Hidden Order: The Memory Test Made Famous by a Chimpanzee
A young chimp called Ayumu once beat university students at this task. What the study showed, and what it did not.
Hidden Order looks simple: numbers appear in random squares and you tap them in order. The catch is that after your first tap, the rest go blank. You need to have taken a mental snapshot.
How to play
Numbers appear in random squares. Tap 1 first; the others then turn blank. Keep tapping in order from memory. Level 1 has 3 numbers, and each level adds one, for 20 levels. One mistake ends the test.
Where it comes from
In 2007, Sana Inoue and Tetsuro Matsuzawa at Kyoto University published a study of young chimpanzees doing this task. When the numbers were shown very briefly, a chimp named Ayumu was more accurate than the university students tested. The study made headlines around the world.
Later research suggested that humans given more practice can do much better than in the original comparison, so the debate is about practice as much as species.
What the task uses
A quick spatial snapshot: where each number was, in order. It relies on visual and spatial working memory, plus speed.
What practice can change
Practice helps a lot on this task. As with other memory tasks, there is little evidence that it improves memory in daily life.
A worked example
On a level with 6 numbers, look at where 1 is, then trace a mental line to 2, 3, 4, 5 and 6 before you tap anything. Once you tap 1, the others turn blank, so the path needs to be in your head already. Tapping steadily along that path is usually better than tapping very fast.
Common mistakes
Tapping 1 as soon as the numbers appear, before you have looked at the rest, is the most common mistake. Another is trying to remember the numbers instead of the path between them. On later levels, numbers close together are easy to swap, so check those pairs before you start.
Questions people ask
Are chimpanzees really better at this? In one well-known 2007 study, young chimpanzees outperformed the students tested when the numbers were shown very briefly. Later work suggests practice matters a lot, so humans can improve considerably.
Why is there no time limit before the first tap? So you can choose how long to study the layout.
Does this train general memory? It trains this task.
Tips
Before tapping 1, take a second to trace the path from 1 to the last number. Not medical advice.
Sources
Not medical advice. Stop if you feel dizzy, nauseous or strained.