Need for an internal communication system
Communication amongst different parts of the body is very important. Special cells are designed to meet the demands of the communication superhighway within complex organisms, such as the human body. Just as the phone provides a means for people to communicate amongst each other as do nerve cells provide the means for rapid communication between different parts of the body.

In a fraction of a second a cricketer must decide what shot to play and how to execute the shot. Information is pouring in to the brain for processing. The cricketer must first sight the ball and work out its speed, direction and spin. The brain deciphers all the information and arrives at the best possible decision. Signals are quickly dispatched via the nervous system to the appropriate muscles that will take part in playing the shot. Muscle contractions are coordinated so that the cricketer executes the shot correctly.

This cricketer practices many hours a day. By practicing repeatedly, communication pathways within the body are reinforced and signals travel quickly through these pathways when the time comes.
Why do you think sports stars spend many hours practicing the basics of their particular sport? Repetition develops communication pathways within the brain and body which enable the player to execute a perfect technique with little thought and effort when required.
Communication pathways are not infinitely fast. Time is required for signals to reach the brain, be interpreted and the response relayed to the muscles or organs. Below is a little exercise that shows how slow communication can be.

You will need a ruler and some reward such as a ten dollar note. Hold the ruler vertically and ask a friend to place their index finger and thumb around the ruler 7cm from the top, as shown on the right.

Ask your friend to grab the ruler as it falls. If they succeed they get the ten dollars. Don't worry they haven't a chance. Release the ruler without a warning and watch. No matter how hard they concentrate it is impossible to catch the ruler. Why?
The time it takes for the signal to alert the brain that the ruler is falling and for the response signal to reach the muscles of the fingers, is longer than the time required for the ruler to fall 7cm.

Mental visualisation

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