Virtual Reality as an Innovative Tool for Numerosity Perception

Numeracy, the ability to use basic mathematical skills in everyday life, is essential in modern society. Recent studies have shown a connection between numeracy and visual numerosity perception, yet traditional 2D screen-based assessment methods often lack ecological validity and participant engagement. This study evaluates the viability of conducting numerosity estimation tasks in virtual reality (VR) and to determine whether hallmarks of numerosity processing, typically observed in laboratory settings, can be replicated in immersive environments. Six participants completed a psychophysical evaluation in VR, comparing the numerosity of visual stimuli consisting of two sets of spheres. The VR experiment successfully replicated two distinctive patterns found in traditional psychophysical studies: increased precision and decreased response times at high numerosities. Specifically, Weber fractions drop by approximately a factor of two, with values ranging from ~15% for low and intermediate conditions to ~8% in high numerosities, and response times decreases from ~663 ms for low numerosities to ~593 ms for high numerosities. These findings highlight that VR can be effectively used for numerosity estimation tasks, providing a controlled and immersive environment that traditional methods cannot achieve, while significantly expanding methodological possibilities in psychophysical research.