Research in cognitive development helps explain how people develop perceptual and intellectual skills throughout the lifespan. I was privileged to study how children develop numerical cognition with Dr. Elizabeth Brannon of the Department of Psychology as part of the Penn Undergraduate Research Mentoring Program (PURM). As a research assistant, I studied how children learn numbers and mathematical skills from a variety of angles, including infant behavioral studies, brain imaging studies, and computer-based studies with children and adults.
One study that I focused on, “child division of visual quantity,” examined whether children know how to divide approximate quantities before formally learning division in school. Subjects aged 6-9 were shown an array of dots divided onto a flower’s petals. Children then had to estimate whether one petal from the flower contained more or fewer dots than a comparison petal. Subjects also completed a similar task which used numerals instead of groups of dots. We found that children performed significantly better than chance on both the symbolic (numbers) and non-symbolic (dots) versions of the task, indicating that they can perform approximate division without formal training.
I was also involved in a fMRI mapping study which used brain imaging to study how children learn the meanings of number words. Typically, children first learn to recite the count sequence (1,2,3) and gradually learn that each number represents a specific quantity. Eventually, they acquire a cardinal principle, meaning that they understand that the last number recited when counting objects represents the number of objects that there are. Our study, which took place while subjects were in an MRI scanner, examined whether children understand the relationship between number and quantity. Children were shown a certain number of dinosaur eggs and heard a spoken number. Half of the time, the spoken number matched the number of eggs, but half of the time it did not. We used MRI scans to compare the brain’s response when the numbers matched and when they did not match to see whether children understand the relationship between spoken number and quantity of objects.
As a research assistant, I helped with many studies and was involved in various aspects of the lab, including preparation, data collection, and analysis. I also had the chance to read and learn a lot about numerical cognition and to hear how researchers design experiments. These varied experiences gave me a broad sense of what it is like to do research in psychology, enriching my academic experience and informing my future career choices.