Crawling and Walking Infants See the World Differently
- The project was supported by Award R37HD033486 from the Eunice Kennedy Shriver National Institute of Child Health & Human Development to Karen Adolph and by Graduate Research Fellowship 0813964 from the National Science Foundation to Kari Kretch. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Eunice Kennedy Shriver National Institute of Child Health & Human Development, the National Institutes of Health, or the National Science Foundation. Portions of this work were presented at the 2012 International Conference on Infant Studies, the 2012 meeting of the Vision Sciences Society, and the 2013 meeting of the Society for Research in Child Development. We gratefully acknowledge Julia Brothers and members of the NYU Infant Action Lab for helping to collect and code data. We thank Gladys Chan for her beautiful illustration of the experimental apparatus.
How does visual experience change over development? To investigate changes in visual input over the developmental transition from crawling to walking, thirty 13-month-olds crawled or walked down a straight path wearing a head-mounted eye tracker that recorded gaze direction and head-centered field of view. Thirteen additional infants wore a motion tracker that recorded head orientation. Compared to walkers, crawlers' field of view contained less walls and more floor. Walkers directed gaze straight ahead at caregivers, whereas crawlers looked down at the floor. Crawlers obtained visual information about targets at higher elevations—caregivers and toys—by craning their heads upward and sitting up to bring the room into view. Findings indicate that visual experiences are intimately tied to infants' posture.