cortex.
The American Psychological Association’s (APA’s) stance on the psychological maturity of adolescents has been criticized as inconsistent. In its Supreme Court amicus brief in Roper v. Simmons (2005), which abolished the juvenile death penalty, APA described adolescents as developmentally immature. In its amicus brief in Hodgson v. Minnesota (1990), however, which upheld adolescents’ right to seek an abortion without parental involvement, APA argued that adolescents are as mature as adults. The authors present evidence that adolescents demonstrate adult levels of cognitive capability earlier than they evince emotional and social maturity. On the basis of this research, the authors argue that it is entirely reasonable to assert that adolescents possess the necessary skills to make an informed choice about terminating a pregnancy but are nevertheless less mature than adults in ways that mitigate criminal responsibility. The notion that a single line can be drawn between adolescence and adulthood for different purposes under the law is at odds with developmental science. Drawing age boundaries on the basis of developmental research cannot be done sensibly without a careful and nuanced consideration of the particular demands placed on the individual for “adult-like” maturity in different domains of functioning.
To function effectively, individuals must voluntarily postpone immediate gratification and persist in goal-directed behavior for the sake of later outcomes. The present research program analyzed the nature of this type of future-oriented self-control and the psychological processes that underlie it. Enduring individual differences in self-control were found as early as the preschool years. Those 4-year-old children who delayed gratification longer in certain laboratory situations developed into more cognitively and socially competent adolescents, achieving higher scholastic performance and coping better with frustration and stress. Experiments in the same research program also identified specific cognitive and attentional processes that allow effective self-regulation early in the course of development. The experimental results, in turn, specified the particular types of preschool delay situations diagnostic for predicting aspects of cognitive and social competence later in life.
This article reviews progress in the application of evolution theory to human growth and development, particularly adolescence. Evolution theory includes a variety of topics and only two of these are treated here: life history and biocultural modelling. “A broad definition of life history includes not only the traditional foci such as age–related fecundity and mortality rates, but also the entire sequence of behavioural, physiological, and morphological changes that an organism passes through during its development from conception to death” (1). This approach may be applied to both the study of the stages of life of modern people and to the evolution of the human pattern of growth.
Background:
The amygdala plays a central role in the human response to affective or emotionally charged stimuli, particularly fear-producing stimuli. We examined the specificity of the amygdala response to facial expressions in adults and children.
Methods:
Six adults and 12 children were scanned in a 1.5-T scanner during passive viewing of fearful and neutral faces using an EPI BOLD sequence. All scans were registered to a reference brain, and analyses of variance were conducted on the pooled data to examine interactions with age and gender.
Results:
Overall, we observed predominantly left amygdala and substantia innominata activity during the presentation of nonmasked fearful faces relative to fixation, and a decrease in activation in these regions with repeated exposure to the faces. Adults showed increased left amygdala activity for fearful faces relative to neutral faces. This pattern was not observed in the children who showed greater amygdala activity with neutral faces than with fearful faces. For the children, there was an interaction of gender and condition whereby boys but not girls showed less activity with repeated exposure to the fearful faces.
Conclusions:
This is the first study to examine developmental differences in the amygdala response to facial expressions using functional magnetic resonance imaging.
Novelty seeking as well as amphetamine sensitization were studied in adult (postnatal day "PND" > 60) and periadolescent (PND 33–43) mice treated with saline or amphetamine (2 or 10 mg/kg once per day) for 3 days in a familiar environment. After a 48-hr wash-out period, mice were challenged with either saline or amphetamine (2 mg/kg) in the same environment. When given a choice, animals showed a preference for a novel environment, an effect more marked in periadolescents. Acute amphetamine strongly increased novelty seeking in adults, whereas it had an opposite effect in periadolescents. Adult mice in the chronic amphetamine 2 group showed a conditioned preference for the drug-paired compartment, whereas an aversion characterized adult mice in the amphetamine 10 group. Periadolescents in the latter group exhibited a greater sensitization of the locomotor response, but did not show the compulsive licking typical of adults. This appears to be a useful model to study psychobiological risk factors involved in vulnerability to addiction during human adolescence.
