Wednesday, October 18, 2017

Impaired Facial Processing As A Marker for Detecting Autism Spectrum Disorder


            Autism Spectrum Disorder is still a disorder being heavily researched and to this day, we still do not know much about the cause of the disorder or how it is developed. However, in terms of diagnosis, there are several markers: one of them being impaired facial processing. In an article written by Pam Belluck for The New York Times, Pam describes a study linking genes to facial processing and how this may lead to children developing autism.
            
             The study conducted by Dr. Warren Jones, an assistant pediatrics professor at Emory School of Medicine, and colleagues is significant as it points towards a neurological differences from birth that affect social development in people who are diagnosed with autism. Furthermore, there may also be a genetic link in regards to the development of autism. In fact, genes may actually be responsible for certain social behaviors exhibited in autism such as eye contact or perceiving facial expressions. Dr. Nelson who is a professor of neuroscience at Harvard Medical School, as well as an expert on autism, believes this study may create a breakthrough in terms of how genes can impact the development of autism.

            338 toddlers’ eye movements were tracked as they were watching videos of other children and mothers in a daycare. These toddlers were all between the ages of 18 months to 24 months old. Of these toddlers, 88 had autism. There were also 42 pairs of nonidentical twins, 41 pairs identical twins, and 84 unrelated children that were all developing normally. Studying identical twins helped to determine a genetic basis for facial processing. Identical twins matched about 91% of the time with how they looked at people’s eyes on screen. This was also the case when looking at mouths, but only with the identical twins demonstrating that the way children are processing faces is influenced by genetic factors.

            The children with autism tended to look more at objects rather than on faces. On average, they looked at objects twice as much as typical children and about half as much at faces. Dr. Jones and colleagues found that babies around the age of two months to six months were very likely to be diagnosed with autism by the age of three if they showed that they looked at people’s eyes less than normal. Hence, eye-tracking can serve as an early marker of autism.

            Dr. Maggie Guy and colleagues also conducted research to determine neural correlates in facial processing of infants at high-risk for autism, as well as infants who had fragile X syndrome and low-risk infants. However, a difference in this study compared to the one conducted by Dr. Jones is that all the infants showed more event-related potentials to faces rather than toys. In the study conducted by Dr. Jones and colleagues, these results were slightly different with the children diagnosed with autism where they tended to focus on objects rather than faces. However, the group of children at high-risk for autism exhibited the lowest N290 amplitude to faces out of the three groups studied.

            Both studies demonstrate a neural basis for autism spectrum disorder and how certain social behaviors, specifically dealing with facial processing, can serve as markers for diagnosis.

Belluck, P. (2017, July 12). Study of How We Look at Faces May Offer Insight Into Autism. Retrieved October 18, 2017, from https://www.nytimes.com/2017/07/12/health/autism-faces-genes-brain-development.html


Guy, M.W., et al., Neural correlates of face processing in etiologically-distinct 12-month-old infants at high-risk of autism spectrum disorder. Dev. Cogn. Neurosci. (2017), http://dx.doi.org/10.1016/j.dcn.2017.03.002

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