Social facilitation of object-oriented hand use in a Rett syndrome variant girl: implications for partial preservation of an hypothesized specialized cerebral network.

Partial preservation of object-oriented hand use (OOHU) was studied behaviorally in a 6-1/2-year-old girl with the preserved speech variant (PSV) of Rett syndrome (RS), associated with a T 158 missense MeCP2 mutation and favorably skewed X-inactivation. At home, OOHU was limited except for self-feeding. When examined, overall time invested in toy play was only 38% of that of healthy subjects, and also, by comparison with healthy subjects, less when autonomous than when socially-facilitated (13% vs 63%). Good interest in and responsiveness to people translated into better motivation for OOHU. She responded to others' requests for grasping and handling objects and used them to reinforce affiliations with people. Results were discussed in terms of a disruption of the formation of a specialized OOHU cerebral network in RS, partially compensated for by the favorably skewed X-inactivation, which among other effects permitted functional retention of the network segment incorporating social influence and motivation.

Child language with mother and with stranger at home and in the laboratory: a methodological study.

This methodological study in 33 two-year-olds shows that child speech (total utterances, word roots, MLU) occurs at about the same level in different settings (the familiar home vs. the unfamiliar laboratory), but that children speak more and in more differentiated ways with different people (mother vs. stranger). Child speech also shows significant short-term stability. Girls use more different word roots and speak in longer utterances than do boys. In spontaneous child speech, cross-context generalizations appear warranted, but they also depend on conversational partner and gender of child.

Representational abilities and the hearing status of child/mother dyads.

Two representational abilities, expressive and receptive language and symbolic play, were assessed in multiple formats in hearing and deaf 2-year-old children of hearing and deaf mothers. Based on maternal report, hearing children of hearing and deaf mothers produced more words than deaf children of hearing mothers, hearing children of hearing mothers more words than deaf children of deaf mothers, and deaf children of deaf mothers more words than deaf children of hearing mothers. Based on experimenter assessments, hearing children in both groups produced and comprehended more words than deaf children in both groups. By contrast, no differences emerged among these groups in child solitary symbolic play or in child-initiated or mother-initiated child collaborative symbolic play; all groups also increased equivalently in symbolic play between solitary and collaborative play. Representational language and symbolic play were unrelated in hearing children of hearing mothers and in deaf children of deaf mothers, but the 2 abilities were associated in children in the 2 child/mother mismatched hearing status groups. These findings are placed in the context of a proposed developing modularity of verbal and nonverbal symbol systems, and the implications of hearing status in communicative exchanges between children and their mothers in diverse hearing and deaf dyads are explored.

Play in two societies: pervasiveness of process, specificity of structure.

The present study compared Argentine (N = 39) and U.S. (N = 43) children and their mothers on exploratory, symbolic, and social play and interaction when children were 20 months of age. Patterns of cultural similarity and difference emerged. In both cultures, boys engaged in more exploratory play than girls, and girls engaged in more symbolic play than boys; mothers of boys engaged in more exploratory play than mothers of girls, and mothers of girls engaged in more symbolic play than mothers of boys. Moreover, in both cultures, individual variation in children's exploratory and symbolic play was specifically associated with individual variation in mothers' exploratory and symbolic play, respectively. Between cultures, U.S. children and their mothers engaged in more exploratory play, whereas Argentine children and their mothers engaged in more symbolic play. Moreover, Argentine mothers exceeded U.S. mothers in social play and verbal praise of their children. During an early period of mental and social growth, general developmental processes in play may be pervasive, but dyadic and cultural structures are apparently specific. Overall, Argentine and U.S. dyads utilized different modes of exploration, representation, and interaction--emphasizing "other-directed" acts of pretense versus "functional" and "combinatorial" exploration, for example--and these individual and dyadic allocentric versus idiocentric stresses accord with larger cultural concerns of collectivism versus individualism in the two societies.

Sources of child vocabulary competence: a multivariate model.

This study examines sources of individual variation in child vocabulary competence in the context of a multivariate developmental ecological model. Maternal sociodemographic characteristics, personological characteristics, and vocabulary, as well as child gender, social competence, and vocabulary competence were evaluated simultaneously in 126 children aged 1;8 and their mothers. Measures of child vocabulary competence included two measures each of spontaneous speech, experimenter assessments, and maternal reports. Maternal measures, from proximal to distal, included vocabulary, verbal intelligence, personality, attitudes toward parenting, knowledge of parenting, and SES. Structural equation modelling supported several direct unique predictive relations: child gender (girls higher) and social competence as well as maternal attitudes toward parenting predicted child vocabulary competence, and mothers' vocabulary predicted child vocabulary comprehension and two measures of mother-reported child vocabulary expression. In addition, children's vocabulary competence was influenced indirectly by mothers' vocabulary, social personality, and knowledge of child development. Maternal vocabulary itself was positively influenced by SES, maternal verbal intelligence, and mothers' knowledge about parenting. Individual variation in child vocabulary competence might best be understood as arising within a nexus of contextual factors both proximal and distal to the child.

Solitary and collaborative pretense play in early childhood: sources of individual variation in the development of representational competence.

This study evaluates sources of individual variation in child pretense play as an expression of emerging mental representation. Family sociodemographic characteristics, maternal personological characteristics, and maternal affective and cognitive play behaviors, as well as children's gender, language competence, and play, were examined simultaneously. Naturalistic child solitary play and child collaborative play with mother were videorecorded in 141 20-month-olds. Child solitary play, child-initiated and mother-initiated collaborative play with mother, and maternal demonstrations and solicitations of play were then coded into nonsymbolic and symbolic acts. Zero-order relations obtained between child play and, respectively, child gender and language, family SES, and maternal verbal intelligence, personality, physical affection, and play demonstrations and solicitations. Structural equation modeling supported the following unique predictive relations: Child language and mothers' symbolic play positively influenced child collaborative play, and child gender and mothers' verbal intelligence predicted child solitary play. Child gender and mothers' verbal intelligence and physical affection influenced mothers' play and so influenced child collaborative play indirectly. The cognitive advantages of child play and maternal influences on child play are placed in an adaptive parenting framework.