| Abstract: | To examine the hypothesis that young infants ignore differences between lights and sounds and instead respond to auditory and visual stimuli as more or less similar depending on their intensity, a cardiac habituation/dishabituation method with a test for stimulus generalization was employed. In 2 experiments, a total of 40 3-wk-old Ss were repeatedly presented with white-light followed by white-noise stimuli of different intensities. A U-shaped relationship between magnitude of cardiac response (CR) and loudness was found. In view of previous findings that without prior visual stimulation a monotonic increase in CR to the same range of auditory stimuli results, this finding of a significant quadratic relationship with loudness suggests that Ss were responding to the auditory stimuli in terms of their similarity to the previously presented visual stimulus. A separate group of 14 infants presented with a more intense visual stimulus exhibited a shift in the intensity at which a minimal CR occurred. Results of a study with 31 adults did not show any systematic relationship between CR and loudness, indicating that unlike infants, adults do not spontaneously make cross-modal matches of intensity. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
