To our brains, your red is my red

Is my red the same as your red?

It’s a classic puzzler, one that’s fun to debate with your friends and family. Do colors look the same to you as they do to me? Now two neuroscientists weigh in — with a resounding maybe.

There were two possibilities when it comes to how brains react to color, says Andreas Bartels. He works at the University of Tübingen and the Max Planck Institute for Biological Cybernetics in Germany. Perhaps everyone’s brain is unique. Each might have its own snowflake pattern of nerve cells responding when someone sees red. Or it could be that seeing red kicks off a standard, predictable pattern of brain activity. And that pattern might not vary much from you to me.

The answer is overwhelmingly the second option, Bartels and Michael Bannert (also at Tübingen and the Max Planck Institute) report in the October 15 Journal of Neuroscience. They found “commonalities across brains,” Bartels says.

He and Bannert started with 15 people. Each viewed shades of reds, greens and yellows. As they did, the scientists monitored nerve-cell activity across visual areas of the participants’ brains. The researchers then used these data to predict which color each person saw.

The results showed that neural reactions to colors are somewhat standard. They don’t seem to vary much from person to person.

But these findings can’t answer how it feels to see red, Bartels says. How your brain creates inner experiences that are unique to you is a much bigger question about consciousness. And it’s one that will no doubt continue to be debated for a long time.