Proceedings of the Annual Meeting of the Cognitive Science Society

People implicitly map numbers onto space, but what aspect of numbers do people spatialize? When cardinality (i.e. mag-nitude; 5 objects) is pitted against ordinality (i.e., sequential position; the 5th object), people show an implicit ordinalitymapping, at least in lateral space. We hypothesized that if people spatialize numerical magnitude at all, they should do soon the vertical axis, according to the way they talk about numbers (i.e. low, high). Participants memorized sequences ofrandomized numbers (e.g. 85913) and then classified them (as small or large) using two response keys, oriented either lat-erally or vertically. Participants showed reliable ordinality mappings on both axes; they were faster to press the left/upperkey for numbers earlier in the memorized sequence and the right/bottom key for later numbers, regardless of numbersmagnitudes. People map exact numbers onto both lateral and vertical space according to their ordinality.