Estimating relative positions of multiple objects in the weakly electric fish

Abstract

The weakly electric fish have a specialized sensor system of electrolocation. They use the electric field to identify the location of a target object. When the object is near the electric fish, the distortion of electric field is observed and this distortion draws a bell-shaped curve along electroreceptors on the whole surface of weakly electric fish. The ratio of maximal slope to maximal amplitude in this electric image is called relative slope. It is already known that the relative slope can be a distance measure of a target object. However, if there are more than one object, a bell-shaped electric image for each object is superposed. So it is difficult to extract the relative slope information for each object. It means that the location of each target object can hardly be estimated among background objects. In this paper, we provide a new mechanism to figure out the position of a target object, based on the spatiotemporal information of electrosenses. © 2010 Springer-Verlag.