OBJECTIVE: A failure of the anti-phase synchronization between default-mode (DMN) and task-positive networks (TPN) may be involved in a main manifestation of ADHD: moment-to-moment variability. The study investigated whereby methylphenidate may improve TPN/DMN synchronization in ADHD. METHOD: Eleven drug-naive ADHD children and 11 typically developing (TD) children performed a flanker task during functional magnetic resonance imaging. The ADHD group was scanned without and 1 month later with methylphenidate. The signal was analyzed by independent component analysis. RESULTS: The TD group showed anti-phase DMN/TPN synchronization. The unmedicated ADHD group showed synchronous activity in the posterior DMN only, which was positively correlated with response time variability for the flanker task. Methylphenidate initiated a partial anti-phase TPN/DMN synchronization, reduced variability, and abolished the variability/DMN correlation. CONCLUSION: Although results should be interpreted cautiously because the sample size is small, they suggest that a failure of the TPN/DMN synchronization could be involved in the moment-to-moment variability in ADHD. Methylphenidate initiated TPN/DMN synchronization, which in turn appeared to reduce variability.
OBJECTIVE: A failure of the anti-phase synchronization between default-mode (DMN) and task-positive networks (TPN) may be involved in a main manifestation of ADHD: moment-to-moment variability. The study investigated whereby methylphenidate may improve TPN/DMN synchronization in ADHD. METHOD: Eleven drug-naive ADHDchildren and 11 typically developing (TD) children performed a flanker task during functional magnetic resonance imaging. The ADHD group was scanned without and 1 month later with methylphenidate. The signal was analyzed by independent component analysis. RESULTS: The TD group showed anti-phase DMN/TPN synchronization. The unmedicated ADHD group showed synchronous activity in the posterior DMN only, which was positively correlated with response time variability for the flanker task. Methylphenidate initiated a partial anti-phase TPN/DMN synchronization, reduced variability, and abolished the variability/DMN correlation. CONCLUSION: Although results should be interpreted cautiously because the sample size is small, they suggest that a failure of the TPN/DMN synchronization could be involved in the moment-to-moment variability in ADHD. Methylphenidate initiated TPN/DMN synchronization, which in turn appeared to reduce variability.
Authors: Ranganatha Sitaram; Tomas Ros; Luke Stoeckel; Sven Haller; Frank Scharnowski; Jarrod Lewis-Peacock; Nikolaus Weiskopf; Maria Laura Blefari; Mohit Rana; Ethan Oblak; Niels Birbaumer; James Sulzer Journal: Nat Rev Neurosci Date: 2016-12-22 Impact factor: 34.870
Authors: Brittany M Merrill; Joseph S Raiker; Aaron T Mattfeld; Fiona L Macphee; Marcela C Ramos; Xin Zhao; Amy R Altszuler; Jonathan W Schooler; Stefany Coxe; Elizabeth M Gnagy; Andrew R Greiner; Erika K Coles; William E Pelham Journal: Res Child Adolesc Psychopathol Date: 2022-03-05
Authors: Robert P Cary; Siddharth Ray; David S Grayson; Julia Painter; Samuel Carpenter; Leeza Maron; Olaf Sporns; Alexander A Stevens; Joel T Nigg; Damien A Fair Journal: Cereb Cortex Date: 2017-08-01 Impact factor: 5.357