Contributed Talks III: Infants' eye movements to scene statistics in natural behavior.

Infants start to interact with their visual environment during the first postnatal months. Immaturities in gross motor responses and spatial vision constrain their visual behavior during this rapid development. Analyses of first-person video and eye-tracking data from infants were performed to understand key components of visual experience during this period of visual learning.

Methods: Infants wore head-mounted scene and binocular eye-tracking cameras (modified Pupil Labs Core) while engaging in naturalistic behavior in an 8ftx8ft home-like environment. Calibrated eye movements were identified using standard approaches (e.g. Engbert & Mergenthaler, 2006) and image statistics were extracted at fixation locations (>200ms).

Results: Recordings (10.5 hours) at ages 2-3 (n=24) 5-6 (35) 8-9 (27) & 11-12 (11) months were analyzed. Eye position and saccade amplitude distributions relative to the head were tighter for younger infants. The distribution of RMS contrast around fixation was also highest at younger ages.

Conclusions: The youngest infants with limited head and trunk control exhibited the most restricted range of eye movements, suggesting no gaze shift compensation for limited mobility. This likely leads to less active sampling of the scene, slower rates of change in input, and a tight link between head- and eye-centered frames of reference. Early experience also provides a concentration of contrast serving the development of foveal and parafoveal function.