In this review, we are pitting two theories against each other: the more accepted theory, the
number sense theory, suggesting that a sense of number is innate and non-symbolic …

It is widely accepted that human and nonhuman species possess a specialized system to
process large approximate numerosities. The theory of an evolutionarily ancient …

Humans represent numbers along a mental number line (MNL), where smaller values are
located on the left and larger on the right. The origin of the MNL and its connections with …

The approximate number system or «sense of number» is a crucial, presymbolic mechanism
enabling animals to estimate quantities, which is essential for survival in various contexts …

Evidence has been reported for quantity discrimination in mammals and birds and, to a
lesser extent, fish and amphibians. For the latter species, however, whether quantity …

Debates have arisen as to whether non-human animals actually can learn abstract non-
symbolic numerousness or whether they always rely on some continuous physical aspect of …

The ability to represent, discriminate, and perform arithmetic operations on discrete
quantities (numerosities) has been documented in a variety of species of different taxonomic …

An intriguing hypothesis to explain the ubiquity of numerical abilities is that all vertebrates
are born with hardwired neuronal networks for processing numbers. To date, only studies on …

Discrimination of quantity (magnitude) was investigated in zebrafish (Danio rerio). Male
zebrafish chose to approach the location previously occupied by the larger in number …

Numerical abilities are complex cognitive skills essential for dealing with requirements of the
modern world. Although the brain structures and functions underlying numerical cognition in …