The Frontal Cortex

Shyamalan and the Placebo Effect

Posted by Jonah Lehrer on June 16, 2008
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M. Night Shyamalan, the director of the vaguely anti-evolution (and thoroughly mediocre) film The Happening, uses the brain to discuss the limits of science:

There’s so much unexplained stuff. I don’t quite understand the scientific explanation of the placebo effect. What is the core of that? The fact that the placebo effect exists is a fact, but what is it? We have no idea. I love that. I even love that with regard to the home-court advantage in sports. What is that? It’s connected to a belief system. Both things, the placebo and the home-court effect, are a belief system that we can turn thought into actual biological function. In and of itself, that’s something that science says is not possible. But you can document it.

On the one hand, I agree that science has real epistemological limits. And yet, the placebo effect – or any other example that involves a “belief system” or “thought” becoming “actual biological function” – is a terrible example of such limitations. There is nothing inherently mysterious about a psychological thought impacting the activity of neurons. That’s what thoughts do. (What else would they do? It’s like being amazed that my strokes on keyboard impact the activity of silicon microchips somewhere inside a computer.) As for the placebo effect…The precise mechanisms of the effect have been well documented.

Tor Wager, a neuroscientist at Columbia University, has probably done the definitive brain imaging study. His experiment was brutally straightforward: he gave college students electrical shocks while they were stuck in an fMRI machine. Half of the people were then supplied with a fake pain-relieving cream. Even though the cream had no analgesic properties – it was just a hand moisturizer – people given the pretend cream said the shocks were significantly less painful. The placebo effect eased their suffering. Wager then imaged the specific parts of the brain that controlled this psychological process. He discovered that the placebo effect depended on the prefrontal cortex, the center of “rational,” conscious thought. When people were told that they’d just received a pain-relieving cream, their frontal lobes responded by inhibiting the activity of the emotional brain areas (like the insula) that normally respond to pain. Because people expected to experience less pain, they ended up experiencing less pain.

I agree with Shyamalan that there is something inherently wondrous about the idea of conscious thoughts and ethereal daydreams being able to directly influence squirts of neurotransmitter and the electrical firings of neurons. But that’s only because we are natural dualists, innately programmed to believe in a metaphysical soul.

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Comments

  1. #1 Anibal
    June 16, 2008

    From Metacritic concerning the dissapointing film by Mr. M. Night Shyamalan that i saw yesterday, i like this bit:
    “He still sees dead people, only now they’re the best thing in the movie”

    The best way to combat scientifism in culture (cinema) is more science.

    Neverthless, the pseudo-Hitchcock that is Mr. M. Night Shyamalan could still have some sources of creativity and is not all lost.

    And just because we have no clear idea about some natural phenomena, does not mean we have to appeal to extra(supernatural)factors, as in the case about placebo you discuss, Jonah.

  2. #2 tguy
    June 16, 2008

    Nice discussion of placebo and rebuttal of Sham-alot’s babbling. Unfortunately I now have the phrase “Head-on, apply directy to the forehead” running through my mind.

  3. #3 David Rock
    June 16, 2008

    Jonah is right, there is plenty of science illustrating the effects of placebo, including by Don Price with a study showing that placebos in some cases were more effective than a local anaesthetic. Also Robert Coghill showed that expectations themselves may be the causal factor in placebo. He illustrated with an experiment using a heat stimulus that the right ‘dose’ of expectations provided similar pain relief to a clinically active dose of morphine. There’s plenty more. Partly it may be explained by research on priming, where information already active in the brain is more likely to come to the fore in other situations.

  4. #4 Eve
    June 16, 2008

    I don’t think we’re natural dualists. I think we didn’t have the capability to understand the mind 2000 years ago and made up some reasons why things in the brain happen. That concept is so ingrained in our culture now that we have to actively repress it with scientific explanation. We’re taught to be dualists, I don’t think it’s necessarily natural or inate.

  5. #5 Chris Noble
    June 17, 2008

    There is nothing inherently mysterious about a psychological thought impacting the activity of neurons. That’s what thoughts do.

    Or rather that’s what thoughts are.

    The placebo effect only presents problems for dualists. The idea that one brain process can effect another brain process is hardly astounding.

    You have to wonder whether Shyamalan has problems has problems walking too. How do his thoughts get turned into physical movement? Does he think that science says that is impossible too?

  6. #6 Mike Woods
    June 17, 2008

    At the end of the day, he is a filmmaker before a scientist. I think he is in awe of the brain and of science, and that is a great feeling.

