Mu-rhythm

The new format of online communication that emerged during the pandemic has firmly established itself in our lives, particularly in the fields of education and business. While we have gained more freedom and opportunities through this new medium, many people remain dissatisfied with its remote format. Most people believe that face-to-face communication allows for a better understanding and connection with the other person, as it allows the speaker to feel the energy and emotions of the audience, and vice versa. This is because in addition to verbal information, we also receive a stream of non-verbal cues, such as body language and tone of voice, which help us form a more complete picture of the other person's thoughts and feelings.

It has been shown that the mirror neuron system and the motor and sensory-motor areas of the cortex play an important role in the perception of nonverbal visual information, including information about the movements, gestures, postures, and facial expressions of others. To investigate how the activity in these visual and sensory-motor regions of the cortex changes during video-based interactions, the authors of article, the researchers of IHNA & NPh RAS analyzed the electroencephalogram (EEG) response of 83 participants who watched identical actions shown live and through video recordings. The experiment was carefully designed to ensure that the images observed by the participants were as similar as possible, whether they were watching live or watching a video recording.

To prevent the spread of the visual alpha-rhythm to the sensory-motor areas of the brain, the independent component analysis (ICA) method was used. This method allows us to separate the mu and alpha components. For the control task, participants were asked to watch a video of a non-biological object, a ball moving through a maze. A static demonstrator was shown as the baseline. Authors analyzed the mu-rhythm response in two frequency ranges: 8-13 Hz and 13-24 Hz. The authors found that the main mu-rhythm, which ranges from 8 to 13 Hz, is highly sensitive to biological and social movements and depends greatly on the format of interaction. Live demonstrations caused a significantly stronger mu-rhythm response in the sensory-motor areas of the brain. The alpha-rhythm, on the other hand, did not respond to the type of biological movement observed. However, live demonstrations initially caused a greater concentration of visual attention, which then decreased to the video format. At the same time, the higher range of the mu-rhythm was more sensitive to various gestures performed by the participants, which should be taken into consideration when developing neuro-interfaces.

Therefore, it is important to understand that remote communication may affect both the concentration of visual attention and the subtle forms of social non-verbal communication related to the motor and sensory-motor areas of the brain.

https://academic.oup.com/cercor/article-abstract/34/4/bhae168/7659152?redirectedFrom=fulltext

In experiments on observing and performing social gestures, the level of mu rhythm suppression is associated with the activity of the mirror neuron system (MNS), which is responsible for the perception and understanding of nonverbal signals in social communication. In turn, while MNS activity may be associated primarily with empathy, it is also associated with other psychological and demographic factors affecting the effectiveness of cortical neural networks. In this study, we verified the influence of empathy, state and trait anxiety levels, presence and number of children, and age on the mu-suppression level in 40 women. We used 32-channel EEG recorded during observation, and synchronous execution of various hand movements. The ICA infomax method was used for decomposing and selecting the left hemisphere component of the mu-rhythm. Mu-suppression was higher in women with one child, with higher levels of empathy, and with lower anxiety levels. It is possible that MNS activity is stronger in women during parental care.