Cortical–subcortical interplay in speech perception: Time-efficient methodology for simultaneously assessing mismatch and frequency-following responses to speech sounds

Speech sounds are processed in the human brain through intricate and interconnected cortical and subcortical structures. Two neural signatures, cortical mismatch response (MMR) and subcortical frequency-following response (FFR) are critical for assessing speech processing as they both show sensitivity to high-level linguistic information. However, efficiently deriving MMR and FFR in the same session remains challenging due to their distinct acquisition requirements, limiting our understanding of the integrated roles of cortical–subcortical processing in speech perception and their real-world implications in clinical settings. Using a novel experiment paradigm and decoding approach, we concurrently capture both signals across different recording modalities (M/EEG) and age groups (adults/infants). Results from 18 adults with simultaneous M/EEG demonstrated language effects in the MMR and distinct FFRs to different speech sounds. The spatiotemporal patterns align with existing literature. Additionally, we replicated these findings using MEG in 14 infants aged 9–14 months with the same methods. Our improved methodologies extend past research with much fewer trials and shorter experiment time (less than 15 min), demonstrating the feasibility of capturing cortical–subcortical responses in speech perception. This efficient paradigm holds promise for clinical and developmental applications, particularly in early identification of speech and language processing difficulties.