The Autism Spectrum

A cognitive neuroscientist explores autism, Asperger's syndrome, and related disorders.

Lindsay M. Oberman, Ph.D. is a cognitive neuroscientist studying autism spectrum disorders. See full bio

September 21, 2008, Autism

The use of TMS for ASD

What we can learn about ASD by using TMS.

I haven't posted an entry in a while because I have been incredibly busy with collecting data for my studies. When thinking about what I was going to write about for this posting, I realized that I haven't really talked about my research, which is in and of itself arguably a controversial topic in autism. I am currently a research fellow at Beth Israel Deaconess Medical Center of Harvard University. My research involves the use of transcranial magnetic stimulation to explore and influence brain plasticity in adults and adolescents with autism spectrum disorders. Essentially, my goal is to understand the mechanism that developmentally are affected in individuals with ASD that leads to the behavioral symptoms.

We believe that the mechanisms of plasticity (essentially how the brain changes in response to experience) is abnormally high in individuals with ASD. We use transcranial magnetic stimulation to induce a "change" to the brain and measure how it influences responses following this change. Transcranial magnetic stimulation is a technique like none other. It is capable of targeting a small (about 1-2 cubic centimeter) section of brain and either enhance the functioning or reduce the functioning of that section for a period of time. It is noninvasive and only has very limited risk of side effects. It is an extremely powerful tool for a researcher to be able to manipulate the functioning of a specific area of the brain and track the effect of this change over time. So far we have done some amazing things. We have found evidence that we can improve the functioning of the mirror neuron system and some communication skills following repetitive application of TMS and we can explore what is leading to the functional brain changes present in individuals with ASD.

Though TMS has the potential to be an invaluable research tool and potentially the source for novel therapeutic interventions, many are afraid of TMS. It is somewhat scary to think that we have the capability of changing the functioning of the brain for the better or for the worse, but I think it is only scary because of the direct connection. In essence this is the same thing that drugs do (changing the firing of the neurons in the brain), but in an arguably indirect way. Essentially, TMS takes advantage of the fact that the brain functions via electrical impulses and creates a focused fluctuating magnetic field which changes the firing of the neurons directly. Fortunately and I suppose unfortunately (depending on your perspective) the changes that are induced by TMS are not permanent. Typically sessions of TMS (which last between 1-30 minutes) will lead to changes on the order of minutes to several days. So, it's potential as a therapeutic intervention is limited by the participant's willingness to come back for "maintenance stimulation sessions," but it certainly has a great potential for researchers interested in seeing how the brain responds to stimulation in different regions.

I look forward to your questions and comments on TMS and how we may be able to learn about ASD by utilizing this technique.