恒河猴对50以下数目的估计

本研究有６个从易到难的程序，每个程序有标准数目和比较数目，都是白卡片上的黑圆点。每次试验先呈现标准数目作为样本，强化后撤去，随后同时呈现标准数目和比较数目，令动物作二择一反应。实验结果表明，影响恒河猴数目估计的有两个主要因素，即标准数目和比较数目之间的数间距和这两个数目本身的大小。在数间距为４或大于４时，恒河猴能对５０以下的数作出估计；在数间距为２时，恒河猴能对９－２５的数作出估计，但不能对２７－４９的数作估计。作者以为，这里所进行的是一种相对的区域性的数目估计，但它仍然是一种数标签的过程。

ESTIMATION FOR NUMEROUSNESS OF LESS THAN 50 IN RHESUS MONKEYS(macaca mulatta)

Estimation has not yet been systematically investigated with primate. In this experiment, the ability of 2 rhesus monkeys(macaca mulatta) in estimating the numerousness of less than 50 was investigated. In all of the six procedures of the experiment. the delaved-match-to-sample was used to test how accurately the animals could recognize the Standard Number(SN) and Comparative Number(CN). The SN and CN were black-filled circles (dots) that were drawn on white cards. Each number from 9-49 with 2 or 4 apart was represented by 20 individually constructed cards. so each number was represented by 40 discriminable patterns. The fixed patterns were avoided and in order to control the cumulative area, three diameters for black dots were used. The results suggested that. there were two factors. the number distances between SN and CN and the magnitude of SN and CN. affected the numerousness estimation of monkeys. The two monkeys completed all performances of estimation for numerousness of less than 50 when the number distances between SN and CN were 4 or more than 4(80% correct criterion). While when the number distance was 2, the two monkeys reached criterion of performances of estimation for 9- 25, but not for 27- 49. The author suggested that the monkeys completed a relative numerousness estimation and it was a process of assignment of a numerical tag.