This research area addresses a focused comparative-cognition question: do nonhuman primates map number onto space in ways that resemble the human mental number line? In humans, smaller and larger quantities are often associated with different regions of space, but this association is shaped by culture, reading direction, education, and symbolic number use. Studying macaques allows the group to test whether number-space mappings also have deeper, nonlinguistic and evolutionarily older foundations.

The key issue is not simply whether macaques can discriminate quantity. The more interesting question is whether numerical magnitude, numerical change, or relative quantity expectations bias spatial choice. This makes the topic relevant to numerical cognition, spatial attention, comparative psychology, and the evolution of abstract representation. The central visual motif of the primate pointing toward numbered positions is therefore a useful public-facing symbol: it suggests that apparently abstract cognitive mappings may arise from embodied spatial behavior.

For the website, this line should be presented as an emerging, hypothesis-driven project. It can explain how spontaneous choice tasks, controlled numerical displays, and left/right spatial-response analyses are used to separate genuine number-space associations from simpler explanations such as side preference, reward history, salience, or motor bias. The wording should remain cautious: the public literature suggests an active and recent research line, with preprint and thesis evidence rather than a long-established publication stream.

Papers