Which aspects are important to elicit gaze following in typically developing infants?

Abstract

Introduction: This eye-tracking study aims to investigate which aspect primarily drives gaze following behavior (GFB). Particularly, we investigated the effect of eyes and of object presence on GFB. Methods: 43 infants between 1 and 2 years of age (M=17.12 months, SD=3.46) saw video clips of an adult turning her head to the right or left in four different conditions: open-eyes condition with objects, open-eyes condition without objects, closed-eyes condition with objects and closed-eyes condition without objects. Eye movements were measured with a Tobii T120. The outcome parameters of GFB were the amount of correct first looks, a difference score for amount (amount of correct minus amount of incorrect first looks) and a difference score for looking duration (looking duration towards the correct minus looking duration towards the incorrect target). Results: A 2x2 repeated measures ANOVA (object/no object*open/closed eyes) revealed a significant main effect for objects on the amount of correct first looks (F=59.9; p<.001). No other significant main or interactions effects of the different outcome parameters were found. Conclusion: The infants showed no difference in GFB between open and closed eyes conditions. However, infants seems to show more GFB in conditions with objects compared to conditions without objects.