Methodological considerations when measuring and analyzing auditory steady-state responses with multi-channel EEG

• Published in: Current research in neurobiology 2022-01, Vol.3, p.100061-100061, Article 100061
• Main Authors: Lu, Hao, Mehta, Anahita H., Oxenham, Andrew J.
• Format: Article
• Language: English
• Subjects: Auditory steady-state response (ASSR); Electroencephalography (EEG); Envelope following response (EFR); Multi-channel EEG; Phase locking value (PLV)
• ISSN: 2665-945X; 2665-945X
• DOI: 10.1016/j.crneur.2022.100061

The auditory steady-state response (ASSR) has been traditionally recorded with few electrodes and is often measured as the voltage difference between mastoid and vertex electrodes (vertical montage). As high-density EEG recording systems have gained popularity, multi-channel analysis methods have been developed to integrate the ASSR signal across channels. The phases of ASSR across electrodes can be affected by factors including the stimulus modulation rate and re-referencing strategy, which will in turn affect the estimated ASSR strength. To explore the relationship between the classical vertical-montage ASSR and whole-scalp ASSR, we applied these two techniques to the same data to estimate the strength of ASSRs evoked by tones with sinusoidal amplitude modulation rates of around 40, 100, and 200 Hz. The whole-scalp methods evaluated in our study, with either linked-mastoid or common-average reference, included ones that assume equal phase across all channels, as well as ones that allow for different phase relationships. The performance of simple averaging was compared to that of more complex methods involving principal component analysis. Overall, the root-mean-square of the phase locking values (PLVs) across all channels provided the most efficient method to detect ASSR across the range of modulation rates tested here. [Display omitted] •The auditory steady-state response (ASSR) measures frequency-specific responses.•ASSR pre-processing and quantification techniques were compared using human data.•Choice of EEG reference affects measured strength and phase of ASSR.•Mastoid channels are not electrically neutral when measuring ASSR.•The all-channel RMS phase locking value is most efficient to detect ASSR.