Abstract
It is well known that the movements of parts of the body and facial expressions, particularly those of the head and hands, are synchronized with spoken language. This is observed not only in the speaker, but also in the listener during conversation. This synchronization phenomenon, which is called “entrainment” in communication, makes information exchange efficient in communication among people.
The object of this research is to develop a quantitative and objective analysis method for this entrainment by introducing an image analysis method using computers. Analysis of the entrainment of mother's talk and neonate's movement, which is one of the primitive forms of communication, and also the entrainment of speaker's talk and listener's nodding in adult conversation, by this method leads to the following two conclusions:
(1) Voice and movement synchronization in mother-neonate entrainment is similar to that of adult communication.
(2) The neonate discriminates the human voice, particularly that of the mother from the voice synthesized by computer, and moves the body in interactional synchronization with the human voice.
This analytical method of entrainment, which can be called “entrainography”, may be applied to detection of the basic process of language acquisition, and may also be applicable to early diagnosis of some neurological diseases.
