Learning and discrimination of audiovisual events in human infants: the hierarchical relation between intersensory temporal synchrony and rhythmic pattern cues

This study examined 4- to 10-month-old infants ’ perception of audio–visual (A-V) temporal synchrony cues in the presence or absence of rhythmic pattern cues. Experiment 1 established that infants of all ages could successfully discriminate between two different audiovisual rhythmic events. Experiment 2 showed that only 10-month-old infants detected a desynchronization of the auditory and visual components of a rhythmical event. Experiment 3 showed that 4- to 8-month-old infants could detect A-V desynchroni-zation but only when the audiovisual event was nonrhythmic. These results show that initially in development infants attend to the overall temporal structure of rhythmic audiovisual events but that later in development they become capable of perceiving the embedded intersensory temporal synchrony relations as well. A ticking metronome, a tap dancer, and a talking person all illustrate the fact that many events in our everyday world are specified concurrently in multiple sensory modalities. In addition, the multimodal sensory information that specifies them is distrib-uted over time. The specific way the information is distributed (i.e., its temporal structure) determines the perceptual and cogni-tive meaning of temporally defined events (Baldwin & Baird, 2001; Zacks & Tversky, 2001). The two best examples of the fundamental importance of temporal structure for perception and cognition are, of course, music and language. In each case, the particular temporal organization of a series of elements, be they notes or phonemes, can give rise to very different meaning