The development of organization in children’s memory has received substantial research attention over the past 10 years (for reviews see Lange, 1978; Mandler, 1979; Moely, 1977; Ornstein & Corsale, 1979). Organization is customarily defined as the structure discovered or imposed upon a set of items by a learner, with this structure facilitating retrieval of items from memory (see Chapter 1 by Ackerman for a discussion of factors affecting retrieval from children’s memory). Organization has generally been thought of as a strategic process (i.e., deliberate and effortful), with age changes in the use of organization being attributed to age differences in strategic functioning. Such a conclusion is supported by the results of numerous studies demonstrating that young children, who show little evidence of spontaneous organization, can be trained to cluster their recall according to adult categorizations (e.g., Bjorklund, Ornstein, & Haig, 1977; Moely & Jeffrey, 1974; Moely, Olson, Halwes, & Flavell, 1969). In this chapter, I dispute this position, arguing instead that most of the age changes in the organization of children’s recall are not strategic, but rather can be attributed to developmental changes in the structure and content of children’s conceptual representations. Organization in memory does become strategic, I believe, sometime during adolescence, resulting in a qualitatively different type of memory functioning. However, I argue that the regular improvements observed in memory organization over the course of the preschool and elementary school years can most parsimoniously be attributed to developmental differences in the structure of semantic memory and the ease with which certain types of semantic relationships can be activated.
Background: Alterations in amygdala function have been implicated in the pathophysiological characteristics of adult anxiety and depressive disorders. Studies with healthy adults and children, as well as with adults who have amygdala lesions, have found facial expressions of emotion to be useful probes of amygdala activity. Our study examined the amygdala response to fearful and neutral facial expressions in healthy, anxious, and depressed children. We hypothesized that children with anxiety and depression may show atypical amygdala responses to emotional stimuli. Methods: Twelve children (8-16 years of age) with generalized anxiety or panic disorder and 12 healthy comparison children underwent noninvasive functional magnetic resonance imaging while viewing photographs of fearful and neutral facial expressions. In a second comparison, 5 girls with major depressive disorder were compared with 5 anxious and 5 healthy girls from the previous sample. Results: Children with anxiety disorders showed an exaggerated amygdala response to fearful faces compared with healthy children, whereas depressed children showed a blunted amygdala response to these faces. In addition, the magnitude of the amygdala’s signal change between fearful and neutral faces was positively correlated with the severity of everyday anxiety symptoms. Conclusions: Our results suggest that amygdala function is affected in both anxiety and depression during childhood and adolescence. Moreover, this disruption appears to be specific to the child’s own rating of everyday anxiety.
DA - 20041015IS - 0959-4965LA - engPT - Journal ArticleSB - IM
Localized amygdalar lesions in humans produce deficits in the recognition of fearful facial expressions. We used functional neuroimaging to test two hypotheses: (i) that the amygdala and some of its functionally connected structures mediate specific neural responses to fearful expressions; (ii) that the early visual processing of emotional faces can be influenced by amygdalar activity. Normal subjects were scanned using PET while they performed a gender discrimination task involving static grey-scale images of faces expressing varying degrees of fear or happiness. In support of the first hypothesis, enhanced activity in the left amygdala, left pulvinar, left anterior insula and bilateral anterior cingulate gyri was observed during the processing of fearful faces. Evidence consistent with the second hypothesis was obtained by a demonstration that amygdalar responses predict expression-specific neural activity in extrastriate cortex.
• Neuropathologic and brain imaging studies have produced evidence of brain abnormalities in schizophrenic patients, often within the cerebrum's limbic lobe, and, less frequently, within basal ganglia. In the present study we used magnetic resonance imaging morphometric techniques to estimate volumes of specific cerebral structures in schizophrenic patients and age- and sex-matched normal controls. Estimates of the volume of mesial temporal lobe structures were reduced and estimates of the volume of the lenticular nucleus were increased in the schizophrenic patients. There was also evidence of reduced cranial volume in some schizophrenics. The magnitude of the lenticular abnormality, but not the temporal lobe abnormality, was associated with age at first psychiatric contact; earlier onset was associated with larger lenticular nuclei. The possible relevance of these results to neurodevelopmental hypotheses about the pathogenesis of schizophrenia is discussed.
Twenty-five adolescents reported their daily activities and the quality of their experiences for a total of 753 times during a normal week, in response to random beeps transmitted by an electronic paging device. In this sample adolescents were found to spend most of their time either in conversation with peers or in watching television. Negative affects were prevalent in most activities involving socialization into adult roles. Television viewing appears to be an affectless state associated with deviant behavior and antisocial personality traits. The research suggests the importance of a systemic approach which studies persons' activities and experiences in an ecological context. The experiential sampling method described in this paper provides a tool for collecting such systemic data.
