An fMRI-Compatible Writing Device For Investigating the Neural Substrates of Drawing, Copying and Tracing

R. Mraz, S. Ferber, N. Baker, S. J. Graham Imaging Research, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario, Canada, Department of Psychology, University of Toronto, Toronto, Ontario, Canada, Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada Introduction Copying or drawing tasks enjoy popularity in clinical settings because they are easy to administer in a bedside context and they reveal constructional apraxia (inability to assemble the elements of a model object in their correct spatial relationships) in a simple and straightforward way. Constructional skills rely on visuospatial and executive functions and are thus required by many everyday activities. Furthermore, drawing a concrete object is a uniquely human skill which cannot be performed by other primates. Only recently, researchers began to unravel the neural correlates of this mental faculty. In contrast to lesion studies which demonstrated that constructional apraxia is associated with unilateral lesions to either the left or the right parietal lobe, functional brain imaging studies showed a network of mostly bilateral fronto-parietal activation patterns [1,2]. However, all of the previous fMRI studies required subjects to perform the drawing task in a rather unnatural way: subjects were not holding a pen in their hand and they did not receive any visual feedback about their performance. Here we employed a new paradigm which enabled subjects to perform drawing tasks during fMRI in a natural way allowing, for proprioceptive and visual feedback.