Supporting dataset for "Evoked EEG responses to TMS targeting regions outside the primary motor cortex and their test-retest reliability"

This repository contains a dataset supporting results in the manuscript: Evoked EEG responses to TMS targeting regions outside the primary motor cortex and their test-retest reliability. Song, Y., Gordon, P. C., Metsomaa, J., Rostami, M., Belardinelli, P., & Ziemann, U. in submission, 2023.

Summary:

We aimed to investigate TEPs and their test-retest reliability when targeting regions outside M1, specifically the left angular gyrus (AG), supplementary motor area (SMA), and medial prefrontal cortex (mPFC), using an optimized sham procedure. We conducted three identical TMS–EEG sessions one week apart involving 24 healthy participants. In each session, we targeted the three areas separately using a figure−of−eight TMS coil for active TMS, while a second coil away from the head produced auditory input for sham TMS. Masking noise and electric scalp stimulation were applied in both conditions to achieve matched EEG responses to peripheral sensory inputs. 

TMS-EEG recording:

For each TMS-EEG session, we divided into three TMS-EEG blocks that correspond to three cortical targets: AG, SMA, and mPFC. EEG signals were recorded with a TMS-compatible system (NeurOne, Bittium). Electrodes were placed according to the International 10-5 system in an elastic cap (EasyCap BC-TMS-64, EasyCap). EEG was sampled at 5 kHz (device filter DC-1250Hz), and electrode CPz served as the reference online. We recorded 150 pulses for the active conditions per cortical target and 150 for sham conditions.

Visual analog scale (VAS):

Participants rated their perception of auditory and somatosensory inputs from the active and sham conditions, ranging from 0 to 10. 0 represented no perception, and 10 described maximal perception. The VAS included items assessing the intensity of auditory sensation, the intensity of scalp sensation, the area size of scalp sensation, and the intensity of pain or discomfort. Each item rating was replicated twice.

Dataset: 

The present dataset consists of: 

• 24 data files from 24 healthy participants, each includes preprocessed eeg signals stored in fieldtrip data structure per cortical target per session [Note: each dataset is merged with active ('1') and sham ('2') events]. Leadfield matrix per session. Head model.
• An example tms-eeg dataset before preprocessing from a participant (in eeglab data structure). The preprocessing steps are described in the method section of the manuscript and in the code: tms_eeg_Cleaningpipeline.m (available in GitHub).
• A generic head model
• VAS scores
• Session information

Data analysis:

The code used to preprocess the TMS-EEG signal and produce results in the manuscript is available in GitHub: https://github.com/Song-Yufei/tms-eeg-using-optimized-sham-outside-M1