Two-dimensional representations of the third dimension and their perception by infants.

Many researchers have examined the perception of the third dimension or the preference for three-dimensional versus two-dimensional stimuli in infants, but little is known about infants' representation of the third dimension in a two-dimensional display. Two experiments were conducted to study this capacity. The first experiment was a replication of earlier work, involving a television screen. No difference was observed between looking durations for the 'normal' and 'strange' events in 4-month-olds. As this situation was cognitively complex, a simpler interposition situation was displayed to 3-month-olds in the second experiment. Infants then looked longer at the 'strange' event than at the 'normal' event, suggesting that in a complex situation more perceptual indices must be given to infants. These different data are discussed.