Circuitry underlying temporally extended spatial working memory.
Extended maintenance delays decrease the accuracy of information stored in spatial working memory. In order to elucidate the network underlying sustained spatial working memory, 16 subjects were scanned using fast event-related fMRI as they performed an oculomotor delayed response task containing trials with "short" (2.5 s) or "long" (10 s) delay periods. Multiple cortical and subcortical regions were common to both delay trial types indicating core task regions. Three patterns of activity were found in a subset of core regions that reflect underlying processes: maintenance-related (e.g., left FEF, right supramarginal gyrus (SMG)), response planning-related (e.g., right FEF, SEF), and motor response-related (e.g., lateral cerebellum (declive)) activation. Several regions were more active during long than short delay trials, including multiple sites in DLPFC (BA 9, 46), indicating a circuitry dynamically recruited to support sustained working memory. Our results suggest that specialized brain processes support extended periods of working memory.
Geier
Charles F
CF
Laboratory of Neurocognitive Development, Department of Psychology, and the Center for the Neural Basis of Cognition University of Pittsburgh, Pittsburgh, PA 15213, USA. geiercf@upmc.edu
Garver
Krista E
KE
Luna
Beatriz
B
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D013647:Task Performance and Analysis; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology