Differences in executive control in autism may be the result of a unique approach

A new study by researchers at the UC Davis MIND Institute suggests that differences in executive control in autism spectrum disorders (ASD) may be the result of a single approach, rather than an impairment.

Executive control difficulties are common in people with autism and are associated with difficulty completing tasks and managing time. The study, published in Biological psychiatry: cognitive neuroscience and neuroimaging, investigated whether these difficulties represented a disruption of proactive executive control (engaged and maintained before a cognitively demanding event) or reactive executive control (engaged when the event occurs).

Using functional magnetic resonance imaging (fMRI), researchers performed brain scans of 141 adolescents and young adults aged 12 to 22 (64 with autism, 77 neurotypical controls) enrolled in the Cognitive study Control in Autism Study. During the analysis, participants performed a task that required them to adapt their behavior.

They were shown a green or red mark, followed by a white arrow (probe) pointing left or right. In half of the trials, participants saw a green signal asking them to press a button corresponding to the direction of the arrow, and in the other half, they saw a red signal asking them to press a button that did not match. The trial drive was randomized throughout the experiment.

“Our brains are apparently wired to be able to respond to a probe with a corresponding action more easily than to do the opposite,” said Andrew Gordon, postdoctoral researcher in the Department of Psychiatry and Behavioral Sciences and senior author of the article.

Autistic participants show a unique approach

Analyzes of brain scans during the detection and probing phases revealed that participants with autism showed significantly greater brain activity than control participants during signaling in networks associated with proactive control processes, but on the trials the most less cognitively demanding – those with the corresponding arrow. . In the most demanding trials – when the arrow did not match – activity was similar in all groups.

“This suggests that proactive control is in fact not impaired, but that people with autism are implementing it in a unique way – and not necessarily most effectively, as they use proactive control to themselves. prepare for the easiest versus the toughest trials, ”said Marjorie Solomon. , professor in the Department of Psychiatry and Behavioral Sciences and lead author of the article.

The researchers also found that during the arrow probe, connectivity between regions associated with reactive control processes was only improved in the more demanding trials in people with autism, but not in developing participants.

The results were a bit surprising, said Gordon. “Previous research suggests that disruption at the neural level may be responsible for differences in behavior. What we’re actually showing is that participants with autism simply engage neural control systems differently than those with neurotypical development.”

The researchers noted that the results do not explain why the autistic participants engaged in a different and less effective strategy during the task than the neurotypical control participants.

“Our results suggest that, like in many other areas, people with autism use a unique strategy to accomplish a task,” Solomon said. “But that leaves open the question of why they exert more control over the easier task, and it may have to do with reductions in cognitive flexibility.”

Solomon and Gordon added that future research would benefit from manipulating the order in which stimuli are presented.

“These results contrast with much previous work on this topic,” Gordon noted. “While no study can be considered sufficient evidence to change the way we think about executive control in autism, these findings suggest that we need to be more nuanced on this topic in the future.”