The chapter provides an overview of linguistic, neuropsychological and experimental psychological approaches and findings that support the idea that spatial relation categories are analog, overlapping, internally structured categories based on prototype comparison and with fuzzy boundaries. The notion of a frame of reference in spatial cognition is related to the more general concept of a frame of reference in categorization.
Categorization constitutes the bridge between spatial vision and spatial language.
For visual space, a spatial framework is proposed that is based on perceptually salient directions which act as standard values in relation to which object relations can be judged.