Cross-modal equivalence in early infancy: Auditory–visual intensity matching.

TLDR

Young infants are thought to focus on quantitative, not qualitative, differences in sensory input. The study tests whether infants treat auditory and visual stimuli as comparable based on intensity, ignoring modality differences. Using a cardiac habituation/dishabituation paradigm, 3‑week‑old infants were repeatedly exposed to white‑light followed by white‑noise stimuli of varying intensities to assess cross‑modal generalization. Infants exhibited a U‑shaped, quadratic cardiac response to loudness, with the minimal response shifting to higher intensities after a more intense visual cue, whereas adults showed no such relationship. No additional information was provided.

Abstract

It has been proposed that young infants are attentive to quantitative variations in stimulation to the exclusion of qualitative ones. To the extent that this is so, young infants should ignore differences between lights and sounds and should instead respond to auditory and visual stimuli as more or less similar depending on their intensity. To examine this hypothesis, a cardia c habituation/dishabituation method with a test for stimulus generalization was employed . Three-weekold infants were repeatedly presented with white-light followed by white-noise stimuli of different intensities. A U-shaped relationship between magnitude of cardiac response and loudness was found. In view of previous findings that without prior visual stimulation a monotonic increase in cardiac response to the same range of auditory stimuli results, this finding of a significant quadratic relationship with loudness suggests that the infants were responding to the auditory stimuli in terms of their similarity to the previously presented visual stimulus. A separate group of infants presented with a more intense visual stimulus exhibited a shift in the intensity at which a minimal cardiac response occurred. Results of a study with adults did not show any systematic relationship between cardiac response and loudness, indicating that unlike infants, adults do not spontaneously make cross-modal matches of intensity. Our perception of the world is based to a