Babies' eyes hold clues to autism
Tracking technology reveals developmental differences as early as two months old in children later diagnosed with the disease
When and how long a baby looks at other people's eyes offers the earliest behavioural sign to date that a child is likely to develop autism, scientists say.
In a study published on Wednesday, researchers using eye-tracking technology reported that children who were found to have autism at age three looked less at people's eyes when they were babies than children who did not develop autism.
But contrary to what the researchers expected, the difference was not apparent at birth. It emerged in the next few months, and autism experts said that might suggest a window during which the progression towards autism can be halted or slowed.
The study, published online in the journal Nature, found infants who later developed autism began spending less time looking at people's eyes between two and six months of age and paid less attention to eyes as they grew older. By contrast, babies who did not develop autism looked increasingly at people's eyes until about nine months old, and then kept their attention to eyes fairly constant into toddlerhood.
"This paper is a major leap forward," said Dr Lonnie Zwaigenbaum, paediatrician and autism researcher at the University of Alberta who was not involved in the study.
These babies look normal. This really gives us a clue to brain development
"Documenting that there's a developmental difference between two and six months is a major, major finding."