infant environment

Older news items (pre-2010) brought over from the old website

Prefrontal cortex activity in poor children like that of stroke victim

An imaging study of 26 normal 9- and 10-year-olds differing only in socioeconomic status has revealed detectable differences in the response of their prefrontal cortex. While not invariant, those from lower socioeconomic levels were more likely to have low frontal lobe response. This is consistent with earlier studies, but is the first to demonstrate the effect when there is no issue of task complexity (the task was very simple; the measure was how fast the child responded to an unexpected novel picture — the response of many from low socioeconomic backgrounds was similar to the response of adults who have had a portion of their frontal lobe destroyed by a stroke). The effect is thought to be due to growing up in cognitively-impoverished and stressful environments, since these have been found to affect the prefrontal cortex in animal studies. Further research is looking into whether these brain differences can be eliminated by training.

Kishiyama, M.M. et al. 2008. Socioeconomic Disparities Affect Prefrontal Function in Children. Journal of Cognitive Neuroscience

http://www.eurekalert.org/pub_releases/2008-12/uoc--esb120208.php

Early life stress can lead to memory loss and cognitive decline in middle age

Age-related cognitive decline is probably a result of both genetic and environmental factors. A rat study has demonstrated that some of these environmental factors may occur in early life. Among the rats, emotional stress in infancy showed no ill effects by the time the rats reached adulthood, but as the rats reached middle age, cognitive deficits started to appear in those rats who had had stressful infancies, and progressed much more rapidly with age than among those who had had nurturing infancies. Middle-aged rats who had been exposed to early life emotional stress showed deterioration in brain-cell communication in the hippocampus.

http://www.eurekalert.org/pub_releases/2005-10/uoc--els100605.php

Varied sensory experience important in childhood

A new baby has far more connections between neurons than necessary; from birth to about age 12 the brain trims 50% of these unnecessary connections while at the same time building new ones through learning and sensory stimulation — in other words, tailoring the brain to its environment. A mouse study has found that without enough sensory stimulation, infant mice lose fewer connections — indicating that connections need to be lost in order for appropriate ones to grow. The findings support the idea that parents should try to expose their children to a variety of sensory experiences.

Zuo, Y., Yang, G., Kwon, E. &Gan, W-B. 2005. Long-term sensory deprivation prevents dendritic spine loss in primary somatosensory cortex. Nature, 436, 261-265.

http://www.sciencentral.com/articles/view.htm3?article_id=218392607

Mother's work schedule may impact her child's cognitive development

A new study suggests that a mother who works nonstandard hours, such as evenings, nights or rotating shifts, may significantly affect her young child's intellectual development. The study used information from the National Institute of Child Health Development's (NICHD) Study of Early Child Care, which tracked 1,364 children from 10 sites around the country from birth in 1991 through 36 months. Her study focused on 900 children whose mothers had worked in the first three years of their child's life. About half the working mothers worked at nonstandard hours during this time. Even after controlling for the quality of the home environment and child care, maternal depression, and the mother's sensitivity towards her children, researchers found that the children of mothers who worked nonstandard work schedules during their first three years of life performed much worse on cognitive tests, particularly if these schedules began in the 1st year, and particularly for measures of cognitive development at 24 months and expressive language at 36 months. It’s suggested that one reason may be the type of care children receive when their mothers work such hours.

Han, W-J. 2005. Maternal Nonstandard Work Schedules and Child Cognitive Outcomes. Child Development, 76 (1), 137-154.

http://www.eurekalert.org/pub_releases/2005-02/sfri-mws020105.php

Growing up in a chaotic home may impair child's cognitive development

An association between disorganized, noisy and cramped homes and lower childhood intelligence has been observed before, but the reasons for the association have never been clear. Now a study of some 8000 3- and 4-year-old twins has perhaps disentangled the variables, and has found that chaos had an influence on cognitive skills independent of socioeconomic status. The findings also suggest that when the environment is more stressful, intelligence is more likely to be constrained by genes.

Petrill, S.A., Pike, A., Price, T. & Plomin, R. 2004. Chaos in the home and socioeconomic status are associated with cognitive development in early childhood: Environmental mediators identified in a genetic design. Intelligence, 32 (5), 445-460.

http://www.newscientist.com/news/news.jsp?id=ns99996323