New Hypothesis Posits Autism as Disorder of Prediction

Massachusetts Institute of Technology (MIT) neuroscientists have posed a new hypothesis for autism, suggesting that the disorder may be rooted in an impaired ability to predict events and other people’s actions.

The researchers assert that, to an autistic child, the world appears to be a “magical” and random place, rather than one of order and predictability. Therefore, symptoms such as repetitive behavior and the need for a highly structured environment may be coping strategies in an unpredictable world.

“At the moment, the treatments that have been developed are driven by the end symptoms. We’re suggesting that the deeper problem is a predictive impairment problem, so we should directly address that ability,” said lead author Dr. Pawan Sinha, an MIT professor of brain and cognitive sciences.

“I don’t know what techniques would be most effective for improving predictive skills, but it would at least argue for the target of a therapy being predictive skills rather than other manifestations of autism,” he said.

The researchers turned toward prediction skills as a possible root cause for autism based on reports from parents that their autistic children demanded a controlled, predictable environment.

“The need for sameness is one of the most uniform characteristics of autism,” said Sinha. “It’s a short step away from that description to think that the need for sameness is another way of saying that the child with autism needs a very predictable setting.”

Most people can easily estimate the probable outcomes of events, such as another person’s behavior, or the path of a flying ball. Perhaps, thought the MIT team, autistic children do not have the same computational abilities when it comes to prediction.

This hypothesized deficit could result in many of the most common autism symptoms. For example, repetitive behaviors and insistence on rigid structure have been shown to soothe anxiety produced by unpredictability, even in people without autism.

“If we were unable to habituate to stimuli, then the world would become overwhelming very quickly. It’s like you can’t escape this cacophony that’s falling on your ears or that you’re observing,” said Sinha.

Children with autism also have a difficult time understanding another person’s thoughts, feelings, and motivations — a skill known as “theory of mind.” Instead, they tend to interpret behavior based only on what is happening in that very moment.

The researchers suggest this could result from an inability to predict another person’s behavior based on past interactions.

The MIT team suggests that different children may show a variety of symptoms of autism based on the timing of the predictive impairment.

“In the millisecond range, you would expect to have more of an impairment in language,” said Sinha.

“In the tens of milliseconds range, it might be more of a motor impairment, and in the range of seconds, you would expect to see more of a social and planning impairment.”

The hypothesis also predicts that certain cognitive skills — those based more on rules than on prediction — should remain untouched, or even get better in autistic individuals. This includes skills such as math, drawing, and music, typical strengths for autistic children.

“The hypothesis is guiding us toward very concrete studies,” said Sinha. “We hope to enlist the participation of families and children touched by autism to help put the theory through its paces.”

Source: MIT