THE PHASE OF SLOW WAVE OSCILLATIONS COUPLES WITH HIGH GAMMA POWER IN HUMAN ELECTROCORTICOGRAPHY DURING PERFORMED AND IMAGINED REPETITIVE MOVEMENTS

High Gamma Band (HGB) and Slow Wave Oscillations (SWOs) have been identified as significant features in movement neurophysiology. HGB reflects local neuronal activity, while SWOs inform on the temporal characteristics of movement, especially during repetitive tasks. However, to date, they have mostly been studied separately, leaving details on their interaction largely unknown. Here, we look at Phase Amplitude Coupling (PAC) to assess interactions between SWO phase and HGB power. We use a publicly-available electrocorticography (ECoG) dataset recorded during repetitive motor execution (ME) and motor imagery (MI) of hand and tongue movements. We find channels with significant SWO-HGB PAC for all subjects and tasks, distributed across multiple brain regions. In the sensorimotor cortex PAC occurs at specific coupling phases and is primarily observed during ME, while frontal and temporal regions exhibit similar PAC levels across ME and MI but lack distinct preferred coupling phases. When training decoders for movement detection, PAC underperforms compared to SWOs or HGB; however, it shows a strong correlation with accuracy when single-channel SWOs are used as decoding feature, highlighting its potential for channel selection. Weaker correlations are found when PAC is compared to task-related HGB power increases, suggesting that these represent distinct neural features.