Joel Nigg, PhD, is director of the division of psychology and professor of psychiatry, pediatrics, and behavioral neuroscience at Oregon Health and Science University. He is the author or coauthor of two books for parents: Getting Ahead of ADHD and What Science Tells Us about Autism Spectrum Disorder.
Educated at Juilliard, Paul Costanzo brings the sensitivity and nuance of a classical music background to his twenty-five-plus years of voice acting, and AudioFile magazine has called his narration "superb."