Impaired visual-motor integration function in children with attention-deficit/hyperactivity disorder: potential neural correlates from resting-state fNIRS.

Visual-motor integration (VMI) impairment is common in Attention-Deficit/Hyperactivity Disorder (ADHD), yet its underlying neurobiological basis remains unclear. This study aimed to explore the characteristics of VMI in children with ADHD and its statistical role in the association between functional connectivity (FC) and core symptoms. A total of 332 children with ADHD and 103 healthy controls (HC) completed the Beery-Buktenica Developmental Test of Visual-Motor Integration (Beery VMI). Group comparisons and dimensional correlation analyses were performed to explore the VMI characteristics of children with ADHD. Subsequently, 127 children with ADHD and 91 HC children underwent resting-state functional near-infrared spectroscopy. Mediation analyses were performed to investigate the role of VMI in the relationship between atypical FC and core symptoms of ADHD. Children with ADHD exhibited deficits in VMI performance, with 28.92% showing abnormal VMI. VMI was negatively correlated with core ADHD symptoms. At the network level, VMI showed significant statistical indirect associations in the relationship between FC of DMN-DMN, DMN-DAN, and DMN-VAN networks and inattention symptoms, and between FC of the DMN-DAN networks and hyperactivity/impulsivity symptoms. At the channel level, VMI was also indirectly associated with FC of the left superior frontal gyrus (SFG)-right middle occipital gyrus (MOG) and ADHD core symptoms. Children with ADHD have deficits in VMI, and poorer VMI performance is associated with greater severity of core ADHD symptoms. Altered intra- and inter- network FC of the DMN may represent a potential neural correlate of VMI impairment in ADHD.