Mixing Memory

Color Memory Changes Color Perception

One of the things that I love the most about cognitive science is that it’s always challenging our intuitions about the world and how we perceive it. Think, for example, of all the classic Gestalt illusions, such as my all time favorite, the Kanizsa Triangle. What these illusions, and many other findings over the history of the study of visual perception show is that perception doesn’t simply represent the world “as it is.” Instead, perception is a fundamentally creative process, relying on inference, subtraction, and all sorts of other alterations of incoming sensory data. Spend a little time in a cognitive science lab, and you will quickly be disabused of any inclinations towards naive realism.

i-96b0b010d2d92dff900bdea0a9b70bbf-colormemory2.JPGI bring this up because there’s another example of the creative nature of visual perception in the November issue of Nature Neuroscience. The paper, by Hansen et al1, describes an experiment in which color memory changes the way we perceive colors. Participants were first presented with images of fruit in their normal color against a gray background (like the banana). They were able to change the color of the object in any direction, and were told to manipulate the color until the fruit looked gray like the background. When adjusting the color of the banana, for example, to gray, participants actually overadjusted in the direction away from the banana’s normal color. For the banana, this means that the participants treated a slightly blueish banana (blue is yellow’s opponent color). This suggests that their memory for the normal color of the banana affected how they perceived the color gray for bananas. As Hansen et al. put it:

[M]emory seemed to have a direct top-down effect that continuously modulated the incoming sensory data and changed basic color sensations.

1Hansen, T., Olkkonen, M., Walter, S., Gegenfurtner, K.R. (2006). Memory modulates color appearance. Nature Neuroscience, 9, 1367-1368.


  1. #1 ME
    October 29, 2006

    For those of us not lucky enough to have access to journals . . . was this tried with anything other than a banana?

  2. #2 Chris
    October 29, 2006

    Yes, several different fruits of different colors (from red to green and so on). I just used bananas as an example because it’s the one they use as an example, and that they include an image of.

  3. #3 anita
    October 29, 2006

    Now let me challenge you…we all know the colors of certain plants and flowers and we always remember them so why those never change…try that…lol….

  4. #4 Chris
    October 29, 2006

    Hi Anita, I”m afraid I Don’t really understand your question. Could you rephrase it?

  5. #5 Anita
    October 30, 2006

    Hi Chris, in your entry here, you mentioned the experiment for the banana and how it was shown against the gray background and the participants percieved the color in a different way…now my question is this as far as when I mentioned plants and flowers…let us take a red rose and when put against a different color background I don’t see how the color would be percieved in another color since the participant of this type of experiment would already know the color is red even though roses can even come in different colors….lol…so let us see how you can explain this question…lol…

    BTW, you are welcome to my blog as well…just click on my name if you wish…

  6. #6 Jonathan Schattke
    November 1, 2006

    Well, first, that’s an awfully orange bananna.

    It’s been shown quite often that the field a color is against will influence the perception of the color; this is because of the nature of how human eyes are made. So, from that, one could easily see that a grey background is actually not a nuetral field (I think black would be). So, naturally, the tendency will be an initial overcompensation. I wonder if the researchers tried various colored backgrounds. I suspect they used grey as a nuetral, which would be a common error.

    I suspect the results are misleading, based on this.

  7. #7 kimmy
    November 21, 2008

    i am doing a project for school and i think this will help me thank you p.s is you a nerd im not

  8. #8 kimberly
    December 15, 2008


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