Facilitating Numerical Processing With Transcranial Stimulation in Developmental Dyscalculia
| Status: | Archived |
|---|---|
| Conditions: | Cognitive Studies, Neurology |
| Therapuetic Areas: | Neurology, Psychiatry / Psychology |
| Healthy: | No |
| Age Range: | Any |
| Updated: | 7/1/2011 |
| Start Date: | August 2010 |
Facilitating Numerical Processing With Transcranial DC Stimulation in Developmental Dyscalculia
Background:
- 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.
Objectives:
- To examine whether the effects of transcranial direct current stimulation can help
individuals with developmental dyscalculia perform mathematical calculations.
Eligibility:
- Individuals between 18 and 50 years of age who have been diagnosed with developmental
dyscalculia, or are healthy volunteers without dyscalculia.
Design:
- Participants will have a screening visit and seven study visits. The screening visit
and six of the study visits will take place consecutively over the course of 6 days,
and the final visit will take place 3 months after the initial participation.
- Participants will be screened with a medical history, physical and neurological
examination, and a brief examination to test for dyscalculia and determine the
participant's dominant hand.
- Participants will be randomly assigned to one of two groups for the study. One group
will receive tDCS during training to perform a task with numbers, and the other group
will receive the same training with sham stimulation. Participants will not know which
group they are in.
- During the study visits, participants will be trained on number tasks on 6 consecutive
days. Before the tDCS or sham stimulation is applied at the beginning of the experiment
and at the end of each training day, participants will perform other tasks with
numbers. Participants will be evaluated based on the accuracy and speed with which they
respond to the questions.
- At the followup visit, participants will perform the same number tasks they completed
during the study visits. No tDCS will be performed at this visit.
Objectives
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.
Study population
30 healthy volunteers and 30 subjects with developmental dyscalculia (DD).
Design
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
Outcome Measures
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).
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Bethesda, Maryland 20892
301-496-2563
National Institutes of Health Clinical Center The National Institutes of Health (NIH) Clinical Center in...
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