Mental Rotation Test

In 1971, Roger Shepard and Jacqueline Metzler showed people pairs of drawings of block shapes and asked whether the two were the same object or mirror images. The further one shape was turned, the longer people took to answer, and the time grew in a straight line with the angle [1]. It looked as if people were turning the shape in their mind at a steady speed. The finding is one of the classics of psychology.

It measures spatial thinking: how accurately and how quickly you can imagine an object turning. This version uses our own flat shapes made of squares, drawn new for every run, instead of the original 3D drawings, so its numbers can't be compared with published studies.

• The left shape is upright. The right one is turned by up to 180°, either way, and in about half of the pairs it is also flipped like a mirror image. No turn can make a mirror image match the original.
• 4 practice pairs with feedback come first (you can skip them), then 24 counted pairs. Tap Same or Mirror, or press S or M.
• A pair you don't answer within 8 seconds counts as a miss. Leaving the page ends the run, because the test is timed.

• Answered right: the share of counted pairs you got right.
• Time per right answer: your average time on the pairs you got right. We also show it by angle, so you can see whether bigger turns took you longer, as in the original study.

This task gets faster with practice, and your device and the size of your screen matter too, so compare with your own earlier runs. For another spatial test, try the visual memory test.