What is this? Try not to look at the solution, it's much more fun when you find it yourself. It's something everybody knows.
You should recognize something in these spots. Really ! Keep trying and try not to cheat. This is one of the most famous "Guess what" pictures on the Web. You can't see the meaningless picture again once you know what it is. This indicates the importance of previous experience in your visual system. The picture was made by R. C. James featured in a book by R. L. Gregory, The Intelligent Eye.
Do you see anything meaningful in this picture ?
This picture was part of a TV experiment in 1983 with 2 million viewers. Sheldrake wanted to test his theory of morphogenetic fields. In this theory, the knowledge of other people can influence your own. In other words, if many people know what this picture is, you would also recognize it easier. The results were surprising ...
Fairly tough. Just try to see it without cheating.
I found this to be the most difficult of them all. Can you see what it is ?