1. Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen, the Netherlands
2. Royal Dutch Visio, Centre of Expertise for Blind and Partially Sighted People, Huizen, the Netherlands
3. Department of General Practice and Elderly Care Medicine, University Medical Center Groningen, Groningen, the Netherlands
4. Department of Neurology, Martini Ziekenhuis Groningen, Groningen, the Netherlands
5. Department of Neurology, University of Groningen, University Medical Centre Groningen, Groningen, the Netherlands