Month: February 2008

Flaxseed Oil: Beware of Lignans

Seth Roberts5 Comments

When I buy flaxseed oil, I have a choice: with or without lignans. I almost always choose without. Apparently that’s the right choice, witness this from the SLD forums:

I’ve been trying to figure out what besides overeating might cause these flare ups with my gallbladder. It seems clear from the last few days that one of the things that can set it off is Flax Seed Oil with lignans. When I consume 2-3 tablespoons a day of FSO without lignans, I don’t notice any problems. The FSO goes down easy and I don’t feel nausea or pain. But with the lignans I often do. To be sure, I decided to switch from FSO to ground up flax seeds mixed into my oatmeal. And today, the first time I tried that, an hour later the familiar nausea is back.

Want to Self-Experiment? A Special Offer

Seth Roberts1 Comment

I’d like to increase the ability of self-experimenters to tell others what they’ve done and get feedback. Blog software can be used to do this.

Instead of posting again and again, as in the usual blog, you just post a few times then edit those posts as you collect new information. Instead of post = diary entry, the concept is post = section of scientific paper. You might have posts corresponding to Introduction, Equipment, Procedure, Raw Data, Data Summary, Interpretation, Strengths, Weaknesses, and Comparison to Other Work. You start by writing the Introduction. As the raw data comes in, you add it to the Raw Data post. After you finish collecting the raw data, you write the Data Summary post. And so on.

Here is the start of an example.

The special offer is that if you want to do a self-experiment and are willing to communicate your results in this form, I will — time permitting — help you do it and write it up and will link to the blog you create. To take advantage of this offer, write me at twoutopias at gmail dot com. Tell me what you want to do and your relevant background. Deadline: Sunday, February 24.

Calorie Learning: Introduction

Seth Roberts7 Comments

In a series of posts, each titled Calorie Learning: [something], I’m going to use a blog to communicate self-experimentation. To see the whole series, look in the category Calorie Learning (under Self-Experimentation).

This research will be about how we (or at least I) learn to associate flavors with calories — more precisely, smells with calories. This learning is at the heart of the Shangri-La Diet, which derives from a theory that says the flavors of your food increase your set point if they are associated with calories. The stronger the association, the bigger the increase.

Why study this? 1. Maybe I can improve the diet. 2. It matters. It happens with every bit of food you eat. It controls what you eat and your appearance (assuming my theory is right). 3. Little is known about it. As I wrote in the appendix to The Shangri-La Diet, Anthony Sclafani has studied this learning extensively in rats. No one has studied it extensively in people. 4. The experiments can be simple and easy — or at least that’s what I think now.

A few weeks ago, a friend told me how much she liked those cellophane-wrapped white-bread sandwiches sold in delis and bodegas. Egg salad sandwiches, for example. They were addictive, she said. That sounded about right: White bread (and bread in general) is digested very fast, witness its very high glycemic index. Fast digestion means the calorie signal it generates in the brain overlaps a great deal with the flavor signal it generates in the brain. The more overlap of the two signals, the stronger the association created. The stronger a flavor’s association with calories, the more you like it.

Her comment gave me an idea: I can create a random new flavor by randomly combining many spices, mixing them into butter, and spreading the butter on white bread. The spices supply the flavor, which I can reproduce as often as I want by making a big enough batch of spicy butter when I start. Spice mixtures are cheap. I can easily and cheaply make a huge number of flavors that should taste entirely new. This means I can start fresh — which is where you want to start when doing a learning experiment — as often as I want. White bread is cheap, easily available, has little flavor, and provides a strong signal per calorie. If I want to increase the time between the flavor and the calories, maybe I can spread the butter on crackers, which have few calories, and eat the bread later.

Will it work? Stay tuned.

The Greatness of Behind The Approval Matrix

Seth Roberts9 Comments

What I like most about magazines is their ability to open new worlds to me. Books — unless by Jane Jacobs — rarely do this. Music, TV, and movies almost never do this. Paintings and other visual arts never do this (to me). Magazines do this regularly. Entertainment Weekly — the best magazine with a dull name — tries to do this (and succeeds). I am now reading The Golden Compass because of EW. An issue of Colors made me visit Iceland. Spy made New York fascinating. (E.g., an NYC map of smells.) It’s the best kind of teaching: you open a door and make what’s inside seem so interesting and wonderful that the student voluntarily decides to enter and explore.

Which is why it isn’t completely surprising that Abu Ayyub Ibrahim, who writes Behind the Approval Matrix, is a teacher. New York magazine’s Approval Matrix has a wonderful way of introducing new things: with humor, poetry (if well-written short captions = poetry), a dash of outrage (calling stuff “despicable”), and an attractive layout. When it calls something Brilliant, I’m instantly curious — thus fulfilling the best function of magazines with remarkable ease. The problem for me, and I assume many others, is that the captions are often obscure. Behind the Approval Matrix — which might have been called The Annotated Approval Matrix — explains each item.

The creators of The Approval Matrix had a great idea and didn’t quite pull it off. It’s often too hard to figure out what they’re talking about. Ibrahim has supplied what is missing.

It’s a bit like my self-experimentation. Previous (conventional) research, for various reasons, couldn’t quite reach practical applications (e.g., omega-3 research couldn’t figure out the best dose); my self-experimentation, building on that research, was able to cover the final mile.

