Booknotes: What’s Going on in There? How the Brain and Mind Develop in the First Five Years of Li

Booknotes: What’s Going on in There? How the Brain and Mind Develop in the First Five Years of Li

I’ve got this book out from the library now and am only in the first chapter. I’ll probably be checking it out a few more times. This is fascinating stuff.

The author, Lise Eliot is a mother and neuroscientist. The book opens with her in her laboratory conducting an experiment on a neuron while trying to nurse her nine-week old baby. An experiment which baby Julia ruins when, distracted by the light of the computer screen, she pulls off the breast and kicks her foot into the delicate micromanipulator.

It gets technical and I kind of skim over some of the details; but it’s readable. The science is punctuated by personal stories. Her explanation of fetal brain development begins with a hypothetical couple, Jessica and Dave and tracks their son, Jack’s growth from the moment of his conception. Personalizing the example makes it so much easier to follow.

A few things that have stood out as I read. (I really wish I owned this book so I could underline and write marginalia. It’s that kind of book. A poor second is typing up notes here.)

Eliot says:

My bias is thus that of a biologist: the conviction that we cannot understand children’s minds until we understand the structure and physiology of their brains. But biology also offers another hope, a way of finally resolving the age-old nature/nurture debate. From the first cell division, brain development is a delicate dance between genes and environment, and it is only by understanding each of these subtle interactions that we can grasp, for each fascinating facet of the mind, the degree to which heredity and experience make us who we are.

I like the idea of biology resolving the nature/nurture debate. I’m looking forward to watching how that develops.
This number just jumped at me: “At its peak, some 15,000 synapses are produced on every cortical neuron, which corresponds to a rate of 1.8 million new synapses per second between two months of gestation and two years after birth!” I look at Ben with new admiration thinking of all those synapses being created as I watch him crawl across the floor.

…laboratory rats that have been reared in an “enriched” environment—in a large cage containing several litters and a wide variety of “toys” to see, smell, and manipulate—have larger brains, with a notably thicker cerebral cortex, than those raised in an “impoverished” environment—isolated in a small empty cage, without any social stimulation and a bare minimum of sensory experience. The reason their cerebral cortex is bigger, researchers have found, is that their neurons are larger, with bigger cell bodies, more dendritic branches, more spines, and more synapses than those in the brains of impoverished rats. In other words, the extra sensory and social stimulation actually enhances the connectivity of the enriched rats’ brains, a difference that probably explains why they are also smarter—they learn their way around a baited maze significantly faster—than their impoverished laboratory mates.

It is no great stretch to see the implication of these experiments for human development:  A young child’s environment directly and permanently influences the structure and eventual function of his or her brain. Everything a child sees, touches, hears, feels, tastes, thinks, and so on translates into electrical activity in just a subset of his or her synapses, tipping the balance for long-term survival in their favor. On the other hand, synapses that are rarely activated—whether because of languages never heard, music never made, sports never played, mountains never seen, love never felt—will wither and die. Lacking adequate electrical activity, they lose the race, and the circuits they were trying to establish- for flawless Russian, perfect pitch, an exquisite backhand, a deep reverence for nature, healthy self-esteem—never come to be.

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