Dynamic population coding for detecting the distance and size of an object in electrolocation

Sensory systems utilize dynamical response properties of neurons to extract features of spatiotemporally varying stimuli. We propose a dynamic population coding of sensory stimuli in which the stimulus features are encoded into a spatiotemporal firing pattern of neuron population. Using electrolocation of weakly electric fish as a model system, we study how the spatiotemporal features of electric field modulated depending on the distance and size of an object are encoded into the spatial distribution and time interval between burst spikes of neuron population. We showed that the information about distance and size of object are represented as a function of the spatial area of and time interval between the synchronous firing of neuron population in a higher nucleus.