How To Build A Baby's Brain

In adults who were abused as children, the memory-making hippocampus is smaller than in nonabused adults. This effect, too, is believed to be the result of the toxic effects of cortisol.

High cortisol levels during the vulnerable years of zero to 3 increase activity in the brain structure involved in vigilance and arousal. (It's called the locus ceruleus.) As a result the brain is wired to be on hair-trigger alert, explains Perry: regions that were activated by the original trauma are immediately reactivated whenever the child dreams of, thinks about or is reminded of the trauma (as by the mere presence of the abusive person). The slightest stress, the most inchoate fear, unleashes a new surge of stress hormones. This causes hyperactivity, anxiety and impulsive behavior. "The kids with the higher cortisol levels score lowest on inhibitory control," says neuroscientist Megan Gunnar of the University of Minnesota. "Kids from high-stress environments [have] problems in attention regulation and self-control."

Trauma also scrambles neurotransmitter signals, ratcheting up some and depressing others. Since neurotransmitters play key roles in telling growing neurons where to go and what to connect to, children exposed to chronic and unpredictable stress--a mother's boyfriend who lashes out in fury, an alcoholic uncle who is kind one day and abusive the next--will suffer deficits in their ability to learn. "Some percentage of capacity is lost," says Perry. "A piece of the child is lost forever."

That is tragedy enough, of course, but it is made even greater by the loss of what could have been. Babies are born into this world with their brain primed to learn. But they cannot do it alone.

53% of all parents say that they read to their child every day; 55% of parents say they sing to or play music for their child every day.

Andrew Murr in Los Angeles

© 1997