Infants’ understanding of signs : linking sounds and concepts

Spoken words are semiotic signs: speech sounds which function to signify concepts in the world. Infants’ emerging understanding of the semiotic relation between sounds and concepts is explored here. First, basic questions from the philosophy of semiotics are recast as broader questions relevant for the psychological study of word-learning in infancy. Developmental aspects of one particular semiotic principle are explored in an empirical study which investigates whether infants bi-directionally link sounds and concepts. Previous research has suggested that this link is present, at least in one direction, very early in infancy: the presence of a word influences the structure of concepts, even before infants are able to robustly learn the referents of new words. The converse question is the topic of the present work: does the presence of an object when hearing speech sounds facilitate discrimination and identification of these sounds as potential word forms? Two studies provide evidence that for 9-month-old infants this is indeed the case. In Study 1, infants were exposed to a familiarization phase in which sounds from two non-native phonetic categories were contrastive, paired concordantly with two objects. In Study 2, another group was exposed to a familiarization phase in which the sounds where not contrastive, paired discordantly with the objects. Infants only succeeded in discriminating the contrast in the former case, suggesting that they must have used the link between sound and object to categorize the phonetic information. At an age when infants begin to have difficultly discriminating non-native phonetic contrasts, this research shows that infants can re-learn to discriminate this contrast if given evidence that it might signify two different words. This provides one example of how semiotic principles can be applied to research in language acquisition.Arts, Faculty ofPsychology, Department ofGraduat