1. Cyclotron Research Centre, University of Liège, 4000 Liège, Belgium.
2. Cognitive and Behavioral Neuroscience Centre, University of Liège, 4000 Liège, Belgium.
3. PHYSIP S.A., 75011 Paris, France.
4. Centre for Chronobiology, Psychiatric Hospital of the University of Basel, CH-4025 Basel, Switzerland.
5. Neuropsychology and Functional Neuroimaging Research Unit (UR2NF), Université Libre de Bruxelles, B-1050 Brussels, Belgium.