Linguistic and Nonlinguistic Turn Direction Concepts

This paper discusses the conceptualization of turn directions along traveled routes. Foremost, we are interested in the influence that language has on the conceptualization of turn directions. Two experiments are presented that contrast the way people group turns into similarity classes when they expect to verbally label the turns, as compared to when they do not. We are particularly interested in the role that major axes such as the perpendicular left and right axis play--are they boundaries of sectors or central prototypes, or do they have two functions: boundary and prototype? Our results support a) findings that linguistic and nonlinguistic categorization differ and b) that prototypes in linguistic tasks serve additionally as boundaries in nonlinguistic tasks, i.e. they fulfill a double function. We conclude by discussing implications for cognitive models of learning environmental layouts and for route-instruction systems in different modalities.