A unique pattern of brain organization may explain why children with autism spectrum disorder (ASD) often possess superior math skills.
A small brain imaging study showed that children between the ages of 7 and 12 years with ASD had significantly superior numerical problem-solving abilities, including the use of more sophisticated strategies to figure out single-digit addition questions, than their age-, sex-, and IQ-matched healthy peers.
In addition, participants with ASD showed different activation patterns in the ventral temporal-occipital cortex (VTOC), the posterior parietal cortex, and the medial temporal lobe during mathematical problem solving — with activation patterns in the VTOC region actually predicting these superior abilities.
“Our findings suggest that altered patterns of brain organization in areas typically devoted to face processing may underlie the ability of children with autism to develop specialized skills,” lead author Teresa Iuculano, PhD, from the Department of Psychiatry and Behavioral Sciences at Stanford University School of Medicine, in California, and from the Stanford Cognitive and Systems Neuroscience Laboratory, said in a release.
She told Medscape Medical News that because children with ASD are often bad at recognizing faces, this particular area was recruited instead for math abilities in this patient population.
“However, this isn’t a universal finding, and we know that the spectrum is very broad. So there could be many different talents discovered, including music and drawing, and should be assessed on a case-by-case basis,” said Dr. Iuculano.
“If a parent sees that a child is strongly interested in something, they should help them to follow their passion. This is important for all children, but especially those with autism. It can be used as a relaxation tool and to help them to enjoy life more.”
The study was published online August 19 in Biological Psychiatry.
Mostly Anecdotal Evidence
The investigators note that although past research has suggested that individuals with ASD often have high mathematical skills, the evidence has been “mostly anecdotal and descriptive.”
For the current study, they sought to assess both the cognitive and neural characterizations of these skills.
“We thought that because math is such a concrete discipline, and with many rules, it could represent a good way to look at superiorities in a group of children on the spectrum,” said Dr. Iuculano.
The researchers enrolled 18 children with ASD (78% boys) and 18 children without the disorder, who were considered the “control group” (also 78% boys).
Standardized tests given during the study’s recruitment stage showed that all of the participants had IQs considered to be in the normal range; and those with ASD had “normal” verbal and reading skills. Standardized math tests were also administered.
While undergoing functional magnetic resonance imaging (fMRI) scans, all children were asked to solve addition problems, one at a time.
During the scans, the researchers also interviewed the participants to determine which of the following types of problem-solving strategies were being used: remembering an answer already known (retrieval), counting on fingers or in their heads, or decomposition.
The latter strategy is a comparatively sophisticated method and consists of breaking down a problem into several components.
Results showed that the group with ASD had significantly higher scores on the numerical operations subscale of the Weschsler Individual Achievement Test–Second Edition for mathematics (WIAT-II) than the control group (P= .012).
They also displayed significantly greater use of decomposition (P = .033), “suggesting that more analytic strategies, rather than rote memory, were the source of their enhanced abilities,” the investigators note.
There were no between-group differences in use of counting or retrieval strategies or on any of the 4 working memory measures assessed.
The MRI scans showed “several cortical regions where arithmetic complexity-related activity patterns differed significantly” between the 2 groups.
“Notably, high cross-validation classification accuracies (80% to 90%) were in [VTOC], including bilateral inferior lateral occipital cortex and fusiform gyrus, as well as posterior parietal cortex, including the left intraparietal sulcus, angular gyrus, and the left precuneus,” write the researchers.
Significant differences in activity patterns were also found in medial temporal lobe regions.
Finally, “numerical abilities in the ASD group were predicted by the pattern of neural activity in an area of the left VTOC encompassing the left fusiform gyrus and lateral occipital cortex,” whereas numerical abilities in the control group were predicted by activity patterns in the left dorsolateral prefrontal cortex.
Overall, “there appears to be a unique pattern of brain organization that underlies superior problem-solving abilities in children with autism,” senior author Vinod Menon, PhD, professor of psychiatry and behavioral sciences at Stanford and from the Child Health Research Institute at the Lucile Packard Children’s Hospital, said in a release.
He added that although instant recall of calendar dates (a skill often found in individuals with ASD) is not likely to help with academic and professional success, “developing good mathematical skills could make a big difference in the life of a child with autism,” including possibly leading to future employment.
“Our study supports the idea that the typical brain development in autism can lead not just to deficits but also to some remarkable cognitive strengths. We think this can be reassuring to parents,” said Dr. Menon.
However, he noted that it is important to realize that not all children with ASD have superior math skills. So future research should examine the neural basis of variations in problem-solving abilities.
Dr. Iuculano added that she is excited about the current study’s findings on both research and clinical levels.
“As a scientist, it’s great that we’re understanding how the brain works in children with autism. And on a practical level, it’s important because it can raise awareness of the fact that these individuals can be contributing in a very good way to society,” she said.
Not Limited to Math
“I think this is not new as such, but it’s a very good study and important because it extends some things we already know,” Laurent Mottron, MD, PhD, professor of psychiatry at the University of Montreal, Quebec, Canada, and scientific director of the University’s Center of Excellence in Pervasive Development Disorders, toldMedscape Medical News.
He added that mathematic cognition has not been really studied before in ASD; but the take-away message is not that these findings are specific only to mathematics.
“This overactivation of the occipital region, and specifically the fusiform gyrus, is found in all tasks involving any visual information,” said Dr. Mottron, who was not involved with this research.
As reported at the time by Medscape Medical News, his investigative team published findings from a meta-analysis in Human Brain Mapping 2 years ago. Their analysis of 26 fMRI studies and more than 700 individuals showed that those with ASD had higher activity in the temporal and occipital regions in relation to visual-based tasks than those without the disorder.
“As scientists, we are happy when something is replicated. Here it’s more than replication, it’s specification. But I think if you want to see the big picture, you need to realize this isn’t only related to mathematics. Because autistics, when reasoning in general, use more of their perceptual expertise than other people,” he said.
“And I’m quite happy that now it’s become a kind of consensual message about autistic intelligence.”