The brain's perception can feel like reality.

My daughter had a dream last night; I blew up in the woods.

It has had a profound affect on her today, almost like it really happened. She had a hard time telling me at first. Like if she told me that she saw me die maybe I actually would die. Then when she told her mom, she started to cry.

You all know what this is like. I think it has happened to most people. You see someone in the distance and something bad is about to happen, and you can't reach them in time. Someone betrays your trust. Or you're running away from something and you keep falling down so it crushes you. Then you wake up, and somehow it feels like it really happened. Sometimes it takes a while to wear off. Married guys have often woken up to the glare of their spouses -- the morning's first words: "you cheated on me."

Now, I'm no child psychologist, so I have no idea how to help my daughter except to let her hug me and know I'm ok. But I wish I could bottle the source of that emotion. It's irrational, because she knows that it didn't actually happen. But somehow the brain interprets it like a real event and it evokes some of the same emotions.

If I could have sold my daughter a helicopter to rescue me at the moment I was about to explode, she would have bought it (assuming I raised her allowance). In the real world, there are emotional conditions that exist where marketers can sell irrational things to irrational people.

So when does someone's mental state make them more susceptible to the influence of advertising or more likely to buy? I don't know yet...but it will fun to find out.