A single dose of antidepressant alters eye-gaze patterns across face stimuli in healthy women
Jonassen R., Chelnokova O., Harmer C., Leknes S., Landrø NI.
Background: Early neurocognitive changes in emotional processing are seen following SSRI administration, which may be involved in mechanisms of action. However, the perceptual processes underpinning these effects have not been specified. Methods: In a double-blind, placebo-controlled eye-tracking study, we assessed the effect of single dose of citalopram (20 mg) in 25 healthy females. Face stimuli with direct and averted gaze were presented while visual scan patterns and pupil sizes were monitored. Subjective state was monitored using visual analogue scales. Results: There were no significant effects of citalopram on subjective state. However, the citalopram group displayed increased saccade numbers and shorter fixation duration during face viewing compared to the placebo group. Volunteers receiving citalopram also showed reduced monitoring of the eye region irrespective of the direct or averted eye position of the stimuli. The citalopram group also showed significantly larger pupil sizes than the control group. Conclusions: These results suggest that the SSRI administration affects the perceptual processing of face stimuli. The current pattern of findings is consistent with anxiogenic-like mechanisms early on in SSRI treatment. Eye-tracking provides a novel method to characterise and detect these effects.