In this lecture - which is the most speculative one in the series of five - I'd like to take up one of the most ancient questions in philosophy, psychology and anthropology, namely what is art? When Picasso said: "Art is the lie that reveals the truth" what exactly did he mean?

As we saw in my previous lectures neuroscientists have made some headway in understanding the neural basis of psychological phenomena like body image, how you construct your body image, or visual perception. But can the same be said of art - given that art obviously originates in the brain?

In particular what I'd like to do is raise the question: "Are there such things as artistic universals?"

Now let me add a note of caution before I begin. When I speak of artistic universals I am not denying the enormous role played by culture. Obviously culture plays a tremendous role, otherwise you wouldn't have different artistic styles - but it doesn't follow that art is completely idiosyncratic and arbitrary either or that there are no universal laws.

Let me put it somewhat differently. Let's assume that 90% of the variance you see in art is driven by cultural diversity or - more cynically - by just the auctioneer's hammer, and only 10% by universal laws that are common to all brains. The culturally driven 90% is what most people already study - it's called art history. As a scientist what I am interested in is the 10% that is universal - not in the endless variations imposed by cultures. The advantage that I and other scientists have today is that unlike we can now test our conjectures by directly studying the brain empirically. There's even a new name for this discipline. My colleague Semir Zeki calls it Neuro-aesthetics - just to annoy the philosophers.

I recently started reading about the history of ideas on art - especially Victorian reactions to Indian art - and it makes fascinating reading.

For example if you go to Southern India, you look at the famous Chola bronze of the goddess Parvati dating back to the 12th century. For Indian eyes, she is supposed to represent the very epitome of feminine sensuality, grace, poise, dignity, everything that's good about being a woman. And she's of course also very voluptuous

Pic. The Goddess Parvati

But the Victorian Englishmen who first encountered these sculptures were appalled by Parvati, partly because they were prudish, but partly also just because of just plain ignorance.

They complained that the breasts were way too big, the hips were too big and the waist was too narrow. It didn't look anything like a real woman - it wasn't realistic - it was primitive art. And they said the same thing about the voluptuous nymphs of Kajuraho - even about Rajastani and Mogul miniature paintings. They said look these paintings don't have perspective, they're all distorted.

They were judging Indian art using the standards of Western art - especially classical Greek art and Renaissance art where realism is strongly emphasized.

But obviously this is a fallacy. Anyone here today will tell you art has nothing to do with realism. It is not about creating a realistic replica of what's out there in the world.

I can take a five dollar camera, aim it at one of you here, take a photograph. It's very realistic but you wouldn't give me a penny for it. In fact art is about the exact opposite. It's about deliberate hyperbole, exaggeration, in fact even distortion in order to create pleasing effects in the brain.

But obviously that can't be the whole story. You can't just take an image and randomly distort it and call it art - although many people in La Jolla where I come from do precisely that. The distortion has to be lawful. The question then becomes: What kinds of distortion are effective? What are the laws?

So one day I was sitting in a temple in India when I was on a sabbatical and in a whimsical frame of mind I just jotted down what I think of as the universal laws of art, the ten laws of art which cut across cultural boundaries. Given our time limits, I'm going to just tell you four or five of my ten laws - the rest are on the BBC Website, so you can go look it up.