Typically, social referencing begins to emerge toward the end of the first year of life. But in individuals with autism, this behavior, along with several other aspects of social cognition, is characteristically impaired.
The current research is in line with earlier work demonstrating that first-degree relatives of autistic children often display milder, or subclinical, features of the disorder.
Carver and her colleagues, UC San Diego psychology professor Karen Dobkins, doctoral student Lauren Cornew and post-doctoral researcher Joseph McCleery, tested 18 high-risk toddlers (18-month-old siblings of children diagnosed with autism) and compared their results to those of 28 age-matched counterparts who had no family history of the disorder.
In the behavioral portion of the experiments, the children were presented with three novel and ambiguous toys – toys that could be taken as either good or bad, scary or fun, or neither – and their caregivers were trained to react with facial expressions and vocal signals that were positive, negative and neutral. The interactions were videotaped and later analyzed.
After the behavioral testing, the children were shown pictures of the same toys and their brain responses were measured – specifically by tracking ERP (event-related potential) activity, or the electrical activity of groups of neurons firing in synchrony in response to a specific event.
The high-risk toddlers differed in almost every element of social referencing, the researchers found: Though they sought emotional information from adults as quickly as the low-risk toddlers, they did so about 30 percent less frequently, and they did not respond to the adult’s information in ways that were consistent with the adult’s reaction.
Brain-activity measurements told a similar story: Where low-risk children showed the expected magnitude of neural response to emotionally tagged objects, the high-risk ones did not. And where the brain activity of low-risk children correlated with their behavior regulation, this pattern was not observed in the high-risk.
"It’s as if the high-risk children do not have as clear an understanding of the meaning of an emotion and don’t connect it to the object in the same way," Carver said.
Data from children who would later go on to a diagnosis of autism are not included in the study results.
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High-resolution images are available.
The study is supported by funding from the National Association for Autism Research, Autism Speaks and the MIND Institute at UC Davis. |
