B - 03 Inhibitory Control and Saccadic Eye Movement in Adults with Attention-Deficit Hyperactivity Disorder: an Eye-Tracking Analysis.

Abstract

The objective of this study was to investigate oculomotor differences between adults with and without attention-deficit hyperactivity disorder (ADHD) during a computerized response inhibition task, utilizing eye-tracking technology. Twenty-nine adults with ADHD and 35 controls (ages 18-32) were recruited from Sona Systems and the Learning Center at a university. Participants completed 120 randomized trials of the flanker task while their eye movements were monitored. Saccadic eye movement was investigated, while reaction time and performance errors were recorded from the flanker task. Participants with ADHD were required to refrain from taking stimulant medication the day of the experiment. A linear mixed-effects regression model was fitted. Having ADHD resulted in significantly slower response times, t(57) = 2.73, p < 0.005, 95% CI [0.04, 0.27], but not significantly more errors than control participants on the flanker task. There were no significant differences in the number of saccades between groups. Further analysis demonstrated that adults with ADHD had a significantly higher number of saccades as the number of trials increased, t(7019) = 3.69, p < 0.001, 95% CI [0.00105, 0.00314]. Slower reaction time in adults with ADHD during the flanker task indicates slower processing, but this did not affect their accuracy. While no differences were found in the number of saccades between groups, higher saccades as trial number increased in adults with ADHD suggests possible fatigue contributing to oculomotor differences. Further research is necessary to investigate potential gaze differences during a task that necessitates increased saccadic eye movement.