Neural systems underlying the coordination of numerical and spatial representations
Professor of Education
2015 Seed Grant: Brain mechanisms of spatial reasoning in mathematics
Mastering the ability to form appropriate internal representations from numerical and mathematical expressions and estimating numerosity are both essential steps toward success in mathematics, engineering, and the quantitative sciences. Fostering these abilities is a goal for education and dovetails with recent advances in methods for understanding brain representations of space and number in parietal cortex and with increased interest among cognitive neuroscientists in the processes involved in representation and processing of numbers. To these ends, we have pursued two lines of research, on the brain representation of number and the relationship between number and space. Using functional Magnetic Resonance imaging and a mental number line marking task, our evidence supported the view that representations of numerical magnitude are distinct from those associated with the representation of a number’s position in space, with the magnitude of numerical symbols coded in anterior intraparietal sulcus (IPS) while the position of a number in space is coded in posterior IPS. Using Steady-state Visual Evoked Potentials, we developed a rapid and objective means of quantifying the sense of “approximate number” – our ability to judge the relative numerosity of objects in a collection. This method also implicates parietal cortex in numerical cognition and may be adaptable for use in studying approximate number representations in school-age children.