Role of Auditory Cortical Oscillations in Speech Processing and Dyslexia

NCT04277351 | Completed

• 1 other identifier: PHONOSTIM
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

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.

Conditions

Dyslexia

Outcome Measures

Primary Outcomes (2)

• Measure low-gamma neural oscillations with electroencephalography recordings

  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.

  6 hour

• Changes in linguistic performance through a battery of behavioral tests

  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.

  6 hours

Study Arms (1)

tACS in individuals with and without dyslexia

EXPERIMENTAL

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

Interventions

Transcranial alternating current stimulation DEVICE

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.

tACS in individuals with and without dyslexia

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• University of Geneva, Switzerland: lead
• Wyss Center for Bio and Neuroengineering: collaborator

Study Sites (1)

Campus Biotech Geneva

Geneva, 1202, Switzerland

Location

Related Publications (1)

• Lehongre K, Ramus F, Villiermet N, Schwartz D, Giraud AL. Altered low-gamma 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.

  PMID: 22196341 BACKGROUND

MeSH Terms

Conditions

Dyslexia

Interventions

Transcranial Direct Current Stimulation

Condition Hierarchy (Ancestors)

Language Disorders; Communication Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Specific Learning Disorder; Learning Disabilities; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Neurodevelopmental Disorders; Mental Disorders

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Study Officials

• Anne-Lise Giraud, Prof.

  University of Geneva

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: 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.
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: February 13, 2020
• First Posted: February 20, 2020
• Study Start: September 1, 2016
• Primary Completion: September 1, 2018
• Study Completion: September 1, 2018
• Last Updated: February 20, 2020

Record last verified: 2020-02

Locations

CH (1)