According to this article in Nature (by Thorsten Hansen, Maria Olkkonen, Sebastian Walter & Karl R Gegenfurtner), low-level perceptual mechanisms can be affected by high-level cognitive processes. They showed how memory modulates color appearance: natural fruit objects tend to be perceived in their typical color.
We asked human observers to adjust the color of natural fruit objects until they appeared achromatic. The objects were generally perceived to be gray when their color was shifted away from the observers' gray point in a direction opposite to the typical color of the fruit. These results show that color sensations are not determined by the incoming sensory data alone, but are significantly modulated by high-level visual memory.
Why do I blog this? first because it is a strange cognitive phenomenon, second because I am always intrigued by the intricacies of cognitive processes (especially when a high level process modulates a low level one). And third, because it's curious to think about the consequences of such result in design.