Facilitating Numerical Processing With Transcranial Stimulation in Developmental Dyscalculia
|First Received Date ICMJE||September 3, 2010|
|Last Updated Date||December 30, 2011|
|Start Date ICMJE||August 2010|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures ICMJE||Not Provided|
|Original Primary Outcome Measures ICMJE||Not Provided|
|Change History||Complete list of historical versions of study NCT01195961 on ClinicalTrials.gov Archive Site|
|Current Secondary Outcome Measures ICMJE||Not Provided|
|Original Secondary Outcome Measures ICMJE||Not Provided|
|Current Other Outcome Measures ICMJE||Not Provided|
|Original Other Outcome Measures ICMJE||Not Provided|
|Brief Title ICMJE||Facilitating Numerical Processing With Transcranial Stimulation in Developmental Dyscalculia|
|Official Title ICMJE||Facilitating Numerical Processing With Transcranial DC Stimulation in Developmental Dyscalculia|
- Developmental dyscalculia is a learning disability in which individuals have difficulty learning or comprehending mathematics or other number concepts (such as keeping score during games, measuring time, or estimating distance). Developmental dyscalculia affects certain parts of the brain that are required for processing numbers. Research has shown that a form of brain stimulation called transcranial direct current stimulation (tDCS), applied when healthy individuals are being trained to carry out tasks with numbers, improved the ability to process numbers and solve math problems. More research is needed about whether tDCS can improve number processing in people with developmental dyscalculia.
- To examine whether the effects of transcranial direct current stimulation can help individuals with developmental dyscalculia perform mathematical calculations.
- Individuals between 18 and 50 years of age who have been diagnosed with developmental dyscalculia, or are healthy volunteers without dyscalculia.
Developmental dyscalculia (DD) is a condition in which subjects cannot process adequately numerical concepts. Performance of arithmetical calculations is associated with fMRI activity in an extended brain network that includes parietal and prefrontal cortices. Areas within the parietal lobe, required for numerical processing in healthy subjects, are abnormal in subjects with DD. The purpose of this single-blinded study is to determine if facilitatory transcranial direct current stimulation (tDCS) of these parietal areas in association with numerical training will improve processing of numerical information relative to sham in subjects with DD and in healthy volunteers.
30 healthy volunteers and 30 subjects with developmental dyscalculia (DD).
Healthy volunteers and subjects with DD will be randomly assigned to one of two groups. Each group will receive anodal tDCS or sham with numerical training. All subjects will participate in 7 sessions. First, they will be trained on an ordinal numerical task (numerical training task) in which they will learn the magnitude relations between two numbers on 6 consecutive days while receiving sham stimulation or tDCS during the training. Subjects will see two numbers on the screen, one viewed on the left side of the screen and the other on the right side of the screen (example, 2, 4), and they have to decide which one is larger. Performance will be evaluated by fitting a power-law function. Before the beginning of the experiment and after each training day subjects will perform a numerical Stroop task that assesses the automaticity of numerical processing, and a number-space task that will provide information on the subject's accuracy of mapping numbers into space. At the end of each of the 6 training days (immediately post training) and 3 months (seventh session) later (retention measure) subjects will be tested on a dyscalculia test (The Dyscalculia Screener),the numerical Stroop task, and the number-space task
The primary outcome measure will be the improvement in automatic numerical processing (numerical Stroop task) as reflected by reaction times. Secondary outcomes are accuracy when mapping numbers into space (number-space task) and improvement in the dyscalculia score (Dyscalculia Screener).
|Study Type ICMJE||Observational|
|Study Design ICMJE||Time Perspective: Prospective|
|Target Follow-Up Duration||Not Provided|
|Sampling Method||Not Provided|
|Study Population||Not Provided|
|Intervention ICMJE||Not Provided|
|Study Group/Cohort (s)||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Recruitment Status ICMJE||Withdrawn|
|Completion Date||July 2011|
|Primary Completion Date||Not Provided|
|Eligibility Criteria ICMJE||
We will include healthy volunteers and DD subjects who meet the following criteria:
Age 18 to 50 years
Able to provide informed consent
No history of math difficulties as determined by Dyscalculia Screener examination > upper 50th percentile (healthy volunteers)
Diagnosed with DD and scored < lower 25th percentile on Dyscalculia screening test (Developmental Dyscalculia subjects)
Edinburgh handedness inventory shows a laterality index (LI) > 75 (dexterity) or LI of less than -75 (left-handedness)
We will exclude healthy volunteers and DD subjects if one of the following conditions applies:
Unable to perform the tasks due to visual problems
History of seizures or brain tumor
History of alcohol or drug abuse (defined as the use of a drug for a nontherapeutic effect ) or psychiatric illness such as severe depression
History of brain surgery
Drug treatment acting primarily on the central nervous system, which lowers the seizure threshold such as antipsychotic drugs (chlorprozamine, clozapine).
|Ages||18 Years to 50 Years|
|Accepts Healthy Volunteers||Yes|
|Contacts ICMJE||Contact information is only displayed when the study is recruiting subjects|
|Location Countries ICMJE||United States|
|NCT Number ICMJE||NCT01195961|
|Other Study ID Numbers ICMJE||100194, 10-N-0194|
|Has Data Monitoring Committee||Not Provided|
|Responsible Party||Not Provided|
|Study Sponsor ICMJE||National Institute of Neurological Disorders and Stroke (NINDS)|
|Collaborators ICMJE||Not Provided|
|Investigators ICMJE||Not Provided|
|Information Provided By||National Institutes of Health Clinical Center (CC)|
|Verification Date||July 2011|
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