L'avenir de l'approche par élaboration de règles

The goal of this study is the elaboration of a computerized diagnostic instrument based on Siegler's rule-assessment approach for assessing the acquisition of the probability quantification scheme in subjects aged 6–18 years. Three versions of the test were used. Version 1 was Siegler's original version (four types of problems and four rules). In version 2 five new rules were added; version 3 contained the five new rules plus eleven types of problems. Results show that version 1 allows the classification of only 50% of subjects; version 2, 60%; and version 3, 70%. Despite improved versions, some weaknesses remain, the most important one being that it is still impossible to evaluate intra-individual variability. Aware of these limits, Siegler has reassigned his model to a local model of problem solving, and suggests a developmental model of information processing inspired by a Darwinian model of variation and strategy selection. The authors hypothesize that computer engineering could not only reaffirm the general status of the rule-assessment approach, but could also allow consideration of intra-individual variability.     

Attitude Change During College: Normative or Informational Social Influence?

Students from a small, tightly knit military college participated in a longitudinal study which assessed attitudes toward sociopolitical issues as well as military attitudes at entrance and three years later. A college-wide change in a conservative direction was predicted and observed (p < .001). While a normative influence explanation argues that peer group pressure is responsible for such attitude change, an explanation based on informational influence would argue that the knowledge communicated by faculty also plays a role. The results confirmed the existence of peer group influence on measures of military attitudes but not on measures of sociopolitical attitudes. Rather, and consistent with a process of informational influence, the academic major pursued by the students emerged as a significant predictor of change in sociopolitical attitudes, regardless of reference group identification.     

Studies in social influence: I. Those absent are in the right: Convergence and polarization of answers in the course of a social interaction

The theories of social influence assert that: a) the existing dependence on the source of influence and hence the presence of the latter, is the cause of the above changes, b) the effective qualities of the stimulus or those which are attributed to it - ambiguity, clarity and certitude, etc., - can be seen in the divergence or convergence of the estimations made on the stimulus have an independent effect from the relations which exist between this source and its target. In this research OUI aim is to question both postulates by using a very well know phenomenon. On the one hand we have shown that the style of behaviour of the source, its consistency, is sufficient to produce the desired influence. On the other hand, we have shown that if this behaviour creates a conflict of response, the subject will adopt the proposed response on the condition that he has done so of his own free will and not because of having given in under pressure. That is why an absent source of influence can be successfull; the subject has the impression of approaching it without giving in to it, while the presence of a source of influence causes the polarization, this being the only means for the subject to preserve his independence. The experimental paradigm used is the same as that of Sherif. Dozens of experiments have shown that the greater the distance between the stooge subjects and the naive subjects, the greater the tendency for response polarization. In the control situation where subjects were confronted with a constant stoodge for the entire duration of the experiment, we obtained the same results. In the experimental situation where the stooge would leave the room with a justified excuse before the end of the experiment, we have found a trend converging towards his judgements. The polarization phenomenon is therefore due to the relation between the source and the target of influence, to the meaning which is assigned to the distances of judgment rather than to the distances themselves. Moreover, the withdrawal of the source in no way diminishes its influence and so, those who are absent are sometimes right.     

Short article one's own face is hard to ignore

One's own face possesses two properties that make it prone to grab attention: It is a face, and, in addition, it is a self-referential stimulus. The question of whether the self-face is actually an especially attention-grabbing stimulus was addressed by using a face-name interference paradigm. We investigated whether interference from a flanking self-face on the processing of a target classmate's name was stronger than interference from a classmate's flanking face on the processing of one's own name as the target. In a control condition a third familiar face served as the flanker for both decisions from the participant's own name and from the classmate's name. The presentation of the self-face as a flanker produced significantly more interference on the identification of a classmate's name than the presentation of that classmate's face did on the identification of one's own name. This result was due to the interfering power of the self-face and not to a particular resistance of one's name to interfering facial stimuli. We argue that the emotional value or the high familiarity of one's own face may explain its attention-grabbing property.     

Computer supported mathematics with Ωmega

Classical automated theorem proving of today is based on ingenious search techniques to find a proof for a given theorem in very large search spaces—often in the range of several billion clauses. But in spite of many successful attempts to prove even open mathematical problems automatically, their use in everyday mathematical practice is still limited.The shift from search based methods to more abstract planning techniques however opened up a paradigm for mathematical reasoning on a computer and several systems of that kind now employ a mix of interactive, search based as well as proof planning techniques.The Ωmega system is at the core of several related and well-integrated research projects of the Ωmega research group, whose aim is to develop system support for a working mathematician as well as a software engineer when employing formal methods for quality assurance. In particular, Ωmega supports proof development at a human-oriented abstract level of proof granularity. It is a modular system with a central proof data structure and several supplementary subsystems including automated deduction and computer algebra systems. Ωmega has many characteristics in common with systems like NuPrL, CoQ, Hol, Pvs, and Isabelle. However, it differs from these systems with respect to its focus on proof planning and in that respect it is more similar to the proof planning systems Clam and λClam at Edinburgh.     

