Mental rotation: Effects of stimulus complexity and familiarity.

The times required for encoding, mental rotation, and comparison of unfamiliar stimuli (patterns of filled-in squares in a 3?×?3 matrix) were found to increase with stimulus complexity (as measured, for example, by the number of separated pieces constituting each figural pattern). However, with continued practice on particular stimuli, rotation time, though still dependent on angle of rotation, became independent of the complexity of those stimuli for most subjects. Subjects may represent a stimulus and imagine its rotation piece by piece, if it is unfamiliar, and as a whole, if (as, presumably, in the experiments by Cooper & Podgorny, 1976) it is sufficiently well learned. However, for a few subjects, who reported using a more analytic, verbally supported strategy throughout, the effects of stimulus complexity were only partially reduced by continuing practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)