Transformational Studies of the Internal Representation of Three-Dimensional Objects 1

In 1969 we initiated the first experiment in a continuing series designed to measure the times that human subjects require to respond discriminatively to spatially transformed visual objects. We are taking advantage of this opportunity to give the first full account of that initial experiment, which was only partially covered in the brief original paper (Shepard & Metzler, 1971); to report a second, corroborative and clarifying experiment that has previously been presented only orally (Metzler & Shepard, 1971); to review briefly the central findings of some still further experiments that one of us has subsequently carried out in a doctoral dissertation (Metzler, 1973); and to present a reasonably complete…