    “There is nothing inherently mysterious about a psychological thought impacting the activity of neurons. That’s what thoughts do.”
    I think that is how thought manifests itself, but is there a conscious aspect somewhere before the neural response? That, to me, is the real question. That’s what thoughts do, but where does thought originate?

  7. #7 amybuilds
    June 17, 2008

    So, does the placebo effect not work in patients with prefrontal damage?

  8. #8 orlox
    June 17, 2008

    Wow. Natural dualists “innately programmed to believe in a metaphysical soul.” That seems to be one of the most ridiculous unqualified assertions that I have ever read. I would like to see you expand that idea so we can have at it. Or, if you have already, I would appreciate a link.

  9. #9 metzgerm
    June 17, 2008

    I think the main problem with his quote is the sentence, “In and of itself, that’s something that science says is not possible.”

    To him it seems that ‘fascinating’ and ‘wonderful’ and even ‘mysterious’ can only be applied to the supernatural–this is bad. Thoughts turning into physical actions are fascinating and even still somewhat mysterious (although we do know quite a bit more than we used to). He seems to be suggesting that if the mechanisms involved in the placebo effect could ever be fully explained by science, he wouldn’t think it was interesting anymore. But our ignorance of the mechanism does not make it more fascinating, and the idea that things are only fascinating if they are inherently unknowable is an odd and destructive, though pervasive, cop-out.

  10. #10 Anibal
    June 18, 2008

    To orlox:
    we are born dualists because our folk or ordinary knowledge pose a barrier between the physical stuff and the mental stuff, processing them cognitively apart and in different manner.

    We are cartesians until we mature.
    Check out this book by Paul Bloom for a scientific treatment.

  11. #11 Chris Noble
    June 18, 2008

    we are born dualists because our folk or ordinary knowledge pose a barrier between the physical stuff and the mental stuff, processing them cognitively apart and in different manner.

    We are cartesians until we mature.
    Check out this book by Paul Bloom for a scientific treatment.

    I thought we were born solipsists.

    Last Saturday I was travelling with a 3-year old in a bus when he announced to me “look the moon is following us”. Piaget got a few things right!

  12. #12 Curtis Bond
    June 18, 2008

    I guess I wouldn’t agree that “the precise mechanisms of the effect have been well documented.” Our brain science is not at the stage yet where we can see neurotransmitters being released in synapses, which is a more precise mechanism that seeing some part of the prefrontal cortex light up on a scan. Secondly, just because a brain area lights up does not mean this is causing the observed effect (pain reduction). This would be a correlation rather than a precise mechanism of causation. Thirdly, the placebo effect goes far beyond analgesic effects. It is pretty standard practice for a placebo to be a part of trials with any new medicine, be it for pain management, bone growth, immunity enhancement, or whatever, and I don’t believe the precise mechanisms of neuronal influence have been shown for the placebo effect in the wider range of observed effects in the human body.

    So for the mean time, rather than claim to have explained this away, I think we should allow ourselves some amazement and a sense of mystery at the power of thought and belief in effecting changes in our bodies, even as we continue to delve more deeply into the scientific mechanisms that underly this effect.

  13. #13 Chris Noble
    June 18, 2008

    Thirdly, the placebo effect goes far beyond analgesic effects. It is pretty standard practice for a placebo to be a part of trials with any new medicine, be it for pain management, bone growth, immunity enhancement, or whatever, and I don’t believe the precise mechanisms of neuronal influence have been shown for the placebo effect in the wider range of observed effects in the human body.

    The inclusion of a placebo group is part of double blind randomised trials that attempts to ensure that researchers and patients are unaware of who is getting the real drug/treatment. It is a good method to protect researchers from confirmation bias. The use of a placebo control does not mean that a strong objective placebo effect exists.

    A review of trials that compared placebo vs no treatment failed to find evidence for a placebo effect outside of analgesia.

    Is the Placebo Powerless?- An Analysis of Clinical Trials Comparing Placebo with No Treatment

  14. #14 Fred Lovett
    July 1, 2008

    Ihave used the placebo effect for the last ten years to control arthritis and other internal problems. I think that we should be using it in normal medicine to reduce the use of drugs with their often major side effects.

    I still use analgesics sometimes because my placebo effects take time to become effective, although their effects hold for much longer than the pills.

    I don’t care how it works, I just lnow that it works for me.