Abstract
Accurate and fluent production of speech strongly depends on hearing oneself which allows for the detection and correction of vocalization errors in real-time. When auditory feedback is disrupted with a time delay (e.g. echo on a conference call), it causes slowed and stutter-like speech in humans. Impaired speech motor control during delayed auditory feedback is implicated in various neurological disorders ranging from stuttering to aphasia, however the underlying neural mechanisms are poorly understood. Here, we investigated auditory feedback control in human speech by obtaining electrocorticographic recordings from neurosurgical subjects performing a delayed auditory feedback (DAF) task. We observed a significant increase in neural activity in auditory sites that scaled with the duration of feedback delay and correlated with response suppression during normal speech, providing direct evidence for a shared mechanism between sensitivity to altered feedback and speech-induced auditory suppression in humans. Furthermore, we find that when subjects robustly slowed down their speech rate to compensate for the delay, the dorsal division of the precentral gyrus was preferentially recruited to support articulation during an early time frame. This recruitment was accompanied by response enhancement across a large speech network commencing in temporal cortex and then engaging frontal and parietal sites. Our results highlight the critical components of the human speech network that support auditory feedback control of speech production and the temporal evolution of their recruitment.
Competing Interest Statement
The authors have declared no competing interest.
Abbreviations
- ECoG
- Electrocorticography
- DAF
- Delayed auditory feedback
- STG
- Superior temporal gyrus
- IFG
- Inferior frontal gyrus
- NMF
- Non-negative matrix factorization
- DTW
- Dynamic time warping