Spatial attention refers to a family of cognitive processes which allow us to interact efficiently with our environment, by selecting relevant stimuli and inhibiting distractors. Unilateral spatial neglect (USN) is a dramatic neurological condition resulting from damage to the right hemipshere of the human brain. USN is mainly characterized by a severe lack of attention for left, contralesional stimuli. This thesis uses USN to demonstrate that a normal distribution of spatial attention needs unimpaired pathways linking the parietal to the frontal lobe. The second part of this thesis deals with the connectional anatomy of long-range brain pathways, the relevance of the study of these pathways to cognitive neuroscience (hodological approach), and the consequences of white-matter disconnections in neurological syndromes.
