Face-scanning behavior to silently-talking faces in 12-month-old infants: the impact of pre-exposed auditory speech

The present eye-tracking study aimed to investigate the impact of auditory speech information on 12-month-olds' gaze behavior to silently-talking faces. We examined German infants' face-scanning behavior to side-by-side presentation of a bilingual speaker's face silently speaking German utterances on one side and French on the other side, before and after auditory familiarization with one of the two languages. The results showed that 12-month-old infants showed no general visual preference for either of the visual speeches, neither before nor after auditory input. But, infants who heard native speech decreased their looking time to the mouth area and focused longer on the eyes compared to their scanning behavior without auditory language input, whereas infants who heard non-native speech increased their visual attention on the mouth region and focused less on the eyes. Thus, it can be assumed that 12-month-olds quickly identified their native language based on auditory speech and guided their visual attention more to the eye region than infants who have listened to non-native speech