Virginie Dardier

Childhood exposure to polybrominated diphenyl ethers and neurodevelopment at six years of age.

Mixtures of polybrominated diphenyl ethers (PBDEs) are present in indoor environments. Studies of the developmental effects of exposure to these chemicals in large prospective mother-child cohorts are required, with data on prenatal exposure and long-term follow-up of the children. We aimed to investigate the relationship between prenatal and childhood exposure to PBDEs and neurodevelopment at the age of six years. We determined the levels of PBDEs and other neurotoxicants in cord blood and dust collected from the homes of children for 246 families included in the PELAGIE mother-child cohort in France. We assessed two cognitive domains of the six-year-old children using the Wechsler Intelligence Scale for Children-IV. Verbal comprehension scores were lower in children from homes with higher concentrations of BDE99 (βDetects<median_vs_NonDetects=-1.6; 95% CI: -6.1, 2.9; βDetects≥median_vs_NonDetects=-5.4; -9.9, -1.0; p trend=0.02) and of BDE209 (β2nd_vs_1st_tertile=-1.8; 95% CI: -6.1, 2.5; β3rd_vs_1st_tertile=-3.2; -7.5, 1.2; p trend=0.15) in dust, particularly for boys (p trend=0.02 and 0.04, respectively). Working memory scores seemed to be lower in children with higher BDE99 concentrations in dust (p trend=0.10). No association was observed with cord blood levels of BDE209. Our findings are in agreement with those of four previous studies suggesting adverse cognitive outcomes among children associated with early-life exposure to penta-BDE mixtures, and provide new evidence for the potential neurotoxicity of BDE209. Several countries are in the process of banning the use of PBDE mixtures as flame-retardants. However, these compounds are likely to remain present in the environment for a long time to come.

A Study of Gender Similarity Between Animated Pedagogical Agents and Young Learners

Gender is strongly involved in the organization of interactions. According to the similarity-attraction hypothesis, learners may be more attracted to animated pedagogical agents that are similar to them, especially with regard to gender. Research on gender matching has so far yielded mixed results. However, the frequent use of tasks related to science, technology, engineering or mathematics may have interfered with the similarity-attraction relationship in these studies, as gender stereotypes suggest that boys are more associated with these fields than women. The aim of our study was to examine the effect of gender similarity on young learners (N = 47) performing a neutral task. Gender similarity was found to have a positive impact on learners’ perceptions of animated pedagogical agents, but in the opposite-gender condition, learners were more engaged in the task. We discuss our results in the light of theory and previous research on gender matching.

Échanges conversationnels avec un partenaire familier : étude comparative entre enfants sourds, implantés cochléaires depuis 2 ans et enfants entendants

Resume Les enfants sourds affichent tres souvent des difficultes a s’approprier les conventions et regles implicites regissant l’utilisation du langage. De ce fait la pose d’un implant cochleaire devrait permettre a des enfants atteints de surdite profonde de presenter des profils de production langagiere se rapprochant de ceux des enfants entendants du meme âge. Dans cette perspective, 18 enfants implantes depuis 24 mois et 18 enfants entendants ont ete filmes en situation de jeu, avec un partenaire familier. Les indices structurels et pragmatiques des productions indiquent, malgre un lexique moins etendu, une predominance de la modalite orale chez les enfants implantes. La repartition des differents actes de langage apparait comme comparable a celle observee chez les enfants entendants. La quantite de tours de parole reste cependant moindre chez les enfants implantes. En conclusion, malgre les differences observees, le developpement des echanges conversationnels permis par l’implant se rapproche de celui de l’enfant entendant.