Brain stimulation boosts social skills in autism
THE first clinical trial aimed at boosting social skills in people with autism using magnetic brain stimulation has been completed – and the results are encouraging.
"As a first clinical trial, this is an excellent start," says Lindsay Oberman of the Beth Israel Deaconess Medical Centre in Boston, who was not part of the study.
People diagnosed with autism spectrum disorder often find social interactions difficult. Previous studies have shown that a region of the brain called the dorsomedial prefrontal cortex (dmPFC) is underactive in people with autism. “It’s also the part of the brain linked with understanding others’ thoughts, beliefs and intentions,” says Peter Enticott of Monash University in Melbourne, Australia.
Enticott and his colleagues wondered whether boosting the activity of the dmPFC using repetitive transcranial magnetic stimulation (rTMS), which involves delivering brief but strong magnetic pulses through the scalp, could help individuals with autism deal with social situations. So the team carried out a randomised, double-blind clinical trial – the first of its kind – involving 28 adults diagnosed with either high-functioning autism or Asperger’s syndrome.
Some participants received 15 minutes of rTMS for 10 days, while others had none, but experienced all other aspects, such as having coils placed on their heads and being subjected to the same sounds and vibrations.
The participants carried out a number of tests of their social skills before the start of the therapy and at the end of the therapy. These showed that those who received rTMS had significantly improved social skills a month later. For instance, one woman began making tea for her sibling who was studying for an exam, suggesting that she understood her sibling’s emotional state and wanted to help. “As far as her family were concerned, this was completely foreign to her,” says Enticott. “She had never shown any inclination toward that sort of activity in her life.”
The therapy also reduced anxiety, as judged by a standard questionnaire that measures reactions in difficult, emotionally charged interactions with others. No such changes were observed in people who received the placebo (Brain Stimulation, doi.org/pnz).
However, participants showed no improvement in computer tasks designed to test whether they could infer the mental states of others, or mentalise. “It surprises me,” says Enticott. “We are stimulating the region of the brain that is most closely associated with these tasks.” Given this, it is unclear why the volunteers showed an improvement in social skills. “We need to figure out whether this is underpinned by changes to mentalising ability, or whether there is some other thing at play,” he says.
Oberman points out that the dmPFC is not near the surface of the brain, so it is hard to target with great accuracy. The rTMS would have stimulated brain regions between the scalp and the dmPFC. This lack of specificity may have driven the changes without affecting mentalising. The next step is to increase the duration and intensity of stimulation and to monitor how long the observed improvements last.
"While the findings are interesting, the research is still in its very early stages," cautions Carol Povey, at the UK’s National Autistic Society. She adds that it is essential that people with autism receive the support they need to reach their full potential.