Low Frequency Brain Oscillations for Brain-Computer Interface applications: from the sources to the scalp domain

Low Frequency Oscillations (LFOs) are brief periods of oscillatory activity in delta and lower theta band localized over the cortical motor areas. Recent animal and human researches have evidenced the LFO power increase, only through the analysis of cortical activity yet, in the preparatory phase of movement. In post-stroke subjects, a decrease in LFOs activity has been observed in the acute phase of the disease with a subsequent re-emergence related to functional recovery. With the ultimate aim to develop a Brain-Computer Interface for post-stroke motor rehabilitation based on LFO, in this study we analyzed LFOs activity on electroencephalographic data (EEG) recorded in a sample of 9 healthy participants during the Motor Execution (ME) and the Motor Imagery (MI) of the finger extension task. We extracted the LFOs activity both in the source and in the scalp domains with the aim of evaluate the reproducibility of the results between domains and analyze the LFO power on the scalp in the MI finger extension task. The results suggest that (i) the LFOs can be observed during the ME of the proposed experimental task in the cortex domain, (ii) the sources’ LFOs activity is reproduced on the scalp level and (iii) the LFOs may be detected also on the scalp during the MI task. In conclusion, in this preliminary study, we verified that LFOs can also be detected directly on the scalp both in the ME and the MI of the finger extension task.