Looking for an answer

In the world of the Internet, there are thousands of people who specialize in the art of "search engine optimization" . This is the practice of designing web sites in such a way as to cause a web site to appear high up in the list of alternative sources presented by a search engine when particular key words or phrases are entered.

The essence of their skills is an appreciation of the ways in which search engines give their weightings to the various alternatives. In other words, they try to discover the nature of the algorithms that the search engines use and the weightings given to the criteria they use.

In a similar way, thousands of psychologists are trying to unravel the mechanisms in the brain that are the equivalent to the search engine algorithms - mechanisms that determine the optional preferences from a variety of different possibilities. For most of the last century this was an impossibly difficult task, but within recent times sophisticated brain imaging techniques and a new understanding of dynamic complex systems have led to major breakthroughs in understanding.

It is now known how emotions play a significant part in selecting, influencing and ordering memories, thoughts and behavior. It is now known how different parts of the brain are brought into play to create perceptions, bring about opinions that result in decision making.

The key to this understanding is an appreciation of the way in which the brain is capable of massive parallel processing, allowing multiple neural mechanisms to be brought into play simultaneously. This is achieved by means of an ingenious switching mechanism, which utilizes some of the special characteristics of chaotic systems.

In the next chapter, we shall be looking at this switching mechanism in detail, seeing how it is able to navigate the complexity of the fifty billion neurons in the brain and arrange for multiple neural networks to be brought into play simultaneously in response to variations in sensory inputs.