Do we need the "lateral" in unilateral neglect? Spatially nonselective attention deficits in unilateral neglect and their implications for rehabilitation.

This paper reviews evidence that the spatial imbalance of attention by which unilateral neglect is often defined is a necessary but not sufficient factor in the persistence of this disorder. A second, nonspatially lateralized loss of attentional capacity is required to coexist with the spatial bias for the disorder to persist in a clinically significant way, it is argued. To this end, I first review evidence from visual and auditory attention studies to show that unilateral neglect is very strongly associated with a fundamental loss of attentional capacity that is not confined to one region of space. Second, I attempt to characterize the nature of this attentional capacity in relation in particular to functional brain imaging studies of attention. Third, I demonstrate that the spatial imbalance in neglect can be reduced by manipulations of the nonlateralized attentional capacity and finish by reviewing the rehabilitation implications of these manipulations. Copyright 2001 Academic Press.