Host: Primate Society of Japan
There have been many reports of space-based representation of numbers and serial order in humans. Here, to explore evolutionary origins of such representations, we examined whether rhesus macaques map an acquired sequence onto space. The subjects were trained to perform a number sequence task in which they touched a sequence of “small” to “large” Arabic numerals presented in random locations. After they had acquired the task, probe trials were interspersed with trained baseline trials. On half of the probe trials 1 was located to the left of 5, whereas on the other half 1 was to the right to 5. On average monkeys responded more quickly when 1 was on the left of the 5 compared to the other way around. This result suggests that rhesus monkeys, like humans, spontaneously novel sequences onto space.
