Noisy Brain Signals Could Underlie Autism

The glow of a lamp, the ring of a musical note, the tickle of a feather — each sensation stimulates a different part of the cortex, the outer layer of the brain. In an adult with autism, these responses vary much more than in someone without the disorder, according to a study published 20 September in Neuron.Using functional magnetic resonance imaging, the researchers exposed participants to the same stimulus — a sight, sound or touch — repeatedly over dozens of trials.When they averaged brain activity across all the trials, they found no difference between the autism and control groups. But when they looked at a single participant's response from one trial to the next, they found that, for those with autism, the same person may show a strong response to a certain stimulus in one trial and a weak response in the next.The results could explain why, for example, some people with autism tend to notice small visual details, and others are extremely sensitive to loud noises or bright lights."It makes you wonder what their own internal or phenomenological experience is," says lead investigator Marlene Behrmann, professor of cognitive neuroscience at Carnegie Mellon University in Pittsburgh. “[It might] make the world much more confusing and less predictable.”Read more at...SFARI, September 2012.