Development of Joint Visual Attention in Infants
The understanding of attention (in particular, the emergence of joint or shared attention) has been identified as playing a number of important roles in the social and cognitive development of the infant (see Adamson & Bakeman, 1991, for a review). Butterworth ( 1991) believes that attention serves an important communicative function during the prelinguistic period in that it permits basic information about objects of interest or desire to be conveyed. For example, joint attention plays an integral part in both the protodeclarative and protoimperative gestures first identified by Bates and her colleagues (e.g., Bates, Camaioni, & Volterra, 1979). Further, joint attention is also implicated in the phenomenon of social referencing whereby emotional information about an ambiguous object or event is conveyed from adult to infant (e.g., Feinman, 1982; Homik, Risenhoover, & Gunnar , 1987; Sorce, Emde, Campos, & Klinnert, 1985). Bruner ( 1983) believes that joint attention provides the basis of shared experience necessary for the acquisition of language. In support of this notion, both the production of conventionalized acts (including referential and regulative words and gestures) toward the end of the first year ( Bakeman & Adamson, 1986) as well as novel word learning in 17-month-olds ( Tomasello & Farrar, 1986), 18-month-olds ( Dunham, Dunham, & Curwin, 1993), and 16-19-month-olds ( Baldwin, 1991), have been found to be greatly facilitated by involvement with an adult in joint attention toward an object. Finally, other authors (e.g., Baron-Cohen, 1991, this volume; Mundy, Sigman, Ungerer, & Sherman, 1986) have proposed that understanding attention in others may be a necessary precursor to the development of a "theory of mind," and that it is this understanding that is initially disrupted in autism.