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Authors & Affiliations
Alina Schüller, Achim Schilling, Patrick Krauss, Stefan Rampp, Tobias Reichenbach
Abstract
Selective attention allows us to focus on relevant information while filtering out distracting signals. Research on the neural mechanisms of selective attention to speech has primarily explored low-frequency responses to amplitude modulations in the auditory cortex. EEG studies revealed, in addition, attentional modulation of subcortical neural responses at the fundamental frequency of speech (speech-FFR). Recent MEG studies have identified cortical contributions to the speech-FFR (Coffey et al. (2017), Kulasingham et al. (2020), Schüller et al. (2024)), but it remains unclear if these cortical contributions are also modulated by selective attention. We recorded MEG data from 22 healthy individuals with normal hearing during a 40-minute session of continuous speech stimuli featuring two competing male speakers, one with a higher and one with a lower pitch (Schüller et al. (2023)). Attention alternated regularly between the two speakers. We determined the cortical speech-FFRs through source reconstruction of the MEG data followed by the computation of source-level Temporal Response Functions (TRFs). We then explored how selective attention shapes these neural responses. Our study revealed a significant impact of selective attention on the cortical contribution to the speech-FFR (Schüller et al. (2023)). The neural response increased when the participants attended a speaker compared to when ignoring it, evident at both population and individual subject levels. Moreover, irrespective of attention, the lower-pitch speaker consistently triggered a larger cortical contribution to the speech-FFR than the higher-pitch speaker. Attentional modulation of speech-FFRs hence occurs not only on the subcortical but also on the cortical level