SPEECHSTIM: Modulating Speech Perception With Current Stimulation

Sponsor

University Hospital, Toulouse (Other)

Overall Status

Recruiting

CT.gov ID

NCT05446350

Collaborator

Centre National de la Recherche Scientifique, France (Other)

126

Enrollment

Location

Arms

Anticipated Duration (Months)

3.3

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

This study aims to further develop tACS as a tool to improve speech perception, by manipulation of brain-speech synchronisation ("entrainment"), thereby transforming a promising approach into a technique that can benefit to society on a large scale.

Condition or Disease	Intervention/Treatment	Phase
Healthy	Procedure: transcranial alternating current stimulation (tACS) Procedure: electroencephalography (EEG) Procedure: brain imaging (fMRI) Procedure: electroencephalography (EEG) with neurofeedback	N/A

Detailed Description

Neural oscillations align their phase to the rhythm of speech. This phenomenon is termed neural entrainment and associated with successful speech comprehension. Importantly, we have demonstrated that transcranial alternating current stimulation (tACS) can be used to manipulate how neural activity aligns to speech rhythm, leading to changes in speech perception. The aim of Experiment 1 is to understand how tACS operates on the neural level. This aim will be reached by testing whether tACS produces rhythmic electroencephalography (EEG) responses that outlast the stimulation, indicating an involvement of endogenous oscillatory activity. The aim of Experiment 2 is to increase efficacy of tACS and, consequently, its potential to play an important role in research and everyday life applications. This aim will be reached by using brain imaging (fMRI) to predict optimal stimulation protocols for individual participants. The aim of Experiment 3 is to reveal how tACS can boost speech perception in a multi-speaker scenario. This aim will be reached by using tACS to enhance attended speech or suppress distracting speech, and by comparing these two approaches in their efficacy to boost speech perception. The aim of Experiment 4 is to combine established techniques to create novel opportunities to improve speech perception. This aim will be reached by using neurofeedback to teach participants to enhance their own neural entrainment, applying tACS to support them in this process.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

126 participants

Allocation:

Non-Randomized

Intervention Model:

Parallel Assignment

Masking:

Single (Participant)

Masking Description:

masking to the conditions of the experiments

Primary Purpose:

Basic Science

Official Title:

Modulating Speech Perception With Current Stimulation (SPEECHSTIM)

Actual Study Start Date :

Jul 1, 2022

Anticipated Primary Completion Date :

Sep 1, 2025

Anticipated Study Completion Date :

Sep 1, 2025

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Experiment 1 The aim of Experiment 1 is to understand how tACS operates on the neural level	Procedure: transcranial alternating current stimulation (tACS) transcranial alternating current stimulation (tACS) used to manipulate how neural activity aligns to speech rhythm, leading to changes in speech perception Procedure: electroencephalography (EEG) analyse rhythmic electroencephalography responses that outlast the stimulation
Experimental: Experiment 2 The aim of Experiment 2 is to increase efficacy of tACS and, consequently, its potential to play an important role in research and everyday life applications	Procedure: transcranial alternating current stimulation (tACS) transcranial alternating current stimulation (tACS) used to manipulate how neural activity aligns to speech rhythm, leading to changes in speech perception Procedure: brain imaging (fMRI) Using brain imaging (fMRI) to predict optimal stimulation protocols for individual participants
Experimental: Experiment 3 The aim of Experiment 3 is to reveal how tACS can boost speech perception in a multi-speaker scenario.	Procedure: transcranial alternating current stimulation (tACS) transcranial alternating current stimulation (tACS) used to manipulate how neural activity aligns to speech rhythm, leading to changes in speech perception
Experimental: Experiment 4 The aim of Experiment 4 is to combine established techniques to create novel opportunities to improve speech perception	Procedure: transcranial alternating current stimulation (tACS) transcranial alternating current stimulation (tACS) used to manipulate how neural activity aligns to speech rhythm, leading to changes in speech perception Procedure: electroencephalography (EEG) with neurofeedback Using neurofeedback to teach participants to enhance their own neural entrainment

Outcome Measures

Primary Outcome Measures

correctly identified words [Day 1]
percentage of correctly identified words during or after tACS who will permit to evaluate efficacy of tACS to modulate speech perception and neural responses in different experimental conditions (involving electrophysiological, brain imaging, and perceptual measures)

Secondary Outcome Measures

correctly identified words with different modality [day 1]
percentage of correctly identified words during or after tACS between different modality
oscillatory activities [Day 1]
measurement of oscillatory activities resulting from electrical stimulation: (frequency, power, and phase, latency) on the scalp and at the level of the sources and their synchronization with during or after tACS
neural activity [Day 1]
measurement of neural activity that results from electrical stimulation: fMRI (BOLD response) during or after tACS

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 50 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Subject aged between 18 and 50 years old
informed written consent
Absence of pro-epileptogenic drugs
Absence of visual or hearing impairment incompatible with participation in the study

Exclusion Criteria:

Pregnant or breastfeeding women,
Persons protected by law adults under guardianship or curatorship
Persons not affiliated to a Social Security scheme
Subjects with progressive psychiatric or neurological pathology
Subjects with a contraindication to tCS or MRI (history of epilepsy, severe head injury or brain/spinal cord surgery, cardiac pacemaker/defibrillator, implanted equipment activated by electrical, magnetic or mechanical system, hemostatic clip carriers of intracerebral aneurysms or carotid arteries, orthopedic implant carriers, claustrophobic, pregnancy).