Functional overlap between regions involved in speech perception and in monitoring one’s own voice during speech production

摘要

The fluency and reliability of speech production suggests a mechanism that links motor commands and sensory feedback. Here, we examine the neural organization supporting such links by using fMRI to identify regions in which activity during speech production is modulated according to whether auditory feedback matches the predicted outcome or not, and examining the overlap with the network recruited during passive listening to speech sounds. We use real-time signal processing to compare brain activity when participants whispered a consonant-vowel-consonant word (‘Ted’) and either heard this clearly, or heard voice-gated masking noise. We compare this to when they listened to yoked stimuli (identical recordings of ‘Ted’ or noise) without speaking. Activity along the superior temporal sulcus (STS) and superior temporal gyrus (STG) bilaterally was significantly greater if the auditory stimulus was a) processed as the auditory concomitant of speaking >and b) did not match the predicted outcome (noise). The network exhibiting this Feedback type by Production/Perception interaction includes an STG/MTG region that is activated more when listening to speech than to noise. This is consistent with speech production and speech perception being linked in a control system that predicts the sensory outcome of speech acts, and that processes an error signal in speech-sensitive regions when this and the sensory data do not match.