Little empirical investigation has focused on how specific situational variables, such as negative consequences, interact with cognitive developmental variables, such as moral judgment stage, to influence moral decisions and moral thinking. In this study, 223 high school and college students completed 2 questionnaires. In the first, students answered the short form of the Defining Issues Test, which provided a measure of their predisposition to use principled-level rationales in solving moral dilemmas. In the second, students made moral judgments about what they should and would do, and they indicated their use of principled-level thinking in resolving 4 versions of the Heinz dilemma. Each version presented a different combination of negative consequences for the actor (Heinz) and for another (Heinz's wife). Results indicated that, when the negative consequences for the actor were severe, students were less certain that they should and would act to help another person; they also displayed less principled thinking. When the consequences for another were severe, individuals who had displayed a greater predisposition to make use of principled thinking were more certain of acting to help.
Cognitive activity has been viewed from a variety of research perspectives, but there have been few attempts to integrate these different perspectives theoretically or empirically in order to gain a more general picture of human cognition. The 3 perspectives of developmental psychology, experimental psychology, and differential psychology are used in this research in an attempt to understand better the nature of mental ability. Specifically, we searched for differences in basic cognitive processing which could be systematically related to either developmental or individual differences between the subjects. In 3 experiments (simple vs. choice reaction time, Posner letter identification, and Sternberg memory scanning), we looked for interactions of experimental condition with age or ability (defined by Raven's matrices scores). Interactions with age were found in the reaction time and letter identification studies and with ability in letter identification and memory scanning. Additional analyses revealed that a substantial amount of test-score variance was accounted for by the processing variables and that the interrelations of the processing variables provided some evidence for a sequential model of cognitive activity.
Pascual-Leone (1970) proposed the Mental Operator (M) as the set measure of Piaget's “field of centration.” He also demonstrated, for one task, that its value increases one unit every. Piagetian substage. To see if M can be considered a task-independent mental capacity construct, these norms were validated on a new measure.Each subject (S) saw a series of n − 1 ascending numerals, one at a time; (e.g., 5, 11, 16) then an nth numeral (e.g., 14). His task was to indicate where the nth numeral belonged in the initial series. The 180 Ss aged 6, 8, and 10 were tested with n set one higher than m: the hypothesized value of their M. A stochastic analysis was performed to generate the expected error distribution for populations with M = m + 1, M = m, and M = m − 1. A computer search program determined the weights which should be attached to each theoretical error distribution in order for their sum to provide a least squares fit to the empirical error distribution.At each age level, the weight for the second theoretical distribution (M = m) was at least .75. The majority of Ss were therefore assumed to have a mental operator of the value hypothesized.
Crime, smoking, drug use, alcoholism, reckless driving, and many other unhealthy patterns of behavior that play out over a lifetime often debut during adolescence. Avoiding risks or buying time can set a different lifetime pattern. Changing unhealthy behaviors in adolescence would have a broad impact on society, reducing the burdens of disease, injury, human suffering, and associated economic costs. Any program designed to prevent or change such risky behaviors should be founded on a clear idea of what is normative (what behaviors, ideally, should the program foster?), descriptive (how are adolescents making decisions in the absence of the program?), and prescriptive (which practices can realistically move adolescent decisions closer to the normative ideal?). Normatively, decision processes should be evaluated for coherence (is the thinking process nonsensical, illogical, or self-contradictory?) and correspondence (are the out-comes of the decisions positive?). Behaviors that promote positive physical and mental health outcomes in modern society can be at odds with those selected for by evolution (e.g., early procreation). Healthy behaviors may also conflict with a decision maker's goals. Adolescents' goals are more likely to maximize immediate pleasure, and strict decision analysis implies that many kinds of unhealthy behavior, such as drinking and drug use, could be deemed rational. However, based on data showing developmental changes in goals, it is important for policy to promote positive long-term outcomes rather than adolescents' short-term goals. Developmental data also suggest that greater risk aversion is generally adaptive, and that decision processes that support this aversion are more advanced than those that support risk taking. A key question is whether adolescents are developmentally competent to make decisions about risks. In principle, barring temptations with high rewards and individual differences that reduce self-control (i.e., under ideal conditions), adolescents are capable of rational decision making to achieve their goals. In practice, much depends on the particular situation in which a decision is made. In the heat of passion, in the presence of peers, on the spur of the moment, in unfamiliar situations, when trading off risks and benefits