The infants of the contingent group, the group whose mothers responded directly after they vocalized, increased not only their number of vocalizations but also the quality of their sounds. Their sounds were more advanced and they had a higher rate of syllable production. The infants in the yoked group, the group whose mothers were instructed to wait a short period of time before positively reinforcing their infants, did not increase the quality of their sounds. They did, however, increase the number of responses in the extinction period because the responsiveness of their mothers was so much greater during the last 10 minutes than when their interactions were strictly scheduled (Goldstein, 2003). All of these results carry great significance when applied to mechanisms of speech
The infants of the contingent group, the group whose mothers responded directly after they vocalized, increased not only their number of vocalizations but also the quality of their sounds. Their sounds were more advanced and they had a higher rate of syllable production. The infants in the yoked group, the group whose mothers were instructed to wait a short period of time before positively reinforcing their infants, did not increase the quality of their sounds. They did, however, increase the number of responses in the extinction period because the responsiveness of their mothers was so much greater during the last 10 minutes than when their interactions were strictly scheduled (Goldstein, 2003). All of these results carry great significance when applied to mechanisms of speech