RESUMO
INTRODUCTION: After being largely neglected as a contributor to the organisation of the cognitive operations for many years, the white matter of the brain is now again the object of much research. These advances are complemented with the latest neuroimaging techniques, such as diffusion tensor imaging, which make it possible to obtain a more detailed view of the role played by the pathways of the white matter in the cognitive operations. DEVELOPMENT: The study reviews the relation between lesions in the white matter and different cognitive processes and functions such as language, attention, visuospatial and visual-constructional skills, spatial negligence, processing speed, memory and executive functions. CONCLUSIONS: Focusing attention on the white matter and its disorders promises to further our knowledge of the brain as an extraordinarily complex organ in which the connectivity and processing speed provided by the white matter are key features in cognition, emotion and consciousness itself. The white matter does not appear to be the deposit for cognitive processes and functions, but rather its role would seem to be linked to two properties that are essential for a highly complex system like the brain to be effective: speed and connectivity. Further studies must be conducted to delve deeper into these processes and perhaps begin to clarify the different roles they play in the outcome of cognitive processes.
