The Role of Auditory Feedback at Vocalization Onset and Mid-Utterance (original) (raw)

Control of vocalization at utterance onset and mid-utterance: Different mechanisms for different goals

Brain Research, 2009

A large body of evidence suggests that the motor system maintains a forward model that predicts the sensory outcome of movements. When sensory feedback does not match the predicted consequences, a compensatory response corrects for the motor error and the forward model is updated to prevent future errors. Like other motor behaviours, vocalization relies on sensory feedback for the maintenance of forward models. In this study, we used a frequency altered feedback (FAF) paradigm to study the role of auditory feedback in the control of vocal pitch (F0). We adapted subjects to a one semitone shift and induced a perturbation by briefly removing the altered feedback. This was compared to a control block in which a 1 semitone perturbation was introduced into an unshifted trial, or trials were randomly shifted up 1 semitone, and a perturbation was introduced by removing the feedback alteration. The compensation response to mid-utterance perturbations was identical in all conditions, and was always smaller than the compensation to a shift at utterance onset. These results are explained by a change in the control strategy at utterance onset and mid-utterance. At utterance onset, auditory feedback is compared to feedback predicted by a forward model to ensure the pitch goal is achieved. However, after utterance onset, the control strategy switches and stabilization is maintained by comparing feedback to previous F0 production.

Vocalization-induced enhancement of the auditory cortex responsiveness during voice F0 feedback perturbation

Clinical Neurophysiology, 2009

Objective: The present study investigated whether self-vocalization enhances auditory neural responsiveness to voice pitch feedback perturbation and how this vocalization-induced neural modulation can be affected by the extent of the feedback deviation. Methods: Event-related potentials (ERPs) were recorded in 15 subjects in response to +100, +200 and +500 cents pitch-shifted voice auditory feedback during active vocalization and passive listening to the playback of the self-produced vocalizations. Results: The amplitude of the evoked P 1 (latency: 73.51 ms) and P 2 (latency: 199.55 ms) ERP components in response to feedback perturbation were significantly larger during vocalization than listening. The difference between P 2 peak amplitudes during vocalization vs. listening was shown to be significantly larger for +100 than +500 cents stimulus. Conclusions: Results indicate that the human auditory cortex is more responsive to voice F 0 feedback perturbations during vocalization than passive listening. Greater vocalization-induced enhancement of the auditory responsiveness to smaller feedback perturbations may imply that the audio-vocal system detects and corrects for errors in vocal production that closely match the expected vocal output. Significance: Findings of this study support previous suggestions regarding the enhanced auditory sensitivity to feedback alterations during self-vocalization, which may serve the purpose of feedback-based monitoring of one's voice.

Dynamics of Vocalization-Induced Modulation of Auditory Cortical Activity at Mid-utterance

PloS one, 2013

Background: Recent research has addressed the suppression of cortical sensory responses to altered auditory feedback that occurs at utterance onset regarding speech. However, there is reason to assume that the mechanisms underlying sensorimotor processing at mid-utterance are different than those involved in sensorimotor control at utterance onset. The present study attempted to examine the dynamics of event-related potentials (ERPs) to different acoustic versions of auditory feedback at mid-utterance.

Altered auditory feedback induces coupled changes in formant frequencies during speech production

2019

Speaking is one of the most complicated motor behaviours, involving a large number of articulatory muscles which can move independently to command precise changes in speech acoustics. Here, we used real-time manipulations of speech feedback to test whether the acoustics of speech production (e.g. the formants) reflect independently controlled articulatory movements or combinations of movements. During repetitive productions of "head, bed, dead", either the first (F1) or the second formant (F2) of vowels was shifted and fed back to participants. We then examined whether changes in production in response to these alterations occurred for only the perturbed formant or both formants. In Experiment 1, our results showed that participants who received increased F1 feedback significantly decreased their F1 productions in compensation, but also significantly increased the frequency of their F2 productions. The combined F1-F2 change moved the utterances closer to a known pattern of...

