Institut for Kommunikation og Kultur

We investigate mother-child linguistic adaptation in 33 ASD and 33 matched TD children at two time-scales: conversational match and longitudinal development. We employ a longitudinal corpus (6 visits over 2 years) consisting of controlled playful activities between mothers and their children (Goodwin et al. 2012). We quantified amount (number of words and utterances) and complexity (lexical repertoire and utterance length) of linguistic behavior in both mother and child. We used mixed-effects growth curve models to quantify i)match within-conversation and ii)longitudinal impact between visits. Child and mother are strongly correlated in their linguistic behaviors (R2 between .07 and .62, p<0.001), with number of words and lexical repertoire becoming increasingly matched with age. Mother-child pairs in the ASD group, however, show a shallower increase in match. Amount and complexity of the mother’s speech statistically predicts the amount and complexity in the child’s speech in the following visit (R2 between .1 and .26, p<0.001), with ASD playing no role. Likewise, the child’s linguistic behavior predicts the mother’s linguistic behavior in the following visit (R2 between .1 and .3, p<0.001), In the ASD group, however, the impact of child’s linguistic behavior on mother’s linguistic behavior was significantly less(p<.05).