Cognitive Daily

Deep brain stimulation for clinical depression?

Wed, 11 Nov 2009 11:49:20 -0500

This week on SEED, I'm writing about Deep Brain Stimulation (DBS), a promising new way to treat clinical depression. Here's a snippet:

In DBS therapy, one or more electrodes the size of a spaghetti strand are precisely positioned in the patient's brain, then connected by wire around the skull and through the neck to a pacemaker-like device, a neurostimulator, just below the collarbone. The neurostimulator is activated and deactivated by a magnet that the patient carries, so if a tremor is beginning to become disruptive, DBS can be self-administered in an instant, with near-instantaneous results. A video provided by the manufacturer of a DBS device shows how it works in ideal cases.
Now new uses for the treatment are being tested. One observed side effect of DBS for Parkinson's is excessive happiness, to the point of uncontrollable elation--the sort of unhealthy, personality-changing reaction that everyone fears when they think of electrodes being implanted in their brain. Tuning the device can minimize this side effect, but its very existence suggests that DBS might be a useful therapy for clinical depression.

For more, read the whole article.

Also, in case you missed it, here are my picks for psychology and neuroscience from ResearchBlogging.org:

Can you tell how strong someone is just by looking at their face? Michael Meadon looks at research suggesting that you can.
What does your genome say about how likely you are to go into debt? Quite a lot, says the Neurocritic.
Think you've finally got control over your weight? Now's about the time you'll probably start putting those pounds back on.
How do you make a non-threatening area seem unsafe? Just put a closed-circuit surveillance camera there.

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Do chimps understand what Jon Stewart (or another chimp) believes?

Tue, 10 Nov 2009 17:09:04 -0500

Take a look at this video from last night's episode of Jon Stewart's "The Daily Show."

If you'd like, you can skip past all the political snark to the 4:47 mark to watch Jon bring cognitive psychology into prime time (or at least latenight cable)! That's right; you saw it: Jon Stewart mentioned the psychological concept of "object permanence" on national TV. Object permanence was introduced by Jean Piaget as a way of measuring the growing cognitive ability of children. Three-month-olds don't have it; most 6-month-olds do. More recently, researchers have investigated similar milestones in animals. Parrots, it turns out, have object permanence, as do chimpanzees. Insects don't.

But what about higher-order cognitive functions? Do chimps understand that others have thoughts distinct from their own? Humans understand this around the age of 1, but the evidence is less clear with chimps. Some chimps will use gestures alone to beg for food from a blindfolded human. Does this mean they don't "know" the human can't see them? Perhaps not, but normally a chimp doesn't expect to communicate with a human. When two chimps are in two separate rooms, but can see into a third room where food is being hidden, the subordinate chimp will behave differently if she knows the dominant chimp saw the food being hidden. This suggests chimps do understand that other chimps have different thoughts from their own.

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What's the best way to take a study break?

Thu, 05 Nov 2009 16:20:43 -0500

Greta and I did our undergraduate studies at the University of Chicago, or as a commonly-sold T-shirt on campus put it, "where fun goes to die." To say that Chicago didn't emphasize academics over a social life is to deny that people literally lived in the library (a full-scale campsite was found behind one of the stairwells in the stacks; students had been living there for months). It's not that the administration didn't try to encourage its students to socialize. The library did close at 10 p.m. on Friday nights. There was not one but two film societies, so often students had to choose between, say, the Hitchcock fest at one theater and the Kurosawa marathon at the other.

Still, studying was the primary focus of campus life. There may have been five fraternities, but there were 30 coffee shops on campus. We didn't have "parties," we had "study breaks." But one thing we never managed to do while we were there was figure out what the most effective study break might be. When you're studying during nearly every free moment, what's the best way to clear up your mind and refocus yourself for the next round of studying?

One old idea that has re-emerged recently is called "attention restoration theory", or ART. William James actually discussed a similar concept in his 1892 psychology textbook. The idea that taking a walk in the woods can help you refocus your thoughts is at least as old as Immanuel Kant, and probably older. But how exactly does interacting with nature help focus attention? ART says that the natural world engages your attention in a bottom-up fashion, by features of the environment (e.g. a sunset, a beautiful tree). The artificial world demands active attention, to avoid getting hit by cars or to follow street signs. Since intellectual activities like studying or writing also demand the same kind of attention, taking a break in the artificial world doesn't really function like a rest.

