CORTICAL METABOLIC-ACTIVATION IN HUMANS DURING A VISUAL MEMORY TASK

A delayed match-to-sample (DMS) task of abstract, visual memory was pe rformed during the uptake period of F-18-fluorodeoxyglucose. The incre ase in glucose uptake of cortical and subcortical regions (''activatio n'') during the DMS task was compared with that during a control, imme diate match-to-sample task using positron emission tomography. Both di scriminant analysis and paired t tests supported the observation that the dorsolateral prefrontal area underwent the greatest activation, wh ile a factor analysis revealed the functional correlation matrices of the tasks, Activations in the ventral premotor cortex and supramargina l and angular gyri were highly correlated with the change in the dorso lateral prefrontal cortex, The basal forebrain/ventral pole region sho wed a smaller but independently significant change, The findings suppo rt the role of the dorsal prefrontal region in the nonspatial working memory of humans.