Hidden Markov model analysis reveals the advantage of analytic 1 eye movement patterns in face recognition across cultures 2

27 It remains controversial whether culture modulates eye movement behavior in 28 face recognition. Inconsistent results have been reported regarding whether cultural 29 differences in eye movement patterns exist, whether these differences affect 30 recognition performance, and whether participants use similar eye movement patterns 31 when viewing faces from different ethnicities. These inconsistencies may be due to 32 substantial individual differences in eye movement patterns within a cultural group. 33 Here we addressed this issue by conducting individual-level eye movement data 34 analysis using hidden Markov models (HMMs). Each individual’s eye movements 35 were modeled with an HMM. We clustered the individual HMMs according to their 36 similarities and discovered three common patterns in both Asian and Caucasian 37 participants: holistic (looking mostly at the face center), left-eye-biased analytic 38 (looking mostly at the two individual eyes in addition to the face center with a slight 39 bias to the left eye), and right-eye-based analytic (looking mostly at the right eye in 40 addition to the face center ).The frequency of participants adopting the three patterns 41 did not differ significantly between Asians and Caucasians, suggesting little 42 modulation from culture. Significantly more participants (75%) showed similar eye 43 movement patterns when viewing ownand other-race faces than different patterns. 44 Most importantly, participants with left-eye-biased analytic patterns performed 45 significantly better than those using either holistic or right-eye-biased analytic 46 patterns. These results suggest that active retrieval of facial feature information 47 through an analytic eye movement pattern may be optimal for face recognition 48 regardless of culture. 49 50