Perception of bimodal distance relations by 5-month-old human infants
This research investigated whether, and on what basis, 5-month-olds perceive auditory-visual distance relations. Previously, infants have been shown to match a film of an approaching automobile with an engine sound of increasing intensity, and a retreating automobile with a sound of decreasing intensity. However, little is known regarding the basis and specificity of this intermodal matching. To address this issue, four conditions were presented wherein infants viewed side by side films along with a central soundtrack matching one of them. To determine whether infants detected the relationship between films and sounds, observers monitored infants' visual fixations to the films. In Condition 1, infants' ability to match sights and sounds specifying approach and retreat in the natural environment was assessed. Infants viewed films of a toy train approaching and retreating over a natural landscape, paired with engine sounds of increasing versus decreasing intensity. Infants looked significantly longer to the approach film when the increasing intensity sound was presented, and vice versa. Three other conditions were presented to assess the specificity of infants' matching. In Condition 2, infants viewed films of the train increasing and decreasing in size, along with increasing and decreasing intensity sounds. Infants looked significantly more to the increasing size film when increasing intensity sound was presented, and vice versa. However, matching was significantly different (less robust) than in Condition 1. This suggested that changing size was sufficient to allow matching, however the availability of diverse, naturalistic depth information in Condition 1 facilitated matching beyond the level observed for size information alone. Infants in Condition 3 showed no evidence of matching a film of the train increasing in brightness with a sound of increasing intensity, or vice versa. This weakened an explanation of matching on the basis of auditory-visual intensity relations. Nor did infants show evidence, in Condition 4, of matching an up motion of the train with increasing intensity sound, or vice versa. This diminished an explanation of matching on the basis of more abstract auditory-visual relations. These results indicate that 5-month-old infants are sensitive to ecological auditory-visual relations specifying changing distance. ^
Pickens, Jeffrey N, "Perception of bimodal distance relations by 5-month-old human infants" (1990). ProQuest ETD Collection for FIU. AAI9024304.