NO MODULATION OF THE CORTICAL CONTRIBUTION TO THE SPEECH-FFR BY VISUAL INFORMATION

Visual information from a speaker’s face can aid speech comprehension, especially in acoustically adverse conditions. An early neural correlate of audiovisual speech processing is the frequency-following response to speech (speech-FFR), a response phase-locked to the fundamental frequency of speech and generated by both subcortical structures and contributions from the auditory cortex. Previous work has shown that the subcortical contributions to the speech-FFR are attenuated when visual input from the talker’s face is available. In the present study, we investigated the cortical component of the speech-FFR and its susceptibility to visual stimuli. Magnetoencephalographic (MEG) responses were recorded while participants were presented with four audiovisual conditions: a still image, an artificially generated avatar, a degraded video, and a natural video of the speaker [1]. All audiovisual conditions elicited robust speech-FFRs in the auditory cortex at an early latency of approximately 30 ms. However, the magnitude of this cortical response was neither enhanced nor reduced by the presence or quality of visual speech information. Furthermore, the strength of the cortical speech-FFR did not account for a significant proportion of the variance in comprehension performance. These findings indicate that any visual modulation of the cortical speech-FFR is either absent or too subtle to be detected when substantial background noise is present.
[1] J. Riegel, A. Schüller, C. Jehn, A. Wißmann, S. Zeiler, D. Kolossa, T. Reichenbach, The cortical contribution to the speech-FFR is not modulated by visual information, in review; bioRxiv https://doi.org/10.64898/2026.01.26.701703.