Researchers have identified the brain network which emerges in infants around four years of age and enables them to predict what others think, an advance that may lead to better understanding of developmental disorders like autism.
According to the scientists, including those from the University College London in the UK, infants use two different nerve networks in their brains, which mature at different rates, to predict others' behaviour by taking on their perspective.
The study, published in the journal PNAS, referred to these brain structures as regions for implicit and explicit "Theory of Mind", which mature at different ages to fulfil their function.
According to the scientists, a region called the supramarginal gyrus that supports non-verbal action prediction matures earlier.
They said this region is also involved in visual and emotional perspective taking.
"This enables younger children to predict how people will act," said study co-author Charlotte Grosse Wiesmann from the Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) in Germany.
"The temporoparietal junction and precuneus through which we understand what others think -- and not just what they feel and see or how they will act -- only develops to fulfil this function at the age of four years," Wiesmann added.
The study said there's already another mechanism for a basic form of perspective taking by which very young children simply adopt the other's view.
"In the first three years of life, children don't seem to fully understand yet what others think," added Nikolaus Steinbeis, another co-author from the University College London.
In the study, published in the journal PNAS, the researchers investigated the relations between these brain regions, and the ability of infants to predict others' behaviour.
They assessed a sample of three- to four-year-old children who watched video clips that showed a cat chasing a mouse.
In the video, the cat watches the mouse hiding in one of two boxes, and while the feline is away the rodent sneaks over to the other box unnoticed.
When the cat returns it is expected to still believe that the mouse is in the first location.
As the participants watched the video, the scientists used eye-tracking technology to assess the looking behaviour of the children.
They noticed that both the three- and four-year-olds expected the cat to go to the box where the mouse had originally been, meaning they had predicted correctly where the cat was going to search for the mouse based on the feline's belief.
When the researchers asked the children directly where the cat will search for the mouse, instead of looking at their gaze, the three-year-olds answered incorrectly, but the four-years-olds succeeded, the study noted.
They used control conditions to ensure that this was not because the younger children misunderstood the question.
According to the scientists, different brain structures were involved in verbal reasoning about what the cat thought, as opposed to non-verbal predictions of how the feline was going to act.
