Oculomotor behaviors in youth with an eating disorder: findings from a video-based eye tracking task.

Background: The oculomotor circuit spans many cortical and subcortical areas that have been implicated in psychiatric disease. This, combined with previous findings, suggests that eye tracking may be a useful method to investigate eating disorders. Therefore, this study aimed to assess oculomotor behaviors in youth with and without an eating disorder. Methods: Female youth with and without an eating disorder completed a structured task involving randomly interleaved pro-saccade (toward at a stimulus) and anti-saccade (away from stimulus) trials with video-based eye tracking. Differences in saccades (rapid eye movements between two points), eye blinks and pupil were examined. Results: Youth with an eating disorder (n = 65, M_age = 17.16 ± 3.5 years) were compared to healthy controls (HC; n = 65, M_age = 17.88 ± 4.3 years). The eating disorder group was composed of individuals with anorexia nervosa (n = 49), bulimia nervosa (n = 7) and other specified feeding or eating disorder (n = 9). The eating disorder group was further divided into two subgroups: individuals with a restrictive spectrum eating disorder (ED-R; n = 43) or a bulimic spectrum eating disorder (ED-BP; n = 22). In pro-saccade trials, the eating disorder group made significantly more fixation breaks than HCs (F(1,128) = 5.33, p = 0.023). The ED-BP group made the most anticipatory pro-saccades, followed by ED-R, then HCs (F(2,127) = 3.38, p = 0.037). Groups did not differ on rate of correct express or regular latency pro-saccades. In anti-saccade trials, groups only significantly differed on percentage of direction errors corrected (F(2, 127) = 4.554, p = 0.012). The eating disorder group had a significantly smaller baseline pupil size (F(2,127) = 3.60, p = 0.030) and slower pro-saccade dilation velocity (F(2,127) = 3.30, p = 0.040) compared to HCs. The ED-R group had the lowest blink probability during the intertrial interval (ITI), followed by ED-BP, with HCs having the highest ITI blink probability (F(2,125) = 3.63, p = 0.029). Conclusions: These results suggest that youth with an eating disorder may have different oculomotor behaviors during a structured eye tracking task. The oculomotor behavioral differences observed in this study presents an important step towards identifying neurobiological and cognitive contributions towards eating disorders. Plain English summary: Video based eye tracking is a promising method for studying differences between individuals with and without a psychiatric disease of interest. While some studies have explored oculomotor behaviors in individuals with an eating disorder, much remains unknown. The present study investigated saccades (fast eye movements between two points), eye blinks and pupil responses between female youth (aged 10–25 years) with and without an eating disorder during a pro-saccade (looking at a point) and anti-saccade (looking away from a point) eye tracking task. Individuals with an eating disorder made more pro-saccade guesses, had a smaller pupil size and blinked less before a trial started. In individuals with a restrictive type eating disorder (e.g., anorexia nervosa restrictive type), pupil responses may have a relationship with emotional dysregulation (poorly regulated emotional responses). Overall, this study represents an important step towards identifying oculomotor behavior differences in individuals with an eating disorder compared to controls. [ABSTRACT FROM AUTHOR]