Inhibitory Control Deficits in Children with Tic Disorders Revealed by Object-Hit-and-Avoid Task.

Area of Science:

• Neuroscience
• Developmental Psychology
• Clinical Neurology

Background:

• Tic disorders are hypothesized to involve deficits in inhibitory control.
• Previous behavioral assessments of inhibitory control in tic disorders have produced inconsistent findings.
• This study investigates inhibitory control using a novel approach with simultaneous, mobile stimuli.

Purpose of the Study:

• To evaluate inhibitory control in children diagnosed with tic disorders.
• To compare inhibitory control performance between children with and without comorbid ADHD and typically developing controls.
• To identify potential neural mechanisms underlying impaired inhibitory control in tic disorders.

Main Methods:

• A cohort of 64 children with tics and 146 typically developing controls participated.
• A robotic exoskeleton system (Kinarm) was employed for an object-hit-and-avoid task.
• Participants were instructed to hit targets while avoiding distractors presented dynamically on a screen.

Main Results:

• Children with tics struck significantly more distractors than controls, indicating impaired inhibitory control.
• Participants with comorbid ADHD also showed reduced target accuracy compared to controls.
• Movement speed and area did not significantly differ between groups, suggesting specific inhibitory deficits rather than general motor impairments.

Conclusions:

• Children with tic disorders, particularly those without ADHD, exhibit a reduced ability to suppress responses to potential action triggers.
• These findings suggest a potential link between impaired inhibitory control in tics and increased sensorimotor noise or abnormal sensory gating.
• The results highlight the utility of advanced behavioral tasks in elucidating the neurobiological underpinnings of tic disorders.