Information-based analysis of the relationship between brain and facial muscle activities in response to static visual stimuli.

BACKGROUND Human facial muscles react differently to different visual stimuli. It is known that the human brain controls and regulates the activity of the muscles. OBJECTIVE In this research, for the first time, we investigate how facial muscle reaction is related to the reaction of the human brain. METHODS Since both electromyography (EMG) and electroencephalography (EEG) signals, as the features of muscle and brain activities, contain information, we benefited from the information theory and computed the Shannon entropy of EMG and EEG signals when subjects were exposed to different static visual stimuli with different Shannon entropies (information content). RESULTS Based on the obtained results, the variations of the information content of the EMG signal are related to the variations of the information content of the EEG signal and the visual stimuli. Statistical analysis also supported the results indicating that the visual stimuli with greater information content have a greater effect on the variation of the information content of both EEG and EMG signals. CONCLUSION This investigation can be further continued to analyze the relationship between facial muscle and brain reactions in case of other types of stimuli.