Is the red I see the same as the red you see?
At first, the question seems confusing. Colour is an inherent part of visual experience, as fundamental as gravity. So how could anyone see colour differently than you do?
To dispense with the seemingly silly question, you can point to different objects and ask, “What colour is that?” The initial consensus apparently settles the issue.
But then you might uncover troubling variability. A rug that some people call green, others call blue. A photo of a dress that some people call blue and black, others say is white and gold.
You are confronted with an unsettling possibility. Even if we agree on the label, maybe your experience of red is different from mine and – shudder – could it correspond to my experience of green? How would we know?
Neuroscientists, including us, have tackled this age-old puzzle and are starting to come up with some answers to these questions. One thing that is becoming clear is the reason individual…