Larger Amygdala but no Change in Hippocampal Volume in 10-Year-Old Children Exposed to Maternal Depressive Symptomatology since Birth
Référence bibliographique 
Lupien, Sonia J., Parent, Sophie, Evans, Alan C., Tremblay, Richard E., Zelazo, Philip David, Corbo, Vincent, Pruessner, Jens C. et Séguin, Jean R. 2011. «Larger Amygdala but no Change in Hippocampal Volume in 10-Year-Old Children Exposed to Maternal Depressive Symptomatology since Birth ». Proceedings of the National Academy of Sciences, vol. 108, no 34, p. 1-6.
Intentions : The authors want «[t]o determine if poor maternal care associated with maternal depressive symptomatology has a similar pattern of association to the volumes of the hippocampus and amygdala in children [...].» (p. 1)
Échantillon/Matériau : The sample of this study is composed of 38 children born in 1996 selected from a ongoing Quebec Longitudinal Study of Child Development. «Two-way repeated-measure ANOVAs were performed on amygdala and hippocampal volumes using MDS group and sex as the between-subject factors and hemisphere (left versus right volume) as the within-subject factor. [And] a two-way repeated-measure ANOVA was performed on salivary glucocorticoid levels using MDS group and sex as the between-subject factors, time (arrival versus prescan versus postscan) as the within-subject factor, and time of sampling as a covariate.» (p. 2)
Type de traitement des données : Anlayse statistique
«Maternal separation and poor maternal care in animals have been shown to have important effects on the developing hippocampus and amygdala. In humans, children exposed to abuse/maltreatment or orphanage rearing do not present changes in hippocampal volumes. However, children reared in orphanages present enlarged amygdala volumes, suggesting that the amygdala may be particularly sensitive to severely disturbed (i.e., discontinous, neglectful) care in infancy. Maternal depressive symptomatology has been associated with reductions in overall sensitivity to the infant, and with an increased rate of withdrawn, disengaged behaviors. [...] Results revealed no group difference in hippocampal volumes, but larger left and right amygdala volumes and increased levels of glucocorticoids in the children of mothers presenting depressive symptomatology since birth. Moreover, a significant positive correlation was observed between mothers’ mean depressive scores and amygdale volumes in their children. The results of this study suggest that amygdala volume in human children may represent an early marker of biological sensitivity to quality of maternal care.» (p. 1)
Closing the Gap in Academic Readiness and Achievement: The Role of Early Childcare
Référence bibliographique 
Geoffroy, Marie-Claude, Côté, Sylvana, Giguère, Charles-Edouard, Dionne, Ginette, Zelazo, Philip David, Tremblay, Richard E., Boivin, Michel et Séguin, Jean. 2010. «Closing the Gap in Academic Readiness and Achievement: The Role of Early Childcare ». Journal of Child Psychology and Psychiatry, vol. 51, no 12, p. 1359-1367.
Intentions : « Socially disadvantaged children with academic difficulties at school entry are at increased risk for poor health and psychosocial outcomes. Our objective is to test the possibility that participation in childcare – at the population level – could attenuate the gap in academic readiness and achievement between children with and without a social disadvantage (indexed by low levels of maternal education). » (p. 1359)
Échantillon/Matériau : « A cohort of infants born in the Canadian province of Quebec in 1997/1998 was selected through birth registries and followed annually until 7 years of age (n = 1,863). » (p. 1359)
Instruments : - Lollipop Test for School Readiness - Peabody Picture Vocabulary Test Revised - Number Knowledge Test - Kaufman Assessment Battery for children
Type de traitement des données : Analyse statistique
« Children of mothers with low levels of education showed a consistent pattern of lower scores on academic readiness and achievement tests at 6 and 7 years than those of highly educated mothers, unless they received formal childcare. Specifically, among children of mothers with low levels of education, those who received formal childcare obtained higher school readiness (d = 0.87), receptive vocabulary (d = 0.36), reading (d = 0.48) and math achievement scores (d = 0.38; although not significant at 5%) in comparison with those who were cared for by their parents. Childcare participation was not associated with cognitive outcomes among children of mothers with higher levels of education. [...] Public investments in early childcare are increasing in many countries with the intention of reducing cognitive inequalities between disadvantaged and advantaged children. Our findings provide further evidence suggesting that formal childcare could represent a preventative means of attenuating effects of disadvantage on children’s early academic trajectory. » (p. 1359)