Role of Auditory Cortical Oscillations in Speech Processing and Dyslexia

Dyslexia Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04277351
• Other study ID #: PHONOSTIM
• Status: Completed
• Phase: N/A
• Start date: September 1, 2016
• Est. completion date: September 1, 2018

Study information

• Verified date: February 2020
• Source: University of Geneva, Switzerland
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 30
• Est. completion date: September 1, 2018
• Est. primary completion date: September 1, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

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.

Related Conditions & MeSH terms

• Dyslexia

Intervention

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.

Locations

Country	Name	City	State
Switzerland	Campus Biotech Geneva	Geneva

Sponsors (2)

Lead Sponsor	Collaborator
University of Geneva, Switzerland	Wyss Center for Bio and Neuroengineering

Country where clinical trial is conducted

Switzerland, 

References & Publications (1)

Lehongre K, Ramus F, Villiermet N, Schwartz D, Giraud AL. Altered low-? 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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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
Primary	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