Attenuated response to methamphetamine sensitization and deficits in motor learning and memory after selective deletion of β-catenin in dopamine neurons

In the present study, we analyzed mice with a targeted deletion of β-catenin in DA neurons (DA-βcat KO mice) to address the functional significance of this molecule in the shaping of synaptic responses associated with motor learning and following exposure to drugs of abuse. Relative to controls, DA-βcat KO mice showed significant deficits in their ability to form long-term memories and displayed reduced expression of methamphetamine-induced behavioral sensitization after subsequent challenge doses with this drug, suggesting that motor learning and drug-induced learning plasticity are altered in these mice. Morphological analyses showed no changes in the number or distribution of tyrosine hydroxylase-labeled neurons in the ventral midbrain. While electrochemical measurements in the striatum determined no changes in acute DA release and uptake, a small but significant decrease in DA release was detected in mutant animals after prolonged repetitive stimulation, suggesting a possible deficit in the DA neurotransmitter vesicle reserve pool. However, electron microscopy analyses did not reveal significant differences in the content of synaptic vesicles per terminal, and striatal DA levels were unchanged in DA-βcat KO animals. In contrast, striatal mRNA levels for several markers known to regulate synaptic plasticity and DA neurotransmission were altered in DA-βcat KO mice. This study demonstrates that ablation of β-catenin in DA neurons leads to alterations of motor and reward-associated memories and to adaptations of the DA neurotransmitter system and suggests that β-catenin signaling in DA neurons is required to facilitate the synaptic remodeling underlying the consolidation of long-term memories.     

THE DISRUPTIVE EFFECT OF SELF-OBJECTIFICATION ON PERFORMANCE

Self-objectification is the act of viewing the self, particularly the body, from a third-person perspective. Objectification theory proposes numerous negative consequences for those who self-objectify, including decreased performance through the disruption of focused attention. In the current study, we examined whether women in a state of self-objectification were slower to respond to a basic Stroop color-naming task. Results showed that regardless of the type of word (color words, body words, or neutral words), participants in a state of self-objectification exhibited decreased performance. This study lends further evidence to objectification theory and highlights the negative performance ramifications of state self-objectification.     

Indirect influence of maternal social contacts on mother-child interactions: A setting event analysis

Fourteen mother-child dyads who had sought psychological help for severe interaction problems took part in a study that investigated the relationship between maternal social interactions with adults outside the family and mother-child interactions in the home. Social interactions outside the family were based on maternal self-reports; mother-child interactions in the home were based on direct observations and included both base-rate and sequential measures. Results indicated that mothers were significantly more aversive toward their children on days in which they had themselves experienced a high proportion of aversive interactions with adults than on days in which they had not. This higher level of aversiveness was evident in their responses to both aversive and nonaversive child behavior and could not be attributed to any corresponding change in child behavior. Implications for research and clinical practice are discussed.This work appeared first as a paper presented at the 92nd Annual Convention of the American Psychological Association, Toronto, August 1984. The research data reported in this article were generated by support from the National Institute of Mental Health, Crime and Delinquency Section, Grant No. R01-1068-58, to Robert G. Wahler. His permission to use these data is gratefully acknowledged.     

ACTIVITÉ MÉTACOGNITIVE DE L'ENFANT ET DIFFICULTÉ DE LA TÂCHE COGNITIVE

The influence of the type of difficulty of a cognitive task on metacognitive activity (metacognitive experiences and metacognitive strategies) was studied in six- and eight-year-old children. Children had to make decisions about the correspondence of statements and drawings presented in pairs one after the other, starting either with a statement, or with a picture. They encounter two kinds of difficulties: (1) one due to the information conveyed by drawing (non-correspondence with the statement); (2) another due to the order in which the statements and drawings are presented: when the drawing comes first the child must retain it in his memory until a statement can guide him in his decoding of it; this difficulty is unexpected given the expectations the child has due to the cognitive task proposed. The principal findings were as follows: (1) Compared to the six-year-olds, the eight-year-olds demonstrated three times more metacognitive control strategies for expressing information, more cognitive skills (reasoning), and a higher level of performance (understanding and recall). (2) The two types of difficulties do not have the same effects: (a) the difficulty due to the information conveyed by the drawing leads to an increase in the latency time; the performance (understanding) is not as good; (b) in the case of difficulty due to the statement-drawing order, twice as many verbalizations expressing metacognitive experiences and a decrease in the latency time were observed. The interpretation of the findings underscores the importance for the child of the indicators he has to orient him in mobilizing metacognitive and cognitive activities.     

ETUDE COMPARATIVE DES EVALUATIONS COLLECTIVES ET INDIVIDUELLES DE LA PENSEE FORMELLE

The purpose of the present study is to examine the effects of different individual and group testing procedures on the success rate obtained by subjects on different formal problems. Four testing conditions were compared: a clinical interview; an individual interview without intervention; a group test with a demonstration of the material; and a group paper-and-pencil test. The four conditions are defined according to several variables that were deemed important for the explanation of potential performance outcomes. All subjects were administered the following four Piagetian derived tasks: a projection of shadows task; a permutation task; an equilibrium in the balance task; and an interrupter combinations task. According to the general hypothesis, subject performance should be optimal for the clinical interview and decline gradually as the assumed advantages of this method are systematically removed, i.e., counterquestioning of the examiner, retrials, subject-examiner interactions, familiarization with the material, etc. The results show that there are performance differences between the conditions, but mainly across the individual and group situations. However, mean ranks obtained from each condition indicate that the facilitating variables identified in the first three conditions have a certain influence on subject performance. Implications regarding a choice of a valid mesurement of formal thought are discussed.     

Phenomenology of film music

This is a revised version of a paper written for Professor David Raksin's class in film music, Fall 1976, at the University of Southern California.     

Gender concept development of preschool-aged children in the United States and Egypt

Thirty-one American and 31 Egyptian children were given the Slaby-Frey Gender Concept Test to measure gender understanding of children from two cultures assumed to differ in level of androgyny. The subject's sex, age, parent's education, and siblings' sex and age were explored in relation to gender concept. A multivariate analysis of variance (Nationality × Sex of Subject) yielded a significant nationality effect. American children had a higher mean score on gender identity than Egyptian children. In addition, a Pearson product-moment correlation revealed significant positive relationships between the age of the subject and two gender constructs, identity and stability. Future research on specific cognitive, developmental, and cultural influences on the gender development of young children was proposed.     

Variations on a theme

Epstein (1986) has demonstrated that aggregation leads to high correlations which are not spurious but which reflect only stability. He claims that there is no distinction between a demonstration of test-retest reliability and behavioral stability. It is suggested that Epstein has confused personality theory and measurement models and has made the logical fallacy of claiming that high correlation coefficients uniquely reflect stability. Epstein has failed to distinguish clearly between reaction variables and mediating variables and between temporal stability and cross-situational consistency. While high correlation coefficients may reflect stability there is no necessary one-to-one relationship between personality theories and their measurement models nor between reaction variables and mediating variables. The interaction model recognizes that behavior is consistent in the sense of coherence, i.e. a lawful idiographically predictable pattern of behavior. This pattern involves personsituation interactions, and changes over time. Aggregation may obscure these patterns.