WASHINGTON – Some children with autism have weak brain connections in regions that link speech with emotional rewards, possibly signaling a new pathway in treatment, researchers said Monday.
The study in the Proceedings of the National Academy of Sciences is the first to suggest that the reason why children with autism display an insensitivity to speech may be linked to faulty circuitry in the brain’s reward centers.
“Weak brain connectivity may impede children with autism from experiencing speech as pleasurable,” said Stanford University professor Vinod Menon, the study’s senior author.
Researchers took brain scans of 20 children with a high-functioning type of autism; they had normal-range IQs and could speak and read, but had a hard time in conversation or understanding emotional cues.
Comparing the scans to those of children without autism, they found that the brains of youngsters with autism showed poor links to brain regions that release dopamine in response to rewards.
On the left side of the brain, the autistic children showed weak connections to the nucleus accumbens and the ventral tegmental area. On the right, where vocal cues and pitch are detected, there was a weak link to the amygdala, which processes emotional cues.
The findings suggest that people with autism have a deficit in social motivation that explains their inattention to voices and words, rather than a sensory deficit that prevents them hearing words.