The confederate's and others' self-conversion: a neglected phenomenon

The authors analyzed a neglected phenomenon: self-conversion. Rather than concentrating on the influence exerted by a confederate on a naive participant, the authors studied how the confederate is himself or herself influenced by the position that he or she defends at the request of the experimenter. This experiment is particularly revealing with respect to a fundamental aspect of the psychology of the proselytizing of minority groups: In the process of convincing others, one also convinces oneself. Exerting influence on others thus leads to self-conversion, which allows the group to reinforce its beliefs and to stand up to conformity pressures.     

Aging affects both perceptual and lexical/semantic components of word stem priming: An event-related fMRI study

In this event-related fMRI study, brain activity patterns were compared in extensive groups of young (N=25) and older (N=38) adults, while they were performing a word stem completion priming task. Based on behavioral findings, we tested the hypothesis that aging affects only the lexical/semantic, but not the perceptual component of word stem priming. To this end, we distinguished between priming-related activity reductions in posterior regions involved in visual processing, and regions associated with lexical/semantic retrieval processes, i.e., left lateral temporal and left prefrontal regions. Both groups revealed significant priming-related response time reductions. However, in accordance with earlier findings, a larger priming effect was found in the group of young participants. In line with previous imaging studies, the groups showed common priming-related activity reductions in the anterior cingulate, and the left inferior prefrontal cortex extending into the anterior portion of the left superior temporal gyrus, and at lower thresholds also in the right occipital lobe. However, when directly comparing the groups, greater priming-related reductions were found for the young group in the left anterior superior temporal gyrus and the right posterior occipital lobe. These findings suggest that, converse to current psychological views, aging affects both perceptual and lexical/semantic components of repetition priming.     

Social dominance and anti-immigrant prejudice: A cross-national and prospective test of the mediating role of assimilation,multiculturalism, colour blindness,and interculturalism

Decades of research have shown that social dominance orientation (SDO) is one of the most important predictors of anti-immigrant attitudes. However, the mechanisms through which SDO can explain prejudice have been studied insufficiently. Using rich and diverse samples from France and from the province of Québec in Canada, the present research provides a cross-national (N = 1,852) and prospective (N = 534) analysis of a theoretical model in which the dimensions of SDO are indirectly predicting anti-immigrant prejudice via the intergroup ideologies of assimilation, multiculturalism, colour blindness and interculturalism. Results showed that interculturalism, a hierarchy-attenuating ideology was found to be a robust mechanism to explain the subtle effects of SDO-E on anti-immigrant prejudice whereas assimilation, a hierarchy-enhancing ideology was playing a more important role to explain direct and blatant effects of SDO-D on prejudice. The two most studied diversity approaches, multiculturalism and colour blindness, were largely redundant once interculturalism was considered. This pattern occurred in both France and Québec hence, favouring the context-independent pathway.     

Increase in Syntaxin 1B mRNA in Hippocampal and Cortical Circuits During Spatial Learning Reflects a Mechanism of Trans-synaptic Plasticity Involved in Establishing a Memory Trace

It has long been proposed that the cellular and molecular mechanisms responsible for LTP may well involve the mechanisms that lead to the type of synaptic modification that occurs during learning. However, it is also known that a single memory trace is encoded in spatially distributed networks; implying that alterations of synaptic strength occur at multiple sites along circuits of connected cells. Recent evidence suggests that regulation of the gene encoding syntaxin 1B, a presynaptic protein involved in exocytosis, plays an important role in the mediation of trans-synaptic LTP, a candidate mechanism for the propagation of plasticity in neural circuits during learning. Using in situ hybridization to measure the mRNA levels at different time points after learning a spatial working or reference memory task, we show that expression of the gene encoding this protein in the hippocampal and corticoprefrontal circuits increases linearly with performance at a critical window of learning when rats are reaching between 75% and 100% of their maximal performance. No changes were observed during the early phases of learning or when rats where overtrained. The correlational analysis indicates that coordinated increases in syntaxin 1B expression occurs in hippocampal circuits during working memory and in more widespread hippocampocortical circuits during reference memory. These results suggest that a form of trans-synaptic plasticity mediated in part by regulation of the expression of syntaxin 1B may play an active role in configuring specific spatially distributed circuits during the laying down of memories.