THE ROUGH GUIDE TO PSYCHOLOGYthat isn’t dedicated to processing any one type of information. Moving
from front to back across the cortex, we find the frontal lobes beginning
above the eyes (including the anterior cingulate cortex characterized by
some as part of the “oh shit!” circuit of error monitoring), followed by the
parietal cortex near the crown of the head, and then the occipital cortex
at the back of the head. On either side of your ears we find the temporal
lobes. If you unfolded the cortex and laid it out on a table, it would cover
an area about 1m^2 and about 2 to 5mm deep.
Also visible from the outside of the brain, roughly level with the nape
of your neck, is the cauliflower-like cerebellum, which plays an impor-
tant role in movement and learning. It almost looks like a mini-version
of the brain, with its own two hemispheres and, amazingly, although it
only accounts for ten percent of the brain’s volume, it contains more
neurons than the rest of the brain put together. In relative terms, the
cerebellum is particularly large in organisms like fish, which depend on
agility for survival.
Some myths about the brain
T The ten percent myth. The most enduring and ubiquitous brain
myth must surely be the idea that we use only ten percent of our
brains. Sadly, this is far from true as the suffering and disability
experienced by many a stroke sufferer surely illustrates. Even the
tiniest area of brain damage can have devastating consequences.
It’s true the brain has an impressive ability to adapt to damage. But
this doesn’t mean that under normal circumstances all our healthy
nervous tissue isn’t put to good use. This can be seen to dramatic
effect in brain scanner images, which show the whole organ
pulsing with activity.
T Left brain vs. right brain. This is perhaps more of a simplifica-
tion than a myth – the popular idea that the left side of the
brain is cold and logical while the right-hand side is creative and
intuitive. It’s true that we have two brain hemispheres that appear
to be differentially activated by different kinds of task. The most
obvious example is language functions, which in most people are
predominantly localized to the left hemisphere. But the reality
is rather more complex than the myth suggests. For example,
while the left hemisphere is dominant for language, the right
hemisphere is involved in language processing too, especially
when it comes to understanding the gist of what’s said. In reality,
our two hemispheres work together, so it’s unwise to think of the
brain as comprising two separate specialist systems.