Anatomically Veridical On-Scalp Sensor Topographies

Area of Science:

• Neuroimaging
• Biophysics
• Data Visualization

Background:

• Standard 2D sensor position representations (e.g., 10-20 system) are common in electroencephalography (EEG) for anatomical referencing.
• Optically pumped magnetometer-based magnetoencephalography (OP-MEG) often uses non-standard sensor arrays, hindering anatomical referencing and cross-individual comparisons.
• Current visualization methods for OP-MEG, like polar projections, lack anatomical accuracy and impede group data averaging.

Purpose of the Study:

• To develop a flexible, anatomically veridical 2D projection method for on-scalp neuroimaging sensor data, specifically addressing challenges in OP-MEG.
• To enable consistent and comparable visualization of OP-MEG data across individuals and varying sensor array configurations.
• To extend the utility of 2D topographies, familiar from EEG, to the growing field of OP-MEG.

Main Methods:

• Adapted and extended the established 10-20 system for electrode placement.
• Developed a projection method utilizing digitized head shape, fiducials, and OPM sensor positions.
• Validated the method's ability to maintain spatially veridical representations across individuals with varying sensor array densities.

Main Results:

• The proposed method generates anatomically accurate 2D sensor topographies for OP-MEG data.
• Demonstrated improved spatial veridicality compared to standard polar projections, especially with sparse or focal OPM sensor arrays.
• Successfully enabled consistent visualization of OP-MEG data, facilitating group studies.

Conclusions:

• The adapted 10-20 system projection method provides anatomically veridical 2D topographies for OP-MEG.
• This approach overcomes limitations of non-standard sensor arrays and polar projections in OP-MEG visualization.
• Facilitates more robust group analysis and interpretation of OP-MEG data by ensuring spatial consistency across individuals.