Researchers studying autistic children have discovered their brain activity appears to be out of sync compared to their peers at a very early stage.
They found that language areas in the right and left sides of the brain are less synchronised in autistic toddlers.
The weaker the synchronisation, the more severe the communication difficulties exhibited by the child.
The findings could help doctors to lower the average diagnosis of autistic children in the UK from the age of five to one.
Researchers from the Weizmann Institute of Science in Israel made the discovery after measuring the neural activity of sleeping toddlers using MRI scans.
Lead scientist Dr Ilan Dinstein, said: ‘In a normal brain, neurons in separate areas belonging to a system with a particular function, such as vision or language, always stay in sync, even during sleep.
‘Our study shows that in most brains of toddlers with autism this ‘sync’ is significantly weaker in brain areas that are responsible for language and communication abilities.
‘Many things need to be set up right during brain development to enable normal sync between different brain areas.
‘The wiring between the brain areas needs to be right and the neurons within each brain area need to send and receive their messages properly.
The findings, published in the journal Neuron, could lead to a method of diagnosing autism in one-year-olds, he said.
Autism encompasses a ‘spectrum’ of conditions characterised by poor social skills and difficulty communicating with others.
Although the exact cause is unknown, many experts believe it arises from the development of abnormal neural networks with irregular connectivity.
‘There’s a tremendous amount of misdiagnosis in many different forms,’ Dinstein said.
‘A child that might seem autistic at one and a half years old may turn out at three years old to have language delay or some other developmental disorder.
‘So one of the reasons to look for a biological measure is to clarify the issue of diagnosis very early on.’
The study was published in the journal Neuron