Marc Berman, John Jonides, and Stephen Kaplan wanted to see if they could measure the effect of ART. They paid 38 student volunteers to do a backwards digit-span task. The volunteers were given sequences of 3 to 9 numeric digits and had to repeat them in reverse, so if the experimenter said "6-1-9" then the student would say "9-1-6". After 14 tests (two of each length), the students took an hour-long walk either through an arboretum, or through downtown Ann Arbor. Then the digit-span test was repeated. Did a walk through nature improve the digit-span score? Here are the results:

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Can artificial sweeteners really help us lose weight?

Wed, 04 Nov 2009 12:34:05 -0500

My SEED column this week focuses on artificial sweeteners. Can switching to artificial sweeteners help solve the obesity problem in the U.S.? Here's a snippet:

Saunders says an August report from the American Heart Association (AHA) made it quite clear that excessive sugar consumption is dangerous, and he argues that sugar should be seen as a toxic substance. But how much is too much? The new AHA guidelines suggest limiting added sugar to no more than half of discretionary calories--calories consumed after basic nutritional needs are met. For the average male, Saunders says, this works out to about 150 calories per day: one can of Coke, or one candy bar. No free refills.
Again, the answer seems obvious: Just switch to diet drinks. They taste about the same, but with no sugar and no calories. Not so fast, says BikeMonkey, an anonymous biomedical researcher and former bike racer who blogs at DrugMonkey. BikeMonkey cites a 2008 study published in Behavioral Neuroscience where rats were given either sugar-sweetened or artificially sweetened yogurt in addition to their usual diet of rat chow. The rats who ate artificial sweeteners gained significantly more weight over five weeks than the rats who had sugar-sweetened yogurt.

There's much more to it than that, though. Click here to read the whole thing.

Also, in case you missed them, here are my picks for psychology and neuroscience posts from ResearchBlogging.org:

How much does make-up affect perceived age? The Psychology of Beauty blog looks at a recent study -- and questions its methodology.
Is caffeine just a placebo? The Neuroskeptic looks at recent study -- and questions its methodology.
Do women prefer an attractive outsider or their primary partner during ovulation? Primate Diaries looks at a recent study -- and pretty much agrees with its methodology.
Do food ads actually sell the foods they're advertising, or do they just make us eat more? Lucid Thoughts looks at a recent study -- and doesn't really discuss methodology so much as examine its implications.

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Anime film characters: Do we perceive the intended race, or our own?

Tue, 03 Nov 2009 14:34:47 -0500

One of my favorite cartoons as a child was "Speed Racer." It featured an all-American boy (first name, "Speed," last name, "Racer") engaging in that most American of pastimes: driving fast cars. Except that "Speed Racer" wasn't really American; it was made in Japan, and the original Japanese voices were crudely overdubbed in English. Perhaps I can be excused for not noticing the Japanese origins of the show -- I was only 10 years old. Even now, as an adult looking back at those cartoons, the characters do seem awfully American-looking. Or perhaps that's just my Caucasian bias.

Does everyone see a little bit of themselves in animated cartoon characters? Or do the artists actually draw the characters to look more generic, less racially distinctive? There have been few studies about the perceived race and ethnicity of animated cartoon characters, and none focusing on the unique Japanese anime style.

So Amy Shirong Lu randomly selected 341 main characters out of 3,098 anime films made between 1958 and 2005. Each image was carefully edited to depict only a head-on, facial portrait-style picture. All clothing and background images were edited out, like this:

The character depicted here is Asuka Langley Soryu, from the movie Neon Genesis Evangelion, and of mixed Japanese and German descent. Lu recruited 1,046 people to view a randomly-selected set of 90 of the pictures and judge the characters' race based on the features depicted in the pictures. The animators' intended race of each character was judged based on the promotional materials for the film, or watching the movie itself. Still, in 125 of the cases, it was either impossible to determine the character's race or the character was of mixed ancestry. About half of all the characters were intended to be Asian, while only about 10 percent were Caucasian. Did the viewers responses match the actual race of the characters? Here are the results:

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Casual Fridays: Is political wishy-washiness a general phenomenon?

Fri, 30 Oct 2009 17:05:37 -0500

Political opinion polls are very tricky. Answers to questions depend on the order they're asked in, and on precisely how they are phrased. If you ask people whether they're in favor of killing unborn children, you'll get a much different response than if you ask if there's any situation where women should be allowed to terminate a pregnancy.

