Intersensory Redundancy Facilitates Discrimination of Tempo in 3-Month-Old Infants Lorraine E. Bahrick Ross Flom Robert Lickliter Department of Psychology Florida International University Miami, FL 33199 Received 16 July 2001; Accepted 14 January 2002 ABSTRACT: L. Bahrick and R. Lickliter (2000) proposed an intersensory redundancy hypothesis that states that information presented redundantly and in temporal synchrony across two or more sensory modalities selectively recruits infant attention and facilitates perceptual learning more effectively than does the same information presented unimodally. In support of this view, they found that 5-month-old infants were able to differentiate between two complex rhythms when they were presented bimodally, but not unimodally. The present study extended our test of the intersensory redundancy hypothesis to younger infants and to a different amodal property. Three-month-olds’ sensitivity to the amodal property of tempo was investigated. Results replicated and extended those of Bahrick and Lickliter, demonstrating that infants could discriminate a change in tempo following bimodal, but not unimodal, habituation. It appears that when infants are first learning to differentiate an amodal stimulus property, discrimination is facilitated by intersensory redundancy and attenuat- ed under conditions of unimodal stimulation. ß 2002 Wiley Periodicals, Inc. Dev Psychobiol 41: 352–363, 2002. DOI 10.1002/dev.10049 Keywords: intersensory perception; intersensory redundancy; tempo discrimination; infancy We live in a world of objects and events that are multimodal and dynamic. Organisms make sense of this flux of stimulation by perceiving events that are unitary despite changing stimulation to multiple sen- sory systems. Research has demonstrated that young human infants are capable of perceiving unitary multi- modal events by detecting amodal properties in stimu- lation. That is, they detect information that is not specific to a particular sensory modality, but conveyed by more than one sense (redundant across the senses). For example, in the first half year of life, infants detect the relationship between a face and a voice on the basis of temporal synchrony, rhythm, and tempo as well as certain types of spectral information common to the movements of the mouth and timing of the speech sounds (Dodd, 1979; Kuhl & Meltzoff, 1984; Lewkowicz, 1996, 1998; Mendelson & Ferland, 1982). Infants also detect amodal information speci- fying affective expression across the visual and aco- ustic stimulation of speech (Walker-Andrews, 1997) as well as information specifying the age and gender of a speaker (Bahrick, Netto, & Hernandez-Reif, 1998; Walker-Andrews, Bahrick, Raglioni, & Diaz, 1991). In perceiving moving objects, infants detect amodal temporal information specifying the sub- stance and composition of an object across the sights and sounds of its impacts against a surface (Bahrick, 1983, 1988, 1992) as well as the common tempo of Correspondence to: L. Bahrick Contract grant sponsor: NICHD Contract grant number: RO1 HD25669 Contract grant sponsor: NIMH Contract grant numbers: RO1 MH62226, K02 MH01210, and RO1 MH62225 ß 2002 Wiley Periodicals, Inc.