ReflexiveVisual Inspection of Cleft Lip Faces - Analysis of Lookzone Focus Over Time
Thanapoom Boonipat, MD1, Soravis Prakkamakul, BS2, Kevin Fleming, PhD3, Mitchell Stotland, MD, MPH4.
1Mayo Clinic, Rochester, MN, USA, 2University of California, Berkeley, Berkeley, CA, USA, 3Norwich University, Norwich, VT, USA, 4Weill Cornell Medical College in Qatar and Sidra Medical Center, Doha, Qatar.
Humans reflexively inspect faces. Elucidating facial lookzone focus over time of cleft lip faces may offer insight into the early visual processing of facial normality/abnormality. By delineating the time sequence of visual impression formation, surgeons and their patients may pinpoint the most salient facial features so as to better direct prioritization of surgical reconstruction. METHODS: 179 experimental and 179 control facial images were obtained from the senior author's practice. Experimental images included 41 individuals with repaired cleft lip, and a variety of other facial diagnoses. 720 subjects rated the images for attractiveness. Twenty standardized lookzone regions were mapped onto each facial image. A separate group of 402 subjects observed the images while an infrared eye-tracking camera continuously recorded their eye movements for 6 seconds. R console TraMineR was utilized to analyze the time sequence data. The gender and personal history of observer facial deformity was recorded.
OUTCOMES MEASURED:Image attractiveness was rated on a 1-7 Likert scale. Total number of eye fixations within different lookzone regions was recorded continuously over the 6 seconds viewing period. RESULTS: (i) All observers start focusing on the face after 500ms, and on the cleft defect 200ms after facial scanning, but they revert to the control pattern of focusing on the periorbital area after 2400ms. (ii) Male maintain their focus on cleft defect much longer than females (3600ms vs 1800ms) (iii) Observers with family history of facial deformity maintain their focus on cleft defect throughout the 6000ms viewing period, while those without facial history lose focus on the cleft defect after 2000ms. (iv) The attractiveness ratings of the cleft images had no discernable impact on the sequence of reflexive inspection of the cleft images, except for the most attractive cleft images, for which the lip was not focused upon at all (but rather the nasal deformity). (v) Laterality of the cleft deformity did not impact the sequence of facial inspection, but bilateral clefts were less of a visual draw, with reversion to a control pattern of inspection early, versus a more continued focus on the cleft defect for unilateral clefts. CONCLUSION:Observers are reflexively drawn to the abnormal region of cleft faces upon immediate exposure, before reverting to a more natural pattern of facial inspection after about 2.5 seconds. Unilateral clefts - and cleft faces that are considered less attractive overall - induce a more sustained fixation within the perioral region. A personal history of facial deformity in general appeared to heighten sensitivity for cleft deformity. Males focused longer on the cleft defect compared to females.
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