Stimulation of one sensory modality can induce perceptual experiences in another modality that reflect synaesthetic correspondences among different dimensions of sensory experience. In visual-hearing synaesthesia, for example, higher pitched sounds induce visual images that are brighter, smaller, higher in space, and sharper than those induced by lower pitched sounds. Claims that neonatal perception is synaesthetic imply that such correspondences are an unlearned aspect of perception. To date, the youngest children in whom such correspondences have been confirmed with any certainty were 2- to 3-year-olds. We examined preferential looking to assess 3- to 4-month-old preverbal infants' sensitivity to the correspondences linking auditory pitch to visuospatial height and visual sharpness. The infants looked longer at a changing visual display when this was accompanied by a sound whose changing pitch was congruent, rather than incongruent, with these correspondences. This is the strongest indication to date that synaesthetic cross-modality correspondences are an unlearned aspect of perception.

No abstract

Filling in the gaps in what humans see is a fundamental perceptual skill, but little is known about the developmental origins of occlusion perception. Three experiments were conducted with infants between 2 and 6 months of age to investigate perception of the continuity of an object trajectory that was briefly occluded. The pattern of results across experiments provided little evidence of veridical responses to trajectory occlusion in the youngest infants, but by 6 months, perceptual completion was more robust. Four-month-olds' responses indicated that they perceived continuity under a short duration of occlusion, but when the object was out of sight for a longer interval, they appeared to perceive the trajectory as discontinuous. These results suggest that perceptual completion of a simple object trajectory (and, by logical necessity, veridical object perception) is not functional at birth but emerges across the first several months after onset of visual experience.

No abstract

Nine month old infants search correctly for an object which they have seen hidden in one position. but cease to do so after they have been moved to the opposite side of the display, searching instead at a position which is apparently defined egocentrically from their experience before movement. This error can be explained on the one hand in terms of response dependence or egocentrism. or on the other hand as due to a lack of adequate spatial cues to allocentric position. In order to distinguish between these hypotheses. 64 nine month old infants were presented with a hidden object problem in which the two alternative positions had covers of different colours. The results show that infants could search correctly for an object in one location although they saw the problem from different sides. This result combines with those of other conditions to indicate that cover colour provides an adequate spatial cue, allowing the infant to specify position allocentrically, provided the correct cover maintains a stable position.