Differential involvement of NMDA and AMPA receptors within the nucleus accumbens in consolidation of information necessary for place navigation and guidance strategy of mice

Recent evidence now points to a role of glutamate transmission within the nucleus accumbens (Nacc) in spatial learning and memory. Unfortunately, the role of the distinct classes of glutamate receptors within this structure in mediating the different steps of the memorization process is not clear. The aim of this study therefore was to further investigate this issue, trying to assess the involvement of the two classes of glutamate receptors within the Nacc in consolidation of spatial information using an associative spatial task, the water maze. For this purpose, focal injections of the NMDA antagonist, AP-5, and of the AMPA antagonist, DNQX, have been performed immediately after the training phase, and mice have been tested for retention 24 h later. Two different versions of the water-maze task have been used: In the place version, animals could learn the position of the platform using visual distal cues, and in the cue version, the location of the platform was indicated by a single proximal cue. The results demonstrated that posttraining NMDA receptor blockade affects mice response in the place but not in the cue water-maze task. On the contrary, AMPA receptor blockade induced no effect in either version of the task. These data confirm a functional dissociation between glutamate receptors located in the Nacc in modulating spatial memory consolidation and indicate that they are specifically involved in consolidation of information necessary to acquire a place but not to a guidance strategy.     

Typicality of Interpersonal Situations: The Role of Affect in Determining Contextual Variations in Typicality Norms

This study deals with the relationship between affect and cognition. This relationship is conceptualized in the terms of Bower's (Bower & Cohen, 1982) theory. Subjects (early adolescents aged 12 or 14, boy or girl) were asked to imagine themselves as the actor in an interpersonal situation. The situation was either intimate or non-intimate, and the hypothetical partner was either a boy or a girl. The subject's task was to produce a series of sentences expressing the behaviours considered representative of each situation. The results indicated (1) the existence of a typicality hierarchy (whose characteristics are examined here) and (2) variations in this hierarchy according to the affective tone of the situation (intimate or non-intimate). We explain how the cultural, interpersonal situation norms acquired by adolescents can account for these variations. Thus, contrary to what some authors contend, variations in typicality are not random.     

Performance feedback and self-focused attention in the classroom: When past and present interact

An experiment tested the impact of performance feedback on self-focused attention in high and low achievers. On the basis of previous research, which suggested that inconsistent feedback (i.e., feedback which contradicts one's performance history) receives considerable attention, it was predicted that such feedback would increase self-focus regardless of its valence (i.e., positive or negative). As predicted, high achievers were more self-focused when receiving failure feedback than when receiving success feedback or no feedback. The low achievers were more self-focused when receiving success feedback than when receiving failure feedback or no feedback. These findings are discussed in relation to Kluger and DeNisi's (1996) Feedback intervention theory and the literature on self-focused attention.     

The Influence of Social Comparison Situations on Individual Task Performance: Experimental Illustrations

In the past ten or so years, numerous experiments have been conducted to illustrate the intervention of social regulations in cognitive functioning (e.g., social coordination, sociocognitive conflict, and social marking). However, in that way, social comparison processes have not received any extended theoretical and empirical attention. Several experimental results are reported here in an attempt to show that the social conditions, in particular personal and categorical comparison situations, in which subjects are led to perform memory and problem-solving tasks constitute a determining factor in their cognitive performances. The discussion presents some new theoretical prospects for the study of social regulations of cognitive functioning.     

Relative contributions of kind- and domain-level concepts to expectations concerning unfamiliar exemplars: Developmental change and domain differences

Two inferential routes allow children to produce expectations about new instances of ontological categories like “animal” and “artefact.” One is to generalise information from a “look-up table” of familiar kind-concepts. The other one is to use independent expectations at the level of ontological domains. Our experiment pits these two sources of information against each other, using a sentence-judgement task associating properties with images of familiar and unfamiliar artefacts and animals. “Strange” properties are compatible with the ontological concept, but not encountered in any familiar kind. A look-up strategy would lead children to reject them and an independent expectation strategy to accept them. In both domains, we find a difference in reaction to strange properties associated with familiar vs. unfamiliar items, which shows that even young children do use independent domain-level information. We also found a U-shaped curve in propensity to use such abstract information. In addition, animal categories are the object of much more definite domain-level expectations, which supports the notion that the animal domain is more causally integrated than the artefact domain.     