favors bad long-term outcomes, and when behavioral inhibition is required for good outcomes, adolescents are likely to reason more poorly than adults do. Brain maturation in adolescence is incomplete. Impulsivity, sensation seeking, thrill seeking, depression, and other individual differences also contribute to risk taking that resists standard risk-reduction interventions, although some conditions such as depression can be effectively treated with other approaches. Major explanatory models of risky decision making can be roughly divided into (a) those, including health-belief models and the theory of planned behavior, that adhere to a "rational" behavioral decision-making framework that stresses deliberate, quantitative trading off of risks and benefits; and (b) those that emphasize nondeliberative reaction to the perceived gists or prototypes in the immediate decision environment. (A gist is a fuzzy mental representation of the general meaning of information or experience; a prototype is a mental representation of a standard or typical example of a category.) Although perceived risks and especially benefits predict behavioral intentions and risk-taking behavior, behavioral willingness is an even better predictor of susceptibility to risk taking - and has unique explanatory power - because adolescents are willing to do riskier things than they either intend or expect to do. Dual-process models, such as the prototype/willingness model and fuzzy-trace theory, identify two divergent paths to risk taking: a reasoned and a reactive route. Such models explain apparent contradictions in the literature, including different causes of risk taking for different individuals. Interventions to reduce risk taking must take into account the different causes of such behavior if they are to be effective. Longitudinal and experimental research are needed to disentangle opposing causal processes - particularly, those that produce positive versus negative relations between risk perceptions and behaviors. Counterintuitive findings that must be accommodated by any adequate theory of risk taking include the following: (a) Despite conventional wisdom, adolescents do not perceive themselves to be invulnerable, and perceived vulnerability declines with increasing age; (b) although the object of many interventions is to enhance the accuracy of risk perceptions, adolescents typically overestimate important risks, such as HIV and lung cancer; (c) despite increasing competence in reasoning, some biases in judgment and decision making grow with age, producing more " irrational" violations of coherence among adults than among adolescents and younger children. The latter occurs because of a known developmental increase in gist processing with age. One implication of these findings is that traditional interventions stressing accurate risk perceptions are apt to be ineffective or backfire because young people already feel vulnerable and overestimate their risk. In addition, research shows that experience is not a good teacher for children and younger adolescents, because they tend to learn little from negative outcomes (favoring the use of effective deterrents, such as monitoring and supervision), although learning from experience improves considerably with age. Experience in the absence of negative consequences may increase feelings of invulnerability and thus explain the decrease in risk perceptions from early to late adolescence, as exploration increases. Finally, novel interventions that discourage deliberate weighing of risks and benefits by adolescents may ultimately prove more effective and enduring. Mature adults apparently resist taking risks not out of any conscious deliberation or choice, but because they intuitively grasp the gists of risky situations, retrieve appropriate risk-avoidant values, and never proceed down the slippery slope of actually contemplating tradeoffs between risks and benefits.
impact of puberty on family relations / transformations in the family relations of human adolescents / puberty and family relations in nonhuman primates
puberty and parent-child distance: a reciprocal relationship / impact of parent-adolescent distance on pubertal maturation: evidence from studies of nonhuman primates / impact of parent-child distance on pubertal maturation: evidence from a study of human adolescents and their parents
puberty and parent-child distance: psychological interpretations
an evolutionary perspective on parent-adolescent distance (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The prefrontal cortex (PFC) is thought to provide an excitatory influence on the output of mesoaccumbens dopamine neurons. The evidence for this influence primarily arises from findings in the rat that chemical or high-intensity and high-frequency (60–200 Hz) electrical stimulations of PFC increase burst activity of midbrain dopamine neurons, and augment terminal release of dopamine in the nucleus accumbens. However, PFC neurons in animals that are engaged in PFC-dependent cognitive tasks increase their firing frequency from a baseline of 1–3 Hz to 7–10 Hz, suggesting that the commonly used high-frequency stimulation parameters of the PFC may not be relevant to the behavioral states that are associated with PFC activation. We investigated the influence of PFC activation at lower physiologically relevant frequencies on the release of dopamine in the nucleus accumbens. Using rapid (5-min) microdialysis measures of extracellular dopamine in the nucleus accumbens, we found that although PFC stimulation at 60 Hz produces the expected increases in accumbal dopamine release, the same amplitude of PFC stimulation at 10 Hz significantly decreased these levels. These results indicate that activation of PFC, at frequencies that are associated with increased cognitive demand on this region, inhibits the mesoaccumbens dopamine system.
