Charles Nelson: Searching for early signs of autism

Sara Webb, who was a graduate student in Nelson’s lab from 1996 to 2001, says she will always remember Nelson’s cheeky contribution to her otherwise stressful dissertation defense.

Webb’s project was about how memory works in the infant brain. “Out of nowhere, Chuck asked me about what type of memory systems his dog had, giving me some illustration of what his dog had just done,” Webb recalls, laughing. “Looking back, it was a fantastic question. For one, it broke the ice. But also, I couldn’t have expected it, and yet I was prepared to answer it.”

Nelson is also known for his openness to collaboration — even when that means sharing preliminary data. “He is extraordinarily kind and non-dogmatic about his science,” says Nathan Fox, distinguished professor of human development at the University of Maryland, who has known Nelson since the early ‘80s. “He puts new data out there because he wants people to respond to it and interact with it. It broadens his own thinking.”

Environmental effects:

In the late 1990s, Fox, Nelson and nine other researchers were part of the MacArthur Foundation’s Research Network on Early Experience and Brain Development. For nine years, the group met a few times a year to share ideas and launch pilot projects. One of these studies investigated the effects of maternal separation on rhesus macaque monkeys.

The results showed that it all comes down to timing: When 1-week-old monkeys are separated from their mothers, they tend to develop severe social deficits. If they are separated when they’re 1 month old, they wind up anxious and nervous, and if at 3 or 6 months, have no problems at all.

In 1999, at Nelson’s request, Dana Johnson, one of Nelson’s colleagues at the University of Minnesota, spoke to the group about Johnson’s work on international adoptions. “He showed us these videos of kids in Romanian institutions, and they looked just like the baby monkeys,” Nelson recalls. “It was really unnerving.”

Inspired, in 2000 the group launched the Bucharest study on the effects of foster care. The years since have seen growing international awareness about the dangers of institutional care, in large part because of the highly publicized scientific reports from the project. “When I travel to other countries, like Russia and China, they’re aware of the Bucharest study,” says Johnson, professor of pediatrics at the University of Minnesota. “There’s been a real change in attitudes.”

In 2005, Nelson moved from Minneapolis to Boston and launched an autism research program. Although he had never studied the disorder before, his science had influenced the field a great deal.

Geraldine Dawson, chief science officer of the autism science and advocacy organization Autism Speaks, remembers sitting on a park bench with him one day many years ago in Seattle, discussing how she could apply EEG to children with autism. That conversation led in 2002 to the first EEG study of face processing in children with the disorder⁵, and dozens of others since. “What makes him exceptional is his ability to integrate developmental psychology with basic neuroscience,” Dawson says.

His search for brain-based biomarkers in autism is also beginning to bear fruit. In June he reported that brain imaging can distinguish children with the genetic syndrome tuberous sclerosis and autism from those who have tuberous sclerosis alone⁶. And last year he showed that EEG recordings can identify infant siblings of children with autism.

Back at St. Catherine’s, Nelson maintains a lab of about ten people who are following the lives of the original group of orphans. Now that those children are reaching adolescence, he says, he wants to find out whether their early social isolation affected their brain development into the teen years, a volatile period even for the most privileged children.

All of his work, Nelson says, suggests that the environment shapes the brain just as much as the genome does. And that has big implications for the autism field.

“The simplistic model that there is a genetic vulnerability, whatever that means, and some environmental hit, whatever that means, is probably the right one,” he says. “But so much attention has been paid to genetics, and too little to the environment.”

Correction: This article has been modified from the original. It has been changed to reflect the fact that the Research Network on Early Experience and Brain Development was funded by the MacArthur Foundation, not the Rockefeller Foundation and that Romanian dictator Nicolae Ceaușescu was executed rather than assassinated.