Bimanual volume perception of 3-D objects

In the present study, blindfolded subjects had to explore differently shaped objects with two hands and to judge their volume. The results showed a significant effect of the shape of objects on their perceived volume. Additional analysis showed that this effect could not be explained by the subjects´ tendency to base the volume judgment on a specific object dimension other than the volume itself. This contrasts with the results from previous studies, which used cylindrical objects or objects that could fit in one hand, in which the effect of shape on volume perception could be explained by the height/width ratio or the surface area of objects, respectively.