Resumen

FREITASI, Maria Clara de; BENITEZ, Priscila; DOMENICONI, Camila  y  BARROS, Romariz. Capuchin monkeys' discrimination of quantities: the influence of occupied area and numerical distance. Temas psicol. [online]. 2015, vol.23, n.1, pp. 111-121. ISSN 1413-389X.

Numerical abilities are documented in the literature in different species. The variables that contribute to this kind of discrimination have been pointed as continuous (area, density, etc.) or numerical. The present study evaluated the capability of capuchin monkeys (Sapajus spp) for numerical discriminations in discrete trials without explicit training, having as control the variables related to the area occupied by the stimulus: area versus amount of elements. Besides that, the ratio between the number of elements in each set was kept unchanged and the numerical distance varied. Six male capuchin monkeys, with experimental history of discrimination training with two-dimensional stimuli presented on computer screen, participated of the study. Experimental sessions consisted of presentation of discrete trials presenting two stimuli (sets of pieces of food) for the animal to choose without any previous explicit training. Responses were analyzed by mean of the subjects' choice of the container with bigger or smaller amount of stimuli (pieces of food). Responses showed a tendency to the selection of the pair with bigger amount of pieces of food, especially when the subjects had as cue continuous (area) and numerical variables. When the variable "area" was controlled (Condition B), the subjects showed responses close to indifference, with tendency to the choice of the stimulus with smaller amount, suggesting that the area had an important role in the discrimination of amounts. We discuss the importance of investigating the continuous cues that the organisms use for discrimination between amounts.

Palabras clave : Numerical discrimination; continuous variable; Sapajus spp.

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