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

Abstract

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.

Figure 1

Comparison of the evoked cortical neural responses to three different pitch-shifting stimulus magnitudes during a) active vocalization of the vowel sound /a/ and b) passive listening to the playback of the self-generated vocalization. The vertical dashed lines in each subplot mark the onset of the pitch-shifting stimulus.

Figure 1

Comparison of the evoked cortical neural responses to three different pitch-shifting stimulus magnitudes during a) active vocalization of the vowel sound /a/ and b) passive listening to the playback of the self-generated vocalization. The vertical dashed lines in each subplot mark the onset of the pitch-shifting stimulus.

Figure 2

Comparison of the evoked cortical neural responses during active vocalization and passive listening conditions for a) 100 cents b) 200 cents and c) 500 cents pitch-shifting stimulus magnitudes. The vertical dashed lines in each subplot mark the onset of the pitch-shifting stimulus.

Figure 2

Comparison of the evoked cortical neural responses during active vocalization and passive listening conditions for a) 100 cents b) 200 cents and c) 500 cents pitch-shifting stimulus magnitudes. The vertical dashed lines in each subplot mark the onset of the pitch-shifting stimulus.

Figure 2

Comparison of the evoked cortical neural responses during active vocalization and passive listening conditions for a) 100 cents b) 200 cents and c) 500 cents pitch-shifting stimulus magnitudes. The vertical dashed lines in each subplot mark the onset of the pitch-shifting stimulus.

Figure 3

Topographical distribution of the grand average auditory neural responses to pitch-shifted auditory feedback perturbation for a) P₁ (latency: 73.51 ms), b) N₁ (latency: 117.41 ms) and c) P₂ (latency: 199.55 ms) ERP components. The maps are calculated for 13 recording sites on the surface of the scalp (C_Z, C₃, C₄, T₃, T₄, F_Z, F₃, F₄, F₇, F₈, P_Z, P₃, P₄) and the neural responses are grand averaged over 15 subjects for three stimulus magnitudes (100, 200 and 500 cents) during active vocalization and passive listening conditions.

Figure 4

Topographical distribution of the averaged auditory neural responses to pitch-shifted auditory feedback perturbation across 15 subjects. The maps are calculated for 13 recording sites on the surface of the scalp (C_Z, C₃, C₄, T₃, T₄, F_Z, F₃, F₄, F₇, F₈, P_Z, P₃, P₄) and the distributions of the P₁ (latency: 73.51 ms), N₁ (latency: 117.41 ms) and P₂ (latency: 199.55 ms) peak amplitudes are shown in three separate rows. The distribution topographies are arranged in six columns to show the maps for three stimulus magnitudes (100, 200 and 500 cents) across active vocalization and passive listening conditions separately.

Figure 5

Comparison of normalized difference index (NDI) across three different levels of the pitch-shifting stimulus magnitude for a) P₁ and b) P₂ peak amplitudes on the left and right hemispheres separately.