Researchers explore why those with autism avoid eye contact

neurosciencestuff:

Individuals with autism spectrum disorder (ASD) often find it difficult
to look others in the eyes. This avoidance has typically been
interpreted as a sign of social and personal indifference, but reports
from people with autism suggests otherwise. Many say that looking others
in the eye is uncomfortable or stressful for them – some will even say
that “it burns” – all of which points to a neurological cause. Now, a
team of investigators based at the Athinoula A. Martinos Center for Biomedical Imaging
at Massachusetts General Hospital has shed light on the brain
mechanisms involved in this behavior. They reported their findings in a Nature Scientific Reports paper.

“The
findings demonstrate that, contrary to what has been thought, the
apparent lack of interpersonal interest among people with autism is not
due to a lack of concern,” says Nouchine Hadjikhani, MD, PhD, director
of neurolimbic research in the Martinos Center and corresponding author
of the new study. “Rather, our results show that this behavior is a way
to decrease an unpleasant excessive arousal stemming from overactivation
in a particular part of the brain.”

The key to this research
lies in the brain’s subcortical system, which is responsible for the
natural orientation toward faces seen in newborns and is important later
for emotion perception. The subcortical system can be specifically
activated by eye contact, and previous work by Hadjikhani and colleagues
revealed that, among those with autism, it was oversensitive to effects
elicited by direct gaze and emotional expression. In the present study,
she took that observation further, asking what happens when those with
autism are compelled to look in the eyes of faces conveying different
emotions.

Using functional magnetic resonance imaging (fMRI),
Hadjikhani and colleagues measured differences in activation within the
face-processing components of the subcortical system in people with
autism and in control participants as they viewed faces either freely or
when constrained to viewing the eye-region. While activation of these
structures was similar for both groups exhibited during free viewing,
overactivation was observed in participants with autism when
concentrating on the eye-region. This was especially true with fearful
faces, though similar effects were observed when viewing happy, angry
and neutral faces.

The findings of the study support the
hypothesis of an imbalance between the brain’s excitatory and inhibitory
signaling networks in autism – excitatory refers to neurotransmitters
that stimulate the brain, while inhibitory refers to those that calm it
and provide equilibrium. Such an imbalance, likely the result of diverse
genetic and environmental causes, can strengthen excitatory signaling
in the subcortical circuitry involved in face perception. This in turn
can result in an abnormal reaction to eye contact, an aversion to direct
gaze and consequently abnormal development of the social brain.

In
revealing the underlying reasons for eye-avoidance, the study also
suggests more effective ways of engaging individuals with autism. “The
findings indicate that forcing children with autism to look into
someone’s eyes in behavioral therapy may create a lot of anxiety for
them,” says Hadjikhani, an associate professor of Radiology at Harvard
Medical School. “An approach involving slow habituation to eye contact
may help them overcome this overreaction and be able to handle eye
contact in the long run, thereby avoiding the cascading effects that
this eye-avoidance has on the development of the social brain.”

The
researchers are already planning to follow up the research. Hadjikhani
is now seeking funding for a study that will use magnetoencephalography
(MEG) together with eye-tracking and other behavioral tests to probe
more deeply the relationship between the subcortical system and eye
contact avoidance in autism.