title: Motor persistence and inhibition in autism and ADHD.
abstract: The present study compared performance of children with Attention-Deficit/Hyperactivity Disorder (ADHD) and high functioning autism (HFA) with that of controls on 4 tasks assessing 2 components of motor control: motor response inhibition and motor persistence. A total of 136 children (52 ADHD, 24 HFA, 60 controls) ages 7 to 13 years completed 2 measures of motor inhibition (Conflicting Motor Response and Contralateral Motor Response Tasks) and 2 measures of motor persistence (Lateral Gaze Fixation and NEPSY Statue). After controlling for age, IQ, gender, and basic motor speed, children with ADHD performed significantly more poorly than controls on the Conflicting Motor Response and Contralateral Motor Response Tasks, as well as on Statue. In contrast, children with HFA achieved lower scores than controls only on measures of motor persistence, with no concomitant impairment on either motor inhibition task. These results are consistent with prior research that has demonstrated relatively spared motor inhibition in autism. The findings highlight the utility of brief assessments of motor control in delineating the unique neurobehavioral phenotypes of ADHD and HFA.
authors.affiliation: Kennedy Krieger Institute and Johns Hopkins University School of Medicine, 1750 East Fairmount Avenue, Baltimore, MD 21231, USA. mahone@kennedykrieger.org
authors.forename: E Mark
authors.initials: EM
authors.lastname: Mahone
authors.forename: Stephanie K
authors.initials: SK
authors.lastname: Powell
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Loftis
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Goldberg
authors.forename: Martha B
authors.initials: MB
authors.lastname: Denckla
authors.forename: Stewart H
authors.initials: SH
authors.lastname: Mostofsky
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D001321:Autistic Disorder / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology