On the cover of “Drawing Autism” (Akashic) by Jill Mullin is a colorful drawing that features 397 species of birds. The artist, David Barth, 10 years old when he created it, knows the names of most of them. Like many people with autism spectrum disorder (ASD), he has obsessions. Drawing helps him quiet his mind. Mullin, a behavior analyst, brings together fascinating works by 40 artists on the spectrum with their answers to her questions about their process. Temple Grandin, in her foreword, calls on parents and everyone who works with individuals on the spectrum to help them develop their visual talents.