Page 174 - (DK) How to be a GENIUS?

HOW THE BRAIN Making connections

During the months after birth, the brain
GROWS structure that can control only the basic
develops fast. At first it has a simple cell
survival functions. But every new
stimulus to the senses triggers the
restructuring of nerve cells into the
k th t t
i f
net
tworks that store information and
ti
d
enable us to think. Like the girders
below, they are rearranged into
a new, more complex form.
Most of the development of the braain takes place before
a baby is born, so at birth the brain contains almost all the
D
nerve cells that it will ever have. During childhood, these
cells are rearranged into increasingly complex networks
n
that allow us to learn and remembber. The brain reaches
peak weight in early adulthood and then starts to shrink.

3 weeks 7 weeks 1 11 weeks
Beginnings
During the early stages of a baby’s development in the
womb, the brain forms at the end of a tube of cells that
l
eventually becomes the spinal cord. At first it reseembles
w
the brain of a fish, with all the “primitive” parts well
formed. But at around 11 weeks, the cerebrum sttarts
n
io
to expand, until at birth it looks like a smaller version
of a mature human brain.

Trimming down
Once the brain is up and running,
it starts economizing on nerve cells.
Inactivated cells are allowed to die
off—a process that starts at the age of
around four and continues for the rest of
your life. This does not affect the brain’s
efficiency, however, because inactive
brain cells have no function and simply
waste energy. So they are thrown away,
just like these spare girders being
tossed into a Dumpster.

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