Spatio-temporal decorrelated activity patterns in functional MRI data during real and imagined motor tasks

We present a new method for separating multiple task-related events from other physiological and physical events revealed by functional magnetic resonance imaging (fMRI) signals. The method separates fMRI signals into different events by minimizing the spatial and temporal correlations between events. The method was used to analyze fMRI data sets from subjects performing real and imagined motor tasks. The method successfully separated task-related events (e.g, the activation in primary motor cortex during real motion and in supplementary motor area during imagined motion) from unrelated events (e.g., an activation in auditory area and slow changes probably associated with head drifts). (C) 2002 Elsevier Science B.V. All rights reserved.