1. Department of Psychology & Neuroscience; Dalhousie University, PO Box 15000 Halifax; NS B3H 4R2 Canada
2. Department of Psychology; Mount Allison University, 49A York Street; Sackville NB E4L 1C7 Canada
3. Department of Pediatrics; Dalhousie University, Autism Research Centre, IWK Health Centre, PO Box 9700; Halifax NS B3J 6R8 Canada