Comparative cognitive studies on visual categorization in chimpanzees : effects of labeling on recognition.

本研究旨在探讨人类分类能力的进化起源。在研究1中，八只黑猩猩参与了一项类别选择任务，以探讨典型性的影响。在研究2中，六只黑猩猩中只有一只在两年的训练阶段后达到了学习标准。学会了符号关系的幼年黑猩猩参与了以下任务，以检查符号的认知过程。结果表明，从符号中提取语义属性可能有助于黑猩猩记忆的保持。

The present study aimed to investigate the evolutionary origin of abilities of categorization in humans. In Study 1, eight chimpanzees participated in a category choice task to investigate the effect of typicality. In Study 2 with a symbolic matching-to-sample task, only one of the six chimpanzees reached the learning criterion after two years of training phase. The juvenile chimpanzee that learned symbolic relations participated in the following tasks to examine cognitive processes of symbols. The results suggest that extraction of a semantic attribute from the symbol might help retention of the memory in the chimpanzee.