Seth's Blog

A week ago, this passage appeared in an article about timing and the brain:

If you’re hiking through a jungle and a tiger growls in the underbrush, your brain will instantly home in on the sound by comparing when it reached each of your ears, and triangulating between the three points. The difference can be as little as nine-millionths of a second.

As if people had three ears. “Triangulating between the three points” is gibberish. The between-ear time-of-arrival comparison gives you a direction, not a location (which is what triangulation does). Perhaps it was added by a copy editor. If you delete it, the passage makes sense.

Wouldn’t that make a nice newsbreak (one of The New Yorker’s column-ending “Funny Usage Mistakes Made by Other Publications”)? I tried to submit it but couldn’t. So I wrote a Letter to the Editor about it.

In this week’s issue, Hendrik Hertzberg, the magazine’s main editorial writer, calls the idea that “global warming is a hoax” a “denial of reality”. He lumps it with birtherism and the ideas that “evolution is just another theory, on a par with the theory that the earth is six thousand years old.” In case you are reading this blog for the first time, I’ll say it again: Claims that humans have dangerously warmed the planet are based on climate models that are far from fully verified. That these models manage to fit past temperatures means little because the models have many adjustable parameters. Alas, this was no over-zealous editing mistake.

• This study suggests calcium supplements are dangerous. They can raise your risk of heart attacks. There are probably better ways to reduce osteoporosis.
• Conventional clinical trials overstate the value of drugs, says this paper. One reason is that they compare drug to placebo. In clinical practice, the choice is never drug or placebo; it is drug or other treatment (usually a different drug). “We need to put an end to this kind of gaming of the system” — a system in which standards of evidence grossly favor drug companies at the expense of everyone else.
• Doctors use patient’s need for help to remove bad reviews. “The doctors simply make their patients sign a contract handing over the copyright of any review they might publish online afterwards. So, if the patients post any bad review, the company is able to send a DMCA notice demanding that the content be removed immediately.”
• The end of mercury amalgam in dentistry.
• paleolithicdiet.com, a new site from the founder of Paleohacks

This reviewer hated it, this reviewer panned it (“trivializes history”), but I loved it. Never has “behind every great fortune lies a great crime” (here, a great criminal, Joe Kennedy) been so well dramatized. Yet I came away from this series executive-produced by a Republican with a higher opinion of JFK and Bobby.

When I was in sixth grade, I did a survey in which I phoned random strangers and asked them history questions. To my chagrin, one of my “correct” answers (to the question “what year was the Bay of Pigs?”) was wrong. Until I watched this series, I didn’t really know what the Bay of Pigs was. Until I watched this series, I didn’t know important details of several other big events of the time, such as the struggle to admit James Meredith to the University of Mississippi. Supposedly JFK threatened the Governor of Mississippi with loss of all future NCAA Bowl invitations. “You can’t do that!” said the Governor. Surely fictional, but a nice touch.

For ten years Alex Chernavsky has measured and recorded his weight (above). I asked what he learned from this. Here’s what he said:

I started the tracking because I thought that the very act of measuring (and recording) my weight every day would inspire me to lose weight. I don’t think it really worked that way, though. In order to lose weight, I had to take active measures.

What did I learn? I learned that low-carb diets work well in the short-run (as you said), and I also learned that eating low-carb is far, far easier than eating a calorie-restricted diet (which I’ve tried in the past, before I began recording my weight daily). I learned that regular exercise does lead to weight loss, although I can’t rule out a possible confounding factor: I wouldn’t be surprised if it turned out that I changed my eating habits at the same time that I started an exercise regime. That’s probably what Gary Taubes would claim.

I also learned that the Shangr-La diet works well for me. I think that the current upward trend is caused (at least in part) by the fact that I’m eating breakfast more and more often. I didn’t start eating breakfast until sometime last autumn. I will try eliminating breakfast again to see if it reverses the trend. I must say, though, that it’s a little difficult to watch my wife eating some scrumptious morning meal while I just drink coffee. The temptation is hard to resist.

I also learned that my weight fluctuates for no apparent reason at all. If you look at the period of roughly April 20, 2008 through mid-July 2008, you’ll see a drop of about ten pounds. I remember being surprised and puzzled during this time, because I could not think of any plausible reason why this weight loss would occur. I still don’t know. In any case, it was short-lived.

I also learned that I should have kept much better notes about what was going on during those ten years. I’m kicking myself now. I plan on continuing to collect data, and I will try to annotate the data better in the future.

My comments here.

Here is another example of the efficiency graphs I’ve blogged about (here, here and here). The line is the current day; it shows how well I’m doing compared to previous days. It goes up when I work, down during breaks. The number in the right corner (“77″) is the percentile of my current efficiency (at the time the graph is made) compared to measurements within one hour (e.g., a measurement at 2 pm is compared to previous measurements between 1 pm and 3 pm).

The blue points come from before I started the feedback; the green points, afterwards. The red and black points are the final points of a day (that is, at quitting time). That the green points are above the blue points suggests that the graphical feedback helped. Here is a better way of seeing the effect of the feedback.

I didn’t expect this, as I’ve said. It is not “the effect of feedback”; before the graphical feedback, I’d gotten non-graphical feedback. It is a comparison of two kinds of feedback.

Why was the new feedback better? Here’s my best guess. It helped a little that it was pretty (compared to text). It helped a lot that it was in percentile form (today’s score compared to previous scores). This meant the score was almost never bad (from the beginning the percentile was was usually more than 50) and yet could always be detectably improved (e.g., from 68 to 70) with a little effort. I wish I could get such continuous percentile feedback in other areas of life – e.g., wwhile treadmill running. I think feedback works poorly when it is discouraging or unpleasant and when it is too hard to improve. When I taught a freshman seminar at Berkeley, I got feedback (designed by a psychology professor) that was so unpleasant I stopped teaching freshman seminars. Because it came only at the end of the term, it was hard to improve — you’d have to teach the class again to get a better score. Moreover, it compared your score to everyone else’s.  I think I was in the lower 50%, which I found really unpleasant. There was no easy way to give feedback about the feedback; maybe it is still in use.

In contrast, I love the feedback shown in the upper graph. Not only does it really help, as the lower graph shows, it leaves me at the end of the day with a feeling of accomplishment.