[1] Univ Georgia, Dept Psychol, Athens, GA 30602 USA
[2] Loyola Univ, Chicago, IL 60611 USA
[3] Childrens Hosp, Dept Anesthesiol Perioperat & Pain Med, Div Pain Med, Boston, MA 02115 USA
[4] Harvard Univ, Sch Med, Dept Psychiat, Boston, MA 02115 USA
[5] Emory Univ, Childrens Healthcare Atlanta, Atlanta, GA 30322 USA