Use of a Dynamic Eye-Tracking Percept to Evaluate the Social Attention Paid to Facial Palsy: A Pilot Study

Background: Peripheral facial palsy (PFP) affects up to 30 people per 100,000 person-years, leading to functional, aesthetic and social implications in patients. The aim of this study was to measure the attention paid to paralyzed faces versus healthy faces using a dynamic eye-tracking percept. Methods: Thirty observers watched video sequences of patients and healthy volunteers performing four facial movements, and their gaze was recorded. Results: In all cases, the observers focused their attention on the face’s central triangle and particularly on the eyes. Still, more attention was paid to the patients’ eyes (54.3 ± 25.0 s vs. 49.8 ± 26.4, p = 0.001) and mouth (27.1 ± 13.9 s vs. 23.3 ± 14.2, p = 0.002) and less to their nose (24.6 ± 17.9 s vs. 31.3 ± 22.4, p < 0.001). Gaze analysis of bisected faces revealed an attentional bias towards the right visual field, particularly for healthy faces (64.21 ± 24.56 s vs. 45.97 ± 23.91 for the left visual field, p < 0.05), while more attention was still paid to the paralyzed side of patients (117.50 ± 29.40 s vs. 105.99 ± 24.68 for the non-paralyzed side, p < 0.01), and in particular to the mouth (31.54 ± 16.36 s vs. 24.48 ± 11.97, p < 0.01). Conclusions: The visual exploration process differed between healthy and paralyzed faces, as more attention was paid to the face’s mobile units and to the paralyzed side in patients. In the future, this protocol could be applied to various diseases and allow clinicians to improve their patients’ treatment and follow-up.