Most of us seek cues from other people when we’re faced with
novel situations—and we do so automatically. For example, a
young child who spies a caterpillar in the park might turn to look
for a parent’s reaction before toddling over to examine it.
And a grown-up, startled by a sudden jolt during a commercial flight,
might glance at a flight attendant to determine from his expression
whether or not it was something to be concerned about.
Called social referencing, the behavior typically emerges toward
the end of the first year of life. But it is a behavior that, like
several aspects of social cognition, is characteristically impaired
in individuals with autism. Now, new research from
the UCSD Infant Autism Project suggests that the brothers and sisters
of autistic children, around 18 months, also do not reference adults
as often as other babies do.
The finding is one of several from the project, headed by psychology
professors Karen Dobkins and Leslie Carver. At 6 months, it appears
that the siblings of autistic children process light-dark contrasts
abnormally and are nearly twice as sensitive as typically developing
children. And at 10 months, when babies usually respond much faster
to faces, the siblings, by contrast, show much faster responses
to objects.
Research has shown that first-degree relatives of people with
autism often display milder, or sub-clinical, features of the disorder.
Siblings, meanwhile, are at increased risk of receiving the diagnosis
themselves: About 8 percent will go on to develop autism, as compared
to about 0.5 percent of the general population.
The UCSD Infant Autism Project is currently focused on the siblings
of autistic children and does not include data from those who are
later diagnosed. But eventually, it is hoped that the data from
the children with autism will help to uncover which traits or combination
of traits result in the disorder and which might serve as the earliest
markers for early diagnosis.
Carver and Dobkins take a neuro-developmental approach in their
search for clues,
investigating features of behavior and brain activity as they develop
in the growing infant. Dobkins believes that a small modular problem
early on could later results in a cascade of effects. “We’re
trying,” she says, “to catch the culprits as the system
is developing.”
— Inga Kiderra |
