When computers were first developed, it soon became apparent that these machines have many features in common with the nervous system. First, all computers have input circuits that can be compared with the sensory portion of the nervous system, as well as output circuits that are analogous to the motor portion of the nervous system.
In simple computers, the output signals are controlled directly by the input signals, operating in a manner similar to that of simple reflexes of the spinal cord. In more complex computers, the output is determined both by input signals and by information that has already been stored in memory in the computer, which is analogous to the more complex reflex and processing mechanisms of our higher nervous system. Furthermore, as computers become even more complex, it is necessary to add still another unit, called the central processing unit, which determines the sequence of all operations. This unit is analogous to the control mechanisms in our brain that direct our attention first to one thought or sensation or motor activity, then to another, and so forth, until complex sequences of thought or action take place.
Figure 1 is a simple block diagram of a computer. Even a rapid study of this diagram demonstrates its similarity to the nervous system. The fact that the basic com ponents of the general-purpose computer are analogous to those of the human nervous system demonstrates that the brain has many features of a computer, continuously collecting sensory information and using this along with stored information to compute the daily course of bodily activity.
Fig1. Block diagram of a general-purpose computer showing the basic components and their interrelations.
