I continue to be fascinated by the fact that feelings are not just the shady side of reason but that they help us to reach decisions as well.

There is a sequence of events in our lives and so there's a temporal aspect to our experience that brings by itself, sense into the story. In other words, you were not walking before you were born and you were not doing X and Y before you did something else first. So there's a sequencing of events that imposes a certain structure to the story.

So, you can define emotions very simply as the process of perceiving what is going on in the organs when you are in the throws of an emotion, and that is achieved by a collection of structures, some of which are in the brain stem, and some of which are in the cerebral cortex, namely the insular cortex, which I like to mention not because I think it's the most important, it's not.

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.

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you experience the emotion of sadness, there will be changes in facial expression, and your body will be closed in, withdrawn.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.

Emotions are enmeshed in the neural networks of reason.

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.