William Rand Kenan Professor Emeritus, Department of Psychology & Neuroscience, University of North Carolina @ Chapel Hill, Chapel Hill, NC, USA

Linda Dykstra

Chauncey Leake Distinguished Professor of Pharmacology & Toxicology and Psychiatry & Behavioral Sciences and Director, Center for Addiction Sciences and Therapeutics, John Sealy School of Medicine at the University of Texas Medical Branch, Galveston, TX, USA

Kathryn Cunningham

Correspondence to Linda Dykstra.