Role of Auditory Cortical Oscillations in Speech Processing and Dyslexia

Sponsor

University of Geneva, Switzerland (Other)

Overall Status

Completed

CT.gov ID

NCT04277351

Collaborator

Wyss Center for Bio and Neuroengineering (Other)

Enrollment

Location

Arm

Actual Duration (Months)

1.3

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

This study aims at investigating the role of low-gamma activity in phonemic encoding and its implication in dyslexia. Indeed, a phonological deficit, i.e. a difficulty in perceiving the sounds of speech, is strongly suspected in dyslexia but has never been conclusively associated with a specific underlying mechanism.

The study employs transcranial alternating current stimulation in adults with and without dyslexia to exploit the effect of the stimulation on phonemic processing and neural activity measured with electroencephalography. In doing so, it would be possible to establishing a causal link between gamma oscillations and the phonological deficit in dyslexia.

Condition or Disease	Intervention/Treatment	Phase
Dyslexia	Device: Transcranial alternating current stimulation	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

30 participants

Allocation:

N/A

Intervention Model:

Single Group Assignment

Masking:

Single (Participant)

Masking Description:

One of three different tACS conditions is administered to all participant during three experimental days. The conditions differ in the frequency of stimulation (condition 1 and 2) and in whether the stimulation is active or faked (sham). The order of the three stimulation conditions is counterbalanced across participants, who are not aware of which tACS condition they are undergoing.

Primary Purpose:

Basic Science

Official Title:

Role of Auditory Cortical Oscillations in Speech Processing and Its Dysfunction in Dyslexia Through Transcranial Alternating Current Stimulation

Actual Study Start Date :

Sep 1, 2016

Actual Primary Completion Date :

Sep 1, 2018

Actual Study Completion Date :

Sep 1, 2018

Arms and Interventions

Arm	Intervention/Treatment
Experimental: tACS in individuals with and without dyslexia Each participant in both the group of normo-readers and individuals with dyslexia receive all tACS stimulation conditions (fixed frequencies and sham) over different experimental days.	Device: Transcranial alternating current stimulation Focal transcranial stimulation over auditory cortex by means of 5 electrodes delivering an electric current (max. 2mA). In addition to active stimulation, also a placebo (sham) stimulation is employed as a control condition. All subjects included in the study receive all tACS stimulation conditions.

Arm

Intervention/Treatment

Experimental: tACS in individuals with and without dyslexia

Each participant in both the group of normo-readers and individuals with dyslexia receive all tACS stimulation conditions (fixed frequencies and sham) over different experimental days.

Device: Transcranial alternating current stimulation

Focal transcranial stimulation over auditory cortex by means of 5 electrodes delivering an electric current (max. 2mA). In addition to active stimulation, also a placebo (sham) stimulation is employed as a control condition. All subjects included in the study receive all tACS stimulation conditions.

Outcome Measures

Primary Outcome Measures

Measure low-gamma neural oscillations with electroencephalography recordings [6 hour]
Auditory-steady state responses to auditory stimuli are measured to assess specific differences between individuals with dyslexia and normo-readers, and between the different tACS stimulation conditions before, after and 1h after the 20 min. tACS stimulation. These neural correlated are estimated by considering the power of EEG signal at the frequency used to modulate the auditory stimuli.
Changes in linguistic performance through a battery of behavioral tests [6 hours]
Measurement of phonemic and syllabic processing (pseudoword repetition and spoonerism test), and reading (reading a 3 min. text, both accuracy and reading speed are considered) skills. These tests are repeated before, after and 1h after the tACS stimulation.

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 65 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

18-65 years old;
French native speakers;
normally-hearing;
intellectual quotient (IQ) around average;
for the dyslexia group: previous diagnosis of dyslexia as assessed by a speech therapist.

Exclusion Criteria:

Presence of metal or electronic implants in the brain/skull;
Presence of metal or electronic device at other in other parts of the body;
Have experienced a seizure or a loss of consciousness or a severe head trauma;
Severe brain related illness ;
Intake of central nervous system-effective medication;
Pregnant and nursing women;
Relatives affected by epilepsy.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Campus Biotech Geneva	Geneva		Switzerland	1202

Sponsors and Collaborators

University of Geneva, Switzerland
Wyss Center for Bio and Neuroengineering

Investigators

Principal Investigator: Anne-Lise Giraud, Prof., University of Geneva

Study Documents (Full-Text)

None provided.

More Information

Publications

Lehongre K, Ramus F, Villiermet N, Schwartz D, Giraud AL. Altered low-γ sampling in auditory cortex accounts for the three main facets of dyslexia. Neuron. 2011 Dec 22;72(6):1080-90. doi: 10.1016/j.neuron.2011.11.002.

Responsible Party:

Anne-Lise Giraud, Professor, University of Geneva, Switzerland

ClinicalTrials.gov Identifier:

NCT04277351

Other Study ID Numbers:

PHONOSTIM

First Posted:

Feb 20, 2020

Last Update Posted:

Feb 20, 2020

Last Verified:

Feb 1, 2020

Studies a U.S. FDA-regulated Drug Product:

Studies a U.S. FDA-regulated Device Product:

Additional relevant MeSH terms:

Dyslexia

Study Results

No Results Posted as of Feb 20, 2020