EEG (128 ch) on presentation of cardinal and oblique grids

Subjects

The study involved 20 subjects (9 women and 11 men) without signs of pathology, without the absence of complaints and severe neurological symptoms (found by questioning). The average age of volunteers is 22.5±4 years. In all cases, the subjects were informed about the methodology, which was approved by the ethics committee of the Institute of Higher Nervous Activity and Neurophysiology of RAS (protocol No. 5 dated 02.12.2020). Recordings were made in 2020 and 2021.

Registration

Registration was carried out on a 128-channel Geodesic-400 electroencephalograph during the task. The central electrode Cz was used as a reference electrode. For each subject, the positions of the electrodes were recorded using the Geodesic GPS (Geodesic Photogrammetry System) photographic system. MRI was used to calculate the surfaces of the head, skull, and cerebral cortex.

Visual stimulation

During the study, the subjects sat in a comfortable chair in a darkened room at a distance of 57 cm from the screen. Illumination at eye level was 3 lux. After recording the background EEG signal for two minutes at rest with eyes closed, the volunteers began to perform the task. Visual stimuli appeared on the screen in the form of a grid with different inclinations: vertical (90°), horizontal (0°), tilt to the left (135°), tilt to the right (45°) The slope types are grouped into two groups: cardinal (90° and 0°) and oblique (45° and 135°). The size of the stimulus on the screen was 4.7 cm, which at a distance of 57 cm from the screen was 4.71 angular degrees. The duration of each stimulus was 100 ms. The interstimulus interval was changed randomly from 3 to 4 seconds. Each stimulus was presented 34 times, also in random order. The total duration of the experiment was about 9 min. The subject, upon presentation of the stimulus, had to recognize the slope of the lines and choose one of the answer options: cardinal or inclined lines by pressing the appropriate key.

File codes

* The subject was recorded MEG in 2022. See his data including MRI in another dataset: https://doi.org/10.5281/zenodo.7458233

Acknowledgments

The reported study was funded by RFBR, project number 20-015-00475.