Abstract. 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.

Abstract. On the distal lamina surface of stomatoped eyes a matrix of horizontal and vertical nerve fibers processes the complex input patterns. The output of these integrating fibers is a spike discharge pattern correlated to the input pattern. Here we introduce a ___ neuron which either subtracts or sums the outputs from the set of horizontal and vertical fibers activated at that moment. The output pattern of spike frequencies of the + neuron locates a target in space. Over a parallel channel outputs from the vertical fibers pass a bandpass filter and constitute one of the inputs for a decision neuron. The other input derives from specialized ommatidia at the center of the eye. If both inputs arrive within a short time interval, they sum, the threshold is reached and the decision neuron fires. Spikes from the decision neuron are the final cue for the muscles of the raptorial appendages. The appendages shoot forward and hit the prey with high precision.

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