Abstract: Disclosed herein, in certain embodiments, are methods and systems for utilizing spike trains. In one aspect, encompassed by the disclosure is a method comprising: determining, by at least one processor, a plurality of spike trains from a plurality of neurons of a cerebral cortex of a subject. The method may comprise determining, by the at least one processor, a plurality of first layer feature vectors, the plurality of first layer feature vectors including a first feature vector that comprises temporal-relation values of a subset of the plurality of spike trains with respect to a time instance of a reference spike train of the subset, corresponding to a time constant ? having a first value. The method may comprise establishing, by the at least one processor, a first layer comprising a first plurality of clusters of the first layer feature vectors.

Abstract: A pixel cell circuit comprises an electrode, one or more main photosensitive elements electrically coupled to the electrode for outputting a stimulation signal to the electrode responsive to light illumination, and a shunt arrangement comprising a shunt switch electrically coupled in parallel across the one or more photosensitive elements, and a control arrangement operatively coupled to the shunt switch and configured for placing the shunt switch in an open state responsive to incident light received at the pixel cell and placing the shunt switch in a closed state if no incident light is received at the pixel cell.

Abstract: A pixel cell circuit comprises an electrode, one or more main photosensitive elements electrically coupled to the electrode for outputting a stimulation signal to the electrode responsive to light illumination, and a shunt arrangement comprising a shunt switch electrically coupled in parallel across the one or more photosensitive elements, and a control arrangement operatively coupled to the shunt switch and configured for placing the shunt switch in an open state responsive to incident light received at the pixel cell and placing the shunt switch in a closed state if no incident light is received at the pixel cell.