Abstract
Although it is natural to suppose that visual mental imagery is important in human deductive reasoning,
the evidence is equivocal. This article argues that reasoning studies have not distinguished between
ease of visualization and ease of constructing spatial models. Rating studies show that these factors
can be separated. Their results yielded four sorts of relations: (1) visuospatial relations that are
easy to envisage visually and spatially, (2) visual relations that are easy to envisage visually but hard
to envisage spatially, (3) spatial relations that are hard to envisage visually but easy to envisage spatially,
and (4) control relations that are hard to envisage both visually and spatially. Three experiments
showed that visual relations slow down the process of reasoning in comparison with control relations,
whereas visuospatial and spatial relations yield inferences comparable with those of control relations.
We conclude that irrelevant visual detail can be a nuisance in reasoning and can impede the process.
