The causes, symptoms, and effects of autism are some of the most puzzling mysteries in all of psychology and neuroscience, but researchers at Stanford University may have connected a few of the dots. They dove deep into the brains (not literally) of a selection of kids with and without autism, and found that those with autism respond differently to the human voice than those without.
The researchers took 20 kids with similar IQs and reading abilities, 10 with high-functioning autism and 10 without any sign of autism, and examined activity between several parts of the brain. There is a theory, says the lead researcher, that social cues don't interact with the brain's reward system in the same way as in non-autistic people. This study supports that: it found that in the brains of the kids with autism, there's a significantly weaker connection between the parts of the brain that interprets voices and the part that doles out pleasure. In other words, the sound of the human voice gives those with autism less joy.
There's also a weaker link between those voice-processing centers and the amygdala, which is the part of the brain that deals in emotion. That suggests a neurological reason for an autistic person's inability or disinterest in social cues - their brains don't reward them for caring about these things.
The study doesn't have any immediate ramifications for the treatment or even diagnosis of autism, and it only tested one very particular segment of those on the autism spectrum. Still, it's pretty fascinating, and may lead these or other researchers down a path that could help treat or diagnose autism in the future.