Joonkoo Park, Ph.D.
May 31(Wed) - May 31(Wed), 2023
4PM
N Centre 86314 & ZOOM (ID: 728-142-6028)
CNIR Seminar
Date: 4pm, Wed, May 25th
Speaker: Joonkoo Park, Ph.D. (University of Massachusetts)
Title: The emergence of number sense in the brain: psychophysical, neural, and computational investigations
Abstract: The brain is known to encode numerosity—or the number of items—in a visual scene. The representation of numerosity is thought to give rise to the sense of number that is prevalent in the animal kingdom. However, it is not clear how a discrete value (i.e., number) is encoded in the brain when neural signals are inherently continuous. In a series of psychophysical, neural, and computational studies, I demonstrate that early visual cortex happens to become sensitive to the magnitude dimension that is closest to number, as a byproduct of a canonical neurocomputational process termed divisive normalization. The results suggest that what we call number sense is not driven by number per se but instead emerges from an inherent perceptual mechanism, the output of which best matches with the conceptual content of number. These findings call for a clear distinction between percepts and concepts of number, which should resolve outstanding theoretical debates about number sense and its origins.