Cognitive Science & Psychology Division, ULAB

A core paradox within cognitive science is the emergence of cultural functions, such as writing systems and arithmetic, that develop across time spans far too short for our neural systems to evolve to support them. Previous work has addressed this question with the neural recycling hypothesis, proposing that these newer functions are mapped onto pre-existing interconnected regions of the brain, called neural circuits. We replicated results from a study exploring the specific functions that have been recycled to allow for symbolic subtraction and multiplication. Original findings suggested that numerosity circuitry, typically responsible for comparing the size or quantity of two groups, is employed for subtraction and verbal processing circuitry for multiplication. We reviewed the collected fMRI data to construct a model of the brain with the region responsible for numerosity localized. We confirmed that the region localized by the numerosity task corresponded to the right intraparietal sulcus (IPS). Future research should focus on the corollary of the neural circuitry hypothesis—that later-evolving processes are subject to the restrictions of the circuitry they recycle. In particular, analyzing data obtained from incorrect answers to tasks would help confirm that recycling underlies the correlations we see between the neural activity of certain tasks.