Place and direction learning in a spatial T-maze task by neonatal piglets

Pigs are a valuable animal model for studying neurodevelopment in humans due to similarities in brain structure and growth. The development and validation of behavioral tests to assess learning and memory in neonatal piglets are needed. The present study evaluated the capability of 2-week old piglets to acquire a novel place and direction learning spatial T-maze task. Validity of the task was assessed by the administration of scopolamine, an anti-cholinergic drug that acts on the hippocampus and other related structures, to impair spatial memory. During acquisition, piglets were trained to locate a milk reward in a constant place in space, as well as direction (east or west), in a plus-shaped maze using extra-maze visual cues. Following acquisition, reward location was reversed and piglets were re-tested to assess learning and working memory. The performance of control piglets in the maze improved over time (P < 0.0001), reaching performance criterion (80 % correct) on day 5 of acquisition. Correct choices decreased in the reversal phase (P < 0.0001), but improved over time. In a separate study, piglets were injected daily with either phosphate-buffered saline (PBS; control) or scopolamine prior to testing. Piglets administered scopolamine showed impaired performance in the maze compared to controls (P = 0.03), failing to reach performance criterion after 6 days of acquisition testing. Collectively, these data demonstrate that neonatal piglets can be tested in a spatial T-maze task to assess hippocampal-dependent learning and memory.     

Dopaminergic modulation of incentive motivation in adolescence: age-related changes in signaling, individual differences, and implications for the development of self-regulation

Behavioral activation that is associated with incentive-reward motivation increases in adolescence relative to childhood and adulthood. This quadratic developmental pattern is generally supported by behavioral and experimental neuroscience findings. It is suggested that a focus on changes in dopamine neurotransmission is informative in understanding the mechanism for this adolescent increase in reward-related behavioral activation and subsequent decline into adulthood. Evidence is presented to indicate that incentive-reward motivation is modulated by mesoaccumbens dopamine, and that it increases in adolescence before declining into adulthood because of normative developmental changes at the molecular level. Potential mechanisms of variation in functional mesoaccumbens dopamine transmission are discussed with a focus on the interplay between tonic and phasic modes of dopamine transmission in modulating both general incentive-motivational biases and the efficacy of reward learning during exposure to novel reward experiences. Interactions between individual difference factors and these age-related trends are discussed.     

Semantic Language as a Mechanism Explaining the Association between ADHD Symptoms and Reading and Mathematics Underachievement

ADHD is associated with academic underachievement, but it remains unclear what mechanism accounts for this association. Semantic language is an underexplored mechanism that provides a developmental explanation for this association. The present study will examine whether semantic language deficits explain the association between ADHD and reading and mathematics underachievement, taking into account alternative explanations for associations, including verbal working memory (WM) impairments, as well as specificity of effects to inattentive and hyperactive-impulsive ADHD symptom domains. Participants in this cross-sectional study were 546 children (54?% male) ages six to twelve (M?=?9.77, SD?=?1.49). ADHD symptoms were measured via maternal and teacher report during structured interviews and on standardized rating forms. Children completed standardized semantic language, verbal WM, and academic testing. Semantic language fully mediated the ADHD-reading achievement association and partially mediated the ADHD-mathematics achievement association. Verbal WM also partially mediated the ADHD-mathematics association but did not mediate the ADHD-reading achievement association. Results generalized across inattentive and hyperactive-impulsive ADHD symptom domains. Semantic language explained the association between ADHD and reading underachievement and partially explained the association between ADHD and mathematics underachievement. Together, language impairment and WM fully explained the association between ADHD and reading underachievement, in line with developmental models suggesting that language and WM conjointly influence the development of attention and subsequent academic achievement. This work has implication for the development of tailored interventions for academic underachievement in children with ADHD.     

Dysregulated negative emotional reactivity as a predictor of chronic peer victimization in childhood

This study examined the relations of dysregulated negative emotional reactivity, emotional distress, and chronic peer victimization in childhood. A model was proposed whereby dysregulated reactivity was directly and indirectly related to concurrent peer victimization through victimization‐related emotional distress. The model further proposed that dysregulated reactivity directly incrementally predicted longitudinal peer victimization above and beyond the effect of concurrent victimization. Two hundred thirteen 9‐ to 13‐year‐old children and their parents completed measures of dysregulated reactivity and victimization experiences at baseline and 6‐month follow‐up. Children also related narratives of personal victimization experiences at baseline that were coded to assess victimization‐related emotional distress. Model testing strongly supported the direct association of dysregulated reactivity with concurrent victimization and incremental predictive effects of dysregulated reactivity on peer victimization over time. Model testing also provided support for an indirect effect of dysregulated reactivity on concurrent peer victimization through victimization‐related emotional distress. This study demonstrated the powerful role that dysregulated negative emotional reactivity plays in the development of chronic peer victimization over time. Aggr. Behav. 38:414‐427, 2012. © 2012 Wiley Periodicals, Inc.     

