Abstract
Introduction:
Amblyopia is a neurodevelopmental disorder of vision that has been associated with visual attention deficits. We investigated whether attentional capture by fearful facial expressions was affected by amblyopia.
Methods:
Participants (n = 30 controls; 10 amblyopia) completed a cued peripheral target (0.9 deg x 0.9 deg) detection task. The cue was a centrally presented face with left or right gaze. The face adopted a fearful, happy or neutral expression for 500 ms. The target was then presented in a location either congruent or incongruent to the face’s direction of gaze. Participants indicated target location (left/right) and reaction times were measured. Central fixation was ensured using an eye tracker. Gaze cueing for each emotional expression was computed as the difference in reaction time between congruent and incongruent trials. 128 trials were performed for each facial expression across 3 viewing conditions in a randomized order: monocular non-dominant/amblyopic eye (NDE), monocular dominant eye (DE), and binocular (BE). Participants also rated the valence and intensity of each facial expression, viewing with the non-dominant eye.
Results:
Ratings for the facial expressions were not affected by amblyopia. Reaction times for the non-dominant/amblyopic eye were analyzed with a 3 (Emotion: fear, neutral, happy) x 2 (Congruency: congruent, incongruent) x 2 (Group: control, amblyopia) ANOVA. Consistent with previous work, there was a significant interaction between Emotion and Congruency, characterized by a stronger gaze cueing effect for fearful versus neutral and happy expressions. There was no effect of Group. Post-hoc analysis revealed that the significant interaction between Emotion and Congruency was present for both groups independently. The expected interaction between Emotion and Congruency was also present in the other two viewing conditions.
Conclusion:
Although spatial attention deficits are associated with amblyopia, attentional capture with emotional cues appears to remain intact.