How the Baby Learns to See: Critical Periods Re-visited

Newborns have very limited vision. Yet they are already learning to see. We discovered this when we took advantage of a natural experiment: children born with dense cataracts in one or both eyes that blocked all patterned visual input until the cataracts were removed during infancy and the eyes given compensatory contact lenses. Even when the babies missed only a few months of visual input, they later developed a host of deficits in both low-level (e.g., acuity, peripheral vision), and high-level (e.g., perceiving the direction of motion, face processing) vision. Important clues about the developmental mechanisms come from recent studies of other senses after early visual deprivation. Overall, the results indicate that perceptual development is driven by visual experience and perturbed by imbalances, be they between the eyes or between the senses. Nevertheless, there is residual plasticity in adulthood that allows some recovery.

Daphne Maurer is a Distinguished University Professor from McMaster University. Although officially retired, she continues to do fundamental research on how perception develops, beginning from birth and influenced by the experience of seeing. Now based in Toronto, she also is working on an effective system for checking the vision of kindergarten children to identify the approximately 15% who have as-yet-undetected eye problems. She has over 200 peer-reviewed publications and many awards.