Abstract: Kosslyn suggested that there are two distinct spatial relation processing systems which are Categorical spatial relation processing subsystem and Coordinate relation processing subsystem. As well as a functional dissociation between the two subsystems, there is a neural-level dissociation between the hardware of brain circuits involving this two types of processing, which can be indicated by brain hemisphere specialization. The left hemisphere is specialized for coding categorical spatial relations, whereas the right hemisphere is specialized for coding coordinate spatial relations. This article reviews studies extending from low-level spatial perception into multiple domains including spatial relation processing in visual mental imagery, memory, language, motor action and object identification etc., in which diverse methodologies are adopted: visual half field methodology, neural network simulation, PET, fMRI, ERP, rTMS, studies with brain damaged patients and comparative animal study. In general, it can be summarized that, although hemisphere specialization provides convergent evidence for the neural-level dissociation of categorical and coordinate spatial relation processing systems, the obtaining of hemisphere specialization in various studies is unstable and sensitive to methodological factors. The reason for the dissociation, however, is still open for debate, although it appeared to be linked with the hemispheric specialization for processing the output of neurons with different receptive field properties

Key words: categorical spatial relation processing, coordinate relation processing, hemisphere specialization, dissociation