Analyse d'une Sepreuve d'image mentale chez des adolescents presentant des difficultis d'apprentissage scolaire1

Le travail faisant l'objet de cet article s'inscrit dans le cadre d'un programme de recherche plus large qui s'intéresse à la variabilité individuelle des processus cognitifs et à son influence éventuelle sur les lois générates du développement de l'intelligence. Une partie des résultats a déjàété présentée dans d'autres publications auxquelles le lecteur pourra se référer pour plus de détails (par exemple, Rieben et al., 1983). Nous nous contenterons de les décrire brièvement afin d'introduire l'aspect spécifique sur lequel nous nous sommes centrées ici.     

Temporal integration of spatially filtered visual images.

Factors which govern the temporal integration of spatial information were examined in a group of five experiments. A series of high-pass and low-pass spatially filtered versions of a visual scene were generated. Observers' ratings of these filtered versions of the scene for perceived image quality indicated that quality was determined both by the bandwidth of spatial information and the presence of high-spatial-frequency edge information. When sequences of three different versions of the scene were presented over an interval of 120 ms the perceived quality of the resulting composite image was determined both from the ratings of the individual components of that sequence and from the order in which these components were presented. When the order of spatial information in a sequence moved from coarse to fine detail the perceived quality of the composite image was significantly better than when the order moved from fine to coarse. This evidence of a coarse-to-fine bias in pattern integration was further investigated with a detection paradigm. The pattern of errors once again indicated that temporal integration of spatial information was superior when a coarse-to-fine mode of information delivery was employed. Taken together the data indicate that the pattern-integration mechanism has an inherent order bias and does not accumulate spatial information so efficiently when the 'natural' coarse-to-fine order is violated.