Summary: The way in which an infant visually examines an object may predict a later autism diagnosis, researchers say. Unusual visual inspection of items at 9 months was a strong predictor of an ASD diagnosis later in childhood.
Source: UC Davis
Unusual visual inspection of objects by infants 9 months of age and older is predictive of a later diagnosis of autism spectrum disorder (ASD), a new UC Davis Health study has found.
Unusual visual inspection is defined as:
looking out of the corners of the eyes,
holding an object up very close to the face,
looking at something with one eye closed, or
staring at an object uninterrupted for more than 10 seconds.
“Unusual visual inspection behavior has long been associated with autism but never yet as early as 9 months of age,” said Meghan Miller, associate professor in the Department of Psychiatry and Behavioral Sciences and UC Davis MIND Institute and the first author on the study.
The study, published in the Journal of Abnormal Psychology, also found that this behavior at 9 months predicted 12-month social behavior, but not vice versa.
“The findings support major theories of autism which hypothesize that infants’ over-focus on objects might be at the expense of their interest in people. Ultimately, this study suggests that unusual visual inspection of objects may precede development of the social symptoms characteristic of ASD,” Miller said.
Visual inspection, repetitive behavior and social engagement in children with autism
About 1 in 54 children in the U.S. has been identified with ASD. Younger siblings of children with autism are at an elevated risk of being diagnosed with autism, at a rate of approximately one in five.
The researchers evaluated 89 infants whose older siblings have ASD (High-Risk group) and 58 infants with siblings with typical development (Low-Risk group). The infants completed a task designed to measure a variety of different ways of playing with and using objects at 9, 12, 15, 18, 24 and 36 months of age.
The examiners rated each infant’s social engagement behavior after every assessment session. They measured the infant’s frequency of eye contact, frequency of smiling at other people, and overall social responsiveness.
They also tallied the number of times the infant engaged in unusual visual inspection, spinning, and rotating behaviors with the objects. Spinning was defined as dropping, tossing or manipulating an object in order to make it spin or wobble. Rotating behavior indicated turning, flipping, or rotating the object at least twice.
At 36 months, the infants were classified into one of three groups: Low-Risk Non-ASD (58 children), High-Risk Non-ASD (72 children) and Diagnosed with ASD (17 children).
The study found that differences in unusual visual inspection were most prominent, consistent and present earliest in infants who developed ASD. At 9 months, the ASD group engaged in this behavior more frequently than both other groups and the behavior continued at higher rates at all ages.
Differences in frequencies of spinning and rotating were later-appearing, more time-limited, and related to familial ASD risk rather than the infant’s autism diagnosis.
“An increased focus on objects early in life may have detrimental cascading effects on social behavior,” said Sally Ozonoff, professor in the Department of Psychiatry and Behavioral Sciences and the MIND Institute at UC Davis and principal investigator of the study. “Findings from our study suggest that unusual visual exploration of objects may be a valuable addition to early screening and diagnostic tools for ASD.”
Funding: This study was supported by grants from National Institute of Mental Health (NIMH) (R01 MH068398) and National Institute of Child Health and Human Development Intellectual and Developmental Disabilities Research Center (P50 HD103526).
The co-authors on this study are Shuai Sun, Ana-Maria Iosif, Gregory S. Young, Ashleigh Belding, and Andrew Tubbs at University of California, Davis. Sun is now at Ohio State University and Tubbs at University of Arizona.
Repetitive behavior with objects in infants developing ASD predicts diagnosis and later social behavior as early as 9 months
We evaluated repetitive behavior with objects in infants at risk for autism spectrum disorder (ASD) from 9 to 36 months of age, and associations between early repetitive behavior and social engagement.
Infant siblings of children with ASD (high-risk) or typical development (low-risk) were administered a task eliciting repetitive object use at 9, 12, 15, 18, 24, and 36 months of age. Infants (n = 147) were classified into 1 of 3 outcome groups at 36 months: Low-Risk Non-ASD (n = 58), High-Risk Non-ASD (n = 72), and ASD (n = 17). Behavior was coded from video for frequencies of unusual visual inspection, spinning, and rotating behaviors.
Differences in unusual visual inspection were most prominent, consistent, and present earliest: At 9 months, the ASD group engaged in this behavior more frequently than both other groups, persisting through 36 months. Differences in frequencies of spinning and rotating were later-appearing, more time-limited, and/or related to familial ASD risk rather than ultimate diagnosis.
Sensitivity and specificity estimates for the presence of unusual visual inspection at 9 months of age were in the moderate range (.60 and .68, respectively) for ASD versus Low-Risk Non-ASD comparisons, generally increasing over time. Unusual visual inspection at 9 months predicted 12-month social behavior controlling for 9-month social behavior, but not vice versa, with no evidence of moderation by ASD diagnosis.
In summary, unusual visual inspection of objects is present and stable by 9 months of age in infants developing ASD and predicts reduced social engagement three-months later. Close monitoring of this behavior may aid early detection.