Methods in Psychology (Nov 2020)
‘Mental rotation’ in depth as the superficial correlation of pictures
Abstract
The Shepard-Metzler effect has been taken as evidence of a mental process of rotation in depth. Simple methods of image processing account for response time differences from the effect as well. The correlation of picture pairs presents an intervening variable between pictured solids and response times. This superficial description illuminates empirical findings such as variation in mental rotation over differences in solid form, and the rate of mental rotation over pictured directions of rotation in depth. The Shepard-Metzler effect is well described in terms of the absolute difference of the areas of profiles of pictures: in other terms, the autocorrelation coefficient of their absolute difference. It follows that ‘mental rotation’ in depth has no necessary bearing on the identity of solid forms.
