EAPSI:A Comparative Test of the Spatial Hypothesis for the Mental Representation of Order in Nonhuman Primates

人类沿着心理数字线思考数字。数字的空间表示与提高数学能力有关。目前还不清楚这些空间表征在多大程度上是由文化训练引起的，比如学习从左到右阅读。由于非人类动物还没有学会从左到右阅读，它们可以作为一个很好的模型来研究缺乏文化的空间表征。数字和顺序有相似的性质，所以早期的非人类动物研究集中在顺序表征上。京都大学灵长类研究所的黑猩猩是第一批表现出与人类相似的秩序空间表征的非人类灵长类动物。在与Tetsuro Matsuzawa博士的合作中，研究人员将使用触摸屏计算机来测试PRI的黑猩猩对顺序的记忆和对空间位置的记忆如何相互作用。研究人员还将把类似的任务交给恒河猴，以测试人类、黑猩猩和更远的灵长类亲戚在多大程度上对数字有类似的思考。由于非人类灵长类动物在阅读和数学教学方面没有文化影响，它们是测试文化如何影响这些能力及其进化历史的理想模型。在革命制度研究所，黑猩猩将在触摸屏电脑上完成命令和记忆测试。大多数证据表明人类和非人类动物对顺序或数字的空间表征是间接的和类比的，几乎没有动物的数据可以直接与人类数据相比较。最近的研究表明，顺序的空间组织发生在工作记忆中。如果黑猩猩在工作记忆中空间上代表顺序，那么在空间工作记忆测试的延迟期间执行顺序任务将比非空间控制任务对空间记忆任务的表现干扰更大。如果获得干扰效应，这将表明黑猩猩在空间上代表秩序，并使用工作记忆机制。比较非人类灵长类动物和人类的表现有助于阐明支持秩序记忆的潜在机制。这个NSF EAPSI奖是与日本科学促进协会合作资助的。

Humans think about numbers along a mental number line. The spatial representation of numbers has been linked to improved math abilities. It is unclear how much these spatial representations are caused by cultural training, such as learning to read from left to right. Because nonhuman animals have not learned to read from left to right, they can be used as a good model to investigate spatial representations in the absence of culture. Number and order have similar properties, so early nonhuman animal research has focused on order representations. Chimpanzees at the Primate Research Institute (PRI) of Kyoto University are some of the first nonhuman primates to have shown similar spatial representations of order as humans. In collaboration with Dr. Tetsuro Matsuzawa, the researcher will use touchscreen computers to test how memory for order and memory for spatial locations interact in the chimpanzees at the PRI. The researcher will also give similar tasks to rhesus monkeys, to test the extent to which humans, chimpanzees, and more distant primate relatives similarly think about number. Because nonhuman primates do not have cultural influences in the form of reading and math instruction, they are an ideal model in which to test how culture influences these abilities and their evolutionary history. At the PRI, chimpanzees will work on touchscreen computers to complete order and memory tests. Most evidence for a similar spatial representation of order or number in humans and nonhuman animals is indirect and analogical, and there are almost no data from animals that is directly comparable to human data. Recent research suggests that the spatial organization of order occurs in working memory. If chimpanzees represent order spatially in working memory, then performing an order task during the delay of a spatial working memory test will interfere more with performance on the spatial memory task than with performance on a non-spatial control task. If interference effects are obtained, it will indicate that chimpanzees represent order spatially and do so using a working memory mechanism. Comparing performance of nonhuman primates and humans can help elucidate the underlying mechanism supporting memory for order. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.