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Completed

NCT Number: NCT04277351

Role of Auditory Cortical Oscillations in Speech Processing and Dyslexia

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.

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Key information

Conditions

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

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Campus Biotech Geneva

Geneva, 1202, Switzerland

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

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.

Primary outcomes

  1. Measure low-gamma neural oscillations with electroencephalography recordings

    Time frame: 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.

  2. Changes in linguistic performance through a battery of behavioral tests

    Time frame: 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.

Sponsors and collaborators

Lead sponsor

University of Geneva, Switzerland

Other

Collaborators

  • Wyss Center for Bio and Neuroengineering

Registry information

Official study title

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

Important dates

Study start
2016
Primary completion
2018
Study completion
2018
First posted
Feb 20, 2020
Registry last updated
Feb 20, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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