VKC member Eric Wilkey, Ph.D., is assistant professor of Psychology and Human Development. Dr. Wilkey’s research focuses on the development of mathematical skills, the neurocognitive mechanisms that enable mathematical cognition, and the neurobiological origins of persistent learning difficulties in mathematics, such as the learning disability dyscalculia.
From basic numerical processing to higher-level cognition such as executive function skills (e.g., working memory, cognitive flexibility, and inhibitory control), his work investigates how these brain mechanisms develop and appear in relevant life and academic skills. Wilkey also collaborates with intervention scientists to study the effect of educational interventions on brain development.
In the interview below, Wilkey shares what inspires his research, what he has learned through his work, and how membership with the Vanderbilt Kennedy Center helps him achieve his goals.
Tell me about your attraction to developmental disabilities research.
I’m fundamentally interested in how people learn to solve problems and act with agency in their environment. One powerful problem-solving tool that takes nearly all our childhood and adolescence to master is mathematics. Math gives us the language and rules for interacting with the spatial and numerical information and patterns in our world. Thinking mathematically relies on a wide range of cognitive abilities, from basic perception of number to advanced language and symbolic thinking. Developmental differences in any of these abilities can have a profound impact on the way an individual interacts with the mathematical aspects of their world, and in turn, their world at large. In my research, I aim to understand how and when children struggle in their development of mathematical thinking so that we can take measured steps to identify the specific issues early on and improve the learning process.
What are your current research interests?
I like to approach problems from an interdisciplinary lens with a collaborative, team-oriented approach that can leverage the perspective and experience of multiple academic fields. We understand quite a bit about how the brain represents number, but things get very murky beyond that. That is the very first step in thinking mathematically, so we have a long way to go. For example, how do we attend to some numerical information and disregard irrelevant information? And how do we flexibly apply rules on the fly, like the different arithmetic operations, exactly when they are needed? To do these things, we need to integrate multiple brain systems – some that are used specifically for numerical or mathematical things, and others that are used across many different domains of thinking. A central theme of my research is addressing how these systems are integrated.
One current project focuses on how children learn types of numbers beyond integers, such as fractions and decimals. The first symbolic numbers that children learn are whole numbers. They have the property of cardinality (i.e., 2 means two items, 3 means three items, etc.) and ordinality (i.e., 4 comes after 3 and before 5). If you ask a child how many numbers are between 5 and 7, they would say, “one number, six!” And, at a certain developmental stage, we would tell them that’s correct. Then, soon after, we introduce the idea that there are an infinite number of numbers between 5 and 7, because decimals and fractions open this door to numbers that behave differently. Children then must adapt the way they think about numbers and what they mean. This is one thing that makes understanding fractions very difficult to master. It also recruits additional brain networks. We are currently trying to understand just what that processing looks like so that we can help make this challenging step in the development of math skills easier.
Another area of study for my lab is understanding the math learning disability developmental dyscalculia. About 3 to 5 percent of the population have severe and persistent learning difficulties with math. These individuals have trouble mastering some of the most fundamental aspects of thinking mathematically, like understanding what numbers mean and doing basic calculations. And, while these difficulties all manifest in a limited range of mathematical behaviors, like trouble with arithmetic, the reasons for this difficulty – and the brain systems that are involved – are numerous. We have a few projects that are trying to sort through the heterogenous profiles of children with developmental dyscalculia to understand different subtypes that may be present within this broader group and the brain systems that are implicated.
Do you have a story about a research participant or a breakthrough that illustrates the impact of your work?
One issue that many children with math learning difficulties have trouble with is estimating the number of items in a set. So, for example, they may have trouble looking at a set of seven yellow dots and 12 blue dots, and quickly estimating which set has more. This has been known for a while. But it turns out that there is a specific scenario of this task that may be especially important: when the seven yellow dots look like more, because the dots are bigger, and you still need to understand that the 12 blue dots are more numerous. This version of the task involves choosing among competing streams of information. It requires children to use their inhibitory control, a commonly studied component of executive function ability (a set of cognitive skills that help people regulate their behavior and achieve goals). There is a neural signature to this action, and we found that it is related to children’s math ability overall and that children with dyscalculia have trouble with the task.
In the Number Lab at Vanderbilt, we are pushing further to understand what this finding means by exploring this phenomenon with symbolic numbers (and fractions) and with other executive functions such as memory and cognitive flexibility. We hope that understanding these basic neurocognitive mechanisms will help us understand how the brain does more complex math, like problem solving, and why some children struggle more than others with specific skills.
What are your reasons for becoming a Vanderbilt Kennedy Center (VKC) Member? How does the VKC enhance the work you do?
The Vanderbilt Kennedy Center, with its dynamic community of experts from various scientific disciplines, is dedicated to understanding developmental disabilities. This center enables us to synergize our efforts, creating a collective impact that surpasses our individual contributions. Whether it involves exploring new methodologies, seeking specialized expertise, or assembling a team for large-scale challenges, the resources and collaborative environment of the Vanderbilt Kennedy Center are instrumental in addressing these complex issues.
