DEVELOPMENT IN THE UNDERSTANDING OF PERCEPTION - THE DECLINE OF EXTRAMISSION PERCEPTION BELIEFS

Ancient philosophers, including Plato, Euclid, and Ptolemy, believed i n an extramission theory of visual perception, which held that there a re emissions from the eyes during the act of vision. Three studies, co mparing college and elementary school students, documented a decrease over age in the belief of emissions from the eye during the act of vis ion and an increase in the belief that vision involved only incoming i nformation. Questions about hearing and smelling were less difficult t han those on vision but yielded analogous age trends. The results have implications for cognitive theories of development, for education, an d for understanding the child's concept of mind.