EEG data: anxiety patients & control group
The final sample included 47 participants: 24 anxiety patients and 23 volunteers without any neurological or psychiatric diagnoses as control group. Demographic information and clinical features are presented in Table 1. The selection criteria for the patient group were the following: right-handedness, age from 18 to 45 years, the presence of a leading anxiety and additional depressive syndrome, F41.0 (mixed anxiety and depressive disorder) or F41.2 (panic disorder) diagnosis according to ICD-10, and the duration of the disorder from six months to 5 years. Data collecting EEG data was acquired for each participant during the active tasks and the baseline. EEG was recorded using a 19-channel Electroencephalograph-analyzer EEGA-21/26 “Encephalan-131-03”. Data was sampled at 256 Hz with filter settings of 0.5 to 60 Hz in DC acquisition mode with impedances kept below 10 kΩ. Electrodes were positioned using the 10-20 international system. We also used four electrodes to record the electrooculogram (horizontal and vertical), electrocardiogram and electromyogram. All electrodes were referenced to A1 and A2 located on the left and right mastoids, respectively. 2.6. Data processing and analysis Processing (including filtering, artifact minimization, epoch division, fast Fourier transform, spectral analysis, data export) was performed using the embedded commercial software “Encephalan-EEGA-pro” (Medicom-MTD) and LORETA software. EEG records for each subject were divided into five groups according to stimuli – baseline, observation, imagination, execution, execution+observation together. The registered fragments were cleared of artifacts, then were processed with Fast Fourier Transform in 3 frequency bands: alpha1 (8-10.5 Hz), alpha2 (10.5-13 Hz), beta1 (13-24 Hz).