The Evolutionary History of Brains for Numbers

Schiona

et al. 2021

Animals

It is widely acknowledged that vertebrates can discriminate non-symbolic numerosity using an evolutionarily conserved system dubbed Approximate Number System (ANS). Two main approaches have been used to assess behaviourally numerosity in fish: spontaneous choice tests and operant training procedures. In the first, animals spontaneously choose between sets of biologically-relevant stimuli (e.g., conspecifics, food) differing in quantities (smaller or larger). In the second, animals are trained to associate a numerosity with a reward. Although the ability of fish to discriminate numerosity has been widely documented with these methods, the molecular bases of quantities estimation and ANS are largely unknown. Recently, we combined behavioral tasks with molecular biology assays (e.g c-fos and egr1 and other early genes expression) showing that the thalamus and the caudal region of dorso-central part of the telencephalon seem to be activated upon change in numerousness in visual stimuli. In contrast, the retina and the optic tectum mainly responded to changes in continuous magnitude such as stimulus size. We here provide a review and synthesis of these findings.

Section: Discussionmentioning

confidence: 99%

“…Given that evolutionarily distant species differ widely in brain organization and complexity, how could they develop similar numerical abilities? This could be either the outcome of common ancestry from which they inherit it, or the outcome of convergent evolutionary processes promoted by similar selective pressures [ 40 , 41 ].…”

Section: Introductionmentioning

confidence: 99%

The Sense of Number in Fish, with Particular Reference to Its Neurobiological Bases

Messina

Schiona

et al. 2021

Animals

“…Studies investigating the neural basis of number representation revealed selectivity of response of neurons in some areas of the brain such as the parietal and prefrontal cortex in humans [37,38] and in monkeys [39,40], the nidopallium caudolaterale in crows [15,41] and the most caudal dorsal-central part of the pallium in zebrafish [42,43], suggesting that common selective pressures led to convergent evolution of numerical representation in different species [44,45].…”

Section: Numerical Discrimination Seems To Be Supported By An "Approximate Numbermentioning

confidence: 99%

Archerfish number discrimination

Zanon

Vallortígara

2021

Preprint

Debates have arisen as to whether non-human animals actually can learn astract non-symbolic numerousness or whether they always rely on some continuous physical aspect of the stimuli covarying with number. Here we investigated archerfish (Toxotes jaculatrix) non-symbolic numerical discrimination with accurate control for co-varying continuous physical stimulus attributes. Archerfish were trained to select one of two groups of black dots (Exp. 1: 3 vs. 6 elements; Exp. 2: 2 vs. 3 elements); these were controlled for several combinations of physical variables (elements' size, overall area, overall perimeter, density and sparsity), ensuring that only numerical information was available. Generalization tests with novel numerical comparisons (2 vs. 3, 5 vs. 8 and 6 vs. 9 in Exp. 1; 3 vs. 4, 3 vs. 6 in Exp. 2) revealed choice for the largest or smallest numerical group according to the relative number that was rewarded at training. None of the continuous physical variables, including spatial frequency, were affecting archerfish performance. Results provide evidence of the spontaneous use of abstract relative numerical information in archerfish for both small and large numbers.

“…Studies investigating the neural basis of number representation revealed selectivity of neuronal response in some areas of the brain, such as the parietal and prefrontal cortex in humans ( Kutter et al, 2018 ; Piazza et al, 2004 ) and in monkeys ( Nieder et al, 2002 ; Nieder and Merten, 2007 ), the nidopallium caudolaterale in crows ( Ditz and Nieder, 2016 ; Ditz and Nieder, 2015 ) and the most caudal dorsal-central part of the pallium in zebrafish ( Messina et al, 2020 ; Messina et al, 2021a ) (see also reviews in Lorenzi et al, 2021 ; Messina et al, 2021b ), suggesting that common selective pressures led to convergent evolution of numerical representation in different species ( Nieder, 2021 ; Vallortigara, 2021 ).…”

Section: Introductionmentioning

confidence: 99%

Archerfish number discrimination

Zanon

Vallortígara

2022

eLife

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 stimuli, covarying with number. Here we investigated archerfish (Toxotes jaculatrix) non-symbolic numerical discrimination with accurate control for co-varying continuous physical stimulus attributes. Archerfish were trained to select one of two groups of black dots (Exp. 1: 3 vs. 6 elements; Exp. 2: 2 vs. 3 elements); these were controlled for several combinations of physical variables (elements’ size, overall area, overall perimeter, density and sparsity), ensuring that only numerical information was available. Generalization tests with novel numerical comparisons (2 vs. 3, 5 vs. 8 and 6 vs. 9 in Exp. 1; 3 vs. 4, 3 vs. 6 in Exp. 2) revealed choice for the largest or smallest numerical group according to the relative number that was rewarded at training. None of the continuous physical variables, including spatial frequency, were affecting archerfish performance. Results provide evidence that archerfish spontaneously use abstract relative numerical information for both small and large numbers when only numerical cues are available.