Poster B67, Tuesday, August 20, 2019, 3:15 – 5:00 pm, Restaurant Hall
Distinct auditory neural populations track vocalization feedback delays
Muge Ozker Sertel1, Qingyang Zhu1, Zhuoran Huang1, Beenish Mahmood1, Daniel Maksumov1, Werner Doyle2, Orrin Devinsky1, Adeen Flinker1;1New York University School of Medicine, Department of Neurology, 2New York University School of Medicine, Department of Neurosurgery
Neural responses in the auditory cortex are suppressed during self-generated vocal sounds. This auditory suppression mechanism has been hypothesized to facilitate the detection of vocalization errors. Nevertheless, while such a link has been demonstrated in the primate vocalization literature, it remains unclear in humans. To test this hypothesis, we conducted an auditory repetition task and a delayed auditory feedback task with neurosurgical human subjects using electrocorticography (ECoG) recordings. Neural responses in the high-gamma broadband frequencies (70-150 Hz) were used as the primary measure of neural activity. In the auditory repetition task, subjects listened to a word and repeated it afterwards. In line with previous findings, auditory responses were suppressed during speaking compared to listening, but to a different extent in different electrodes. In the altered feedback task, subjects read aloud visually presented words, while their voice was recorded by a microphone and played back to them through earphones in real time with 0, 50, 100 or 200 millisecond delays. Behaviorally, articulation duration increased with increasing amount of delays. Recordings from auditory cortex exhibited different types of responses to delayed feedback. Some electrodes showed a response profile sensitive to articulation duration, exhibiting longer response durations for increasing delays. While other electrodes showed sensitivity to the amount of feedback perturbation, exhibiting larger response amplitudes for increasing delays. Moreover, the degree to which electrodes were sensitive to feedback delays was significantly correlated with the amount of suppression in each electrode. These results suggest that distinct neural populations of the auditory cortex are sensitive to articulation duration and alterations in the auditory feedback during speech production and these responses are linked to vocalization-induced suppression in the auditory cortex. These findings constitute one of the first reports from neural recordings in humans, providing direct evidence that auditory suppression is linked to a mechanism for vocalization error detection.
Themes: Speech Motor Control, Multisensory or Sensorimotor Integration
Method: Electrophysiology (MEG/EEG/ECOG)