title: Blink rate and blink timing in children with ADHD and the influence of stimulant medication.
abstract: Spontaneous eye blink rate is modulated by task demands and internal state, and is demonstrated to reflect central dopamine activity. Also, spontaneous eye blinks are strategically timed around salient stimuli. This study investigates whether children with attention deficit hyperactivity disorder (ADHD) show reduced blink rates, blink modulation and blink timing, and whether this is influenced by stimulant medication. The electrooculogram was measured in 18 typically developing children, 16 children with ADHD off methylphenidate (Mph), and 16 children with ADHD on Mph during a rest period and during performance of a 60-min visual selective attention task. Blink rate and timing was extracted from the electrooculogram. No evidence was found for aberrant blink rate or blink modulation in children with ADHD off Mph. All groups increased blink rates from rest to task, and no group differences were found in blink rate during rest and task, or in the modulation of blink rate from rest to task. Time-on task resulted in a similar increase in blink rates in all three groups. Stimulant medication appeared not to influence blink rate and blink modulation, except that in the ADHD off Mph group the blink rate was enhanced only under conditions with performance feedback. All groups inhibited blinks before stimulus presentation and strategically timed their blinks after the stimulus. Children with ADHD off Mph showed reduced blink inhibition before the stimulus; however, given the low incidence (<1 % of the trials) and long latency this is not likely to impair their visual intake.
authors.affiliation: Department of Clinical and Developmental Neuropsychology, Faculty of Behavioural and Social Sciences, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands. y.groen@rug.nl.
authors.forename: Y
authors.initials: Y
authors.lastname: Groen
authors.affiliation: Department of Clinical and Developmental Neuropsychology, Faculty of Behavioural and Social Sciences, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands.
authors.forename: N A
authors.initials: NA
authors.lastname: Börger
authors.affiliation: Department of Clinical and Developmental Neuropsychology, Faculty of Behavioural and Social Sciences, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Koerts
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Rostock, Gehlsheimer Straße 20, 18147, Rostock, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Thome
authors.affiliation: Department of Clinical and Developmental Neuropsychology, Faculty of Behavioural and Social Sciences, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands.
authors.forename: O
authors.initials: O
authors.lastname: Tucha
mesh_terms: D000704:Analysis of Variance; D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000503:physiopathology*; D001767:Blinking / Q000187:drug effects* / Q000502:physiology; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D004585:Electrooculography; D030141:Feedback, Psychological; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D009483:Neuropsychological Tests; D011930:Reaction Time; D012146:Rest; D012201:Reward; D013997:Time Factors; D014796:Visual Perception
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate
keywords: ADHD; Dopamine; Eye blinks; Methylphenidate