By our bootstraps: Comparing methods for measuring auditory 40 Hz steady-state neural activity

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Biomedical Engineering

Background:

• The 40 Hz auditory steady-state response (ASSR) is clinically relevant, but its construct validity using electroencephalography (EEG) and magnetoencephalography (MEG) is uncertain.
• Previous findings indicate an age association with the left-hemisphere 40 Hz ASSR and right-hemisphere dominance in ASSR strength.

Purpose of the Study:

• To evaluate the construct validity of various EEG and MEG metrics for measuring 40 Hz ASSR cortical microcircuits.
• To determine if analysis methods align with known ASSR properties, such as left-hemisphere age association and hemispheric differences.

Main Methods:

• Fifty-three adults underwent MEG and EEG recording during 40 Hz modulated auditory stimulation.
• Assessed ASSR using intertrial coherence and total power, comparing spherical and realistic head models with various source modeling strategies.
• Tested several EEG sensor analysis strategies.

Main Results:

• EEG sensor measures did not detect the expected left-hemisphere 40 Hz ASSR and age association or hemispheric differences.
• MEG and EEG source-modeling approaches showed consistent 40 Hz ASSR measures and accurately estimated age and left-hemisphere ASSR associations.
• Source modeling demonstrated good construct validity across different head models.

Conclusions:

• Source modeling of 40 Hz ASSR using MEG and EEG exhibits good construct validity for assessing cortical microcircuits.
• EEG sensor measures are less valid for capturing specific 40 Hz ASSR characteristics compared to source modeling approaches.