Boundaries and Prototypes in Categorizing Direction

Abstract. Projective terms such as left, right, front, back are conceptu-ally interesting due to their exibility of contextual usage and their cen-tral relevance to human spatial cognition. Their default acceptability ar-eas are well known, with prototypical axes representing their most central usage and decreasing acceptability away from the axes. Previous research has shown these axes to be boundaries in certain non-linguistic tasks, indi-cating an inverse relationship between linguistic and non-linguistic direc-tion concepts under specic circumstances. Given this striking mismatch, our study asks how such inverse non-linguistic concepts are represented in language, as well as how people describe their categorization. Our nd-ings highlight two distinct grouping strategies reminiscent of theories of human categorization: prototype based or boundary based. These lead to dierent linguistic as well as non-linguistic patterns.