Temperament and common disruptive behavior problems in preschool

The study evaluated trait associations with common Disruptive Behavior Disorders (DBD), Oppositional Defiant Disorder (ODD) and Attention-Deficit/Hyperactivity Disorder (ADHD), during an understudied developmental period: preschool. Participants were 109 children ages 3–6 and their families. DBD symptoms were available via parent and teacher/caregiver report on the Disruptive Behavior Rating Scale. Traits were measured using observational coding paradigms, and parent and examiner report on the Child Behavior Questionnaire and the California Q-Sort. The DBD groups exhibited significantly higher negative affect, higher surgency, and lower effortful control. Negative affect was associated with most DBD symptom domains; surgency and reactive control were associated with hyperactivity-impulsivity; and effortful control was associated with ADHD and inattention. Interactive effects between effortful control and negative affect and curvilinear associations of reactive control with DBD symptoms were evident. Temperament trait associations with DBD during preschool are similar to those seen during middle childhood. Extreme levels of temperament traits are associated with DBD as early as preschool.     

The effect of family processes on school achievement as moderated by socioeconomic context

This longitudinal study examined a model of early school achievement in reading and math, as it varies by socioeconomic context, using data from the NICHD Study of Early Child Care and Youth Development. A conceptual model was tested that included features of family stress, early parenting, and school readiness, through both a single-group analysis and also a multiple-group analysis. Latent profile analysis was used to identify subgroups of more advantaged and less advantaged families. Family stress and parenting were shown to operate differently depending on the socioeconomic context, whereas child-based school readiness characteristics were shown to operate similarly across socieodemographic contexts. Implications for intervention are discussed.     

A model-based cluster analysis of social experiences in clinically anxious youth: links to emotional functioning

Social difficulties are commonly associated with anxiety disorders in youth, yet are not well specified in the literature. The aim of this study was to identify patterns of social experiences in clinically anxious children and examine the associations with indices of emotional functioning. A model-based cluster analysis was conducted on parent-, teacher-, and child-reports of social experiences with 64 children, ages 7–12 years (M = 8.86 years, SD = 1.59 years; 60.3% boys; 85.7% Caucasian) with a primary diagnosis of separation anxiety disorder, social phobia, and/or generalized anxiety disorder. Follow-up analyses examined cluster differences on indices of emotional functioning. Findings yielded three clusters of social experiences that were unrelated to diagnosis: (1) Unaware Children (elevated scores on parent- and teacher-reports of social difficulties but relatively low scores on child-reports, n = 12), (2) Average Functioning (relatively average scores across all informants, n = 44), and (3) Victimized and Lonely (elevated child-reports of overt and relational victimization and loneliness and relatively low scores on parent- and teacher-reports of social difficulties, n = 8). Youth in the Unaware Children cluster were rated as more emotionally dysregulated by teachers and had a greater number of diagnoses than youth in the Average Functioning group. In contrast, the Victimized and Lonely group self-reported greater frequency of negative affect and reluctance to share emotional experiences than the Average Functioning cluster. Overall, this study demonstrates that social maladjustment in clinically anxious children can manifest in a variety of ways and assessment should include multiple informants and methods.     

Self-critical Rumination and Associated Metacognitions as Mediators of the Relationship Between Perfectionism and Self-esteem

Journal of Rational-Emotive & Cognitive-Behavior Therapy - Past research has shown that perfectionism, can negatively impact self-esteem. However, the mediating factors that explain this...     

Collective Action on Behalf of Women: Testing the Conceptual Distinction Between Traditional Collective Action and Small Acts in College Women

Sex Roles - The current study examines the nature of actions that U.S. college women (N?=?267) engage in to promote, protect, or enhance the welfare of other women. The study had two...     

Forms and Functions of Aggression in Adolescents: Validation of the Portuguese Version of the Peer Conflict Scale

Aggression in adolescence may assume different forms and functions, and is often associated with maladjustment. To adequately assess aggression in adolescence, instruments need to evaluate both its forms and its functions, as is the case with the Peer Conflict Scale. This research presents and evaluates the Portuguese version of this instrument, and evaluates levels of aggression in an adolescent community sample (n?=?785; 63.6 % female, mean age of 15.97 years old). The four factor structure originally proposed for the instrument (i.e. proactive overt, reactive overt, proactive relational and reactive relational aggression) represented a satisfactory solution for the data, and for both girls and boys. Results also have shown adequate reliability. Regarding levels of aggression, boys reported being overall more aggressive than girls. When aggression is impulsive/ reactive, both boys and girls practice its overt form. It is only when the aggression is pondered upon (proactive) that boys and girls chose to use different forms of aggression. Accurately evaluating different forms and functions of aggression has implications for designing, implementing and evaluating adequate and tailored interventions.