Do supercharged brains give rise to autism?
By Maia Szalavitz IMAGINE a world where every sound jars like a jackhammer, every light is a blinding strobe, clothes feel like sandpaper and even your own mother’s face appears as a jumble of frightening and disconnected pieces. This, say neuroscientists Kamila and Henry Markram of the Swiss Federal Institute of Technology in Lausanne, is how it feels to be autistic. According to their “intense world” hypothesis, all of autism’s baffling and sometimes incongruous features – social problems, language impairment and obsessive behaviour, sometimes allied to dazzling savant abilities – can be explained by a single neurological defect: a hyperactive brain that makes ordinary, everyday sensory experiences utterly overwhelming. If they’re right – and the idea is generating a deal of interest among autism experts – the husband-and-wife team could be on course to add a significant new theory to autism research. “It is a very compelling idea,” says neurobiologist Asaf Keller at the University of Maryland School of Medicine in Baltimore, who has arranged a symposium to discuss it at November’s Society for Neuroscience meeting in Washington DC. Recognition of sensory disturbance in autism goes back as far as the 1940s, and today it is widely seen as a fundamental aspect of the condition. “There is a lot of evidence for sensory hypersensitivity,” says Simon Baron-Cohen, director of the Autism Research Centre at the University of Cambridge. He notes that hypersensitivity can affect the vision, hearing and touch of people with autistic spectrum disorders (ASD, see “Autism basics”). “If you talk to practitioners, invariably they will say, ‘I’ve never seen a child with autism who doesn’t have sensory problems’,” adds Keller. “There’s a strong correlation,