Blog Power (continued)

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What Jonathan Schwarz calls “the Lost Kristol Tapes” is a taped debate between William Kristol (the new NY Times columnist) and Daniel Ellsberg about the invasion of Iraq. The debate was on C-Span’s Washington Journal, of which I have fond memories; I watched it for years to get morning faces for my self-experimentation. Schwarz called Kristol’s comments “a double album of smarm, horrifying ignorance, and bald-faced deceit.”

The debate has been watched about 5000 times. Three days ago, just before Schwarz’s piece, it had been watched four times, three by Schwarz himself. My long self-experimentation article would have been read by almost no one had not Andrew Gelman blogged about it. Now it’s been downloaded thousands of times.

More blog power: here and here.

Addendum. Funny coincidence: The day after I posted this, the formerly-obscure Wikileaks hit the news for a super-charged version of the same thing. Wikileaks exposed Cayman Island tax shelters.

In Science, What Matters?

Seth Roberts2 Comments

And how do you learn what matters?

When I was a grad student, I read Stanislav Ulam’s memoir Adventures of a Mathematician. I was impressed by something Ulam said about John von Neumann: that he grasped the difference between the trunk of the tree of mathematics and the branches. Between core issues and lesser ones. Between what matters more and what matters less. I wanted to make similar distinctions within psychology. Nobody talked about this, however. Not even other books.

Some research will be influential, will be built upon. Some won’t. To put it bluntly, some research will matter, some won’t. I once thought of teaching a graduate course where students learn to predict how many citations an article will receive. You take a 10-year-old journal issue, for example, and try to predict how many citations each article will receive. I like to think it would have been a helpful class: The key to a successful scientific career is writing articles that are often cited. I even had a title: “What Will You Do After You Stop Imitating Your Advisor?”

When I was a grad student the short answer to “what matters?” in experimental psychology was clear enough:

1. New methods. The Skinner box, for example, was a new way to study instrumental learning. Skinner didn’t discover or create the first laboratory demonstration of instrumental learning; he simply made it easier to study.

2. New effects. New cause-and-effect linkages. For example, John Garcia discovered that if you make a rat sick after it experiences a new flavor it will avoid foods with that flavor.

My doctoral dissertation was about a new way to study animal timing.

A few months ago I had coffee with Glen Weyl, a graduate student in economics at Princeton. We discussed his doctoral research, which is about how to test theories. One of Glen’s advisors had told him about a paper by Hal Pashler and me on the subject. Hal and I argued that fitting a model to data is a poor way to test the model because there is no allowance for the model’s flexibility. The first reviewers of our paper didn’t like it. “You don’t realize how hard it is to find a model that fits,” one of them wrote.

Glen’s interest in this question began during a seminar in Italy, when he realized the speaker was more or less ignoring the problem. The speaker was comparing how well two different theories could explain the same data without taking into account their different amounts of flexibility. Glen’s thesis proposes a Bayesian framework that allows you to do this. His main example uses data of Charness and Rabin from choice experiments. (Matt Rabin is a MacArthur Fellow.) Taking flexibility into account, he reaches a different conclusion than they did.

I wondered how Glen decided this was important. (It’s a method, yes, but a highly abstract one.) I asked him. He replied:

Sadly, despite my interest in the history of economic thought, I don’t have a lot of insight about why I came upon these thoughts. But one thing: my interests are very interdisciplinary . . . My work is based on drawing connections between economics, philosophy of science, and computer science (and meta-analysis from psychology and bio-statistics). Most of my work takes this form: as you’ll see on my website, I’ve used theoretical insights from economics and computer science as well as evidence from neuroscience, psychology and biology to critique the individualist foundations of liberal rights theory; I’ve used ideas from decision theory to lay firmer foundations for goals set out by computer scientists designing algorithms; I’ve used tools from information theory to instantiate insights from psychology to help understand the design of auctions; and I’ve used computational neuroscience to model biases in economic information processing. Broad interests are hard to have, because they limit the time for learning a particular area in depth, but I prefer to read broadly and draw connections rather than to read deeply and chip away at open questions.

That was interesting. I read broadly, and so does Hal, who knows more about the philosophy of science than I do. I wrote to Glen:

The usual comment about interdisciplinary knowledge is that it’s good because you can bring ideas from one area, including solutions and methods, to solve problems in another area. . . . But maybe it’s also good because by learning about different areas you absorb a range of different value systems and this makes you less sensitive to fads (which vary from field to field), more sensitive to longer-lasting and more broadly-held values.

The more trees you know, the easier it is to see the forest.

Evaluating new product ideas.

My Theory of Human Evolution (Civil Rights Movement edition)

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From Eyes on the Prize, about an Easter boycott of Nashville stores:

Easter was a most important time to buy. All blacks had to have a full, brand new outfit at Easter, no matter how poor you were, right? You may start three months ahead of time paying for that Easter outfit, and you may be paying for it for three months later.

There is a similar tradition in China: At the start of the new year you buy new clothes. I’ve blogged before about how rituals, ceremonies, and holidays promoted technological development: They increased the demand for high-end items. This helped skilled craftspeople make a living.