## About Dataset

### Recording Method :

Neurocom EEG 23-channel system (21 channels were selected finally) where used to record the EEGs monopolarly from 36 subjects. A high-pass filter with a 30 Hz cut-off frequency and a power line notch filter (50 Hz) were used. All recordings are artifact-free EEG segments of 60 seconds duration. At the stage of data preprocessing, the Independent Component Analysis (ICA) was used to eliminate the artifacts.

### Data

The data files with EEG are provided in EDF (European Data Format) format. Each subject has 2 files:

with "_1" suffix -- the recording of the background EEG of a subject (before mental arithmetic task)

with "_2" suffix -- the recording of EEG during the mental arithmetic task.

In this experiment all subjects are divided into two groups:

Group "G" (24 subjects) performing good quality count (Mean number of operations per 4 minutes = 21, SD = 7.4).

Group "B" (12 subjects) performing bad quality count (Mean number of operations per 4 minutes = 7, SD = 3.6).

In subject-info.csv, the "Count quality" column indicates which subjects correspond to which group (0 - Group "B", 1 - Group "G"). Additionally, subject-info.csv provides basic information about each subject (gender, age, job, date of recording).

### Contributors

This database was contributed by Igor Zyma, Sergii Tukaev, and Ivan Seleznov, National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Department of Electronic Engineering.

For further information, please contact:

Ivan Seleznov

National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Department of Electronic Engineering.

ivan.seleznov1@gmail.com