Although regional brain abnormalities underlying spatial working memory (SWM) deficits in schizophrenia have been identified, little is known about which brain circuits are functionally disrupted in the SWM network in schizophrenia. We investigated SWM-related interregional functional connectivity in schizophrenia using functional magnetic resonance imaging (fMRI) data collected during a memory task that required analysis of spatial information in object structure. Twelve schizophrenia patients and 11 normal control subjects participated. Patients had SWM performance deficits and deficient neural activation in various brain areas, especially in the high SWM load condition. Examination of the covariation of regional brain activations elicited by the SWM task revealed evidence of functional disconnection between prefrontal and posterior visual association areas in schizophrenia. Under low SMW load, we found reduced functional associations between dorsolateral prefrontal cortex (DLPFC) and inferior temporal cortex (ITC) in the right hemisphere in patients. Under high SWM load, we found evidence for further functional disconnection in patients, including additional reduced functional associations between left DLPFC and right visual areas, including the posterior parietal cortex (PPC), fusiform gyrus, and V1, as well as between right inferior frontal cortex and right PPC. Greater prefrontal-posterior cortical functional connectivity was associated with better SWM performance in controls, but not in patients. These results suggest that prefrontal-posterior functional connectivity associated with the maintenance and control of visual information is central to SWM, and that disruption of this functional network underlies SWM deficits in schizophrenia.
|Original language||English (US)|
|Number of pages||12|
|State||Published - Aug 2011|
Bibliographical noteFunding Information:
This work was supported by Grants from the National Institutes of Mental Health ( 5R24MH069675 and RO1MH77779 ), and by Grants from the Department of Veterans Affairs Medical Research Service to Dr. Scott Sponheim, as well as by the Mental Health Patient Service Line at the Veterans Affairs Medical Center , Minneapolis, Minnesota. We are grateful to the participants and also for the efforts of Rachel Force, John J. Stanwyck, Amy Silberschmidt, JoAn Laes, and James N. Porter.
- Controlled visual processing
- Functional connectivity
- Spatial working memory