Consciousness begins when brains acquire the power, the simple power I must add, of telling a story.

Consciousness, much like our feelings, is based on a representation of the body and how it changes when reacting to certain stimuli. Self-image would be unthinkable without this representation.

Narratives are not fixed. We change our narratives for ourselves and we change them not necessarily deliberately. In other words, some people do, some people will constantly reconstruct their biography for external purposes, it's a very interesting political ploy.

Emotion consists of a very well orchestrated set of alterations in the body that has, as a general purpose, making life more survivable by taking care of a danger, of taking care of an opportunity, either/or, or something in between.

Imagine, for example, birds. When they look out at the world, they have a sense that they are alive. If they are in pain, they can do something about it. If they have hunger or thirst, they can satisfy that. It's this basic feeling that there is life ticking away inside of you.

There's something that intervenes and is very important which has to do with value. Value in the true biological sense, which is that contrary to what many people seem to think, taking it at face value - sorry for the pun - we do not give the same amount of emotional significance to every event.

When you experience the emotion of sadness, there will be changes in facial expression, and your body will be closed in, withdrawn. There are also changes in your heart, your guts: they slow down. And there are hormonal changes.