ABSTRACT
The nervous system, unlike other organ systems, is concerned primarily with signals, information encoding and processing, and control rather than manipulation of energy. It acts like a communication device whose components use substances and energy in processing signals and in reorganizing them, choosing, and commanding, as well as in developing and learning. A central question that is often asked is how nervous systems work and what are the principles of their operation. In an attempt to answer this question, we will, at the same time, ignore other fundamental questions, such as those relating to anatomic or neurochemical and molecular aspects. We will concentrate rather on relations and transactions between neurons and their assemblages in the nervous system. We will deal with neural signals (encoding and decoding), the evaluation and weighting of incoming signals, and the formulation of outputs. A major part of this chapter is devoted to higher aspects of the nervous system, such as memory and learning, rather than individual systems, such as vision and audition, which are treated extensively elsewhere in this book.
