Posted on July 3, 2017 at 12:00 AM by Jami Milne
In June, University Museums sat down with Stephen Biggs, Philosophy Professor at Iowa State University, discussing the topic of perception vs. prediction. We eagerly engaged in a series of questions that followed: How does bias play a part in how one views art? How have our past experiences shaped what we see when we look at a work of art? How might our members interactions with a painting, sculpture or photograph differ if they see it a second or third time, instead of just that one spin through an exhibit? We were so interested in the topic presented, perception vs. prediction, we asked that Biggs also share with you.
Remember "the dress"? If not, type "the dress" into images in your favorite search engine. You'll probably find a seemingly unremarkable image of a striped dress.
When people discuss the dress, however, strangeness ensues. Some say it's blue and black. Others say it's white and gold. Neither group understands how others can see it so differently. Some find the disagreement amusing. Others find it frustrating. After a few minutes, everyone moves on.
But "the dress" teaches two important lessons: first, a tempting view of perception fails; second, a surprising view of perception succeeds.
Because perception often gets the world right, we're tempted to think that to perceive is to passively receive the world. We might say that the role the brain plays in perception is analogous to the role the dark room plays in analogue photography: processing in the brain yields a visual experience that matches the image on the eye, just as processing in the dark room yields a print that matches the image on the film.
"The dress" shows otherwise. A blue and black dress under ordinary indoor light would look exactly as the image of "the dress" looks. A white and gold dress under ordinary outdoor light also would look exactly as the image of "the dress" looks. Since we can't see ambiguously (for example, we can't see any single stripe as entirely white and entirely blue), our brains automatically pick a theory about the light, thereby determining which colors we seem to see. Our brains then, use the image on the eye to predict the colors.
Generalizing: to perceive is to actively predict the world, not passively receive it.
Why is this important? As with any prediction, the predictions that become what we see, hear, touch, taste and smell, can be wrong. And the more you learn about perception, the more you understand both how much room for error there is, and how effectively, nonetheless, our perceptual systems predict the world.
(Still struggling with the dress? This might help.)
Do you have an experience to share? We're always interested in broadening our world with outside perspective. We'd love to hear from you.