Spatial Components in the Mental Representation of Physical Dimensions

Spatial components in the representation of ordinal information were initially revealed by Dehaene, Bossini and Giraux (1993). The authors found faster left- than right-hand responses to small numbers and a reverse effect with large numbers. This SNARC effect (Spatial-Numerical Association of Response Code) was also found with overlearned and newly learned non-numerical information (Gevers, Reynvoet & Fias, 2003). The current study examined whether physical dimensions are also mentally represented with a spatial component. Response times to mentally visualized clothing of different weight and brightness were analyzed. Subjects were asked to either categorize the items as lighter vs. heavier or brighter vs. darker than a reference. The characteristic interaction of position (before or after the reference) and side of response (left or right) was found with the dimension of weight: left (right) hand responses were faster for lighter (heavier) clothing. Findings suggest that the representation of physical dimensions may also include spatial components.