Differences in spatial language in signed and spoken languages represent one of the great challenges for many linguistic fields, including psycholinguistic studies. Being articulated spatially, signed languages, compared to spoken languages, enable their users to express more fine-grained spatial information within a single segment, using simultaneous classifier constructions.
In addition, signers project the spatial relations onto iconic signing space, and so they are required to maintain different perspectives that demand complex mental imagery. Possible effects of these modality specific aspects of spatial language on signers' non-linguistic spatial cognition have been studied, especially with respect to the involvement of mental rotation during language processing.
In the present paper, I review previous research on mental rotation skills in users of signed languages (especially American Sign Language) and present interim outcomes of an ongoing study with CzSL signers and hearing Czech speakers.