Group-level test–retest reliability assessment using systemic physiology augmented functional near-infrared spectroscopy during a passive-listening task

Significance: Functional near-infrared spectroscopy (fNIRS) is a valuable neuroimaging technique for auditory-research tasks. However, fNIRS data are influenced by systemic-physiological processes, resulting in noisier signal quality that may compromise test-retest reliability. fNIRS reliability may also be influenced by changes in cap placement across sessions. Aim: We investigated the effectiveness of systemic-physiology denoising methods on the test-retest reliability of group-level fNIRS data during a passive-listening task. Approach: Fifteen participants completed two identical sessions of a passive-listening task; source-detector optode locations were digitized for each session. Different denoising methods were compared to investigate the effect of systemic-physiology correction on the consistency of across-session hemodynamic response amplitudes. Test-retest reliability for each method was assessed using the intraclass correlation coefficient (ICC). Changes in optode and channel locations across sessions were calculated to track shifts in cap placement. Results: Results revealed significant speech-evoked activity in bilateral auditory cortices following stimuli presentation. Group-level test-retest reliability metrics demonstrated good reliability across two identical test sessions. Accounting for the influence of systemic physiology resulted in improved reliability. Slight variations in optode placement did not significantly affect signal repeatability. Conclusion: This study supports the use of fNIRS for group-level task-evoked studies, demonstrating that systemic-physiology denoising methods can modestly improve test-retest reliability.