1. Clinical and Developmental Neuropsychology, University of Groningen, Groningen, Netherlands
2. Centre of Expertise for blind and partially sighted people, Royal Dutch Visio, Huizen, Netherlands
3. Department of Neurology, University of Groningen, University Medical Centre Groningen, Groningen, Netherlands
4. MS Centrum Noord Nederland, Groningen, Netherlands
5. Department of Neurology, Martini Hospital Groningen, Groningen, Netherlands