The preceding examples all demonstrated that top-down processing affects colour perception. Even if you knew that the examples were illusions, chances are you still perceived the differences in colour (which did not really exist). Click hereto see the illusion revealed.

For each example, click "Show me" to see the illusion revealed.

Example 2

Similarly, most students think the square on the bottom (A) is lighter than the square on the top (B), but they are also the same colour. You indicated that was lighter.

Example 3

Most students also indicate that A is darker than B, even though they are in fact the same colour. You indicated that was darker.