Realtime phase-amplitude coupling analysis of micro electrode recorded brain signals

OBJECTIVE: To demonstrate a method to calculate phase amplitude coupling (PAC) quickly and robustly for realtime applications. METHODS: We designed and implemented a multirate PAC algorithm with efficient filter bank processing and efficient computation of PAC for many frequency-pair combinations. We tested the developed algorithm for computing PAC on simulated data and on intraoperative neural recording data obtained during deep brain stimulation (DBS) electrode implantation surgery. RESULTS: A combination of parallelized frequency-domain filtering and modulation index for PAC estimation provided robust results that could be calculated in real time on modest computing hardware. CONCLUSION: The standard methods for calculating PAC can be optimized for quick and robust performance. SIGNIFICANCE: These results demonstrated that PAC can be extracted in real time and is suitable for neurofeedback applications.