title: Motor preparation, motor execution, attention, and executive functions in attention deficit/hyperactivity disorder (ADHD).
abstract: Attention and executive functions were investigated in medicated and unmedicated children with ADHD combined type using a novel selective reaching task. This task involved responding as rapidly as possible to a target while at times having to ignore a distractor. Results indicated that unmedicated children with ADHD showed slow and inaccurate responding. Slow responding reflected problems at the stage of movement preparation but not movement execution. An attentional impairment, rather than a motor planning problem per se, appeared to underlie the slow movement preparation. Inaccurate responding reflected problems with response inhibition and selective attention, impulsivity, set-shifting, and difficulties in maintaining vigilance. Although medicated children with ADHD did not show slow movement preparation, they did show some response inaccuracy, resulting especially from impulsive responding. These findings suggest that ADHD is characterized by slow motor preparation (but not motor execution), and deficits in selective attention, vigilance, and executive functions. Preliminary results suggest that stimulant medication may resolve some of these motor, attentional and executive function deficits.
authors.affiliation: School of Psychology, Psychiatry, and Psychological Medicine, Monash University, Clayton, Victoria, 3800, Australia. Ester.Klimkeit@med.monash.edu.au
authors.forename: Ester I
authors.initials: EI
authors.lastname: Klimkeit
authors.forename: Jason B
authors.initials: JB
authors.lastname: Mattingley
authors.forename: Dianne M
authors.initials: DM
authors.lastname: Sheppard
authors.forename: Paul
authors.initials: P
authors.lastname: Lee
authors.forename: John L
authors.initials: JL
authors.lastname: Bradshaw
mesh_terms: D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000453:epidemiology*; D002648:Child; D015897:Comorbidity; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007806:Language Disorders / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D019957:Motor Skills Disorders / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D011930:Reaction Time