1. Mouse Imaging Centre, Hospital for Sick Children, 25 Orde Street, Toronto, Ontario, Canada
2. Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
3. Department of Psychology, McGill University, Montreal, Quebec, Canada
4. Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
5. Department of Psychology, University of Alabama, Birmingham, Alabama, USA