Tuesday, 7 September 2010

The Horror, The Horror

You're watching a horror movie.

The characters are going about their lives, blissfully unaware that something horrifying is about to happen. You the viewer know that things are going to end badly, though, because you know it's a horror movie.

Someone opens a closet - a bloody corpse could fall out! Or they're drinking a glass of water - which could be infected with a virus! Or they're talking to some guy - who's probably a serial killer! And so on.

The effect of this - and a good director can get a lot of mileage from it - is that scenes which would otherwise be entirely mundane, are experienced as scary, purely because you know that something scary is going to happen, so you see potential horror in every innocent little thing. An expectation as to what's going to happen, leads to you interpreting events in a certain way, and this creates certain emotions.

In a medical context, that would be called a placebo effect. Or a nocebo effect when expectations make people feel worse rather than better.


The horror movie analogy is useful, because it shows that placebo effects don't just happen to other people. We all like to think that if we were given a placebo treatment, we wouldn't be fooled. Unlike all those silly, suggestible, placebo responders, we'd stay as sick as ever until we got a proper cure.

I wouldn't be so sure. We're always interpreting the world around us, and interpreting our own thoughts and feelings, on the basis of our expectations and beliefs about what's going on. We don't suddenly stop doing this when it comes to health.

Suppose you have the flu. You feel terrible, and you're out of aspirin. You don't think you'll be able to make that meeting this afternoon, so you phone in sick.

Now, clearly, flu is a real disease, and it really does make you feel ill. But how do you know that you wouldn't be able to handle the meeting? Unless you have an extensive history of getting the flu in all its various forms, this is an interpretation, a best guess as to what you'll feel in the future, and it might be too pessimistic.

Maybe, if you tried, you'd get on OK. Maybe if you had some aspirin that would reassure you enough to give it a go. And just maybe it would still have worked even if those "aspirins" were just sugar pills...

Link: See my previous posts I Feel X, Therefore Y and How Blind is Double Blind?

3 comments:

Anonymous said...

The placebo effect is just amazing. It even occurs in drug trials for dementia and schizophrenia! And who said God doesn't have a sense of humor!

spike said...

So is the point of this post any different from the following:
we live in a probabilistic life and our minds are probabilistic as well. Now, I don't know to what extent the second is a consequence of the first (probabilistic environment) but surely all the examples you have given could be seen as cases in which you shift the probability distributions by an external input say the horror movie or sneezing which is a sign of flue!

Neuroskeptic said...

Spike: That's pretty much it. Depending upon the perceived context (expectations and beliefs), you interpret things differently e.g. watching a comedy movie, you interpret drinking a glass of water as most likely innocent (or the start of a joke), watching a horror movie called "Virus Apocalypse" you interpret it as potentially the start of an epidemic.

Which is pretty much common sense in the case of movies, the point is that in real life, we're often unaware that our interpretations are interpretations, we just experience them as "how things are".