One of the major accomplishments of perceptual development is the ability to detect intersensory relationships such as those provided by inputs from different modalities specifying equivalent information. For example, the ability to detect the correspondence between the visible movements of the lips and an utterance produced by those lips allows the observer to perceive the unity of the event. The studies outlined in this proposal are designed to systematically examine the development of infants' ability to detect intersensory equivalences during the first year of life. The principal aim of the studies is to critically and empirically evaluate the differentiation view of intersensory development proposed by E. Gibson and to determine whether other mechanisms of intersensory organization may also be operative during early infancy. The differentiarion view proposes that detection of intersensory equivalences (referred to as a modal invariants by Gibson) is dependent on the infants' sensitivity to modal invariants which are perceptually differentiated during development. Four sets of studies are proposed in which infants' intersensory response ro modal invariants based on temporal variations in stimulation will be assessed. The first set of studies will examine the development of infants' ability ro perform bisensory matches of rate and duration. Using the paired- comparison technique, infants' visual fixation of each member of a pair of visual stimuli will be studied while he or she listens to a sound corresponding to one of the members of the pair. The second set will examine the development of infants' ability to learn about multisensory compounds that are either united or not by an amodal invariant. Infants will first be habituated to a compound stimulus composed of an auditory and visual component and then will be tested with compounds where either one or both components are changed. In the third set, the development of infants' ability to make bisensory matches based on a higher-order invariant (i.e. rhythm) will be studied with the paired-comparison method. In the final set of studies, infants' ability to extract modal invariance across transformations will be examined with the abituation/test technique. It is hoped that the findings from the proposed studies will help advance our theoretical notions of intersensory development as well as provide much-needed data on the development of intersensory perceptual skills in healthy infants.
| Lewkowicz, D J (1992) Infants' responsiveness to the auditory and visual attributes of a sounding/moving stimulus. Percept Psychophys 52:519-28 |
