Continuous theta burst stimulation over left and right supramarginal gyri demonstrates their involvement in auditory feedback control of vocal production

Abstract

The supramarginal gyrus (SMG) has been implicated in auditory-motor integration for vocal production. However, whether the SMG is bilaterally or unilaterally involved in auditory feedback control of vocal production in a causal manner remains unclear. The present event-related potential (ERP) study investigated the causal roles of the left and right SMG to auditory-vocal integration using neuronavigated continuous theta burst stimulation (c-TBS). Twenty-four young adults produced sustained vowel phonations and heard their voice unexpectedly pitch-shifted by ±200 cents after receiving active or sham c-TBS over the left or right SMG. As compared to sham stimulation, c-TBS over the left or right SMG led to significantly smaller vocal compensations for pitch perturbations that were accompanied by smaller cortical P2 responses. Moreover, no significant differences were found in the vocal and ERP responses when comparing active c-TBS over the left vs. right SMG. These findings provide neurobehavioral evidence for a causal influence of both the left and right SMG on auditory feedback control of vocal production. Decreased vocal compensations paralleled by reduced P2 responses following c-TBS over the bilateral SMG support their roles for auditory-motor transformation in a bottom-up manner: receiving auditory feedback information and mediating vocal compensations for feedback errors.

Transcranial direct current stimulation over left dorsolateral prefrontal cortex facilitates auditory-motor integration for vocal pitch regulation

“…In contrast, prolonged peak times of vocal responses were found when inhibitory cTBS was applied over the left DLPFC (Liu et al, 2020). Other NIBS studies targeting other brain regions have shown that a-tDCS over the right cerebellum prolonged the peak times of vocal responses to pitch perturbations (Peng et al, 2021), while cTBS over the right cerebellum (Lin et al, 2022) or the left or right SMG (Li et al, 2023) shortened them. Prolonged vocal responses to pitch perturbations have been observed in patients with PD (Kiran and Larson, 2001) or aphasia (Johnson et al, 2020), reflecting their impaired sensorimotor integration in speech processing.…”

Aberrant brain functional network strength related to cognitive impairment in age-related hearing loss

“…Interestingly, we found that SMG was involved in ARHL compared with healthy controls. On the one hand, the SMG can be activated by pure tones and is causally implicated in auditory-motor integration ( 24 ). On the other hand, the SMG becomes a convergence zone of various networks associated with attention and verbal working memory ( 25 ).…”

Using altered auditory feedback to study pitch compensation and adaptation in tonal language speakers

“…More specifically, cTBS over right, but not left pSTG resulted in reduced compensations for pitch perturbations accompanied by smaller N1 and larger P2 responses in Mandarin speakers. In contrast, both the left and right supramarginal gyrus (SMG) has been found to causally contribute to pitch compensation in Mandarin speakers ( Li et al, 2022 ).…”

“…By combining AAF paradigm with brain stimulation and neuroimaging techniques, a series of studies have been conducted by Liu’s group to investigate the neural basis of pitch control in tonal language speakers (e.g., Liu et al, 2020 , 2023 ; Li et al, 2022 ). They have demonstrated the causal role of left dorsolateral prefrontal cortex (DLPFC) in pitch compensation by showing that inhibitory continuous theta burst stimulation (cTBS) over DLPFC elicited larger compensatory responses and smaller event-related potential (ERP) P2 responses in Mandarin speakers experiencing pitch perturbation (+200 or +500 cents), compared to sham stimulation ( Liu et al, 2020 ).…”