An Approach to Simultaneous Acquisition of Real-Time MRI Video, EEG, and Surface EMG for Articulatory, Brain, and Muscle Activity During Speech Production

TL;DR

This work presents the first simultaneous acquisition of real-time (dynamic) MRI, EEG, and surface EMG, capturing several key aspects of the speech production chain: brain signals, muscle activations, and articulatory movements.

Abstract

Speech production is a complex process spanning neural planning, motor control, muscle activation, and articulatory kinematics. While the acoustic speech signal is the most accessible product of the speech production act, it does not directly reveal its causal neurophysiological substrates. We present the first simultaneous acquisition of real-time (dynamic) MRI, EEG, and surface EMG, capturing several key aspects of the speech production chain: brain signals, muscle activations, and articulatory movements. This multimodal acquisition paradigm presents substantial technical challenges, including MRI-induced electromagnetic interference and myogenic artifacts. To mitigate these, we introduce an artifact suppression pipeline tailored to this tri-modal setting. Once fully developed, this framework is poised to offer an unprecedented window into speech neuroscience and insights leading to brain-computer interface advances.

Figures (6)

• Figure 1: Experimental setup for simultaneous acquisition of rtMRI, EEG, and EMG, along with audio.
• Figure 2: Stimulus presentation protocol.
• Figure 3: Comparison of rtMRI videos with and without the EEG/EMG device. We observe no significant impact on the articulatory regions of interest.
• Figure 4: Magnetic artifact correction around stimulus onset. Raw EEG recording inside the scanner (Fig. \ref{['fig:raweeg']}) shows large-amplitude periodic transients by gradient switching, which is substantially suppressed after the correction (Fig. \ref{['fig:aftermag']}), exhibiting temporal and spectral characteristics comparable to the reference (Fig. \ref{['fig:outsideeeg']}). Each row presents representative time-domain waveforms (left) and corresponding frequency magnitude spectra (right).
• Figure 5: Comparison of ERPs and topographies before and after myogenic and ocular artifact removal. Prior to artiface removal, high-amplitude activity is heavily concentrated in the frontal region, indicative of artifact contamination. After the denoising pipeline, this frontal dominance is substantially attenuated, revealing a distinct lateralization of activity over the left hemisphere, consistent with language processing areas.