Recognition of Amodal Language Identity Emerges in Infancy.

Audiovisual speech consists of overlapping and invariant patterns of dynamic acoustic and optic articulatory information. Research has shown that infants can perceive a variety of basic audio-visual (A-V) relations but no studies have investigated whether and when infants begin to perceive higher order A-V relations inherent in speech. Here, we asked whether and when infants become capable of recognizing amodal language identity, a critical perceptual skill that is necessary for the development of multisensory communication. Because, at a minimum, such a skill requires the ability to perceive suprasegmental auditory and visual linguistic information, we predicted that this skill would not emerge before higher-level speech processing and multisensory integration skills emerge. Consistent with this prediction, we found that recognition of the amodal identity of language emerges at 10-12 months of age but that when it emerges it is restricted to infants' native language.