What's even more difficult is to assess public opinion on complex pending legislation. Most polls find that most Americans like the idea of requiring everyone to buy health insurance. But it's only a slim margin -- 56 to 41 percent. Kevin Drum cited a recent study that asked a follow up: would you change your mind if low-income families got government assistance to pay for insurance? Now 34 percent of naysayers changed their mind to support the requirement. But Kevin wondered if it's a fair question. Wouldn't some people change their minds no matter what?

So Kevin suggested that someone do a study to see if some people flip-flop no matter what question is asked. If some people will always flip-flop, then that suggests poll questions about flip-flops aren't very helpful in determining what the "true" public opinion is. We decided to take him up on the suggestion. Last week we created a set of six opinion questions about issues we felt our readers were likely to disagree on. 491 people responded. For each question, we came up with two different follow-ups. So, for example, everyone was asked "Should the United States adopt a government-run health care system based on Medicare?" But each respondent saw only one of the follow-ups:

Suppose the plan involved a required pay-cut for doctors of 10 percent. Would your opinion change?
Suppose the plan involved a required pay-increase for doctors of 10 percent. Would your opinion change?

Each of these groups was divided in half again. One group just answered the questions, while the other group had to keep track of the total number of flashes of a flashing square (like this) in the corner of their screen while they answered. The hope was that this task might simulate some of the distractions a typical respondent might face while answering the polling questions over the phone.

So, did the flashing square affect whether respondents flip-flopped their answers? Here are the results:

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Are older kids and adolescents really as good as adults at recognizing emotions in faces?

Thu, 29 Oct 2009 15:53:11 -0500

Take a look at this face:

Does it look more angry or fearful? It may be rather difficult to tell: About fifty percent of adults say faces like this are angry and fifty percent say it's fearful. However, for children, the story is different. Researchers have found that small children aren't as good as adults at recognizing emotions in faces. Young children would see this picture as more fearful than angry. However, most research has suggested that kids are just about as good as adults by the time they're five years old.

But neuroscientists have consistently found that the portions of the brain responsible for processing key emotions, particularly anger and fear, continue to develop all the way through adolescence. If our brains are still changing, shouldn't we see some impact in the way kids and teens perceive emotions?

A team led by Laura Thomas felt that earlier studies of children's perception of emotion were flawed because the tests were too easy. Instead of viewing subtle emotional variations like the photo above, kids saw dramatic, obvious facial expressions -- even schematic diagrams of emotions. Could it be that what's developing as kids mature into teenagers and adults is their ability to detect subtle emotional variations?

Thomas's team showed 102 children, teens, and adults pictures of 10 different actors which had been previously rated as expressing anger, fear, or a neutral emotion. But instead of showing the most obvious emotional expressions, they used morphing software to show the viewers gradations of the emotions, like this:

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Product placements in movies: When they work, and when they don't

Wed, 28 Oct 2009 17:18:16 -0500

Product placements in movies and TV shows are becoming so commonplace that my kids now cynically take note of them whenever they appear. It wasn't always that way. In 1982 when I first saw E.T. I had no idea that Elliott's use of Reeses' Pieces to lure E.T. into his home was part of a clever marketing ploy that had been pre-arranged with the multinational conglomerate selling the candy. Now that nearly every household has a DVR allowing viewers to fast-forward through commercials, advertisers are relying more and more heavily on product placement to show off their wares. But how effective are product placements in getting their message to customers?

There hasn't actually been a lot of published research on product placement, since marketing firms like to keep that information to themselves. And the research that has been done may not be realistic enough to draw useful conclusions: In one study, a researcher used low-production-value films created in the laboratory to test the efficacy of product placements, but that may not tell us much about how people respond to products in slick Hollywood productions. In other studies, a distinction wasn't made between products that simply appeared in a movie and ones that were important to the storyline. From these studies we know that people do tend to remember the brands they see in a movie, but we can't say much about how a particular product's placement makes a difference.

Moonhee Yang and David Roskos-Ewoldsen showed 373 students from the University of Alabama one of 15, 20-minute movie clips taken from major Hollywood films. Around the middle of each clip was a single product placement of interest. These products had been pre-selected by a preference panel to be roughly equally appealing. Another panel assessed the importance of the product in the movie's storyline by placing it in one of three categories: Background (not important to story), Used by Character, and Story Connection (meaning the product was actually related to the plot of the movie). This table lists all the products and films in the study:

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Placebo hype: Do the facts match the headlines?

