Sex Effects on Mirror Overflow during Finger Tapping in Children with ADHD

• Published in: Journal of the International Neuropsychological Society Vol. 28; no. 4; pp. 371 - 381
• Main Authors: Chen, C., Rosch, K.S., Seymour, K.E., Crocetti, D., Mahone, E. M., Mostofsky, S.H.
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 01.04.2022
• Subjects: Adolescent; Age; Attention Deficit Disorder with Hyperactivity; Attention deficit hyperactivity disorder; Child; Child, Preschool; Children; Children & youth; Female; Finger; Girls; Humans; Hyperactivity; Male; Motor task performance; Neural networks; Regular Research; Sex differences; Structure-function relationships; United States > US; Child developmental disorder; Preschool children; Motor skills; Psychomotor performance; Developmental disabilities; School-age population
• ISSN: 1355-6177; 1469-7661
• DOI: 10.1017/S1355617721000576

The presence of excessive mirror overflow in children with Attention Deficit/Hyperactivity Disorder (ADHD) is discussed in numerous published reports. These reports, however, include a limited age range in their samples. The objective of this study is to examine the effects of diagnosis and sex on mirror overflow and standard deviation (SD) of tap time in children with and without ADHD across a larger age range (5-12 years) of children. One-hundred and forty-eight children with ADHD and 112 age- and sex-matched typically developing (TD) children completed a finger sequencing task. Mirror overflow, SD of tap time, and mean tap time were measured using finger twitch transducers. Results reveal a significant diagnostic effect on mirror overflow such that boys and girls with ADHD demonstrate increased overflow compared to same-sex TD children. Boys with ADHD demonstrated more variable tap times compared to TD boys; no diagnostic effect was observed in the girls. Boys with ADHD exhibit anomalous motor variability; girls with ADHD show similar levels of variability as TD girls. Boys and girls with ADHD exhibit similar levels of excessive mirror overflow. This lack of sex differences on mirror overflow is distinct from reports finding sex effects on overflow and could result from an examination of a broader age range than is included in prior reports. Adolescent data would provide a greater understanding of the trajectory of anomalous mirror overflow across development. Examination of functional and structural connectivity would expand the current understanding of the neurobiological foundation of motor overflow.