Comparing Layperson Attention to Faces with Different Types of Facial Paralysis Using Eye-Tracking.

Background: There is a spectrum of facial paralysis patient presentations from complete flaccid facial paralysis (CFFP) to facial aberrant reinnervation syndrome (FARS). Objective: To objectively compare how laypersons direct attention to faces with different facial paralysis subtypes using eye-tracking technology. Methods: Lay observers freely gazed at standardized videos of 24 individuals' faces as follows: 8 with CFFP, 8 with FARS, and 8 nonparalyzed Controls performing common facial expressions. Eye-tracking measured observers' gaze and extracted data as time in milliseconds looking at facial subsites. Mixed effects regression was used for comparative analyses. Results: A total of 85 observers completed the study. For faces at rest, measurable differences in gaze patterns were noted for CFFP faces (more attention spent on nonparalyzed hemiface), whereas FARS and Control faces showed similar symmetric gaze patterns. With dynamic movement (smiling and brow-elevation), gaze patterns for both CFFP and FARS faces became altered and asymmetrical compared with Control faces. Conclusions: Faces with CFFP and FARS are viewed differently by casual observers, which has implications for patient care and future research. While CFFP showed gaze alterations (compared with Control) in both rest and facial expression states, FARS caused gaze alterations only with facial movement.