Relationship between fMRI Signals in the Resting-State (R-fMRI) & Task (T-fMRI)

Sridhar Kannurpatti¹, Bart Rypma², Bharat Biswal¹

We test the hypothesis that functional Magnetic Resonance Imaging (fMRI) blood oxygenation (BOLD) activity generated during the resting state (R-fMRI) and task-induced states (T-fMRI)originate from a common system. In other words, the activity is equivalent and independent of whether the subject performs a task or remains at rest in the MRI scanner. Using healthy human subjects for the study, we obtained linear relationships between resting signal and task-induced signal amplitudes (defined as the R-T relationship) on a voxel-wise basis and across subjects. Such a result reflects the resting- and task-induced BOLD-fMRI responses to arise from a common system.