A fundamental issue in cognitive neuroscience is the nature of developmental changes in human cerebral functional organization for higher cognitive functions. Event-related functional magnetic resonance imaging was used to measure developmental changes in the functional neuroanatomy subserving controlled lexical association. First, brain regions showing significant differences in activity between school-age children and young adults, despite equivalent task performance, were identified. Then, activity in these regions was more fully characterized in individuals spanning the ages of 7-32 years old. Cross-sectional and regression analyses showed systematic increases and decreases in levels of activity over age, by region. Age-related increases in activity were primarily newly recruited, later-stage processing regions, such as in left frontal and left parietal cortex. Decreases, on the other hand, were all positive activations that attenuated with age and were found across a wider neuroanatomical range, including earlier processing regions such as bilateral extrastriate cortex. The hemodynamic magnitude, neuroanatomical location and maturational timecourse of these progressive and regressive changes have implications for models of the developing specialization in human cerebral functional organization.
Density of dopamine transporter (DAT) and serotonin transporter (5-HTT) membrane proteins in the caudate-putamen (CPu) and nucleus accumbens (NAc) of rat brain was assessed at seven ages at postnatal days (PD) 7-60, by in vitro quantitative autoradiography. Binding of [3H]GBR-12935 (to DAT) and [3H]paroxetine (to 5-HTT) increased steadily and very similarly, from low levels at PD-7 to maximal levels, to 6–7-fold higher density at PD-60 in both regions. These findings indicate that DAT and 5-HTT follow a synchronized course of development in rat CPu and NAc. In contrast to reported elimination of excessive receptors in CPu and NAc during maturation, there was no evidence of pruning of DAT or 5-HTT in these regions of rat forebrain.
A decision-making perspective is used to review and analyze the literature on risk taking in adolescence. The advantages of such an approach are demonstrated, and then it is applied to some widely held beliefs regarding adolescents' risky behaviors. The implications of this perspective for education are briefly discussed, along with the need for a developmental theory of decision making. A large number of studies related to adolescent risk taking are reviewed, showing whether and how each addresses issues defined by a decision-making perspective. Alternative views of risk taking are also examined. In conclusion, we discuss the possible validity of the claim that adolescents are undue risk takers.
Cognitive and brain maturational changes continue throughout late childhood and adolescence. During this time, increasing cognitive control over behavior enhances the voluntary suppression of reflexive/impulsive response tendencies. Recently, with the advent of functional MRI, it has become possible to characterize changes in brain activity during cognitive development. In order to investigate the cognitive and brain maturation subserving the ability to voluntarily suppress context-inappropriate behavior, we tested 8–30 year olds in an oculomotor response–suppression task. Behavioral results indicated that adult-like ability to inhibit prepotent responses matured gradually through childhood and adolescence. Functional MRI results indicated that brain activation in frontal, parietal, striatal, and thalamic regions increased progressively from childhood to adulthood. Prefrontal cortex was more active in adolescents than in children or adults; adults demonstrated greater activation in the lateral cerebellum than younger subjects. These results suggest that efficient top-down modulation of reflexive acts may not be fully developed until adulthood and provide evidence that maturation of function across widely distributed brain regions lays the groundwork for enhanced voluntary control of behavior during cognitive development.
