This paper reviews the impact on physiology of the revolutions in the communication sciences and technology that have occurred in the last 35 years. Particular attention is given to the significance of the cybernetic suggestions of Norbert Wiener--specifically, the ideas of negative feedback, of the computer as a brain metaphor, and of signal-and-noise considerations in information processing. It is argued that the first two of these have not in fact made much lasting contribution to physiology beyond providing loose analogies. On the other hand, the ready availability of a wide variety of electronic measuring and signal-processing devices from communication technology has clearly had a substantial impact. And it is proposed that the kind of models and concepts that are necessary for the characterization of the nervous system as an information-processing device play now, and will continue to play in the future, a major role in physiology.