Hayashi Misato
Section of Language and Intelligence, Primate Research Institute, Kyoto University, Aichi, Japan.
Cortex. 2007 Apr;43(3):308-18. doi: 10.1016/s0010-9452(08)70457-x.
The nesting-cup task has been used to assess cognitive capability in humans as well as non-human primates. Previous studies have attempted to highlight interesting aspects of behavior by constructing and assessing various categories of manipulation. The present study introduces a new notation system for describing manipulation in nesting-cup tasks in the form of sequential codes. Following this notation, the entire process of manipulating cups can be divided into a sequence of behavioral segments. Each segment corresponds to a single manipulation of a cup, recorded as two numerical and one letter codes indicating object, location, and action, respectively. These codes describe the full extent of the subjects' manipulation, which can thus be traced retrospectively in its entirety by decoding the behavioral segments from the sequence. The subjects were three infant chimpanzees, three adult chimpanzees, and two human children. Segment-based analysis revealed developmental changes in the use of three strategies (pairing, pot, and subassembly), which previous studies have used as reliable indicators of cognitive development. Subassembly, regarded as the most advanced strategy for combining cups in human development, is defined as the placing of a previously constructed structure consisting of two or more cups into or onto another cup or cup structure. The three infant chimpanzees and two adult chimpanzees rarely showed subassembly, in contrast with frequent use by experienced adult chimpanzees and humans. Analysis of transition in cup state revealed a dynamic process in terms of progression and regression within a trial. The tendency to show progressive patterns of transition was related to the use of the subassembly strategy in both humans and chimpanzees. In addition, a case study of nine-cup manipulation by a chimpanzee is reported through sequential codes. Taken together, these data clearly demonstrate the potential of the proposed notation system in describing subjects' performance in nesting-cup tasks.
嵌套杯任务已被用于评估人类以及非人类灵长类动物的认知能力。以往的研究试图通过构建和评估各种操作类别来突出行为的有趣方面。本研究引入了一种新的符号系统，以顺序编码的形式描述嵌套杯任务中的操作。按照这种符号表示，操作杯子的整个过程可以分为一系列行为片段。每个片段对应于对一个杯子的一次操作，分别记录为两个数字和一个字母代码，指示对象、位置和动作。这些代码描述了受试者操作的全部范围，因此可以通过对序列中的行为片段进行解码，完整地追溯整个操作过程。受试者包括三只幼年黑猩猩、三只成年黑猩猩和两名人类儿童。基于片段的分析揭示了三种策略（配对、罐子和子组件）使用上的发展变化，以往的研究将这些策略用作认知发展的可靠指标。子组件在人类发展中被视为组合杯子的最先进策略，定义为将由两个或更多杯子组成的先前构建的结构放置到另一个杯子或杯子结构中或之上。与经验丰富的成年黑猩猩和人类频繁使用子组件不同，三只幼年黑猩猩和两只成年黑猩猩很少表现出子组件行为。杯子状态转换的分析揭示了在一次试验中进步和退步方面的动态过程。在人类和黑猩猩中，表现出进步性转换模式的趋势都与子组件策略的使用有关。此外，通过顺序编码报告了一只黑猩猩对九个杯子进行操作的案例研究。综上所述，这些数据清楚地证明了所提出的符号系统在描述受试者在嵌套杯任务中的表现方面的潜力。
