If a child is kept solitary and never talked to during their first three years, they aren't hearing the sounds that wire their brain for speech. If they aren't hearing those sounds, then at around age 1 when speech areas begin to mature and become hyperactive, the stimulation needed to develop them isn't there. If neglect causes severe deprivation during the time when those areas are designed to grow, their moment in the spotlight will pass on by without the proper neural connections being made. If such a child were rescued at age 3 and given a proper environment, he or she would probably learn to talk, but they would also likely suffer a noticeable, permanent disability in speech and language areas. Experience shows that children who are severely neglected in early childhood show severe and permanent disabilities that can't be fully corrected. (Chugani et al., 2001) The longer the deprivation, the less malleable the brain becomes and the more severe and permanent the disability becomes. Imagine it like a tunicate. The tighter you tie it, the more blood it will cut off. The longer it's kept on, the more cells will die from the deprivation of blood. Severe neglect works under the same principles. The more severe the deprivation, the less of this vital sensory input reaches the brain. The longer such deprivation goes on, the more neural connections in the brain will die off because of it.
We'll explore these different windows in our discussions of different ages and stages. But before moving on, we must say this: windows of opportunity usually only become an issue in cases of severe deprivation. Very few cases of maltreatment rise to the level of severe and complete deprivation that can cause a child to miss their window of opportunity. Having worked with numerous kids considered to have been neglected or have come from "disadvantaged" backgrounds, I know that love and attention in substantial doses will overcome just about any situation or disadvantage they sustained. We certainly wouldn't want to instill readers with any false, harmful beliefs about what a disadvantaged child is capable of. Even if the environment in their past was far from ideal, so long as the sensory input was there to develop their brain in at least some capacity, it can be strengthened and refined through what you do now. It's only when such stimulation is virtually nonexistent that problems with a child's window of opportunity begin to arise. It may be hard playing catch up, but only in cases of severe deprivation does it become impossible.
Child maltreatment can begin long before the child is born. Even in the womb, the fetus is "highly vulnerable to both good and bad experiences." (Jensen, 2006, p. 91) A baby is incubated in the chemical environment of its mother, and can be altered for better or worse by the mother’s environment. Prenatal stress can be a significant factor in reduced brain development, memory formation, and cognition. (Huizink, Mulder & Buitelaar, 2004) Such prenatal stress can even influence the genetic material in the newborn. This ability of the environment to influence and alter genetics starts at conception. (Reik, Dean & Walter, 2001) A mother’s stress is her baby's stress, and stress is a bad thing for the developing fetus. On the more positive side, a positive maternal environment can enrich a newborn. When scientists provide an enriched environment for a female rat, her newborn pups will show positive improvements in cognitive functioning from birth. (Diamond & Hopson, 1999) More on this will be discussed in our chapter on fetal abuse.