A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Fall, 2017 | Number 4, Volume 31

Cortical responses to social stimuli differ in infants with later ASD

Children who later develop autism spectrum disorders (ASD) exhibit unusual cortical reactions to social stimuli early in infancy, a new study reports. 

Sarah Lloyd-Fox and colleagues used a technique called functional near-infrared spectroscopy (fNIRS) to study the brain responses of high-risk infants—younger siblings of children with ASD—to social videos showing people playing peek-a-boo and non-social images of vehicles. In addition, they studied the infants’ responses to human voices and non-vocal sounds. 

The researchers say that at four to six months of age, the five infants who went on to develop ASD showed reduced activation across the inferior frontal and posterior temporal regions of the cortex in response to visual social stimuli when compared to 16 low-risk infants (those without older siblings with autism). In addition, they showed reduced activation to vocal sounds and greater activation to non-vocal sounds in the left-lateralized temporal regions compared to low-risk and high-risk infants who did not develop ASD. Moreover, the researchers say, “The degree of activation to both the visual and auditory stimuli correlated with parent-reported ASD symptomology in toddlerhood.”


“Cortical responses before six months of life associate with later autism,” S. Lloyd-Fox, A. Blasi, G. Pasco, T. Gliga, E. J. Jones, D. G. Murphy, C. E. Elwell, T. Charman, M. H. Johnson, and the BASIS Team, European Journal of Neuroscience, October 23, 2017 (epub prior to print publication). Address: Sarah Lloyd-Fox, Centre for Brain and Cognitive Development, The Henry Wellcome Building, Birkbeck, University of London, London, WC1E 7HX, [email protected].