||Functional topography of a distributed neural system for spatial and nonspatial information maintenance in working memory.
Investigated the degree to which the distributed and overlapping patterns of activity for working memory (WM) maintenance of objects and spatial locations are functionally dissociable among 18-45 yr old subjects. The patterns of response during WM tasks for face identity, house identity, and spatial location were compared using functional magnetic resonance imaging (fMRI). Independence of the neural resources available for spatial and object WM was tested behaviorally using a dual-task paradigm. Results suggest that the mechanisms for the maintenance of house identity information are distributed and overlapping with those that maintain spatial location information, while the mechanisms for maintenance of face identity information are relatively more independent. A consistent functional topography was found that results in superior prefrontal cortex producing the greatest response during spatial WM tasks, and middle and inferior prefrontal cortices producing their greatest responses during object WM tasks, independent of the object type. It is concluded that these results argue for a dorsal-ventral functional organization for spatial and nonspatial information. (PsycINFO Database Record (c) 2009 APA, all rights reserved)