Abstract
Numerical magnitude can bias spatial attention, typically facilitating faster responses to the left for small numbers and to the right for large numbers-an effect traditionally attributed to egocentric spatial mappings. However, in everyday environments, individuals often share space with others, raising the question of whether such spatial-numerical associations can spontaneously reorganize based on another person's visual perspective. To investigate this, we employed a digit-primed visual detection paradigm in which participants judged the location (left, right, up, or down) of a briefly presented peripheral probe following centrally displayed digits. If numerical magnitude implicitly guides attention, probe detection should be faster when its location is congruent with the digit-induced spatial bias. Critically, in the avatar condition, a task-irrelevant avatar was positioned on the participant's left side, such that the avatar's horizontal (left-right) axis corresponded to the participant's vertical (up-down) axis-an axis along which egocentric numerical biases are typically absent. If participants spontaneously adopted the avatar's perspective, numerical cues might induce attentional biases along this axis. Results revealed two simultaneous effects: a canonical egocentric SNARC-like effect (small-left, large-right) and a novel allocentric effect (small-up, large-down) emerged along the vertical axis, implicitly aligned with the avatar's left-right spatial orientation. Numerical extremity enhanced the egocentric SNARC-like effect but had no effect in the allocentric case, pointing to a distinct mechanism rooted in embodied spatial perspective. These findings suggest that numerical magnitude can implicitly map onto both egocentric and allocentric spatial frames, reflecting a implicit and embodied mechanism of social understanding.