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 …

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 …

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

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

We examined how bees solve a visual discrimination task with stimuli commonly used in
numerical cognition studies. Bees performed well on the task, but additional tests showed …

We associate small numbers with the left and large numbers with the right side of space.
Recent evidence from human newborns and non-human animals has challenged the …

We found a region of the zebrafish pallium that shows selective activation upon change in
the numerosity of visual stimuli. Zebrafish were habituated to sets of small dots that changed …