A neural model for localizing targets in space accomplished by the eye of a Mantis shrimp

Stomatopods locate prey, within a short range of distances, with one eye and strike it within a few milliseconds. We developed a model based on the complex input patterns of the eye transferred to a matrix of neural integrators called T2 and T3 fibers. In the integrators graded potentials are summed and generate spikes if the sum reaches threshold. Histograms of instantaneous frequencies were simulated on a PC for the T2 and for the T3 fibers for motion of a luminous point parallel to the T2 fibers and for approach of the point towards the eye. Position, size, speed of motion and distance of the target could be extracted from the frequency-pattern-coded output of the integrators in our model. A critical region in front of the center of the eye could be defined. This region is elliptical in shape and adapted to the size of the animal (respectively to the size of its raptorial appendages). We assume that prey is hit when it is in the critical zone. Histological and electrophysiological results seem to confirm our model.