Scientists have found a neurological cause for this characteristic symptom of autism spectrum disorders.

It is well known that people with an autism spectrum disorder (ASD) tend to avoid direct eye contact with others – a characteristic that may be evident as early as childhood. It is this characteristic that is primarily taken into account when a child is diagnosed with autism.

Until now, however, specialists have understandably not been able to observe what happens in the brain of a person with ASD directly during social interaction.

Thanks to modern technology, staff at the Laboratory for Brain Research at Yale University School of Medicine (USA), whose article was published in the journal Plos One, have managed to cope with this task for the first time.

They found that in people with autism, eye-to-eye contact significantly reduces activity in the occipital parietal cortex, the region of the brain responsible for perception and processing of visual information.

The researchers made this discovery using a non-invasive optical near-infrared functional spectroscopy method. Pairs of participants, one of whom had been diagnosed with autism, communicated with each other while real-time sensory sensors recorded information about their brain activity.

The scientists found that the more severe the symptoms of ASD, the more problems with social interaction, the lower the activity of the occipital area of the parietal cortex during eye contact.