Department of Psychology, Agnes Scott College, Decatur, Georgia, United States of America.
Language Research Center, Georgia State University, Decatur, Georgia, United States of America.
PLoS One. 2018 Apr 11;13(4):e0193229. doi: 10.1371/journal.pone.0193229. eCollection 2018.
Metacognition refers to thinking about one's thinking or knowing what one knows. Research suggests that this ability is not unique to humans and may be shared with nonhuman animals. In particular, great apes have shown behaviors on a variety of tasks that are suggestive of metacognitive ability. Here we combine a metacognitive task, the information-seeking task, with tool use and variable forms of initial information provided to chimpanzees to explore how informational states impact behavioral responses in these apes. Three chimpanzees were presented with an apparatus that contained five locations where food could be hidden. If they pointed to the correct location, they received the reward, but otherwise they did not. We first replicated several existing findings using this method, and then tested novel hypotheses. The chimpanzees were given different types of information across the experiments. Sometimes, they were shown the location of the food reward. Other times, they were shown only one empty location, which was not useful information. The chimpanzees also could use a tool to search any of those locations before making a selection. Chimpanzees typically used the tool to search out the location of the reward when they could not already know where it was, but they did not use the tool when they already had been given that information. One chimpanzee made inferences about the location of hidden food, even when that food was never shown in that location. The final experiment involved hiding foods of differing preference values, and then presenting the chimpanzees with different initial knowledge states (i.e., where the best food was located, where the less-preferred food was located, or where no food was located). All chimpanzees used the tool when they needed to use it to find the best possible item on that trial, but responded by choosing a location immediately when they did not need the tool. This finding highlights that their behavior was not the result of a simple rule following such as pointing to where any food had been seen.
元认知是指对自己思维的思考或知道自己知道什么。研究表明，这种能力并非人类独有，可能与非人类动物共有。特别是，大型猿类在各种任务中表现出的行为表明它们具有元认知能力。在这里，我们将元认知任务——信息寻求任务与工具使用以及初始信息的不同形式结合起来，以探索信息状态如何影响这些猿类的行为反应。我们给三只黑猩猩展示了一个装置，里面有五个可以隐藏食物的位置。如果它们指向正确的位置，就会得到奖励，但如果它们指错了，就得不到奖励。我们首先用这种方法复制了一些现有的发现，然后测试了新的假设。在实验中，黑猩猩得到了不同类型的信息。有时，它们会看到食物奖励的位置。其他时候，它们只看到一个没有食物的空位置，这对它们没有帮助。黑猩猩也可以在做出选择之前用工具搜索这些位置中的任何一个。当黑猩猩无法确定食物的位置时，它们通常会使用工具来寻找奖励的位置，但当它们已经获得了这些信息时，它们不会使用工具。一只黑猩猩甚至可以根据隐藏食物的位置进行推断，即使这些食物从未在那个位置出现过。最后一个实验涉及隐藏不同偏好值的食物，然后给黑猩猩不同的初始知识状态（即最好的食物在哪里，不太喜欢的食物在哪里，或者没有食物的地方）。所有的黑猩猩在需要使用工具找到那一轮最佳物品时都会使用工具，但当它们不需要工具时，它们会立即选择一个位置。这一发现表明，它们的行为不是简单地遵循规则，比如指向任何看到食物的地方。
