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Advanced Neurology MNS in patients with anxiety and depressive symptoms

system are not completely innate and are not fixed after mu rhythm dynamics is an EEG biomarker in depressive
acquisition. Instead, they develop through sensory-motor and anxiety disorders requires more evidence and further
learning. In addition, the plasticity properties of mirror study.
neurons have been used in the rehabilitation of injured
hands after stroke. Numerous studies have revealed a 4.1. Limitations
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deficit of mirror neurons in schizophrenia, describing First, while we investigated patients on the 1 day of their
st
the plasticity of the MNS and its modulation by different acceptance to the medical center before any medications
frequencies. 63,64 In a review article, the authors suggest were prescribed, we did not exclude the possibility
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that the MNS reflects a set of interrelated features, each that some may have taken permitted over-the-counter
with an independent natural history due to unique medications before hospital admission. Second, we did
selective pressure. They also believed that there are at least not use individual head models for EEG source imaging in
three evolutionarily significant trends that have led to the sLORETA, as individual MRI data were not available. Third,
emergence of three MNS subtypes: hand-eye, mouth-eye, psychiatric diagnoses in our study were provided through
and audio-vocal. a systematic approach by qualified psychiatrists; however,
we did not employ a structured diagnostic interview
An EEG study on women suggested that MNS
can change when gaining experience in child-parent (e.g., Structured Clinical Interview for DSM-5 (SCID-5)
or the Mini-International Neuropsychiatric Interview
relationships and increase its effectiveness. Women [M.I.N.I.]). Another important limitation of this work,
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who had children showed a greater response to the MNS which is associated with the need to select a homogeneous
when observing and performing gestures, and increased sample of patients by syndromes, is the small sample size.
activity of the MNS was associated with increased empathy Nevertheless, all results have a significant statistical effect.
and reduced anxiety. In contrast, highly anxious women
showed a reduced response in the sensorimotor cortex. 5. Conclusion
One more EEG study on healthy subjects with an increased
level of depression on the Beck scale showed that they may In this study, several features of MNS activation in
have, on the contrary, increased sensitivity to emotionally patients with anxiety and depressive disorder were
identified, including a wider and more distributed
negative stimuli in the sensorimotor areas of the MNS. activation of additional regions over a wide frequency
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Thus, the MNS is a fairly labile network that changes its range. We discovered that mirror tasks such as observing,
effectiveness and sensitivity depending on the psycho- imagination, and execution of hand clenching caused
emotional state of a person, as well as their social status clear and expressed mu rhythm suppression in the
and experience.
central regions of the brain in the upper-frequency range
Another notable difference from a psychological and (10.5 – 13 Hz) only in the control group. At the same
sociological perspective is the selective reactivity of the time, patients showed suppression of EEG rhythms over
patients’ MNS to the tasks. The suppression of rhythms a wider range of frequencies and in several areas of the
was very clearly expressed in only two tasks: observation brain. Moreover, in patients with anxiety and comorbid
and joint performance of hand clenching. Interestingly, depression, the greatest activation of the MNS was
patients were only in visual contact with the experimenter observed in the tasks of observation and joint execution
during these tasks. From our perspective, the social and of hand clenching. The sLORETA data confirmed a more
motor aspects are most present in the “joint execution” extensive activation area over a wide frequency range. It
task. A situation where the MNS does not respond to seems that patients with anxiety and depressive symptoms
the motor and imagination tasks but only responds with are engaging in additional resources to complete the tasks;
direct visual contact may mean that depressed and anxious in other words, auxiliary neural networks located in the
patients need additional visual support when performing frontal associative arrays and visual cortex compensate
social actions. It can be assumed that people suffering from for the lack of attention and activation of the main mirror
anxiety and depressive symptoms experience significant neural networks. In addition, we believe that the MNS is not
difficulties in planning and mentally analyzing social strictly an anatomically defined system. On the contrary,
interactions because of the difficulty in retaining attention we suppose that mirror neurons are a functional system
and memory. 68-70 This finding appears to be very interesting; that can engage in various structures in social situations.
however, such assumptions remain speculative and require
further investigation. Several studies have been devoted to Acknowledgments
identifying EEG biomarkers for the clinical outcomes of The authors thank the participants and staff of the Scientific
various brain disorders. 71-73 However, the statement that and Practical Psychoneurological Center named after Z.P.

Volume 3 Issue 1 (2024) 9 https://doi.org/10.36922/an.2009