My sister-in-law had a wonderful parrot called Seraphita, beautiful, beautiful green parrot, and one day we noticed that when the- it was a talking parrot, that when Seraphita said something, the pupils of its eyes would go in and out, like that, while it was talking, so if it said- Pretty Polly, like that, the pupils of its eyes went in and out. Then we noticed, this was amazing, that when we talked to it, when it was cocking its head and listening to us, its eyes would go in and out, so we said- Pretty Polly, the same thing happened, with a slight delay and so we photographed this with a cine camera, measured the delay, did some experiments on it, and we came to the conclusion that the pupils of its eyes would respond to sounds or words that it understood but not to other sounds or words, only in the, you know, the vocabulary that it appreciated or that it could itself make or speak, so we had the idea that this was a response to attention and that the pupils get smaller, really from manipulating nuts and things in its paws, in its claws, but this attention of affect was shown up by the pupils in the eye, you got the physiological change, it was a matter of attention, therefore you could measure attention in the parrot by looking at its pupils and there were similar physiological changes in us when we attend to something or when we’re stressed or, you know, when we’re suffering pain or anxiety and these things and this business of relating psychological states to physiological changes is jolly important and I think it’s really fun to look at that in us and also in animals and then relate animals to us physiologically and into psychology into their psychology. Incidentally, I have a sort of vague feeling that this parrot thing with the eyes, may mean that they’ve got what we call mirror cells, they recently discovered it in humans. When you’re watching somebody else performing an action, there are cells in your brain which become active as though you’re doing the action yourself and this gives a kind of empathy from oneself to other people and it’s just possible that in talking parrot, they’ve got mirror cells which at the moment are only known in primates so the next step would be to record from the parrot’s brain whether- discover whether it’s got mirror cells. It would be brilliant if it has.