Guido Marco Cicchini, Giovanni Anobile, Davd Burr

Specialized Visual Module for Numerosity

CNR Annual Retreat 2019

02-04/10/2019 Pisa


There is strong evidence that humans can make rough estimates of the numerosity of a set of items, almost from birth. However, as numerosity covaries with many non-numerical variables, the idea of a direct number sense has been challenged. Here we summarize recent research which test which variable (size, density, numerosity or ink) is the one that subjects consider most when they are asked implicit tasks (i.e. find the oddstimulus or reproduce the pattern). Our research shows that numerosity is the dominating dimension and that changes in density and area do matter only if combined with each other to yield a numerosity estimate. This demonstrates that numerosity is a primary feature with high biological relevance that subjects develop with high reliability. In addition we demonstrate that these properties appear even before schooling begins and are preserved in dyscalculic subjects. Overall our research reveals that numerosity, whilst requiring a complex classification of visual images, it is learned in a formally correct way even early in development and it is preserved throughout lifetime