Gap Effect Abnormalities during a Visually Guided Pro-Saccade Task in Children with Attention Deficit Hyperactivity Disorder

• Published in: PloS one Vol. 10; no. 5; p. e0125573
• Main Authors: Matsuo, Yuka, Watanabe, Masayuki, Taniike, Masako, Mohri, Ikuko, Kobashi, Syoji, Tachibana, Masaya, Kobayashi, Yasushi, Kitamura, Yuri
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.05.2015; Public Library of Science (PLoS)
• Subjects: Abnormalities; Age; Attention Deficit Disorder with Hyperactivity - physiopathology; Attention deficit hyperactivity disorder; Behavior disorders; Biomarkers; Biomarkers - metabolism; Brain research; Child; Child development; Child, Preschool; Children; Children & youth; Diagnostic systems; Environmental health; Eye; Eye movements; Eye Movements - physiology; Female; Humans; Hyperactivity; Life span; Male; Medical imaging; Medicine; Mental disorders; Neural networks; Neurodevelopmental disorders; Neurological diseases; Neurophysiology; Neurosciences; Reaction time; Reaction time task; Saccades (Eye movements); Saccades - physiology; Saccadic eye movements; Standard deviation; Studies
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0125573

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that starts in early childhood and has a comprehensive impact on psychosocial activity and education as well as general health across the lifespan. Despite its prevalence, the current diagnostic criteria for ADHD are debated. Saccadic eye movements are easy to quantify and may be a quantitative biomarker for a wide variety of neurological and psychiatric disorders, including ADHD. The goal of this study was to examine whether children with ADHD exhibit abnormalities during a visually guided pro-saccadic eye-movement and to clarify the neurophysiological mechanisms associated with their behavioral impairments. Thirty-seven children with ADHD (aged 5-11 years) and 88 typically developing (TD) children (aged 5-11 years) were asked to perform a simple saccadic eye-movement task in which step and gap conditions were randomly interleaved. We evaluated the gap effect, which is the difference in the reaction time between the two conditions. Children with ADHD had a significantly longer reaction time than TD children (p < 0.01) and the gap effect was markedly attenuated (p < 0.01). These results suggest that the measurement of saccadic eye movements may provide a novel method for evaluating the behavioral symptoms and clinical features of ADHD, and that the gap effect is a potential biomarker for the diagnosis of ADHD in early childhood.