The adolescent brain

Adolescence is a developmental period characterized by suboptimal decisions and actions that give rise to an increased incidence of unintentional injuries and violence, alcohol and drug 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 childhood and adulthood. This review provides a biologically plausible conceptualization of the neural mechanisms underlying these nonlinear changes in behavior, as a heightened responsiveness to incentives while impulse control is still relatively immature during this period. Recent human imaging and animal studies provide a biological basis for this view, suggesting differential development of limbic reward systems relative to top-down control systems during adolescence relative to childhood and adulthood. This developmental pattern may be exacerbated in those adolescents with a predisposition toward risk-taking, increasing the risk for poor outcomes.     

Sex differences in the adolescent brain

Adolescence is a time of increased divergence between males and females in physical characteristics, behavior, and risk for psychopathology. Here we will review data regarding sex differences in brain structure and function during this period of the lifespan. The most consistent sex difference in brain morphometry is the 9–12% larger brain size that has been reported in males. Individual brain regions that have most consistently been reported as different in males and females include the basal ganglia, hippocampus, and amygdala. Diffusion tensor imaging and magnetization transfer imaging studies have also shown sex differences in white matter development during adolescence. Functional imaging studies have shown different patterns of activation without differences in performance, suggesting male and female brains may use slightly different strategies for achieving similar cognitive abilities. Longitudinal studies have shown sex differences in the trajectory of brain development, with females reaching peak values of brain volumes earlier than males. Although compelling, these sex differences are present as group averages and should not be taken as indicative of relative capacities of males or females.     

Treatment of aggression in a brain injured adolescent

A traumatically brain injured (TBI) adolescent exhibited physical aggression requiring physical intervention. Aggressive behavior was eliminated in 2 weeks when a point system with response cost and contingent home visits were used. The point system alone maintained aggression at zero episodes for 4 weeks. In addition to eliminating aggression, the point system increased attendance to therapies and classes, waking up on time, and prosocial behaviors.     

Minimal brain dysfunction in adolescent and young adult psychiatric inpatients

This paper presents data on a study of 100 consecutive young adult psychiatric admissions to Horsham Hospital, to determine the incidence of minimal brain dysfunction in this population, to define the subcategories of common psychiatric presentation, and to compare these data with those from the companion study conducted by our research group of fifty consecutive adolescent psychiatric admissions, reported by Horowitz, 1981.     

儿童青少年的信息加工及其脑机制研究

对十多年来儿童青少年信息加工发展的机制以及脑机制的研究进行了总结,采用减法反应、指数函数、双曲线函数、微观发生设计、横断设计、脑超慢波等方法,研究了信息加工速度、信息加工策略、信息加工的空间、信息加工的脑机制等问题,对信息加工的发展机制、内部过程进行了讨论,并提出了信息加工的模型和策略发展的模型.     

Neurobehavioral deficits,adolescent traumatic brain injury,and transition to college

Outcome following traumatic brain injury (TBI) has been frequently evaluated for adults, although there has been minimal research on adolescents with TBI. It has been argued that TBI sequelae may be more difficult for adolescents to adjust to given developmental changes in physical (puberty), interpersonal (self-concept), and environmental domains (transition to college). In addition, it is commonly acknowledged that moderator variables such as psychiatric history, family functioning, substance use, and sexuality impact functional outcome following TBI, although it is often difficult to objectively evaluate these variables. The current study examined relationships among TBI-related deficits, moderator variables, and academic outcomes for six adolescents transitioning to college. The findings suggest that it may not be appropriate to predict functional outcome based solely on objective neuropsychological results. However, moderator variables appear to have a more direct relationship with outcome, depending on the moderator variable and the individual.     

The impact of periventricular brain injury on reading and spelling abilities in the late elementary and adolescent years.

