The Shift from Local to Global Visual Processing in 6-Year-Old Children Is Associated with Grey Matter Loss

International audienceBackground: A real-world visual scene consists of local elements (e.g. trees) that are arranged coherently into a global configuration (e.g. a forest). Children show psychological evolution from a preference for local visual information to an adult-like preference for global visual information, with the transition in visual preference occurring around 6 years of age. The brain regions involved in this shift in visual preference have not been described. Methods and Results: We used voxel-based morphometry (VBM) to study children during this developmental window to investigate changes in gray matter that underlie the shift from a bias for local to global visual information. Six-year-old children were assigned to groups according to their judgment on a global/local task. The first group included children who still presented with local visual processing biases, and the second group included children who showed global visual processing biases. VBM results indicated that compared to children with local visual processing biases, children with global visual processing biases had a loss of gray matter in the right occipital and parietal visuospatial areas. Conclusions: These anatomical findings are in agreement with previous findings in children with neurodevelopmental disorders and represent the first structural identification of brain regions that allow healthy children to develop a global perception of the visual world

Etude de l'invariance d'une relation spatiale chez les bébés de 4 à 9 mois : être entre deux objets

Summary : How do 5 to 9 month-old infants master the invariant « to be in between » ? Two experiments investigated the child's apprehension of the spatial relationship, « an object is between two other objects », and their detection of the invariance of this relationship over displacements of the objects. 57 infants, aged 4 to 9 months, were presented with objects undergoing three types of movement : two rotations in the horizontal plane (180° and 90°) and a rotation in the vertical plane. These movements were visible in one experiment and invisible in the second one. Only the central object was moveable, and the infants were expected to look at and to grasp that object after the display was moved. The results show that the infants tended to look at the central object, even when they did not grasp it or grasped a different object. Performance varied as a function of conditions, the easiest condition being the 180° rotation, the 90° one being always the most difficult. It is concluded that infants as young as 5 month master the invariant « to be in between » whether the display is visible or not when moved. Key words : spatial invariant, in between relationship, sensori-motor coordination.Résumé Le but de ces deux expériences est l'étude d'une relation spatiale « un objet est situé au milieu de deux autres » et de l'invariance de cette relation après le déplacement des objets. 57 bébés âgés de 4 à 9 mois ont participé aux deux recherches. On procède à trois types de déplacements : une translation de 180°, de 90° et une rotation dans le plan vertical. La tâche de l'enfant est le repérage visuo-moteur de l'objet central après déplacement. Les résultats montrent que le repérage visuel de l'objet central s'effectue bien, même si le bébé ne prend pas d'objet ou en prend un autre. Les performances varient en fonction des situations, la translation de 180° est la mieux réussie, celle de 90° est toujours la plus difficile. Que l'objet soit visible ou non pendant le déplacement, le bébé possède l'invariant « être au milieu de » dès 4 mois. Mots clés : invariant spatial, relation entre deux objets, coordination sensorimotrice.Pineau Arlette, Streri Arlette. Etude de l'invariance d'une relation spatiale chez les bébés de 4 à 9 mois : être entre deux objets. In: L'année psychologique. 1985 vol. 85, n°4. pp. 489-502

Acquisition de la notion de « pareil-pas pareil » chez l'enfant d'âge préscolaire

Summary : Acquiring the concept « same-not same » in pre-school children. In the present experiment, we wished to find out whether a suitably-devised learning program could help to accelerate in pre-school children, the capacity to discriminate between « same » and « not same » in a manner which would imply some understanding of the concept of identity, as the term is usually used in normal adult logical thinking. The experiment was carried out wiih 2 matched groups of 23 subjects of 5;9 years. There are 3 stages in the experiment : pre-testing, the intermediate stage, and post-testing. The intermediate stage consists either of 10 learning sessions for the experimental group, or 10 game-playing sessions in the case of the control group. In the post test, subjects in experimental group show a significantly higher percentage of accurate responses than those in the control group. The results confirm that learning can improve the quality of judgement about identity. Key words : learning, identity, pre-school children.Résumé Cette expérience a pour but de montrer que grâce à un apprentissage adéquat, on peut accélérer chez l'enfant préscolaire la capacité à utiliser le concept de « pareil - pas pareil » dans son acception logique, c'est-à-dire tel qu'il est normalement défini par l'adulte. Cette expérience a été réalisée sur 2 groupes appariés de 23 enfants âgés de 5;9 ans. Elle comporte 3 phases : un pré-test, une phase intermédiaire, et un post-test. La phase intermédiaire comprend 10 séances d'apprentissage pour le groupe expérimental et 10 séances de jeux pour le groupe contrôle. Au post-test, les enfants du groupe expérimental ont un pourcentage de bonnes réponses significativement supérieur à celui du groupe contrôle. Les résultats confirment que l'apprentissage contribue à améliorer la-qualité des jugements d'identité. Mots clés : apprentissage, identité, âge préscolaire.Pineau Arlette, Beaufils François. Acquisition de la notion de « pareil-pas pareil » chez l'enfant d'âge préscolaire. In: L'année psychologique. 1988 vol. 88, n°3. pp. 343-358

Seeing the Forest Before the Trees Depends on Individual Field-Dependency Characteristics

Numerous studies have demonstrated that the well-known global precedence effect, characterized by a visual bias toward global information, is highly dependent on stimulus characteristics ( Kimchi, 1992 ). Despite the extensive global-local literature, few studies have investigated how interindividual characteristics could affect the global precedence effect. In this framework, we studied the relationship between global-local visual biases and the Group Embedded Figure Test (GEFT), a standardized measure of field dependency. Data from 34 participants were consistent with the idea that an individual’s bias toward the global level is linearly related to his or her degree of field dependence. Given the important role that global-local visual skills play during visuospatial tasks, these results have important implications for future research in this area