Frames of reference in vision and language: where is above?

Spatial terms such as "above" must be used and interpreted with respect to some frame of reference. Perceptual cues for verticality were varied in four experiments to investigate whether the comprehension and production of "above" is based on a viewer-centered (deictic) frame, an environment-centered (extrinsic) frame, or an object-centered (intrinsic) frame of reference. "Above" was usually interpreted with respect to an environment-centered reference frame, but there was a significant contribution from object-centered reference frames as well; the viewer-centered reference frame made no independent contribution to "above". The meaning of "above" appears not to specify a particular reference frame; rather, selection of a reference frame during spatial assignment determines how spatial terms such as "above" and "below" will be used and interpreted.