[Investigation of the relationship of individual characteristics of the brain bioelectrical activity with levels of mental stress, aggression, anxiety, and depression].

Abstract

Objective: To identify relationships between the features of bioelectrical activity (BEA) of the brain and levels of mental stress, aggression, anxiety, and depression.

Material and methods: The study included 50 apparently healthy volunteers (mean age 23-54 years (32.5±8.2), 62% females, 38% males). A set of validated psychological tests was used for clinical and psychological assessment: the neuropsychiatric stress questionnaire, the Spielberger Anxiety Scale for the overall study population (50 subjects); the Beck's Depression Inventory, the Perceived Stress Scale, and the Buss Perry Aggression Questionnaire for the sample with similar sex and age (31 subjects). Electroencephalography (EEG) was used to record brain activity as an accessible and non-invasive method with high time resolution. The amplitude-frequency characteristics of the BEA obtained by spectral analysis of native EEG segments were compared with the test results.

Results: Statistically significant correlations between the results of most psychological tests and BEA parameters were identified. Many scales showed a positive correlation with the amplitude of the dominant alpha activity: for mental stress, in symmetrical zones from the occipital-parietal to the anterior temporal and frontal leads; for stress-associated overexertion, in narrower anterior temporal and temporal zones; for hostility, extensively from the frontal and anterior temporal to the occipital and right parietal regions; for anger, locally in the left frontal and anterior temporal region; for trait anxiety, bilaterally in the parietal and occipital regions. The dominant frequency of alpha activity was negatively correlated with the level of state anxiety in the central and right occipital and temporal lead. In the theta range, there was an acceleration of oscillations in the right posterior and left parietal and temporal leads in subjects with high state anxiety, as well as bilateral enhancement in the posterior regions in subjects with mental stress. In the left hemisphere, the dominant frequency of beta-2 activity was directly related to the scale of depression and its cognitive-affective manifestations, as well as to the stress counteraction scale. A negative correlation was noted between the overall depression score and the frequency of beta-1 activity locally in the left frontal-central lead.

Conclusion: The identified signs need further research as possible markers of the cortex BEA to assess a mental state or personality traits.