Clinical trial NCT05446350: Modulating Speech Perception With Current Stimulation
Official title: Modulating Speech Perception With Current Stimulation (SPEECHSTIM)
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Healthy
Keywords: Transcranial alternating current stimulation (tACS),
speech
perception
neural oscillations
entrainment
phase
neurofeedback
Lead sponsor: University Hospital, Toulouse
Sponsor class: OTHER
Collaborators: name: Centre National de la Recherche Scientifique, France
First posted: 2022-07-06
Enrollment: 126
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.

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.

Eligibility criteria: 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).

Primary outcomes:
measure: correctly identified words
timeFrame: Day 1
Secondary outcomes:
measure: correctly identified words with different modality
timeFrame: day 1
measure: oscillatory activities
timeFrame: Day 1
measure: neural activity
timeFrame: Day 1
Other outcomes:
Locations:
city: Toulouse
country: France
facility: CHU Toulouse
Study officials:
affiliation: CHU Toulouse
name: Mathieu MARX, PU-PH
role: PRINCIPAL_INVESTIGATOR
References:
citation: van Bree S, Sohoglu E, Davis MH, Zoefel B. Sustained neural rhythms reveal endogenous oscillations supporting speech perception. PLoS Biol. 2021 Feb 26;19(2):e3001142. doi: 10.1371/journal.pbio.3001142. eCollection 2021 Feb.
citation: Zoefel B, Davis MH, Valente G, Riecke L. How to test for phasic modulation of neural and behavioural responses. Neuroimage. 2019 Nov 15;202:116175. doi: 10.1016/j.neuroimage.2019.116175. Epub 2019 Sep 6.
citation: Zoefel B, Allard I, Anil M, Davis MH. Perception of Rhythmic Speech Is Modulated by Focal Bilateral Transcranial Alternating Current Stimulation. J Cogn Neurosci. 2020 Feb;32(2):226-240. doi: 10.1162/jocn_a_01490. Epub 2019 Oct 29.