If you want your friends to remember your slide show of this summer's trip to Yosemite, don't play Ansel Adams. People remember color images of natural scenes better than black-and-white images, new research shows.
Even though color splashes the whole world, researchers have had a hard time demonstrating that people's ability to see things in technicolor helps them remember what they see. Earlier studies compared people's memories for line drawings done in color versus black and white and found few differences. But the importance of color for remembering complex natural scenes remained unexplored.
To test whether color makes scenes more memorable, a team led by neuroscientist Karl Gegenfurtner at Giessen University in Germany assembled 48 images of natural scenes in color and made alternate versions in black and white and false color. Subjects watched a series of images flashed on a video screen for 1 second each. Then, the researchers mixed new but similar images with the first batch and asked subjects to identify the ones they'd seen before. People could recognize images they'd first seen in natural color about 5% to 10% better than if they'd first seen the image in black and white. To test whether the color images are easier to remember because they provide a stronger stimulus to the visual system, the team repeated the experiments with falsely colored images. If the color advantage simply reflects visual activity, they reasoned, subjects should remember false-color images as well as naturally colored images. But people remembered false-color images only as well as black and white. Only natural color improves memory, the team reports in the May issue of the Journal of Experimental Psychology: Learning, Memory, and Cognition, suggesting that naturally colored scenes are more memorable because they tap into the brain's expectations of how the world should look.
Calling the work "quite a thorough series of experiments," vision scientist Andrew Derrington of the University of Nottingham, U.K., says it shows unambiguously that color improves the brain's ability to form and access memories through the visual system. Knowing that should help researchers piece apart memory in the future. "It provides a springboard for looking at the components of memory," he says.