1. From the Wellcome Trust Centre for Neuroimaging, Institute of Neurology, London, United Kingdom;
2. the McGill Vision Research Unit, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada;
3. the CUBRIC (Cardiff University Brain Research Imaging Center), School of Psychology, Cardiff University, Cardiff, United Kingdom; and
4. the Helmholtz Institute, Experimental Psychology, Utrecht University, Utrecht, The Netherlands.