Adolescence is associated with an increased risk of developing drug abuse/dependence. During this ontogenetic phase, brain and hormonal systems are still undergoing crucial maturational rearrangements, which take place together with significant modifications in psychosocial development. However, the neurohormonal and behavioral facets of adolescence have been poorly investigated in relation to the vulnerability to psychostimulants such as MDMA (“Ecstasy”) and amphetamine (AMPH). Novelty-seeking, a temperamental/behavioral trait that is typical of this age period, might substantially contribute to both psychological and psychobiological vulnerability. In humans, an elevated score of novelty-sensation seeking and a derangement of monoaminergic function were both associated with late adolescence MDMA users compared to controls. In animal models of periadolescence, the search for novel stimuli and sensations actually shares a common neurobiological substrate (the reward-related brain mesolimbic pathways) with psychostimulants. The present review summarises recent work in mice, which indicates that periadolescent subjects are characterized by an unbalanced and “extremes-oriented” behavior and by elevated novelty-seeking compared to adults. Repeated and intermittent administration of cocaine or AMPH was associated with the development of a prominent locomotor sensitization in periadolescents, which failed to exhibit the marked sensitization of the stereotyped behavioral syndrome—possibly associated with poor welfare—that was typical of adults. A unique profile of integrated behavioral and physiological hyporesponsivity to both forced novelty and acute AMPH administration during periadolescence was also found. As a whole, these results, together with previous work on this topic, suggest that periadolescents may be more “protected” from AMPH-related aversive properties, and perhaps more vulnerable to the experience of internal states of reward, than older animals. Thus, the present animal model of adolescence seems to represent a reliable and useful method for the investigation of vulnerability to a variety of habit-forming agents or emotional experiences whose positive reinforcing properties may rely on common neurobiological substrates. A deeper understanding of psychostimulant effects during adolescence on the complex interaction between genetic, neurobiologic, psychosocial, and environmental factors will lead to earlier and more effective prevention and treatment.
There are several brain regions that have been implicated in the control of motivated behavior and whose disruption leads to the pathophysiology observed in major psychiatric disorders. These systems include the ventral hippocampus, which is involved in context and focus on tasks, the amygdala, which mediates emotional behavior, and the prefrontal cortex, which modulates activity throughout the limbic system to enable behavioral flexibility. Each of these systems has overlapping projections to the nucleus accumbens, where these inputs are integrated under the modulatory influence of dopamine. Here, we provide a systems-oriented approach to interpreting the function of the dopamine system, its modulation of limbic-cortical interactions and how disruptions within this system might underlie the pathophysiology of schizophrenia and drug abuse.
Density of synaptic profiles in layer 3 of middle frontal gyrus was quantitated in 21 normal human brains ranging from newborn to age 90 years. Synaptic profiles could be reliably demonstrated by the phosphotungstic acid method (Bloom and Aghajanian) in tissue fixed up to 36 h postmortem. Synaptic density was constant throughout adult life (ages 16--72 years) with a mean of 11.05 X 10(8) synapses/cu.mm +/- 0.41 S.E.M. There was a slight decline in synaptic density in brains of the aged (ages 74--90 years) with a mean of 9.56 X 10(8) synapses/cu.mm +/- 0.28 S.E.M. in 4 samples (P less than 0.05). Synaptic density in neonatal brains was already high--in the range seen in adults. However, synaptic morphology differed; immature profiles had an irregular presynaptic dense band instead of the separate presynaptic projections seen in mature synapses. Synaptic density increased during infancy, reaching a maximum at age 1--2 years which was about 50% above the adult mean. The decline in synaptic density observed between ages 2--16 years was accompanied by a slight decrease in neuronal density. Human cerebral cortex is one of a number of neuronal systems in which loss of neurons and synapses appears to occur as a late developmental event.
Neuropathologic and brain imaging studies have produced evidence of brain abnormalities in schizophrenic patients, often within the cerebrum's limbic lobe, and, less frequently, within basal ganglia. In the present study we used magnetic resonance imaging morphometric techniques to estimate volumes of specific cerebral structures in schizophrenic patients and age- and sex-matched normal controls. Estimates of the volume of mesial temporal lobe structures were reduced and estimates of the volume of the lenticular nucleus were increased in the schizophrenic patients. There was also evidence of reduced cranial volume in some schizophrenics. The magnitude of the lenticular abnormality, but not the temporal lobe abnormality, was associated with age at first psychiatric contact; earlier onset was associated with larger lenticular nuclei. The possible relevance of these results to neurodevelopmental hypotheses about the pathogenesis of schizophrenia is discussed.
The influence of pubertal age on the differential effect of a familiar versus an unfamiliar environment on social interaction (SI) in pairs of male rats was evaluated. The decrease in SI induced by the unfamiliar environment in adult rats is considered an anxiety-related response. Intact male rats and male rats castrated at 19 days were tested for SI at 28, 35, and 60 days of age. The results revealed that in the intact rats, decreased SI in an unfamiliar environment was evident at 35 and 60 days but not at 28 days. The behavioral composition of the environment-induced response at 35 days was different from that measured at 60 days. Prepubertal castration prevented the decrease in SI in the unfamiliar environment at both 35 and 60 days. This study demonstrated the emergence with the onset of puberty of a specific behavioral response to an anxiogenic condition. Furthermore, the development of this environment-related behavioral response was influenced by gonadal secretion(s), suggesting the importance of gonadal function to the emergence of this response.
