YOUR SENSING BRAIN

Wherever you go, whatever you do, the world stirs your senses. It is there in the sparkle of fireworks, the flavor of watermelon, the crack of a baseball bat and the scent of summer rain.
Sensations like these may seem to come to you automatically. But you only
perceive them thanks to an intricate
chain reaction of signals inside your
brain.

HOW IT WORKS

Specific areas of the brain are devoted
to seeing, hearing, smelling, tasting and
touching. They communicate like the
parts of an orchestra, so that your
experience feels rich, seamless and
complete. Here are two examples of how your
senses work:

SEEING

As you read this, your eyes are sending
information to the part of your brain
called the visual cortex. How does this area shape what you see? Even when you're just standing around,
your skin picks up information about
your surroundings. How does your brain take it in? Vision doesn't happen with the eyes
alone. Instead, many parts of your brain
work together. Your eyes send patterns
of light to the brain in the form of
electrical signals. One set of brain cells
takes them in and relays them to other cells down the line that sense shape,
color, or movement. Bit by bit, your brain
puts together the scene that you see and
finds meaning in the image. A special part of the brain perks up
whenever a human face comes into
view. Neurons in this region, called the
fusiform face area, help you recognize
familiar people by sensing precisely
how their features are arranged. You can identify many faces in an
instant, even when you don't see
clearly.

FEELING.

Even when you're just standing around,
your skin picks up information about
your surroundings. How does your brain take it in? When you come into contact with
objects around you, you feel them
immediately. But the feelings don't come
from your skin and muscles alone—they
form at the top of the brain, in a neatly
organized sensory center (the somatosensory cortex) that is linked
with your body from head to toe. As you interact with your surroundings,
touch signals rush to your brain from
every part of your body. To keep track
of it all, the brain has specialized areas
for taking in signals from each location.
The more sensitive the body part, the larger the brain area. For example,
touch centers for the hands and mouth
are especially large. Touch centers linked to the sensitive
fingers and lips are the largest and have
the most neurons. Touch centers
connected to less sensitive areas, like
the wrist and shoulder, are smaller and
have fewer neurons.