AUTHOR=Tsuji Sho , Alonso Fernanda , Hagihara Hiromichi , Kimura Nanako , Polka Linda , Lovčević Irena 

TITLE=Facial affect and arousal as a complement to gaze measures in infant speech sound perception studies

JOURNAL=Frontiers in Neural Circuits

VOLUME=Volume 19 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/neural-circuits/articles/10.3389/fncir.2025.1553918

DOI=10.3389/fncir.2025.1553918

ISSN=1662-5110

ABSTRACT=This study explores infant facial expressions during visual habituation to investigate perceptual attunement to native and non-native speech sounds. Using automated facial affect analysis based on Facial Action Units, we analyzed valence, arousal, positive affect, and negative affect during the experiment. Valence and arousal decreased with habituation, while positive affect increased, with differences between native and non-native stimuli. Facial affect showed links to discrimination outcomes, with better native discrimination linked to reduced negative affect. These findings highlight the potential of facial expression analysis as a complementary tool to gaze-based measures in early language development research.