1. Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
2. Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, USA
3. Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Visual Impairment, Statped Midt, Melhus, Norway