ERP Correlates of the Magnitude of Pitch Errors Detected in the Human Voice

Neuroscience, 2013

Auditory event-related potentials (ERP)s of the P1-N1-P2 complex are modulated when participants hear frequency-altered feedback (FAF) regarding their ongoing vocal productions. However, the relationship between feedback perturbation magnitudes and the resultant neural responses is at present unclear. In the present study, we exposed speakers to FAF of different magnitudes ranging from 0 to 400 cents. Vocal responses and P1-N1-P2-N2 ERPs were examined in an attempt to relate variation in the magnitude of the imposed feedback perturbation with variation in vocal and neural responses. Overall, vocal response magnitudes remained relatively consistent in response to smaller feedback perturbations (<250 cents), while larger feedback perturbations (>300 cents) resulted in decreased vocal response magnitudes. P1 amplitudes were found to increase in a non-specific manner in response to FAF. Conversely, N1 amplitudes displayed increased specificity: small feedback perturbations evoked one size of response, while larger feedback perturbations resulted in larger responses. The P2 component showed the most systematic amplitude modulation as feedback perturbation magnitude increased. A regression analysis highlighted the relationship between vocal response magnitude and P2 amplitude, with both vocal response magnitude and P2 amplitude increasing in response to perturbations between 50 and 250 cents, and then decreasing in response to larger perturbations. Although not generally observed in FAF studies, a robust N2 was also found; N2 amplitudes increased as stimulus magnitudes increased. The pattern of P1-N1-P2-N2 amplitude modulation in response to different magnitudes of FAF indicates that these components reflect processes involved in the detection and correction of unintended changes in auditory feedback during speech.

Modulation of effective connectivity during vocalization with perturbed auditory feedback

Neuropsychologia, 2013

The integration of auditory feedback with vocal motor output is important for the control of voice fundamental frequency (F 0 ). We used a pitch-shift paradigm where subjects respond to an alteration, or shift, of voice pitch auditory feedback with a reflexive change in F 0 . We presented varying magnitudes of pitch shifted auditory feedback to subjects during vocalization and passive listening and measured event related potentials (ERPs) to the feedback shifts. Shifts were delivered at +100 and +400 cents (200 ms duration). The ERP data were modeled with dynamic causal modeling (DCM) techniques where the effective connectivity between the superior temporal gyrus (STG), inferior frontal gyrus and premotor areas were tested. We compared three main factors: the effect of intrinsic STG connectivity, STG modulation across hemispheres and the specific effect of hemisphere. A Bayesian model selection procedure was used to make inference about model families. Results suggest that both intrinsic STG and left to right STG connections are important in the identification of self-voice error and sensory motor integration. We identified differences in left-to-right STG connections between 100 cent and 400 cent shift conditions suggesting that self-and non-self-voice error are processed differently in the left and right hemisphere. These results also highlight the potential of DCM modeling of ERP responses to characterize specific network properties of forward models of voice control.

ERP correlates of online monitoring of auditory feedback during vocalization

Psychophysiology, 2009

When speakers hear the fundamental frequency (F0) of their voice altered, they shift their F0 in the direction opposite the perturbation. The current study used ERPs to examine sensory processing of short feedback perturbations during an ongoing utterance. In one session, participants produced a vowel at an F0 of their own choosing. In another session, participants matched the F0 of a cue voice. An F0 perturbation of 0, 25, 50, 100, or 200 cents was introduced for 100 ms. A mismatch negativity (MMN) was observed. Differences between sessions were only found for 200-cent perturbations. Reduced compensation when speakers experienced the 200-cent perturbations suggests that this larger perturbation was perceived as externally generated. The presence of an MMN, and no earlier (N100) response suggests that the underlying sensory process used to identify and compensate for errors in mid-utterance may differ from feedback monitoring at utterance onset.