Reference
Roger Shepard
The mental rotation experiment, and the finding that decision time rises linearly with angle, is his with Jacqueline Metzler.
In 1971 Shepard and Jacqueline Metzler showed people pairs of block figures and asked a single question: same object, or mirror image? The result that made it famous was not the accuracy. It was the timing. How long someone took rose in a straight line with how far the second figure had been turned, all the way out to 180 degrees.
A straight line is the interesting part. If people were recognising the answer, or checking features against a list, there would be no reason for 120 degrees to cost reliably more than 60. The linearity suggests something continuous is happening: a representation being transformed at a roughly steady rate, more like turning an object than like looking something up. That finding is why mental rotation became the standard task in spatial cognition, and it is the task our own rotation test is built from.
Referenced work
- Mental Rotation of Three-Dimensional Objects (Science, 1971, with Jacqueline Metzler) reference
Elsewhere
Listed here because we name Roger Shepard in our writing. We are not affiliated with them and this page is our summary, not theirs.