Quotation by Jeremy Campbell

Most of the brain consists of "wires"; a single unit may have thousands of connections with other units and with itself. That is not the case in a standard computer, where a chip usually has less than six connections. Moreover, neurons are much, much slower than the switching elements of the computer. It seems likely that the brain can accomplish its complex feats of perception and thought by means of millions of connections acting in parallel. The connections as a whole define the information content of the system. In this way a vast amount of knowledge can be brought to bear on a decision all at once. The brain seems to be able to perform as many as two hundred trillion operations in a second; not serially, but simultaneously.