Nevertheless, disagreement CYC202 in vitro still exists on how to interpret these skills. According to some studies, joint attention represents a unitary construct that depends on a single cognitive process—either general, such as representational capacity (Bates, Benigni, Bretherton, Camaioni, & Volterra, 1979; Leslie & Happe, 1989) and IQ (Smith & Ulvund, 2003) or specific, such as social understanding (Bretherthon, 1991; Brooks & Meltzoff, 2005; Carpenter et al., 1998; Tomasello, 1995a, 1995b, 1999; Tomasello, Carpenter, Call, Behne, & Moll, 2005). According to others, joint

attention includes two distinct abilities—that of initiating an episode of joint attention and that of responding to it—which relate to different skills, follow different developmental pathways (Mundy & Sigman, 2006; Mundy et al., 2007; Slaughter & McConnell, 2003), and originate in different brain regions (Mundy, Card, & Fox, 2000). It is thus a multifaceted construct that reflects the development of multiple processes. Although they are credited with joint attention skills, 1-year-olds prove to be quite poor at using these skills Dorsomorphin order in

play episodes of triadic interaction. In their pivotal study, Bakeman and Adamson (1984) observed infants from 6 to 18 months of age playing at home with their mothers and a set of appropriate toys. Only one third of 9-month-olds was found to engage in coordinated joint play. Moreover, the amount of time spent in that kind of play did not exceed 10% of the total play period until the age of 15 months, and only at 18 months G protein-coupled receptor kinase were all infants observed in coordinated episodes at least once. The authors concluded that joint attention

begins very early in life but develops very slowly. The same conclusion was drawn in a more recent study (Adamson, Bakeman, & Deckner, 2004) covering a subsequent age period, from 18 to 30 months, when the triadic ability is well established and becomes infused with symbols. Children were found to advance into the symbolic level of joint engagement as slowly as they had into the presymbolic level the year before. In particular, children were able to use symbols routinely only at the end of the observed period and mainly in supported episodes, where most of the responsibility for sharing fell on the mother rather than on the child. Even then, only 50% of the time spent in shared activity was symbol infused, meaning that 30-month-old children still do not use language as an integral part of an activity and need more developmental time before they are able to do so routinely (Nelson, 1996). The gap between the first display of coordinated attention and its use in social play may be owed to the communicative demands that social play places on young children.