Formation of number concept in a chimpanzee

为了教会雌性黑猩猩基数和序数的概念，进行了以下4个实验。在实验1中，训练她将作为基数的阿拉伯数字与随机图案中显示的点数相匹配。从一和二开始，当达到学习的标准时，就一个接一个地增加下一个大数字。实验2和实验3分别在数字2 ~ 6的每个阶段要求16、18、24、45和55次会话，在实验2和实验3中，添加数字7，系统地改变点的图案和密度，以检查这些作为辨别刺激对匹配行为的影响。虽然有些干扰，但她的表现仍然保持在85%以上的正确率。响应时间作为点的数量的函数一致地增加，除了最大的数字7比6更快地响应。实验4采用6对相邻的1 ~ 7个数字序列训练大-小条件判别，作为学习序数词的第一步。达到标准后，插入非相邻对作为探测试验来测试传递性。黑猩猩成功地证明了对较大数字的前向传递性，但对较小数字的后向传递性却没有。

To teach a female chimpanzee the concept of cardinal and ordinal number, the following 4 experiments were carried.In Experiment 1, she was trained to match an Arabic numerals as the cardinal number to the number of dots displayed in a random pattern. Starting with one and two, the next large number was added, one by one, when the criterion of learning was attained. Sixteen, 18, 24, 45, and 55 sessions were required to the criterion in each stage from the number 2 to 6, respectively.In Experiment 2 and 3 in which the number 7 was added, the pattern and density of dots were varied systematically to check those effects as the discriminative stimuli upon matching behavior. Although some disturbance was observed, her performance was still maintained higher than 85% correct. Response time consistently increased as a function of the numbers of dots except that the largest number 7 was reponded faster than 6. Thus, the chimpanzee's matching behavior should be controlled by the number of dots.As the first step to teach the ordinal numbers, the large-small conditional discrimation was trained in Experiment 4 with 6 adjacent pairs in 1 to 7 numeral series. After reaching the criterion, non-adjacent pairs were inserted as probe trials to test the transitivity. The chimpanzee was successful to show the forward transitivity to the larger number, but not the backward transitivity to the smaller number.