Effects of methylphenidate on saccadic responses in patients with ADHD.
This study examined the effects of methylphenidate on different measures of saccade control, using a repeated measurement design, and the experimental and statistical control of practice effects. Twenty-seven boys with ADHD (mean age 12.6 years, range 10-15 years) were randomly assigned to two testing order conditions (first on-, second off-medication versus first off-, second on-medication) and accomplished the pro-saccadic overlap and the anti-saccadic 200-ms gap tasks (200 trials each). Methylphenidate was found to reduce pro- and anti-saccadic reaction times, error correction times, and the proportion of direction errors during the anti-saccade task. Furthermore, the drug augmented the proportions of express saccades and error corrections. Overlain practice effects were found for most of these measures. Our results suggest a weakening of the fixation, and a strengthening of the "voluntary" system of saccade control by methylphenidate.
Klein
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Psychophysiology Research Group, Department of Psychology, University of Freiburg, Belfortstrasse 20, 79085 Freiburg, Germany. klein@psychologie.uni-freiburg.de
Jr  Fischer
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Fischer
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Hartnegg
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K
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy*; D001921:Brain / Q000187:drug effects* / Q000502:physiology; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D002648:Child; D005403:Fixation, Ocular / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects* / Q000502:physiology; D012438:Saccades / Q000187:drug effects* / Q000502:physiology
D000697:Central Nervous System Stimulants; D008774:Methylphenidate