BOLD fMRI Resting State Activity and the Network of Default Mode Brain Function
Fukunaga M, van Gelderen P, Horovitz S, de Zwart J, Duyn J, Balkin T, Fulton S
National Institutes of Health
Recent BOLD fMRI studies suggest that, during rest, some brain regions increase their activity in a spatially correlated fashion. These regions have been hypothesized to constitute a network involved with so-called default mode activity, which possibly supports non goal-directed behavior and monitoring of the environment. In this study, we investigated the role of default mode activity by performing simultaneous EEG-fMRI while subjects rested and slept. The BOLD fluctuation level was maintained during sleep (stages 1-2) in most brain regions, including the default-mode network. This suggests that default mode activity does not represent conscious mentation.