Analyzing EEG and MEG signals recorded during tES, a reply
1Centre for Integrative Neuroscience & MEG Center, University of Tübingen, Germany; IMPRS for Cognitive and Systems Neuroscience, Tübingen, Germany.
Neuroimage
|November 21, 2017
Summary
Transcranial Electric Stimulation (tES) creates artifacts in EEG/MEG. Our research models these artifacts, revealing they are modulated by heartbeat and respiration, aiding brain signal analysis during tES.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Signal Processing
Background:
- Non-invasive brain stimulation techniques like Transcranial Electric Stimulation (tES) are valuable tools.
- Strong stimulation artifacts in electroencephalography (EEG) and magnetoencephalography (MEG) hinder neural activity analysis during tES.
- Understanding tES artifact properties is crucial for accurate brain signal investigation.
Purpose of the Study:
- To characterize the relationship between tES stimulation currents and artifacts in EEG/MEG.
- To provide a mathematical model for tES-induced artifacts.
- To address recent critiques and clarify the applicability of previous findings.
Main Methods:
- Characterization of phase and amplitude relationships between tES currents and artifacts in EEG/MEG.
- Development of a mathematical model for tES artifacts.
- Analysis of artifact modulation by physiological signals (heartbeat, respiration).
Main Results:
- Established a detailed model for tES artifacts in EEG and MEG.
- Demonstrated that tES artifact amplitude is modulated by heartbeat and respiration, independent of stimulation current.
- Refuted concerns regarding stimulation device and methodology, confirming the validity of prior results.
Conclusions:
- The physics of tES artifacts are explained, including their modulation by physiological signals.
- The developed mathematical model aids in understanding and potentially mitigating tES artifacts.
- Strategies for studying brain function during tES in the presence of residual artifacts are discussed.
