title: Reinforcement and Stimulant Medication Ameliorate Deficient Response Inhibition in Children with Attention-Deficit/Hyperactivity Disorder.
abstract: This study examined the degree to which reinforcement, stimulant medication, and their combination impact response inhibition in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Across three studies, participants with ADHD (n = 111, 25 girls) and typically-developing (TD) controls (n = 33, 6 girls) completed a standard version of the stop signal task (SST) and/or a reinforcement-manipulation SST with performance-contingent points. In two of these studies, these tasks were performed under placebo or 0.3 and 0.6 mg/kg methylphenidate (MPH) conditions. Cross-study comparisons were conducted to test hypotheses regarding the separate and combined effects of reinforcement and methylphenidate on response inhibition among children with ADHD relative to TD controls. Baseline response inhibition was worse among children with ADHD compared to controls. MPH produced dose-related improvements in response inhibition in children with ADHD; compared to non-medicated TD controls, 0.3 mg/kg MPH normalized deficient response inhibition, and 0.6 mg/kg MPH resulted in better inhibition in children with ADHD. Reinforcement improved response inhibition to a greater extent for children with ADHD than for TD children, normalizing response inhibition. The combination of MPH and reinforcement improved response inhibition among children with ADHD compared to reinforcement alone and MPH alone, also resulting in normalization of response inhibition despite repeated task exposure. Deficient response inhibition commonly observed in children with ADHD is significantly improved with MPH and/or reinforcement, normalizing inhibition relative to TD children tested under standard conditions.
authors.affiliation: Department of Psychology, University at Buffalo, SUNY, 206 Park Hall, Box 604110, Buffalo, NY, 14260-4110, USA. ksrosch@gmail.com.|Kennedy Krieger Institute, 716 North Broadway, Baltimore, MD, 21230, USA. ksrosch@gmail.com.
authors.forename: Keri S
authors.initials: KS
authors.lastname: Rosch
authors.affiliation: Department of Psychology, University at Buffalo, SUNY, 206 Park Hall, Box 604110, Buffalo, NY, 14260-4110, USA.
authors.forename: Whitney D
authors.initials: WD
authors.lastname: Fosco
authors.affiliation: Department of Psychology, University at Buffalo, SUNY, 206 Park Hall, Box 604110, Buffalo, NY, 14260-4110, USA.|Center for Children and Families, University at Buffalo, SUNY, Buffalo, NY, USA.|Florida International University, Miami, FL, USA.
authors.forename: William E
authors.initials: WE
authors.lastname: Pelham
authors.affiliation: Center for Children and Families, University at Buffalo, SUNY, Buffalo, NY, USA.|Department of Psychiatry, Penn State College of Medicine, Hershey, PA, USA.
authors.forename: James G
authors.initials: JG
authors.lastname: Waxmonsky
authors.affiliation: Department of Psychology, University at Buffalo, SUNY, 206 Park Hall, Box 604110, Buffalo, NY, 14260-4110, USA.
authors.forename: Michelle G
authors.initials: MG
authors.lastname: Bubnik
authors.affiliation: Department of Psychology, University at Buffalo, SUNY, 206 Park Hall, Box 604110, Buffalo, NY, 14260-4110, USA. lhawk@buffalo.edu.|Center for Children and Families, University at Buffalo, SUNY, Buffalo, NY, USA. lhawk@buffalo.edu.
authors.forename: Larry W
authors.initials: LW
authors.lastname: Hawk
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000503:physiopathology; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D002648:Child; D065786:Delay Discounting / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects / Q000502:physiology; D008774:Methylphenidate / Q000008:administration & dosage / Q000494:pharmacology*; D065808:Prepulse Inhibition / Q000187:drug effects / Q000502:physiology; D012054:Reinforcement, Psychology; D016896:Treatment Outcome
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate
keywords: ADHD; Inhibition; Medication; Methylphenidate; Reinforcement