Is green for me the same as green for you?

We put this question to Professor Ron Douglas:Ron - That's almost a philosophical question. The first thing to say is that what's happening in the eye in all of us is the same. We have the same chemicals. We have the same responses to the light but its what our brain makes with this information that's different. So for instance, if you take, you know, if you were I, you'll probably be appalled to hear we're fairly similar. If you have all chips of all different colours and you put them into different piles, we would make a pile for green, a pile for blue, a pile for yellow, a pile for red. But if you ask people for instance some African tribes who've had very little contact with the Western world, they will put them into different piles that they will put yellows and reds together and swear blind that they're the same colour and they will put blues into different piles and closer to home. Even in Welsh, there is a word called glas which encompasses what you and I would call blue but it also encompasses some things that we call green.Chris - Wow! But if you look in the retina, the thing that's doing the seeing and converting light waves into brain waves, is there a dramatic difference between the way the African tribes who do what you've just described are doing that and us.Ron - No! There's absolutely no difference at all in what the eye is doing but it's a difference in the brain, it's where culture comes in to play and interacts with the visual stimulus.