Intensity seeking and novelty seeking: Their relationship to adolescent risk behavior and occupational interests

The aim of this study was to test the hypothesis that individual differences in sensation seeking account for adolescents’ risk behavior and vocational interests. We relied on Arnett’s (1994) conceptualization of sensation seeking as involving a need for intensity and a need for novelty, neither of which includes the willingness to take risks. Self-report scales measuring intensity seeking, novelty seeking, impulsiveness, risk behavior and vocational interest were administered to 636 adolescents. New scales measuring intensity seeking (IS) and novelty seeking (NS) were used. Regression analyses showed that IS and to a lesser extent NS accounted for a small part of variance of risk behavior, independent of impulsiveness. IS and NS accounted for vocational interests. The discussion emphasizes the importance of disentangling sensation seeking as a trait from willingness to take risks when one intends to analyse the effect of the former on risk behavior.     

Tonic Activity Level in the Right Prefrontal Cortex Predicts Individuals' Risk Taking

ABSTRACT— Human risk taking is characterized by a large amount of individual heterogeneity. In this study, we applied resting-state electroencephalography, which captures stable individual differences in neural activity, before subjects performed a risk-taking task. Using a source-localization technique, we found that the baseline cortical activity in the right prefrontal cortex predicts individual risk-taking behavior. Individuals with higher baseline cortical activity in this brain area display more risk aversion than do other individuals. This finding demonstrates that neural characteristics that are stable over time can predict a highly complex behavior such as risk-taking behavior and furthermore suggests that hypoactivity in the right prefrontal cortex might serve as a dispositional indicator of lower regulatory abilities, which is expressed in greater risk-taking behavior.     

Subliminal priming of motivational orientation in educational settings: Effect on academic performance moderated by mindfulness

Recent literature indicates that a motivational orientation can be unconsciously primed. This study examined whether motivational priming influences students’ academic performance within an educational setting and whether this effect is moderated by students’ degree of mindfulness. Two randomly assigned groups of students received an identical lesson. However, the teacher’s slideshow contained different subliminal words according to the condition (autonomous vs. controlled motivation). Results demonstrated an interaction between students’ dispositional mindfulness and priming conditions. The more mindful students were immune to the manipulation whereas the less mindful students were affected by the priming: those primed with autonomous motivation obtained better results than those primed with controlled motivation. These findings contribute to priming research specifying individual differences of priming responsiveness.     

The emergence of a social representation of human rights via interpersonal communication: empirical evidence for the convergence of two theories

To test the common assumption that social representations originate in ordinary communication, ten 24-person groups of American college students exchanged messages for 2 1/2 weeks about six specific issues drawn from a 21-item questionnaire previously used by Clémence, Doise, & Lorenzi-Cioldi (1994) in a cross-cultural investigation on human rights. As expected, interpersonal communication led to increased spatial clustering (neighbors in social space became more similar) and enhanced correlations among these issues, leading to a more coherent factor structure of human rights conceptions. Clustering and correlation simultaneously illustrate the emergence of self-organization in social systems and are taken as evidence for the social origin of social representations. These findings show how Latané's Dynamic Social Impact Theory complements Moscovici's Social Representation Theory, providing a mechanism for understanding how and criteria for knowing when social representations arise from communication. © 1998 John Wiley & Sons, Ltd.     

Competing for a desired reward in the Stroop task: when attentional control is unconscious but effective versus conscious but ineffective.

Recent studies using Stroop's paradigm have shown that word recognition processes can be controlled when the local context of the task is manipulated. In the present study, factors related to the participants' broader context (i.e., presence vs. absence of a competitor and of a desired reward) were manipulated. The results (1) support the conclusion that control of semantic-level activation can be unconscious but effective versus conscious but ineffective, (2) suggest that unconscious control alone operates on line (i.e., when the participant is responding), and (3) clarify the impact of socio-contextual factors that have been confounded in past research. Taken together, these findings strengthen the view that word recognition processes are controllable and offer new reasons to pay constant attention to the social environment of cognition.