10
THE PHYSICAL BRAIN
What the Brain Does 11Emotions
Most theories of
emotion suggest that they
are preordained modes of
behavior that boost our survival
chances when we encounter
confusing or dangerous situations.
Others suggest emotions are
animal instincts leaking
through into human
consciousness.What does the
brain do?
The relationship between the
body and brain has long been a
subject of debate for scientists and
philosophers. In ancient Egypt, the brain
was dismissed as a system for shedding
heat, and the heart was the seat of emotion
and thought. Although our most significant
feelings are still described as heartfelt,
neuroscience shows that the brain
drives all body activities.Communication
A unique feature of the
human brain is the speech
centers that control the
formulation of language and the
muscular execution of speech. The
brain also uses a predictive
system to comprehend what
someone else is saying.Sensory experience
Information arriving from all
over the body is processed in the
brain to create a richly detailed
picture of the body’s surroundings.
The brain filters out a great deal
of sensory data deemed
irrelevant.Thinking
The brain is where thought
and imagination take place.
Thinking is a cognitive activity
that allows us to interpret the
world around us, while our
imagination helps us consider
possibilities in the mind without
input from the senses.Movement
To contract, muscles rely on
the same kind of electrical
impulses that carry nervous signals
through the brain and body. All
muscle movement is caused by
nerve signals, but the conscious
brain has only limited
control over it.Memory
The brain remembers a bank
of semantic knowledge, general
facts about the world, as well as a
personal record of life history. The
function of memory is to aid
future survival by encoding
useful information from
the past.Control
The basic body systems, such
as breathing, circulation,
digestion, and excretion, are all
under the ultimate control of the
brain, which seeks to modify
their rates to suit the needs of
the body.SMOOTHING OUT ALL THE WRINKLES OF THE
BRAIN’S OUTER LAYER WOULD COVER AN AREA
OF ABOUT 2½ SQUARE FT (2,300 SQUARE CM)
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