USING REFLEXIVE BEHAVIORS OF THE MEDICINAL LEECH TO STUDY INFORMATION-PROCESSING

The interneuronal network that produces local bending in the leech is distributed, in the sense that most of the interneurons involved are a ctivated in all forms of local bending, even those in which their outp uts would produce inappropriate movements. Such networks have been fou nd to control a number of different behaviors in a variety of animals. This article reviews three issues: the physiological and modeling obs ervations that led to the conclusion that local bending in leeches is controlled by a distributed system; what distributed processing means for this and other behaviors; and why the leech interneuronal network may have evolved to be distributed in the first place. (C) 1995 John & Wiley & Sons, Inc.