Within-cycle instantaneous frequency profiles report oscillatory waveform dynamics
Quinn AJ., Lopes-dos-Santos V., Huang N., Liang W-K., Juan C-H., Yeh J-R., Nobre AC., Dupret D., Woolrich MW.
We propose a novel analysis approach quantifying nonsinusoidal waveform shape. The approach isolates oscillations with empirical mode decomposition before waveform shape is quantified using phase-aligned instantaneous frequency. This characterizes the full shape profile of individual cycles while accounting for between-cycle differences in duration, amplitude, and timing. We validated in simulations before applying to identify a range of data-driven nonsinusoidal shape motifs in hippocampal theta oscillations.