Spike superposition resolution in multichannel extracellular neural recordings: a novel approach

A classical problem in processing multichannel neural recordings is the ability to resolve temporal superposition of multiple spike waveforms. This situation often occurs when two or more neurons fire simultaneously in the vicinity of the recording microprobe array. In this work, we propose a powerful methodology for resolving this problem with no constraints on the time window in which the superposition occurs or the amount of overlap between spike waveforms. The methodology is part of an ongoing effort to develop a fully automated, optimal system to enhance the signal processing technology of microimplanted devices used for recording and stimulating neural cells at the micro-scale. Simulation results show that the proposed method has a substantial degree of success in resolving an arbitrary number of spikes overlapped together in time without the need for template matching procedures commonly used in offline analysis.