Babies who show lower levels of brain activity in response to social stimuli such as peek-a-boo are more likely to be diagnosed with autism spectrum disorder (ASD), according to research involving UCL.

Academics from Birkbeck, University of London, University of Cambridge, King's College London and UCL used neuroimaging technology (functional near-infrared spectroscopy—fNIRS) to measure the brain activity of infants aged four to six months, contrasting infants who have increased familial likelihood of developing ASD with those without a family link to ASD.

They studied how the infants' brain activity changed in response to 'social' videos, such as people playing peek-a-boo or incy-wincy spider and the sounds of yawning or laughter, with 'non-social' images of objects such as cars.

They also measured the babies' brain activity in response to human vocalizations (coughing, yawning, crying and laughing) compared to non-human sounds such as bells and running water.

Functional brain response

The research is the first to show that functional brain responses before six months of age are associated with a later ASD diagnosis at age three, meaning these findings could show the earliest marker of ASD to date.

Professor Clare Elwell (UCL Medical Physics & Biomedical Engineering) said: "Innovations in physics and engineering are enabling us to shed light on how the brain develops in a way that has not been possible before.

"As well as helping us understand typical brain development, optical imaging has now been used to identify atypical patterns of brain function as early as four months of age in infants who go on to develop autism. This is an important milestone in brain imaging in infants, and we are excited about the prospect of extending this work into toddlers," said Elwell.

Dr. Sarah Lloyd-Fox (Birkbeck Centre for Brain and Cognitive Development) said: "We have found an early indication of different patterns of brain activity in infants who go on to develop ASD from an early age." 

"Given the importance of responding to others in our social world, it is possible that different attentional biases may particularly impact on the development of social brain responses, which can continue to affect the child's developmental trajectory as they get older," said Lloyd-Fox.

"Identifying early patterns of altered development which may later associate with ASD is important because it will allow doctors to offer earlier interventions and provide families with earlier avenues for support," said Lloyd-Fox.

"This might mean giving the child and parents new strategies to re-engage their attention towards important social cues and learn different ways of interacting," said Lloyd-Fox.

ASD is a common developmental disorder thought to affect around 2.8m people in the UK. The younger siblings of diagnosed children are more likely to develop it than the general population.

The emergence of the behavioral symptoms of ASD in toddlerhood is widely known, but there is far less known about its development during the first months of life.