Color perception deficits in co-existing attention-deficit/hyperactivity disorder and chronic tic disorders

Area of Science:

• Neuroscience
• Ophthalmology
• Child Psychology

Background:

• Attention-deficit/hyperactivity disorder (ADHD) and chronic tic disorders (CTD) may involve color perception deficits, particularly with blue-yellow stimuli.
• Previous findings are inconsistent, and the implications for comorbid ADHD + CTD are unclear.

Purpose of the Study:

• To investigate color perception and executive function in children with ADHD, CTD, and comorbid ADHD + CTD.
• To determine if color perception deficits are additive in the comorbid group and if they influence Stroop task performance.

Main Methods:

• Four groups of children (ADHD, CTD, ADHD + CTD, controls) were assessed using the Farnsworth-Munsell 100 Hue Test (FMT) and the Stroop-Color-Word Task.
• A factorial design ensured comparable age, IQ, and gender distributions across groups.

Main Results:

• Color perception deficits, measured by the FMT, were present in both ADHD and CTD groups, with deficits being additive in the comorbid group.
• ADHD was associated with more blue-yellow axis deficits than red-green axis deficits.
• Only the 'pure' ADHD group showed impairments in Stroop task interference control; no significant correlation was found between FMT and Stroop performance.

Conclusions:

• Basic color perception deficits are present in both ADHD and CTD, and these deficits are additive in comorbid ADHD + CTD.
• Executive function deficits in the Stroop task were specific to the 'pure' ADHD group, suggesting potential compensation by CTD-related prefrontal functions in comorbid cases.
• Color perception deficits appear to have a negligible impact on Stroop task performance.