La définition clinique des troubles schizophréniques a toujours accordé une place fondamentale á ce qui, d'un modèle psychologique á l'autre, a été diversement nommé : troubles des associations de la pensée, troubles du langage, troubles dans la théorie de l'esprit, troubles de la communication et plus récemment, troubles des interactions sociales. Les mécanismes cognitifs sous-tendant ces anomalies de la communication ou des interactions sociales ont fait l'objet des recherches de notre équipe depuis plus de 20 ans. Nos travaux ont suivi les avancées en psychologie cognitive puis dans les techniques de neuroimagerie fonctionnelle (technique des potentiels évoqués cognitifs, PET Scan et, plus récemment Magnétoencéphalographie cérébrale) pour préciser les processus spécifiquement atteints chez les schizophrènes et proposer des instruments cliniques d'évaluation plus spécifiques et des techniques de remédiation de ces processus. L'ensemble des données obtenues va dans le sens d'un déficit princeps, le déficit du traitement des indices contextuels chez les patients schizophrènes. Ce déficit explique le trouble de la lecture intentionnelle du sujet mis en situation d'interaction sociale. Selon le modèle de Sperber et Wilson, le sujet va sélectionner, sur la base du traitement des indices contextuels, l'interprétation la plus plausible parmi l'ensemble des hypothèses sur l'intention communicative de l'autre qui peuvent être générées en situation interactive. Une meilleure connaissance de ces mécanismes a permis de répondre á deux des enjeux majeurs de toute recherche médicale - construire une nouvelle clinique, dite cognitive, permettant de construire des instruments diagnostiques spécifiques de cette pathologie - innover en matière thérapeutique en proposant de nouvelles techniques ciblant et remédiant aux déficits cognitifs ainsi définis. The clinical description of schizophrenic disorders always recognized a fundamental role to a set of impairments that received different designation given their respective psychological frameworks: thought association disorders, impairments of basic language processes and of the access to meaning, contextual processing impairment, deficits of theory-of-mind, of intentional consciousness, and more recently, social interaction impairments. This clinical dimension is thought to be highly specific of this clinical population, and, consequently, is essential to define specific phenotypes. Moreover, this dimension should constitute a therapeutic target. The cognitive mechanisms underpinning communication or social interaction disorders have been the aim of our researches for more than 20 years. We believe that a better understanding of those mechanisms should answer two major challenges of medical research: • The design of a new "cognitive clinical framework" and of diagnostic tools that will be specific of the illness; • The conception of innovative therapeutic procedures based on remediation of specific cognitive deficits. Our work followed the advances in cognitive psychology by delineating the processes specifically impaired in schizophrenic patients and by describing a dedicated remediation technique. Our first results, using lexical decision with semantic priming, confirmed a specific impairment of controlled processes and the preservation of automatic activation in those patients. As expected, those abnormalities exhibited correlation with formal thought disorders. These inaugural results raised both methodological and theoretical issues. Which methods should be used to overcome the limits of behavioral measures in order to determine the very nature of the "impaired controlled processes"? What were the relations between the impairments of elementary cognitive processes and the deficits postulated by Christopher Frith that encompassed high-level cognition (metarepresentation) and theory-of-mind? To answer this question, we derived an original comic-strip paradigm from Frith's model, which allowed to test the attribution of intentions to others. Furthermore, we used brain cartography techniques (event related potentials, positron emission tomography, and more recently, magneto-encephalography) to confirm our hypothesis. Data obtained from these researches are in line with the hypothesis of a primary deficit of contextual processing in schizophrenia. In accordance with Sperber and Wilson's cognitive anthropological model, this deficit may account for the impairment of the attribution of intentions to others that occurs during social interaction. Indeed, this model states that individuals select the most plausible interpretation among several hypotheses on other's communicative intentions, by taking into account contextual cues. Acquired knowledge on the cognitive processes involved during social interactions allowed us: 1. To elaborate an evaluation of the postulated abnormalities. The design of this tool, the SCD, relies on a clinical definition of the consequences of schizophrenic cognitive failures, and, consequently, exemplifies the notion of "cognitive clinical assessment". 2. To elaborate a cognitive remediation method targeting the attribution of intentions to others. Learning procedures aims at improving the generation of hypotheses on others' intentions and the selection of the best hypothesis by taking into account contextual cues. The ecological material consists of short video excerpts of French movies that depict intentional social exchanges. Our current researchs aims at determining more precisely the neurocognitive patterns of schizophrenic patients and at following their evolution with time and major therapeutic events. Moreover, within the scope of the Réseau Thématique de Recherches et de Soins, directed by Pr. Marion Leboyer, we wish to develop genetic and pharmacological observations in order to extend our theoretical framework, and to provide genetic researches on schizophrenia with innovative and specific clinical assessment tools, phenotypes and endophenotype. Origine SPI-EAO CERIMES Canal-U Santé et Sport Générique Auteur: Marie-Christine Hardy-Baylé Professeur, Chef du service de Psychiatrie Centre Hospitalier de Versailles Directeur de l'unité de Recherche Mixte Inserm ERI 15 / EA 4047.
Mot(s) clés libre(s) : Collège de France, communication, interactions sociales, langage, psychiatrie, schizophrénie