[1] Univ Guelph, Dept Psychol, Guelph, ON N1G 2W1, Canada
[2] McMaster Childrens Hosp, Pediat Chron Pain Program, Hamilton, ON, Canada
[3] Schulich Sch Med & Dent, Childrens Hlth Res Inst, London, England
[4] Schulich Sch Med & Dent, Dept Paediat, London, England
[5] McMaster Univ, Dept Psychiat & Behav Neurosci, Hamilton, ON, Canada
[6] McMaster Univ, Dept Psychol Neurosci & Behav, Hamilton, ON, Canada