Wed, 28 Oct 2009 10:34:54 -0500

Over at SEEDMAGAZINE.COM, my column discusses the recent flurry of blog posts and media reporting on the placebo effect. Here's a snippet:

This is the primary misconception about placebos: that the placebo itself is somehow "working" to treat a medical condition. You can see it even in the headline for an otherwise well-crafted article that appeared in Wired last August: "Placebos Are Getting More Effective. Drugmakers Are Desperate to Know Why." As internist and medical professor Peter Lipson noted on the Science-Based Medicine blog, placebos by definition have no medical effect. The "placebo effect" is due to the subject's (and sometimes, the experimenter's) expectation that a treatment will work. And, of course, a patient sometimes recovers simply due to chance or because his or her immune response handled the problem. Researchers observe an improvement, and this gets attributed to the placebo. In the case of the Wired article, the misconception in the headline is cleared up by the text of the report: The placebo effect may be getting stronger for reasons that are unclear to researchers. Placebos themselves, as ever, remain ineffective.
The anonymous blogger and UK-based neuroscientist Neuroskeptic also addresses the Wired report in a post entitled "Deconstructing the Placebo." Neuroskeptic points out that many of the issues we have with placebos are more properly directed at the medical conditions a placebo could supposedly address. If a placebo is just as effective at reducing anxiety as a drug designed for that purpose, what does that tell us about the nature of anxiety? Is participation in a research study motivating people to do other ostensibly anxiety-reducing activities? How exactly are these additional activities helping the problem? Even if placebos aren't cures, we should be able to learn more about real medical conditions by investigating how people respond to a fictional "treatment."

Also, in case you missed it, here are my picks from neuroscience and psychology posts this past week on ResearchBlogging.org:

Deep brain stimulation for depressed rats. The Neuroskeptic shows how new research demonstrates how the treatment may work--for both humans and rats.
A new kind of brain stimulation. Doctor Shock discusses a new, less-invasive technique that might work the same way as deep-brain stimulation to treat depression.
The upside of depression. Obviously severe depression is bad. But The Psych Student explores how a little depression could actually be a good thing.

One more thing: The Depression Bipolar Support Alliance is sponsoring a video contest, with a prize of $1,000 for the best video. How cool would it be if the winner incorporated some discussion of peer-reviewed research?

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Casual Fridays: Do your political opinions depend on circumstances?

Fri, 23 Oct 2009 15:55:46 -0500

Political opinion polls are funny things. A recent poll suggests that Americans are much less concerned about global warming than they were a couple years ago. What happened? The science hasn't changed, and the world isn't putting out any fewer greenhouse gases.

It seems that respondents must simply be distracted by other things -- the economic crisis, perhaps, seems more important now. But when a pollster calls a survey respondent, other distractions are at play as well. There might be a screaming baby in the house. Or perhaps the respondent is missing his favorite TV show and isn't really thinking about his answers.

We wondered if we could affect poll responses just by modifying the setting in which the poll is taken. We've created a couple different versions of the same poll. Some allow you to focus your attention completely on the poll responses, but others ask you to do other tasks at the same time. Will that have any impact on the results? There's only one way to find out.

Click here to participate

As usual, the study is brief, with about 15 questions. It should take only a few minutes to complete. You have until Thursday, October 29 to complete your response. There is no limit on the number of respondents. Don't forget to come back next week for the results!

(Just a reminder: All Casual Fridays studies are non-scientific. This doesn't mean we can't use scientific principles to assess what's going on, but we can't make general claims based on the results)

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What does it take to get kids to eat healthy foods?

Thu, 22 Oct 2009 16:15:46 -0500

When Jim and Nora were in elementary school, both Greta and I worked challenging jobs, so we did whatever we could to save time. Instead of bringing lunches made by their parents, the kids bought hot meals at school. The school was proud of its cafeteria. Kids had credit accounts, which meant they didn't have to carry lunch money to school (thus making them less of a target for bullies). The children were encouraged to make "healthy choices" instead of just getting a ladleful of mystery meat plopped on their trays.

After a few billing cycles, however, we noticed that Jim was spending more and more money. A complete lunch was supposed to cost about $3.50, but his bill was nearly $50 a week! We asked the cafeteria what he was buying and a printout was sent home. Here's a typical day's meal:

Chocolate milk (2)
Hamburger
French Fries (2)
Jello (3)

Needless to say, Greta and I soon resigned ourselves to making lunches for the kids. While "healthy choices" sounds appealing, if these were the choices our child was making, then we were going to choose for him.

