MEG-measured auditory steady-state oscillations show high test-retest reliability: A sensor and source-space analysis

Abstract

Stability of oscillatory signatures across magnetoencephalography (MEG) measurements is an important prerequisite for basic and clinical research that has been insufficiently addressed. Here, we evaluated the test-retest reliability of auditory steady-state responses (ASSRs) over two MEG sessions. The study required participants (N. = 13) to detect the rare occurrence of pure tones interspersed within a stream of 5. Hz or 40. Hz amplitude-modulated (AM) tones. Intraclass correlations (ICC; Shrout and Fleiss, 1979) were derived to assess stability of spectral power changes and the inter-trial phase coherence (ITPC) of task-elicited neural responses. ASSRs source activity was estimated using eLORETA beamforming from bilateral auditory cortex. ASSRs to 40. Hz AM stimuli evoked stronger power modulation and phase-locking than 5. Hz stimulation. Overall, spectral power and ITPC values at both sensor- and source-level showed robust ICC values. Notably, ITPC measures yielded higher ICCs (~. 0.86-0.96) between sessions compared to the assessment of spectral power change (~. 0.61-0.82). Our data indicate that spectral modulations and phase consistency of ASSRs in MEG data are highly reproducible, providing support for MEG-measured oscillatory parameters in basic and clinical research.