Spot the Change Game
The scene flickers. One picture is different. Can you find it?
About Change Spot
Change Spot shows a grid of pictures, such as fruit, animals and symbols. The grid flickers between two versions with a short blank in between, and in the second version exactly one picture has been replaced by a different one. You tap the picture you think is changing, as soon as you see it.
This is a version of the flicker paradigm, which was invented to study a surprising feature of vision: without a motion signal to point to the change, even large changes can be hard to see. The grid is 4 by 4 on the first levels and up to 5 by 6 later. The time per version falls from about 950 to 650 milliseconds.
How to play
- Watch the flickering grid. The pictures go away and come back, and one of them comes back different.
- Do not look at the whole picture at once. Scan systematically, row by row, and compare what you see with what you remember.
- Tap the picture that you think has changed. A wrong tap ends the round.
- The result shows which picture changed into which.
A grid of pictures flickers between two versions with a blank in between. One picture is different. Tap it as soon as you see it.
How scoring works
A correct tap scores 100 and a wrong tap or a timeout 0, and in endless mode a right tap counts as a passed round. How quickly you find the change feeds the time bonus of your progress statistics, but not the score of the round.
The grid is 4 by 4 up to level 4, then 5 wide with 5 rows up to level 7 and 6 rows above that. Each version is visible for 950 ms on level 1 and 650 ms on level 10, with a blank of 300 ms and 220 ms. You have 18 seconds on level 1 and 12 seconds on level 10.
What it trains
The game trains visual attention and memory comparison. To find the change you need to hold a part of the scene in memory across the blank and compare it with the next version. It is the skill of noticing differences, as in proofreading or checking a document.
It also shows you how limited attention is. Most people are surprised by how long it takes to find a change that is obvious once you have seen it.
Tips for a higher score
- Scan in a fixed pattern, for example row by row, so that you do not look at the same place twice.
- Focus on a small group of pictures for one cycle and compare them with the next version. Then move on to the next group.
- Name the pictures in a row silently. A name is easier to remember than a visual impression.
- Do not stare at the blank. Use it to rehearse what you saw.
- If you have not found it after a few cycles, look at the places you have scanned the least.
The idea behind it
The flicker paradigm was developed by Ronald Rensink, Kevin O'Regan and James Clark in 1997. They found that when a change is hidden by a brief blank, observers often needed many cycles to find even large changes, because without the local motion signal the visual system has to compare the two scenes using memory.
The phenomenon, known as change blindness, shows that we do not store a detailed copy of the visual world but only what we attend to. Daniel Simons and Christopher Chabris made it famous in 1999 with an experiment in which about half of the viewers did not notice a person in a gorilla suit walking through a basketball game.
Frequently asked questions
Why is it so hard to see?
The blank hides the motion signal that would normally draw your eye to the change. You must find it by comparing details.
Is it a test of eyesight?
No. It is a test of attention and visual memory. People with excellent eyesight still need several cycles.
Which game trains related skills?
Vanishing Shapes asks you to find a missing shape, and Odd One Out in the Focus category trains visual search.
Related games
Free, no account. Your best scores are saved on your device.