The present study was designed: (1) to investigate the long-term consequences of both the presence and the severity of periventricular brain injury (PVBI) on intellectual, academic, and cognitive outcome in extremely-low-birthweight (ELBW: < 1,000 grams) children at a mean age of 11 years; and (2) to determine the nature of the underlying difficulties associated with academic problems in these children. The results indicated that ELBW children without PVBI performed as well as full-term children on intelligence, academic, and cognitive ability tests. In contrast, ELBW children with mild and severe PVBI achieved significantly lower scores than either ELBW children without PVBI or children who were born at term. A second analysis indicated that, after accounting for Full Scale IQ, working memory and phonological processing were significant predictors of reading and spelling performance in ELBW children. These findings suggest that the presence and severity of PVBI, and not ELBW status alone, is associated with performance on tests of intelligence, and academic and cognitive functioning, and that some of the same factors known to be associated with learning disabilities in full-term children contribute to learning disabilities in ELBW children.     

Suicide and the rural adolescent

The rural family, with its particular stressors, is increasingly vulnerable to overwhelming crises. Adolescent suicide, although rare, may result from or add to that stress. The intent of this study was to identify and examine specific stressors with which a rural adolescent must deal, the coping mechanisms utilized, and when these fail, how it leads to suicidal behavior. Therapeutic modalities available to the troubled adolescent were examined and additional services suggested.     

Tutoring Techniques in Algebra

Although one-to-one tutoring has been regarded as the most effective method of teaching (Bloom, 1984), surprisingly little is understood about tutoring expertise. Much educational research focuses on classroom teaching, whereas the few studies that focus on one-to-one tutoring do not offer a precise information-processing account of this skill. This article describes our initial attempts to study one-to-one tutoring. The goal of our research is to construct a detailed cognitive model of the reasoning and knowledge of an expert human tutor. The method we have employed is a variant of knowledge engineering. We videotaped tutoring sessions with expert teachers, subjecting them to a detailed analysis aimed at abstracting the tutor's knowledge structures. In this article, we describe some important tutoring techniques we have isolated using these methods. We discuss several dimensions along which tutors appear to be intelligent planners and problem solvers. Finally, we note several implications of our research, including its potential impact on the construction of intelligent computer-based tutoring systems.     

Reduced N400 semantic priming effects in adult survivors of paediatric and adolescent traumatic brain injury

The immediate and long-term neural correlates of linguistic processing deficits reported following paediatric and adolescent traumatic brain injury (TBI) are poorly understood. Therefore, the current research investigated event-related potentials (ERPs) elicited during a semantic picture-word priming experiment in two groups of highly functioning individuals matched for various demographic variables and behavioural language performance. Participants in the TBI group had a recorded history of paediatric or adolescent TBI involving injury mechanisms associated with diffuse white matter pathology, while participants in the control group never sustained any insult to the brain. A comparison of N400 Mean Amplitudes elicited during three experimental conditions with varying semantic relatedness between the prime and target stimuli (congruent, semantically related, unrelated) revealed a significantly smaller N400 response in the unrelated condition in the TBI group, indicating residual linguistic processing deviations when processing demands required the quick detection of a between-category (unrelated) violation of semantic expectancy.     

Stress,coping, executive function,and brain activation in adolescent offspring of depressed and nondepressed mothers

This study examined the associations among chronic stress, activation in the prefrontal cortex (PFC), executive function, and coping with stress in at-risk and a comparison sample of adolescents. Adolescents (N = 16; age 12–15) of mothers with (n = 8) and without (n = 8) a history of depression completed questionnaires, neurocognitive testing, and functional neuroimaging in response to a working memory task (N-back). Children of depressed mothers demonstrated less activation in the anterior PFC (APFC) and both greater and less activation than controls in distinct areas within the dorsal anterior cingulate cortex (dACC) in response to the N-back task. Across both groups, activation of the dorsolateral PFC (DLPFC; Brodmann area [BA9]) and APFC (BA10) was positively correlated with greater exposure to stress and negatively correlated with secondary control coping. Similarly, activation of the dACC (BA32) was negatively correlated with secondary control coping. Regression analyses revealed that DLPFC, dACC, and APFC activation were significant predictors of adolescents’ reports of their use of secondary control coping and accounted for the effects of stress exposure on adolescents’ coping. This study provides evidence that chronic stress may impact coping through its effects on the brain regions responsible for executive functions foundational to adaptive coping skills.     

