I am retired but continue to do research and occasionally I supervise students' projects. The aim of my research is to understand development—the way in which different types of experience effect change during normal development, how those changes are constrained by the biology of the organism, the way in which the nervous system is able to recover from some perturbations, and the limits to plasticity. To examine these questions about development, I study visual perception, both its development in children with normal eyes and its alteration in children with a history of visual deprivation from cataracts.
The normal development of perception. We investigated developmental changes involving visual capabilities mediated at different levels of the visual pathway: sensitivity to orientation and local motion, which are mediated mainly by the geniculatestriate pathway; integration of local elements into a global percept of form and a global direction of motion, which involve additional processing in extrastriate cortex; the perception of faces, which involves specialized mechansims in the temporal cortex; and the integration of the senses beyond the visual pathway. By using marker tasks for different parts of the visual pathway, we made inferences from the behavioural pattern about the developing nervous system, and sometimes confirmed the inferences using event-related potentials and functional Magnetic Resonance Imaging. Our studies indicated that some capabilities are present during the first hour after birth, but that others, such as expertise in identifying faces, take more than 14 years to become adultlike.
The visual development of children treated for cataracts. At The Hospital for Sick Children in Toronto, we are studying the visual development of children who were deprived of normal visual input until they had surgery to remove dense central cataracts and were fitted with contact lenses. These children allow us to evaluate the effects of visual deprivation on development, including the influence of its timing and duration. We are following over 100 children, the largest research population of this type in the world. Current studies involve cross-model perception and integration.
The psychobiological roots of aesthetics. We normally assume that adults' judgments of beauty are based on cultural stereotypes. Yet 2-month-old infants look longer at a face rated attractive by adults than at a face rated unattractive. Findings like these suggest that some of adults' preferences are rooted in the way the human nervous system works. We conducted developmental and cross-cultural studies to identity the nature of the biological constraint.
Vision screening. About 15% of kindergarten children have visual deficits that are treatable but undiagnosed. We are researching the best tools for screening their vision and the practicality of implementing it in schools.
My interest in the development of perception led to a book with Charles Maurer, The World of the Newborn. In this we integrated the science of infant perception to work out what a young baby perceives from the baby's perspective. It won the book award of the American Psychological Association and has been translated into five languages.
My interest in the roots of aesthetics led to a new and comprehensive framework that grounds aesthetics in the basics of physics and biology, and carries it through all art forms across cultures. This Charles Maurer and I adumbrated in the book Pretty Ugly: Why we like some songs, faces, foods, plays, pictures, poems, etc., and dislike others. This framework we are currently applying to human social behaviour in a book that we are tempted to entitle Prettier and Uglier.
Basic CV with list of publications.