Cognitive science research shows that the brain has two systems for processing visual information, one specialized for spatial information such as position, orientation, and trajectory, and the other specialized for information used to identify objects, such as color, shape and texture. Some individuals seem to be more facile with the spatial visualization system, while others favor the object visualization system. This commentary hypothesizes that geosciences draw heavily on both systems, in contrast to other studied professions whose practitioners tend to be strong at spatial visualization (e.g. physics), or object visualization (e.g. visual arts). Candidate object visualization tasks in geosciences include identifying rocks, minerals and fossils, and interpreting remote sensing images. Candidate spatial visualization tasks include envisioning the folding and faulting of sedimentary strata, and envisioning a 3-D volume from 2-D data. In general education, geoscience activities rich in object-visualization could provide an opportunity to motivate and empower a population--object visualizers--who may have disliked prior science courses. In the education of geoscience specializers, a challenge is to find instructional supports to strengthen the object visualization skills of spatial visualizers, and the spatial visualization skills of object visualizers, to produce graduates with both competencies.