Role of Auditory Cortical Oscillations in Speech Processing and Dyslexia

NCT ID: NCT04277351

Last Updated: 2020-02-20

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 30 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2016-09-01
• Study Completion Date: 2018-09-01

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

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: SINGLE

Study Groups

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.

Group Type: EXPERIMENTAL

Transcranial alternating current stimulation

Intervention Type: 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.

Interventions

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.

Intervention Type: DEVICE

Eligibility Criteria

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.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Wyss Center for Bio and Neuroengineering

OTHER

Sponsor Role: collaborator

University of Geneva, Switzerland

OTHER

Sponsor Role: lead

Responsible Party

Anne-Lise Giraud

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Anne-Lise Giraud, Prof.

Role: PRINCIPAL_INVESTIGATOR

University of Geneva

Locations

Campus Biotech Geneva

Geneva, , Switzerland

Countries

Switzerland

References

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.

Reference Type: BACKGROUND

PMID: 22196341 (View on PubMed)

Other Identifiers

PHONOSTIM

Identifier Type: -

Identifier Source: org_study_id