Date of Award
Doctor of Philosophy
The role of spatial co-location between sight and sound in infants' cross-modal learning was examined. In Experiments 1 and 2, 4- and 6-month-old infants were familiarized with toys and an accompanying soundtrack using a cross-modal learning paradigm. Across conditions, spatial congruity between sight and sound was varied so that the sound was: (1) co-located with one toy (40 cm from midline); (2) 20 cm to the far side of one toy toward midline; (3) 20 cm to the far side of one toy opposite midline; and (4) 60 cm to the far side of one toy opposite midline. In Experiment 1, infants were presented two toys, one on either side of midline, during familiarization. Following familiarization, infants were tested to determine under which familiarization conditions they learned to associate the toy with the sound. Preferential looking to the familiar toy was taken as evidence that cross-modal learning had occurred. Results indicated age-related differences in the precision of co-location between sight and sound necessary to support infants' learning of cross-modal associations. Specifically, 4-month-olds formed a cross-modal association both when the sight and sound were co-located and when the sound was 20 cm to the far side of the toy in Experiment 1. Only one toy was presented during familiarization in Experiment 2 to determine why 4-month-olds in Experiment 1 did not form an association when the sound was 20 cm from the toy toward midline. Results of Experiment 2 indicated that 4-month-olds formed an association, between sight and sound when the toy and sound were co-located and when the sound was 20 cm to either side of the toy. This outcome suggests that 4-month-olds in Experiment 1 did not form an association when the sound was 20 cm from the toy toward midline because they were unsure to which of the two toys the sound was closer. In contrast to the 4-month-olds, 6-month-olds formed a cross-modal association only when the sight and sound had been co-located precisely during familiarization in each of the first two experiments. Experiment 3 was conducted to determine whether 6-month-olds would form cross-modal associations between sights and sounds that were not precisely co-located when the task of detecting a discrepancy in location was made more difficult. Infants were tested in the same manner as in Experiments 1 and 2 except that the sound was positioned at the same location as the toy and 10 cm to either side of the toy. Six-month-olds formed an association under each of these three conditions. Adults were tested in Experiment 4 and results indicated that they could localize accurately the sounds presented to infants in Experiment 3. Taken together, results of this series of experiments suggest that sound location constrains infants' learning of sight-sound pairings to a greater extent at older than at younger ages. Parallel improvements in infants' sound localization abilities across this age span presumably contribute to the obtained developmental trend.
Fenwick, Kimberley Diane, "Infants' Use Of Spatial Co-location In A Cross-modal Perception Task" (1995). Digitized Theses. 2491.