The pre- and postnatal development of the dopaminergic innervation in the prefrontal cortex (PFC) of the rat is described from embryonic day 14 through postnatal day 90. By embryonic day 15 the dopamine (DA)-containing fibers reach the anlage of the lateral neocortex; 2 days later the first fibers have reached the subplate of the future prefrontal cortex. The process of entering the cortical plate starts just before birth. Prenatally, some dopaminergic fibers can be observed in the marginal zone of both the lateral and the medial wall of the hemisphere. Within 48 hours after birth a large number of dopaminergic fibers can be observed in the marginal zone, i.e., the future layer I, in some subareas of the PFC. A transient appearance of DA-positive fibers is noticed in the late embryonic and early postnatal periods especially in the marginal zone and possibly in the superficial layers of the pregenual cingulate cortex. Changes in the morphology of DA fibers at P4 suggest that the actual DA innervation starts at this age. From postnatal day 6 the different subareas of the PFC can be recognized according to the characteristics of the topographical distribution of the dopaminergic fibers. Until postnatal day 60 the density of the dopaminergic fibers continues to increase. No difference in density and topography was observed between postnatal days 60 and 90.
25 infants were tested every 2 weeks on the AB Object Permanence Task devised by Piaget, from the age when they first reached for a hidden object until they were 12 months. The delay between hiding and retrieval necessary to produce the AB error increased continuously throughout this period at an average rate of 2 sec/month, from under 2 sec at 7 1/2 months to over 10 sec by 12 months. All children displayed the AB error repeatedly over the months of testing. Large between-children differences in delay needed for the AB error were found at each age. Girls tolerated longer delays than boys. The characteristic pattern to the AB error did not vary over age or sex. Range of delay producing the AB error in any child was small. Errors disappeared when delays were reduced by 2-3 sec, and reaching became random or severely perseverative when delays were increased 2-3 sec above the level producing AB error. AB provides an index of the ability to carry out an intention based on stored information despite a conflicting habitual tendency.
A distinction is made between 2 alternative hypotheses for explaining an often-reported deficiency in verbally mediated performance during early childhood: (1) the verbal response is made, but tends not to mediate performance ("mediational-deficiency hypothesis"); (2) the verbal response tends not to be made ("production-deficiency hypothesis"). A study is described which attempts to meet the ideal criteria for a test of the production-deficiency hypothesis. The method used was that of direct observation of S's spontaneous verbalizations, and the hypothesis was confirmed by the finding that kindergarteners are less likely than older children to rehearse stimulus names in a nonverbal serial recall task.
The mature functional architecture of the primate prefrontal cortex arises during a protracted period of postnatal development. Although catecholaminergic afferents arrive in the primate cortex quite early during fetal development, several lines of evidence suggest that substantial changes in the dopaminergic innervation of prefrontal cortex may occur during postnatal development. In this study, we used immunocytochemical techniques and antibodies against tyrosine hydroxylase, the rate‐limiting enzyme in catecholamine biosynthesis, to examine the precise time course from birth to adulthood of the maturational changes of tyrosine hydroxylase‐labeled axons in prefrontal cortical areas 9 and 46 and primary motor cortex (area 4) of rhesus monkeys.
In area 9, the densities of tyrosine hydroxylase‐labeled axons and varicosities in the superficial and deep cortical layers remained relatively constant during postnatal development. In contrast, marked developmental changes in innervation density occurred in the middle cortical layers. For example, in deep layer III, the density of tyrosine hydroxylase‐positive varicosities was relatively low and uniform in animals under 1 month of age but then increased by a factor of three in animals 2–3 months of age. The density of labeled varicosities continued to increase, reaching a peak (sixfold greater than in the youngest animals) in aninuds 2–3 years of age before declining to stable adult levels. Similar laminar‐specific patterns of change also occurred in areas 46 and 4, although regional differences were present in the magnitude and precise time course of these developmental changes.
These findings demonstrate that the innervation of monkey frontal cortex by tyrosine hydroxylase‐immunoreactive axons undergoes a protracted, laminar‐specific pattern of change during postnatal development that continues through adolescence and into early adulthood. These developmental refinements may interact with other modifications of cortical circuitry that underlie the functional maturation of these regions. © 1995 Wiley‐Liss, Inc.