[1] Univ Cincinnati, Dept Psychol, POB 210376, Cincinnati, OH 45221 USA
[2] Univ Louisville, Dept Psychol & Brain Sci, Louisville, KY 40292 USA
[3] Univ Cincinnati, Gardner Neurosci Inst, Dept Neurol, 260 Stetson St,Suite 2300, Cincinnati, OH 45267 USA
[4] George Washington Univ, Med Fac Associates, Dept Neurol, 2150 Penn Ave,NW Fl 7, Washington, DC 20037 USA
[5] Univ Wisconsin, Ctr Tobacco Res & Intervent, 1930 Monroe St,Ste 200, Madison, WI 53711 USA
[6] William S Middleton Mem Vet Adm Med Ctr, 2500 Overlook Terrace, Madison, WI 53705 USA