Some theories have proposed that autistic individuals have difficulty learning predictive relationships. We tested this hypothesis using a serial reaction time task in which participants learned to predict the locations of a repeating sequence of target locations. We conducted a large-sample online study with 61 autistic and 71 neurotypical…

Twenty-eight children (ages 5-13) with mental retardation, hyperactivity, and inattentiveness were administered fenfluramine and methylphenidate. Fenfluramine was superior to placebo on the memory task, whereas methylphenidate reduced commission errors on a continuous performance test. Methylphenidate caused shorter response times whereas…