Infants at risk of autism show reduced brain responses to social cues before they are six months old
Direct measures of brain functioning may help further our understanding of autism
Scientists at Birkbeck have shown for the first time that measuring brain activity in babies aged from four to six months may help reveal differences between the brain responses of infants at-risk for autism and infants with no family history of autism when exposed to social cues. The findings suggest that direct brain measures might help to predict the future development of autism symptoms in infants under the age of six months, although the researchers emphasize that the study is only a first step towards earlier diagnosis of the disorder.
The research was conducted by the Centre for Brain and Cognitive Development at Birkbeck and published in the 13 March issue of the Proceedings of the Royal Society B.
Christine Swabey, CEO of Autistica, one of the project funders, says: "Autistica is so proud to have funded this groundbreaking research. These are the very earliest neurological differences to be found in children at risk of later autism. Autism currently affects 600,000 people in the UK. This finding provides another key step in our journey to ensure the earliest possible detection of autism, so that we can provide early interventions at a time when they can make the biggest impact to improve lives.”
The behaviours characteristic of autism emerge over the first few years of life and firm diagnoses are now made in children only after the age of two. As a result, the vast majority of research on autism has necessarily concentrated on children aged two and up, who have already been diagnosed.
Dr Sarah Lloyd-Fox, who led the study, explains: “We still know very little about the earliest appearing symptoms and warning signs of autism. Our findings demonstrate for the first time that direct measures of brain functioning during the first six months of life may help further our understanding of the development of autism."
Working with four-to-six-month-old babies at greater risk of developing autism because they had an older brother or sister with the condition, the researchers used a method called optical imaging, which involved passive sensors being placed on the baby’s head to register brain activity while the babies viewed videos of human actions (such as Peek-a-boo or Incy Wincy Spider) or listened to human sounds such as laughter and yawning, and non-human sounds like running water and toys rattling. The optical imaging system used was Near Infrared Spectroscopy, or ‘NIRS’, built by the Biomedical Optics Research Laboratory at UCL.
Lloyd-Fox says: "At this age, no behavioural markers of autism are yet evident, and so measurements of brain function may be a more sensitive indicator of risk. The earlier that we can measure infants’ responses, the clearer an idea we can develop of how genes and the environment might be interacting, and this will help us to develop interventions which could support typical brain development.
“It is important to note, however, that individual babies did not all show the same pattern of brain responses. It is paramount that we revisit these findings when the babies are over two years of age and can be assessed for a diagnosis of autism. Future work will determine whether these differences in brain responses to socially relevant information are associated with later autism or the broader autism phenotype, which is sometimes seen in unaffected family members.” The method will require further refinement, most likely in combination with other factors, to form the basis of a predictor accurate enough for clinical use in the general population.
Bev Dancer, whose son Martin took part in the study, says: “It is difficult raising a child with social and communication difficulties and without an early diagnosis many mothers blame themselves. Understanding how the brain works during these early years would help many families guide their child and have an enormous impact on their child's development.
“Having been through this myself, I felt it was my duty to ensure I helped in any way I could by involving Martin in the Babylab research. I feel very strongly that this is a very important start towards improving the lives of many families with children on the autistic spectrum.”
The research has been funded by the UK Medical Research Council, Simons Foundation and the BASIS funding consortium led by Autistica, the UK’s leading charitable funder of autism research. Further support comes from the Innovative Medicines Initiative Joint Undertaking under grant agreement n° 115300, resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007 - 2013) and EFPIA companies' in kind contribution.