PT  - JOURNAL ARTICLE
AU  - Davide Potrich
AU  - Mirko Zanon
AU  - Giorgio Vallortigara
TI  - Archerfish number discrimination
AID  - 10.1101/2021.10.04.463045
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.10.04.463045
4099  - http://biorxiv.org/content/early/2021/10/05/2021.10.04.463045.short
4100  - http://biorxiv.org/content/early/2021/10/05/2021.10.04.463045.full
AB  - 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.Competing Interest StatementThe authors have declared no competing interest.