Page 96 - Design in Nature

94 DESIGN IN NATURE

visual cortex is composed of many regions, one on top of the other, about
1/10 inch (2.5 mm) in thickness and 145 square feet (13.5 square metres) in
area. Each one of these regions includes about seventeen million neurons.
The 4th region receives the incoming signal first. After a preliminary
analysis, it forwards the data to neurons in other regions. In any phase, any

neuron can receive a signal from any other neuron.
This way, the man's picture forms in the visual cortex of the brain.
However, the image now needs to be compared to the memory cells, which
is also done very smoothly. Not a single detail is overlooked. Furthermore,
if the friend's perceived face looks slightly more pale than normal then the
brain activates the thought, "why is my friend's face so pale today?"

Greeting
That's how two separate miracles happen within a period of time less
than a second, which we refer to as "seeing" and "recognising".
The input that arrives in hundreds of millions of light particles reaches
the mind of the person, is processed, compared to the memory and enables
the man to recognise his friend.
Agreeting follows recognition. A person deduces the reaction to be
given to acquaintances from within the memory cells in less than a second.
For example, he determines that he needs to say "greetings" upon which the

brain cells controlling facial muscles will command the move that we know
as a "smile". This command is similarly transferred through nerve cells and
triggers a series of other complicated processes.
Simultaneously, another command is given to the vocal cords in the
throat, tongue and the lower jaw and the "greetings" sound is produced by
the muscle movements. Upon release of the sound, air molecules start
travelling towards the man to whom the greeting is sent. The auricle gathers

these sound waves, which travel at approximately twenty feet (six metres)
per one fiftieth of a second.
The vibrating air inside both ears of that person rapidly travels to his