1 Department of Psychology, Georgia State University, P.O. Box 5010, Atlanta, GA, 30302-5010, USA. vdotson1@gsu.edu.
2 Gerontology Institute, Georgia State University, Atlanta, GA, USA. vdotson1@gsu.edu.
3 Division of Psychology, Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, USA.
4 Division of Brain Stimulation and Neurophysiology, Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA.