This concept pertains to Meltzoff and Moore‘s proposed mechanism for facial imitation. Facial imitation involves intermodal matching because the infant sees the adult’s gesture, but does not see his own response as his own face remains unseen by him. Facial imitation thus requires matching across different sensory modalities (hence ‘intermodal’). It is ‘active’ because infants correct and improve their responses over successive attempts; the responses do not simply pop out fully formed.
See Common coding, Cross-modal coordination, Cross-modal matching, Imitation, Intermodal coordination, Intermodal perception, Intersensory redundancy hypothesis