Gazes Regina Paxton, Billas Alison R, Schmitt Vanessa
Department of Psychology and Program in Animal Behavior, Bucknell University, Lewisburg, PA, USA.
Program in Animal Behavior, Bucknell University, Lewisburg, PA, USA.
Learn Behav. 2018 Mar;46(1):89-100. doi: 10.3758/s13420-017-0295-9.
Quantity discrimination abilities are seen in a diverse range of species with similarities in performance patterns, suggesting common underlying cognitive mechanisms. However, methodological factors that impact performance make it difficult to draw broad phylogenetic comparisons of numerical cognition across studies. For example, some Old World monkeys selected a higher quantity stimulus more frequently when choosing between inedible (pebbles) than edible (food) stimuli. In Experiment 1 we presented brown capuchin (Cebus [Sapajus] paella) and squirrel monkeys (Saimiri sciureus) with the same two-choice quantity discrimination task in three different stimulus conditions: edible, inedible, and edible replaced (in which choice stimuli were food items that stood in for the same quantity of food items that were given as a reward). Unlike Old World monkeys, capuchins selected the higher quantity stimulus more in the edible condition and squirrel monkeys showed generally poor performance across all stimulus types. Performance patterns suggested that differences in subjective reward value might motivate differences in choice behavior between and within species. In Experiment 2 we manipulated the subjective reinforcement value of the reward by varying reward type and delay to reinforcement and found that delay to reinforcement had no impact on choice behavior, while increasing the value of the reward significantly improved performance by both species. The results of this study indicate that species presented with identical tasks may respond differently to methodological factors such as stimulus and reward types, resulting in significant differences in choice behavior that may lead to spurious suggestions of species differences in cognitive abilities.
数量辨别能力在多种物种中都有体现，其表现模式具有相似性，这表明存在共同的潜在认知机制。然而，影响表现的方法学因素使得难以在各项研究中对数字认知进行广泛的系统发育比较。例如，一些旧世界猴在选择不可食用（鹅卵石）刺激物而非可食用（食物）刺激物时，更频繁地选择数量较多的刺激物。在实验1中，我们向褐卷尾猴（僧面猴属[褐卷尾猴种]）和松鼠猴（松鼠猴种）呈现了相同的二选一数量辨别任务，该任务设置在三种不同的刺激条件下：可食用、不可食用以及可食用替代（其中选择刺激物是代表与作为奖励给予的相同数量食物的食物项目）。与旧世界猴不同，卷尾猴在可食用条件下更多地选择数量较多的刺激物，而松鼠猴在所有刺激类型下的表现总体较差。表现模式表明，主观奖励价值的差异可能会激发物种之间和物种内部选择行为的差异。在实验2中，我们通过改变奖励类型和强化延迟来操纵奖励的主观强化价值，发现强化延迟对选择行为没有影响，但增加奖励价值显著提高了两个物种的表现。这项研究的结果表明，面对相同任务的物种可能对诸如刺激和奖励类型等方法学因素有不同的反应，从而导致选择行为上的显著差异，这可能会导致关于认知能力物种差异的虚假推断。