On the adolescent neurosis

The author discusses the lifelong impact of adolescence in shaping the adult psyche. Some patients may appear to be as influenced by conflicts of adolescence and the individual solutions arrived at during this period as they are by conflicts and solutions of the oedipal phase, the author maintains. The subphases of early, middle, and late adolescence are discussed both in terms of a review of the psychoanalytic literature and of representative works of literary fiction. Illustrative clinical vignettes are presented as well.     

Algebra Mal-Rules and Cognitive Accounts of Error

We report an empirical study of elementary algebra errors, conducted in three separate schools. The errors are diagnosed using mal-rules, as proposed by Sleeman (1984, 1,985). Our analysis uncovers the following properties of algebra mal-rules: The frequency of mal-rules is severely skewed, there are many infrequent mal-rules and few frequent ones; mal-rules are very unstable, students typically use mal-rules very irregularly; different mal-rules have explanatory power in different schools (many of our most powerful mal-rules are previously unreported); mal-rule diagnosis Is more successful with more skilled students; students' confidence ratings do not partition the total set of mal-rules, every mal-rule we find is associated with high confidence ratings by at least one student. The Implications of our data for cognitive theories of error generation are discussed. Contrary to commonplace assumptions, we argue that It is impossible to make a clear distinction between slips and mistakes; most errors depend on properties of the knowledge base and the cognitive architecture. Errors In a procedural skill cannot be assumed to be purely syntactic In orgin.     

Alcohol-specific parenting,adolescent alcohol use and the mediating effect of adolescent alcohol-related cognitions

Objectives : Previous research indicated that alcohol-specific parenting is an important precursor of adolescent alcohol use, but failed to define the underlying mechanism. Based on social cognitive theory, alcohol-related cognitions such as alcohol refusal self-efficacy and alcohol-related expectancies were hypothesised to mediate this link.

Design : A cross-sectional survey included 1349 mothers and their sixth grade (11–12?years old) adolescent offspring. Structural equation modelling was employed to test the association between alcohol-specific parenting and adolescent alcohol use, mediated by adolescent alcohol-related cognitions.

Main outcome measures : Adolescent alcohol use, drinking refusal self-efficacy and alcohol expectancies.

Results : The associations between frequency of communication, maternal alcohol use and adolescent alcohol use were mediated by negative alcohol-related expectancies. The associations between quality of communication, rules and disclosure and adolescent alcohol use were mediated by self-efficacy.

Conclusions : The present study provides a first indication that the underlying mechanism of the association between the most important alcohol-specific parenting practices and adolescent alcohol use can be contributed to the mediating effect of alcohol-refusal self-efficacy.     

Neurobehavioural profile following cumulative mild traumatic brain injury in adolescent rugby players in South Africa

The study investigated the neurobehavioural components of executive dysfunction following sport-related Mild Traumatic Brain Injury (MTBI) in Grade 12 adolescent rugby players over a rugby season. In a non-equivalent quasi-experimental design, a rugby group (n?=?90) were compared with demographically equivalent noncontact sport controls (n?=?59). The Behaviour Rating Inventory of Executive Functions – Self Report (BRIEF-SR) was employed to assess the neurobehavioural component of executive functions. Independent and dependent t-test analyses were conducted to compare the groups at baseline and end-of-season intervals. The overall findings suggest more pronounced deleterious effects on executive functioning from exposure to the concussive and sub-concussive events among the rugby group. High school rugby players experience adverse neurobehavioural effects in executive dysfunction from contact rugby sport injuries.