Unimpaired trace classical eyeblink conditioning in Purkinje cell degeneration (pcd) mutant mice

Young adult Purkinje cell degeneration (pcd) mutant mice, with complete loss of cerebellar cortical Purkinje cells, are impaired in delay eyeblink classical conditioning. In the delay paradigm, the conditioned stimulus (CS) overlaps and coterminates with the unconditioned stimulus (US), and the cerebellar cortex supports normal acquisition. The ability of pcd mutant mice to acquire trace eyeblink conditioning in which the CS and US do not overlap has not been explored. Recent evidence suggests that cerebellar cortex may not be necessary for trace eyeblink classical conditioning. Using a 500 ms trace paradigm for which forebrain structures are essential in mice, we assessed the performance of homozygous male pcd mutant mice and their littermates in acquisition and extinction. In contrast to results with delay conditioning, acquisition of trace conditioning was unimpaired in pcd mutant mice. Extinction to the CS alone did not differ between pcd and littermate control mice, and timing of the conditioned response was not altered by the absence of Purkinje cells during acquisition or extinction. The ability of pcd mutant mice to acquire and extinguish trace eyeblink conditioning at levels comparable to controls suggests that the cerebellar cortex is not a critical component of the neural circuitry underlying trace conditioning. Results indicate that the essential neural circuitry for trace eyeblink conditioning involves connectivity that bypasses cerebellar cortex.     

Application of Hellison's Teaching Personal and Social Responsibility Model in physical education to improve self-efficacy for adolescents at risk of dropping-out of school

This study evaluated improvement in self-efficacy and personal and social responsibility among at-risk of dropping-out of school adolescents participating in a program in which Hellison's Teaching Personal and Social Responsibility Model was applied in physical education classes during the course of an academic year. Thirty at-risk adolescents aged 13-14 years old (23 boys, 7 girls) were assigned to an intervention group (12 boys and 3 girls) or a comparison group (11 boys, 4 girls), the latter of which did not participate in the program. Quantitative results showed a significant improvement in the students' self-efficacy for enlisting social resources and in self-efficacy for self-regulated learning. Qualitative results showed an improvement in responsibility behaviors of participants in the intervention group. This suggests that the model could be effective for improving psychological and social development in at-risk adolescents, and that physical education classes may be an appropriate arena for working with these young people.     

The goal of consistency as a cause of information distortion

Why, during a decision between new alternatives, do people bias their evaluations of information to support a tentatively preferred option? The authors test the following 3 decision process goals as the potential drivers of such distortion of information: (a) to reduce the effort of evaluating new information, (b) to increase the separation between alternatives, and (c) to achieve consistency between old and new units of information. Two methods, the nonconscious priming of each goal and assessing the ambient activation levels of multiple goals, reveal that the goal of consistency drives information distortion. Results suggest the potential value of combining these methods in studying the dynamics of multiple, simultaneously active goals.     

Impulsivity and reward sensitivity within the pen model: A test of discriminant hypotheses

Impulsivity and reward sensitivity are often treated as interchangeable constructs. This conflation may be traced back to Gray’s interpretation of impulsivity as the trait level manifestation of the Behavioral Activation System (BAS), that mediates sensitivity to rewards. In this study (N = 696) we evaluated discriminant hypotheses regarding the relationships between BAS-mediated reward sensitivity, impulsivity and Eysenck’s PEN superfactors. We hypothesized that reward sensitivity would be mainly linked with Extraversion, and that impulsivity would be primarily connected with Psychoticism. Hypotheses were tested using structural equation modelling and equality constraints tests. Results mostly supported our expectations: reward sensitivity was more strongly related to Extraversion than to the other PEN superfactors, while impulsivity was more strongly related to Psychoticism and Neuroticism. Implications for BAS and impulsivity research are discussed.     

Psychological group memberships as outcomes of resource distributions

We propose that people can and will infer group memberships from resource distributions, and that these distributions have implications for people's understandings of the groups themselves and their own associations with these groups. We derive hypotheses from social identity and self‐categorization theories, and test them in three experiments. In Experiment 1, participants systematically rated specific patterns of group memberships as more likely than others in light of specific resource distributions in a manner consistent with our predictions. In Experiment 2, intragroup distributive fairness led to greater perceived self‐in‐group similarity than intra‐group distributive unfairness, while distributively unfair, in‐group favouritism led to greater perceived self‐in‐group similarity than intergroup fairness. In Experiment 3, social identification dropped following unfair, out‐group favouritism and intragroup unfairness, but not unfair, in‐group favouritism, or intragroup and intergroup fairness. The current data provide support for our hypotheses and clear evidence that resource distributions can be providers of group membership information. Copyright © 2007 John Wiley & Sons, Ltd.     

