1. Department of Physiology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
2. Department of Psychiatry, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
3. Department of Psychiatry, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
4. Neurology Unit, Teaching Hospital Anuradhapura, Anuradhapura, Sri Lanka
5. Department of Physiology, Faculty of Medicine, University of Peradeniya, Peradeniya, Sri Lanka
6. School of Psychological Sciences, The University of Newcastle, Callaghan, NSW, Australia