Brief Summary

This study contributes to fundamental research investigating the role of the articulatory-motor integration and cerebro-acoustic coherence in speech comprehension. In a series of experiments non-invasive brain stimulation (NIBS) techniques including transcranial electric stimulation with alternating current waveforms (tACS) and transcranial magnetic stimulation (TMS) will be applied to the left ventral motor cortex (vMC) to test the contribution of this area to speech comprehension under challenging listening situations. As long as the exclusion criteria for TMS and tACS are strictly considered, only very minimal risks and no long-term effects are expected. There are no known risks associated with NIBS and pregnancy; however, since risks cannot be completely excluded, pregnant women will be excluded from participation. If a female participant is uncertain whether she is pregnant, she will be provided with a pregnancy test at no cost.

Trial Health

At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date

Enrollment

190

participants targeted

Target at P75+ for not_applicable

Timeline

Completed

Started Dec 2020

Typical duration for not_applicable

Geographic Reach

1 country

1 active site

Status

unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

3.2 years study duration

First Submitted

Initial submission to the registry

July 15, 2019

Completed

15 days until next milestone

First Posted

Study publicly available on registry

July 30, 2019

Completed

1.3 years until next milestone

Study Start

First participant enrolled

December 1, 2020

Completed

3.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 28, 2024

Completed

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

February 28, 2024

Completed

Last Updated

November 22, 2022

Status Verified

November 1, 2022

Enrollment Period

3.2 years

First QC Date

July 15, 2019

Last Update Submit

November 21, 2022

Conditions

Electric Stimulation Therapy Transcranial Magnetic Stimulation

Outcome Measures

Primary Outcomes (6)

articulatory motor-evoked potential (aMEP) amplitude (Experiment 1) - time point 1
The comparison of articulatory motor-evoked potential (aMEP) amplitude after tACS and sham stimulation
online (during tACS intervention)
articulatory motor-evoked potential (aMEP) amplitude (Experiment 1) - time point 2
The comparison of articulatory motor-evoked potential (aMEP) amplitude after tACS and sham stimulation
5min after tACS
articulatory motor-evoked potential (aMEP) amplitude (Experiment 1) - time point 3
The comparison of articulatory motor-evoked potential (aMEP) amplitude after tACS and sham stimulation
55min after (tACS)
degraded speech comprehension (Experiment 2)
Subjects will listen and transcribe noise-vocoded sentence according to their subjective intelligibility levels (75% (easy), 50% (medium) and 25% (difficult)) assessed prior to the expermental manipulation Comparison of degraded speech comprehension following tACS over the left ventral motor cortex (vMC) with performance following sham stimulation over the same region.
right after tACS or sham stimulation (cross-over design)
degraded speech comprehension (Experiment 3)
Subjects will listen and transcribe noise-vocoded sentence according to their subjective intelligibility levels (75% (easy), 50% (medium) and 25% (difficult)) assessed prior to the expermental manipulation Comparison of degraded speech comprehension following tACS over the left ventral motor cortex (vMC) with performance following sham stimulation over the same region.
20min after tACS or sham stimulation (between-group design), following a training of degraded speech comprehension
degraded speech comprehension (Experiment 4)
Subjects will listen and transcribe noise-vocoded sentence according to their subjective intelligibility levels (75% (easy), 50% (medium) and 25% (difficult)) assessed prior to the expermental manipulation The comparison of degraded speech comprehension between concomitant low-frequency (theta-band) speech envelope-shaped tACS (env-tACS), reversed env-tACS, and sham stimulation over left ventral motor cortex
during env-tACS or sham stimulation (online)

Secondary Outcomes (9)

syllable discrimination ability (Experiment 1) - time point 1
before tACS or sham stimulation (cross-over design)
syllable discrimination ability (Experiment 1) - time point 2
5min after tACS or sham stimulation (cross-over design)
speech degradation level (Experiment 2)
right after tACS or sham stimulation (cross-over design)
age group dependent tACS modulation (Experiment 2)
right after tACS or sham stimulation (cross-over design)
speech degradation level (Experiment 3)
20min after tACS or sham stimulation, following a training of degraded speech comprehension
+4 more secondary outcomes