The Frontal Cortex

A New State of Mind

My profile of Read Montague and the dopamine prediction-error hypothesis is now online. I wanted to write this article for two main reasons. First of all, I think the dopamine story is incredibly exciting and remains one of the best examples of how subtle shifts in neural firing rates can allow the brain make sense of the real world. Yes, I know there are caveats, but the prediction-error hypothesis is still a very powerful paradigm. Wolfram Schultz should win a Nobel Prize.

Secondly, there’s so much crappy fMRI research out there – and it always get so much press attention – that I wanted to do some reporting on the best brain scanner experiments, even if they required a little more explanation than “The “fill-in-the-blank” brain area is responsible for sarcasm/romantic love/jealousy/etc.” Not only has Montague’s lab helped pioneer some very clever paradigms – he invented hyperscanning – but he insists on using very rigorous analytic techniques. He’s a scientist who is skeptical of the technology and his own data. As Montague told me: “All of these [fMRI] studies with twelve, thirteen subjects are completely bogus. Where we’re at with brain imaging right now is where genetics was thirty years ago. The stuff we think is signal is really noise. We’ve got no handle on individual variation, so we end up throwing out most of the really interesting stuff.” A typical Montague fMRI experiment will involve at least 75 subjects, which is an extremely large n for the field.

Here, by the way, is Montague’s latest Science paper which looks at how people with borderline personality disorder play simple economic exchange games.

Comments

  1. #1 jb
    August 13, 2008

    More mind candy from Jonah: his article about the dopamine prediction-error hypothesis! though the term is not a grabber. Jonah describes a simple experiment done by Schultz that explains a lot of human and animal behavior. This has been used by years by kind, astute animal trainers.
    Writes Jonah:”His experiment observed a simple protocol: he played a loud tone, waited a few seconds, and then squirted a few drops of juice into the mouth of a monkey. While the experiement was unfolding, Schultz was probing the dopamine-rich areas of the monkey brain with a needle that monitored the electrical activity inside individual cells. At first the dopamine neurons didn’t fire until the juice was delivered; they were responding to the actual reward. However, once the animal learned that the tone preceded the arrival of the juice – this requires only a few trials – the same neurons began firing at the sound of the tone instead of the sweet reward. And then eventually, if the tone kept on predicting the juice, the cells were silent. They stopped firing altogether.”
    If you want an animal to repeat a desirable behavior you give them a reward at the exact time they exhibit the behavior. (In so far as is possible you ignore unwanted behavior…this is the kicker).Sometimes this is not convenient (getting a fish to a dolphin in midleap) so you sound a whistle, having earlier sounded the whistle when the dolphin is eating a fish. So the dolphin learns to expect a fish after the behavior you cue and ultimately will enjoy jumping itself. Or if the animal gets bored, you have to reinforce with something different and not everytime. Read “Don’t Shoot the Dog!” by Karen Pryor or “What Shamu Taught Me About Life, Love, and Marriage” for the details of this kind and wise way to communicate with the animals in your life. The hardest part is training yourself but it works on you too!

  2. #2 jb
    August 13, 2008

    PS I wonder if something else isn’t going on with the chronic cigarette smokers. They aren’t just ignoring the regret about smoking another cigarette and shortening their lives; the regret is the reward. If you think that you are a ‘bad person’, a morally weak person, an unlucky person, then feeling bad about yourself confirms this belief and reinforces it. It is a way of paying attention to your self. Negative attention is better than no attention as any parent can tell you. Children will settle for being yelled at rather than be ignored.

  3. #3 Anibal
    August 14, 2008

    The innovative paradigm (hyperscanning)created by Montague and colleagues is a giant step in moving forward our current technical armamentarium to more valid ecological experimentations.

    He is also a pionner in the recent revolution of the new important field of neuroeconomics and he also is announcing another one in his recent book(Why Choose this book: the fusion of psychology with physics.

    The detailed depichering of the dopamine system by Schultz, (and Dayan and Montague himself) recognizing its relevance for multiple phenomena: decisions, addictions, mental disorders, placebo effect… really deserves the Nobel.

    Anyone knows how it is the candidacy to win the nobel in the neuroscience field? and if is there some criteria or regular pattern to follow (the last one was for discoveries in the olfactory system, the rule is for organs, for mechanisms, for countries…)

  4. #4 David
    August 14, 2008

    Just had a chance to read your profile on Montague and wanted to tell you that it is really well done. I recently bought his book but haven’t cracked into it yet, but, inspired by the article, I think I will. Nice work.

  5. #5 sai
    August 17, 2008

    Nice article.
    This claim by Dr. Montague that “neuroscience just wasn’t ready for theory, even if the theory made sense.” is right in an ironic way. A lot of his theoretical work has underpinnings in research done in the seventies by Dr. Stephen Grossberg (A neural theory of punishment and avoidance, I: Qualitative theory. Mathematical Biosciences, 1972; A neural theory of punishment and avoidance, II: Quantitative theory. Mathematical Biosciences, 1972).
    Sadly, the math was probably too involved for experimentalists to appreciate (And there were no self-proclaimed theoreticians yet).

  6. #6 christopher
    October 25, 2008

    yea it’s good but it’s very pop-sci. i’d like to know what you really think. until then, here‘s what i think :)

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