Uludağ University Journal of The Faculty of Engineering (Apr 2021)
EEG ANALYSIS OF REAL AND IMAGINARY ARM MOVEMENTS BY SPECTRAL COHERENCE
Abstract
Revealing the information between similar patterns of brain for a real motor task and its imaginary equivalent can be means to clarify movement intentions and help to improve Brain Computer Interfaces (BCI)s. This paper uses spectral coherence to assess the functional interactions between neural regions engaged in a real and an imagined arm movement task. Magnitude squared coherence values were calculated for two specific bands of Electroencephalogram (EEG) that are 8–12 Hz alpha band and 13–20 Hz beta for 48 channels from selected regions of interest (ROIs). The coherence values are transferred into surface maps. We try to explain how motor cognition in these regions are relevant with the literature. The maximum coherence is observed between the channels in the same hemisphere and surrounding closest channels located vertically and horizontally based on the 10-20 electrode placement. Our results that the supplementary motor area, the premotor, prefrontal, primary motor cortex and the parietal cortex play a role in facilitating real and imaginary motor movements, are in good accordance with the previous studies. Further research can be put on spectral coherence patterns which would be a possible means for prosthetic-interactive BCI systems, interactive multimedia applications, and emerging EEGbased biometric recognition areas.
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