Motor Tasks

Head motion is a fiequent problem in functional magnetic resonance imaging (fMRI) studies due to long expriment times, srnail signal changes associated with brain activation, and head motion produced by behavioural tasks. Current rnethods to minimize and correct for head movement do not completely solve the problem, particularly for specific patient populations. Head motion characteristics of stroke subjects, age-matched controls and young adults were investigated using an MR simuIator and a highly accurate position tracking system. It was found that head motion strongly depended upon the subject group and less upon the task conditions. The stroke subjects exhibited approximately twice the head motion compared to that of the age-matched controls. The latter's head motion was about twice that of the young adults. The dominant translational and rotationai directions of head motion were superior-inferior and pitch (nodding), respectively. This work has important implications for improving the quaiity of fMRI.