Executive Functions in Preschool Children with Aggressive Behavior: Impairments in Inhibitory Control

The question whether executive function (EF) deficits in children are associated with conduct problems remains controversial. Although the origins of aggressive behavior are to be found in early childhood, findings from EF studies in preschool children with aggressive behavior are inconsistent. The current study aimed to investigate whether preschool children with aggressive behavior show impairments in EF. From a population-based sample, 82 preschool children who were showing aggressive behavior as indicated by scores at or above the 93rd percentile on the Aggressive Behavior Scale of the CBCL 1 1/2-5 were selected. These children with aggressive behavior were matched on IQ to a group of typically developing control children (N = 99). Six neuropsychological tasks were administered to assess set shifting, inhibition, working memory and verbal fluency. A factor analysis was conducted which yielded one clear factor: inhibition. Aggressive preschool children showed poorer performance on this inhibition factor than control children and boys performed worse on this factor than girls. This association between aggressive behavior and inhibition deficits was maintained after controlling for attention problems. In addition, gender differences in all EFs measured were found with boys exhibiting more impairment in EF than girls. These findings demonstrate that preschool children with aggressive behavior show impairments in inhibition, irrespective of attention problems.     

The Romance of Self-objectification: Does Priming Romantic Relationships Induce States of Self-objectification Among Women?

Objectification theory suggests that women internalize an observer’s perspective on the body (self objectification; Fredrickson and Roberts, Psychol Women Q 22:173–206, 1997); however, certain contexts and thoughts may make self-objectification more likely. Because the pursuit of relationships is tied to attractiveness, the present study examines whether women have an automatic link between self-objectification and romantic relationships. Using a US undergraduate sample, women (N?=?86) of different relationship statuses were either exposed to relationship-related or neutral words in a lexical decision making task. Following relationship priming, single women showed greater self-objectification and women in relationships showed less self-objectification. These findings are discussed in terms of self-objectification theory and the importance of attractiveness and beauty in the pursuit of relationships.     

Aging and social satisfaction: offsetting positive and negative effects

Social satisfaction in late adulthood originates from competing sources. Older adults tend to be more positive and less negative than younger adults, but social contact and working memory often decrease with age, both of which might limit older adults' social functioning. In the current study of younger and older adults, these socially facilitative vs. socially debilitative changes were found to underlie stasis in social satisfaction. These findings show that the lack of an overall effect for age can mask competing changes in social functioning in late adulthood, as the sources of social satisfaction might change even if the outcome does not.     

Systemic administration of a nitric oxide synthase inhibitor impairs fear sensitization in the plus-maze

The aim of the present study was to evaluate the occurrence of fear sensitization in rats previously treated with an inhibitor of the NO syntheses and submitted to Trial1/Trial2 plus-maze (PM) procedure. Male Wistar rats received a systemic treatment with N(omega)-nitro-L-Arginine-methyl ester (L-NAME; 5, 10 or 50 mg kg(-1)) and were submitted to PM Trial1. In the following day the animals were re-exposed to the PM with no drug administration (Trial2). Some standards spatial-temporal measures, such as the percentage of entries (% Open arm entries) and time spent (% Open arm time) in the open arms and risk assessment frequency were recorded and used to estimate the animal level of fear sensitization in PM Trial2. The results showed that animals receiving L-NAME (50 mg kg(-1)) displayed increased % Open arm entries and % Open arm time in Trial2 in relation to the group receiving 0.9% saline, which is compatible with impaired fear/anxiety acquisition during Trial1/Trial2 PM procedure. In addition, rats treated with L-NAME (50 mg kg(-1)) exhibited low level of risk assessment in Trial2 in relation to the group treated with 0.9% saline, which indicates low level of fear/anxiety during PM re-exposure. The number of entries into the enclosed arms was not changed by any L-NAME treatment, which suggests no bias of the drug treatments on animal locomotor activity. The data suggest that NO synthesis may mediate the fear sensitization process in the PM.