Probing the efficacy of neurostimulation on reading and reading-related measures in adults with developmental dyslexia
- Conditions
- F81.0Specific reading disorder
- Registration Number
- DRKS00030743
- Lead Sponsor
- Professur für Kognitive und Klinische Neurowissenschaften, Fakultät Psychologie, Technische Universität Dresden
- Brief Summary
Not available
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Pending
- Sex
- All
- Target Recruitment
- 85
We plan to include 85 individuals (65 individuals diagnosed with DD and 20 controls) for this study.
The inclusion criteria for the participants with DD will be: (1) right-handed German speakers participants of both genders, diagnosed with DD according to participants’ self-report, lifelong symptoms from childhood; (2) reading accuracy and/or speed, as assessed by measures commonly used for diagnosis of DD in Germany (i.e., LGVT), of at least 1.5 standard deviations (SD) below the mean for typically-reading adults; (3) non-verbal Intelligence Quotient (nvIQ86) higher or equal to 85 (IQ = 85); (4) normal hearing and normal or corrected-to-normal vision.
For the control group, the inclusion criteria will be: (1) right-handed German speakers participants of both genders without any neurological disorders; (2) non-verbal Intelligence Quotient (nvIQ86) higher or equal to 85 (IQ = 85); (3) normal hearing and normal or corrected-to-normal vision.
The exclusion criteria for the participants with DD involve the following: (1) the presence of other primary psychiatric/neurological diagnosis (e.g., depression, anxiety, autism, ADHD, but not dyscalculia); (2) a personal history of neurological/medical/genetic diseases; (3) ongoing drug treatment influencing brain function; (4) a personal history or first-degree relatives’ history of epilepsy; (5) incompatibility with tDCS; (6) incompatibility with MRI.
The exclusion criteria for the healthy participants involve the following: (1) the presence of any psychiatric/neurological diagnosis (e.g., depression, anxiety, autism, ADHD); (2) a personal history of neurological/medical/genetic diseases; (3) ongoing drug treatment influencing brain function; (4) a personal history or first-degree relatives’ history of epilepsy; (5) incompatibility with MRI.
Study & Design
- Study Type
- interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method The primary objective of the current study is testing whether high definition transcranial direct current stimulation (HD-tDCS) over V5/MT will lead to improvements on reading in adults with developmental dyslexia (DD) compared to control conditions (HD-tDCS over V1 and sham). For our primary outcome we will test whether, in adults with DD, HD-tDCS over V5/MT compared to baseline and control conditions (HD-tDCS over V1, sham) will improve reading immediately after the stimulation in terms of accuracy and speed in text, word, and nonword reading measures.
- Secondary Outcome Measures
Name Time Method In our secondary endpoints we will test in adults with DD the following hypotheses:<br>i) HD-tDCS over V5/MT will lead to improvements on reading-related behavioural measures (right visial hemifield (rvh)-motion perception and rapid automatized naming of letters and numbers (RANln) compared to control conditions (HD-tDCS over V1, sham);<br>ii) V5/MT HD-tDCS effects will be largest in those DD who are characterized by slow RANln performance and deficits in rvh-motion perception;<br>iii) the amount of task-dependent modulation of the lateral geniculate nuclei (LGN) for visual speech and structural connectivity strength between LGN and V5 will be correlated with the amount of HD-tDCS effect on rvh- and RANln-behaviour. We assume that the following correlation is the most likely: The more reduction there is in a participant's LGN-V5/MT system (measured via the task-dependent modulation and structural connectivity), the more there will be faciltatory influcence of the HD-tDCS.