Mental Rotation - Shepard and Metzler in Depth

Shepard and Metzler in Depth

In 1971, Roger N. Shepard and Jacqueline Metzler conducted the most famous study done on mental rotation. They were the first to introduce this idea to cognitive science. Their experiment specifically tested mental rotation on three-dimensional objects. Each subject was presented with multiple pairs of three-dimensional, asymmetrical lined or cubed objects. The experiment was designed to measure how long it would take each subject to determine whether the pair of objects were indeed the same object or two different objects. For each pair, the subject was asked to pull a right-handed lever if the two objects were congruent with respect to a three-dimensional shape and to pull a left-handed lever if the objects were not. Shepard’s hypothesis was that this task would be done by creating a mental three-dimensional image of the first depict object and mentally rotating that object to see if it matches its pair. The results of the experiment confirmed the original hypothesis. The time it took for each subject to identify if two objects were identical was directly proportional to the angular rotational difference between them. The greater the angular rotational difference, the greater the time it took to identify the similarity (Shepard & Metzler, 1971).