Characterization of the Effects of Task-Correlated Facial and Head Movements in FMRI

Jeremy F. Magland¹, Anna Rose Childress²

It is generally assumed that facial movements occur randomly throughout the fMRI scan. However, since humans use facial movements to express emotion, task-correlated movement cannot be ruled out. Eight healthy volunteers were instructed to move systematically during fMRI examinations, with various types of movements of the eyes (open/close, squint), face (smile/frown, clench jaw), and body. Standard fMRI analyses were performed to identify false activations. The facial movements resulted in several brain regions having high statistical significance. Jaw clenching yielded the characteristic false activation in the region surrounding the temporal muscles. These data may be used to characterize the potential confounding effects of systematic movements during an fMRI exam.