Page 146 - The Miracle of Electricity in the Body

144 THE MIRACLE OF ELECTRICITY IN THE BODY

Cerebral cortex

Spinal
cord When you pick up a ball or touch the strings
of a guitar, no matter how light your touch
may be, still you detect a feeling of pressure
in your fingers. This light movement sets into
Motor neurons action thousands of touch-sensitive nerve re-
ceptors concentrated in your fingertips.
Together with this pressure, an electrical cur-
rent begins in special cells covering the nerve
Muscle
fibers endings near the skin surface. This current is
transmitted to the brain by nerve fibers at a
speed of 130 meters (426 feet) a second.

example, when you touch a rough surface, you can never know if it is re-
ally rough, because you can never make direct contact with a rough sur-
face. All you know about its surface consists of your brain analyzing spe-
cific stimuli.
Millions of receptors of various sensitivities in the skin react to heat,
cold, touch, pain, pressure and motion. These receptors send electrical
signals to the brain and by means of these signals, we obtain information
about the object we touch.
This book you are holding, together with all its details, is recreated
in your brain. There is a physical book in the outside world, but one you
are interacting with consists of a copy in your brain. The sensations of
touching the book are entirely the analysis of electrical signals.
Therefore, you are actually turning the pages and feeling the texture of
the book in your brain. You can never touch the original book.