Anatomical Evidence

October 21, 2013

Research unlocks understanding of structural differences

A Michigan State University researcher has discovered the first anatomical evidence that the brains of children with a nonverbal learning disability (NVLD)—long considered a “pseudo” diagnosis—may develop differently than the brains of other children.

The finding could ultimately help educators and clinicians better distinguish between—and treat—children with NLVD and those with Asperger’s syndrome, a form of autism. While NVLD and Asperger’s share certain characteristics, researchers and clinicians have been confounded as to the relation of these two groups of children.

“The reason why it’s important to understand the biological differences in children with learning and behavioral challenges is that it’s important to know where to intervene,” said Jodene Fine, lead investigator on the project and assistant professor of school psychology. “Children with nonverbal learning disabilities and Asperger’s can look very similar but they can have very different reasons for why they behave the way they do.”

Children with NVLD tend to have normal language skills but below average math skills and difficulty with solving visual puzzles. Because many of these children also show difficulty understanding social cues, some have argued that NVLD is related to Asperger’s—which this latest study suggests may not be so.

Fine and Kayla Musielak, a doctoral student in school psychology, studied about 150 children ages 8 to 18. Using MRI scans of the participants’ brains, the researchers found that the children diagnosed with NVLD had smaller spleniums than the children who had other learning disorders such as Asperger’s and ADHD and children who had no learning disorders.

The splenium is part of the corpus callosum, a thick band of fibers in the brain that connects the left and right hemispheres and facilitates communication between the two sides. Interestingly, this posterior part of the corpus callosum serves the areas of the brain related to visual and spatial functioning.

In a second part of the study, the participants’ brain activity was analyzed after they were shown videos in an MRI that portrayed both positive and negative examples of social interaction. (A typical example of a positive event was a child opening a desired birthday present with friend; a negative event included a child being teased by other children.)

The researchers found that the brains of children with NLVD responded differently to the social interactions than the brains of children with Asperger’s, suggesting the neural pathways that underlie those behaviors may be different.
“So what we have is evidence of a structural difference in the brains of children with NLVD and Asperger’s, as well as evidence of a functional difference in the way their brains behave when they are presented with stimuli,” Fine said.

While more research is needed to better understand how NVLD fits into the family of learning disorders, Fine said her findings present “an interesting piece of the puzzle.”

“I would say at this point we still don’t have enough evidence to say NVLD is a distinct diagnosis, but I do think our research supports the idea that it might be,” she said.