The brain is split into two separate hemispheres and neural activity is correlated across functionally related cortical areas, like those involved in vision while watching a movie, but also in the complete absence of a task, during rest and sleep, lad study author Dr. Ilan Dinstein of the Weizmann Institute of Science in Israel says.
Dinstein and colleagues used functional magnetic resonance imaging to record neural activity in naturally sleeping toddlers with typical development, language delay and autism.
The study, published in the journal Neuron, found a specific abnormality in synchronization between two brain areas commonly associated with language and communication. This abnormality was evident in 70 percent of toddlers with autism, but in only a handful of typically developing toddlers or toddlers with language delay, Dinstein says.
"Our results suggest that poor neural synchronization is a notable neural characteristic that is evident at the earliest stages of autism development, when toddlers are only beginning to manifest autistic behavioral symptoms, and is related to the severity of those behavioral symptoms," Dinstein says in a statement.