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Concurrent Electroencephalography Recording During Transcranial Alternating Current Stimulation tACS
Published on: January 22, 2016
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Stimulation artifact source separation (SASS) for assessing electric brain oscillations during transcranial
David Haslacher1, Khaled Nasr1, Stephen E Robinson2
1Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - University Medicine Berlin, Berlin, Germany.
Neuroimage
|January 7, 2021
Summary
A new algorithm, Stimulation Artifact Source Separation (SASS), effectively removes transcranial alternating current stimulation (AM-tACS) artifacts from EEG data. This enables real-time, adaptive brain stimulation for enhanced cognitive and perceptual research.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Signal Processing
Background:
- Brain oscillations measured by EEG/MEG are crucial for perception, cognition, and learning.
- Amplitude-modulated transcranial alternating current stimulation (AM-tACS) non-invasively targets brain oscillations.
- Online adaptation of AM-tACS is hindered by stimulation artifacts, especially at target frequencies.
Purpose of the Study:
- Introduce a real-time artifact rejection algorithm (SASS) for adaptive AM-tACS.
- Enable reliable removal of stimulation artifacts while preserving physiological signals.
- Validate SASS's efficacy in real-time EEG recordings during AM-tACS.
Main Methods:
- Developed Stimulation Artifact Source Separation (SASS), a spatial filter for artifact removal.
- Recorded 64-channel EEG during 10 Hz AM-tACS targeting the visual cortex in 7 volunteers.
- Compared single-trial EEG signal amplitude and phase during and absence of AM-tACS with and without SASS.
Main Results:
- AM-tACS artifacts obscured assessment of steady-state visually evoked potentials (SSVEPs) without artifact rejection.
- SASS successfully removed stimulation artifacts, allowing comparable single-trial SSVEP amplitude and phase.
- Validated SASS's ability to distinguish SSVEPs from AM-tACS signals.
Conclusions:
- SASS enables adaptive (closed-loop) AM-tACS by overcoming artifact limitations.
- This technology can be used to precisely target brain functions and study AM-tACS interactions.
- SASS is a significant advancement for neurotechnology and brain oscillation research.
Keywords:
Brain oscillationsElectroencephalography (EEG)Single-trialStimulation artifactTranscranial alternating current stimulation (tACS)
