Decoupling Action Potential Bias from Cortical Local Field Potentials
Figure 1
Removal of spike-coupled LFP signal in simulated data. (a) Average waveform of simulated frequency-tuned spiking activity introduced to a random ( noise) LFP signal. (b) Spike-LFP filter estimated by (5). (c) (Top panel) High-frequency spike signal, , with SUA4 events marked by green circles. (Bottom panel) Raw LFP signal (, black) and “clean’’ LFP signal with SUA4 events removed using filter in (b) (, green). The clean LFP closely matches the underlying LFP signal (, black dotted line) before spiking activity was added. (d) Frequency tuning of SUA4 activity. (e) Frequency tuning measured for raw LFP shows tuning similar to spiking activity (black). After SUA4 activity was removed, frequency tuning disappears (green). When only the mean spike-LFP correlation is subtracted for each spike event, the tuning is only partially removed from the LFP signal (red).
