Lemurs and macaques show similar numerical sensitivity.
We investigated the precision of the approximate number system (ANS) in three lemur species (Lemur catta, Eulemur mongoz, and Eulemur macaco flavifrons), one Old World monkey species (Macaca mulatta) and humans (Homo sapiens). In Experiment 1, four individuals of each nonhuman primate species were trained to select the numerically larger of two visual arrays on a touchscreen. We estimated numerical acuity by modeling Weber fractions (w) and found quantitatively equivalent performance among all four nonhuman primate species. In Experiment 2, we tested adult humans in a similar procedure, and they outperformed the four nonhuman species but showed qualitatively similar performance. These results indicate that the ANS is conserved over the primate order.
Department of Psychology and Neuroscience, Duke University, Durham, NC, USA, Sarah.jones@snc.edu.
Sarah M
SM
Jones
John
J
Pearson
Nicholas K
NK
DeWind
David
D
Paulsen
Ana-Maria
AM
Tenekedjieva
Elizabeth M
EM
Brannon
D000818:Animals; D032882:Comprehension; D003210:Concept Formation; D006801:Humans; D007858:Learning; D007900:Lemur / Q000523:psychology*; D008253:Macaca mulatta / Q000523:psychology*; D008297:Male; D008433:Mathematics; D055815:Young Adult