The Development of Infants' Sensitivity to Arbitrary Intermodal Relations

The development of infants' ability to detect the arbitrary relation between the color/shape of an object and the pitch of its impact sound was investigated using an infant-control habituation procedure. Ninety-six infants of 3, 5, or 7 months were habituated to films of two objects differing in color and shape, striking a surface in an erratic pattern. One object produced an impact sound of a high pitch, and the other object produced a low pitch. During test trials, infants in the experimental conditions received a change in the pairing of pitch with color/shape, whereas controls received no change. Results indicate that visual recovery to the change in pitch-color/shape relations was significantly greater than that of age-matched controls at 7 months, but not at 3 or 5 months. A prior study demonstrated that by 3 months, infants were able to discriminate the color/shape and pitch changes of these events. However, it is not until 7 months that they show evidence of detecting the arbitrary relation between these attributes.