[1] Univ Massachusetts, Dept Psychol, Amherst, MA 01003 USA
[2] Univ Alabama, Coll Commun & Informat Sci, Tuscaloosa, AL 35487 USA
[3] Kansas State Univ, Sch Family Studies & Human Serv, Manhattan, KS 66506 USA
[4] Harvard Univ, Sch Med, Dept Pediat, Ctr Media & Child Hlth, Cambridge, MA 02138 USA
[5] Harvard Univ, Sch Med, Dept Neurol, Cambridge, MA 02138 USA
[6] Harvard Univ, Sch Med, Dept Radiol, Cambridge, MA 02138 USA
[7] Univ Alabama, Dept Psychol, Tuscaloosa, AL 35487 USA