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

Nicolas Poirel,Céline Lanoë,Guy Perchey,Gaëlle Leroux,Mathieu Cassotti,Arlette Pineau,Olivier Houdé,Marie-Renée Turbelin,Sandrine Rossi,Grégory Simon,Amélie Lubin

doi:10.1371/journal.pone.0020879

Abstract

BackgroundA 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 ResultsWe 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.ConclusionsThese 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.

Highlights

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
Recent evidences from magnetic resonance imaging (MRI) show that human brain development is characterized by nonlinear dynamic loss of gray mater (GM) with age that varies according to brain region [1,2]
The contrast analysis between the two groups revealed that compared to the local bias group, the global bias group showed losses in GM in the occipital cortex, along the right part of the calcarine sulcus, the right inferior occipital gyrus extending to the middle occipital gyrus, and the lingual gyri (Fig. 2)

Summary

Introduction

Recent evidences from magnetic resonance imaging (MRI) show that human brain development is characterized by nonlinear dynamic loss of gray mater (GM) with age that varies according to brain region [1,2]. Adult patients with right hemisphere injuries show impaired processing of global level information, whereas patients with left hemisphere injuries present with deficits in processing local elements [10,11]. These observations have been confirmed using functional imaging in healthy adults [12,13] and in 14-year-olds [14]. The authors noted that all of the children showed improved performance in terms of visual perception as they got older, the deficit pattern persisted for both groups These studies revealed important information about the relationships between brain lesions and visuospatial development. The brain regions involved in this shift in visual preference have not been described

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Conclusion