Parents want their children to make good food choices -- we can't be there to decide for them all the time -- but we also want them to eat well now, even when they don't seem capable of making healthy decisions. And of course not all parents have the time or even the capacity to make good decisions for their kids, so for decades, the school lunch has been thought to be an important key to getting kids to eat better.

Unfortunately, many programs designed to get kids to eat well have failed. If children are rewarded for eating good foods, then what happens when they aren't being rewarded? Requiring them to eat a certain amount fruits and vegetables can backfire: even if kids don't mind the taste, too much of anything eventually ends up being unappealing. Comprehensive educational programs sometimes work, but require so much parent and teacher involvement that they aren't always practical.

So Helen Hendy, Keith Williams, and Thomas Camise devised a simpler approach: give kids a choice of fruits and vegetables in addition to their preferred meats, carbs, and milk, and reward them for eating even a little bit. They trained experimenters to observe 346 first-, second-, and fourth-graders for 6 days to see what fruits and vegetables they ate when given a choice of one of two fruits and one of two vegetables. Just one-eighth of a cup was considered a serving.

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Virtual reality for mice (the furry kind)

Wed, 21 Oct 2009 16:13:11 -0500

In case you missed them, here are my picks from ResearchBlogging.org's Psychology and Neuroscience posts from the past week.

Mice navigate a virtual-reality maze. Go for the amazingly cute video. Stay for the science!
Brain imaging for lie-detection doesn't live up to the hype. Remember all those stories about fMRI lie detectors a couple years back? BPS Research Digest shows why fMRI is no better than an old-fashioned polygraph.
How good are you at trading stocks? Apparently the length of your fingers can do a good job predicting your success as a stock trader. Honest.
Many people (especially men) say they enjoy the occasional sexual banter at work, as long as it isn't outright harrassment. Andrew Patrick looks at a study showing that even "enjoyable" sexual behavior at work isn't a good thing.

Also, if you're a member of ResearchBlogging.org, be sure to check out our new widget (like the one on the right of this blog). Now you can place the widget on your own blog so your readers can see the latest posts in your favorite topics, like "Psychology," "Neuroscience," and "Health."

Finally, my column is up on SEEDMAGAZINE.COM. This week I discuss the intriguing new findings about Saturn's moons and rings. Here's a snippet:

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Watch that hybrid! Can sound help us spot objects?

Tue, 20 Oct 2009 16:46:06 -0500

Recently we took our hybrid car into the shop for its annual emissions test. In our state, the test is conducted while the car is idling. A hybrid doesn't actually idle -- it shuts the engine off completely. So our car's emissions were tested at 0 RPM. It may be time to rethink our state's emissions laws.

There's another law that might need rethinking in the age of hybrids. Our car's internal combustion engine often doesn't start up even when the car is moving at low speeds -- it uses electric motors, running nearly silently. This can potentially be dangerous for pedestrians in parking lots and crosswalks: if they can't hear us, they might not notice us at all, and if we don't see them, someone could get hurt. Now some states are actually considering legislation requiring cars to make noise even while idling or moving at low speeds.

But how much does noise help us spot objects? Aren't pedestrians supposed to look for cars, not just listen for them? Aren't drivers supposed to look for hazards, not hear them? Indeed, there has been some research suggesting that sounds do help us locate objects. However, most of this research has been on directional sounds -- a sound from the right helps us spot an object on the right side of the computer screen (for an exception, see this post). Does a sound that's not from a particular direction still help us notice a change?

A team led by Toemme Noesselt flashed images using an extra fast-response computer display to flash images at 16 volunteers. The displays looked something like
this movie (click on the image to play):

For each trial, viewers had to say whether the top or the bottom ring of dots disappeared. It's easy in this version because your computer display is probably not fast enough to show the actual flashes. In the actual experiment, viewers were first tested to determine how quick a flash they could spot. Usually this was around 15 milliseconds (the flash in my movie, for comparison, was 100 milliseconds). Then they were shown movies like mine, where either the central cross changed to a circle to cue viewers that one of the rings of dots were disappearing, or a tone was played while the ring disappeared, or nothing cued them.

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Casual Fridays: Who says "hi" to you, part II

Fri, 16 Oct 2009 17:12:06 -0500

Almost three years ago, we conducted our first-ever Casual Fridays study, where we asked who says "hi" to you while you're outside exercising. The results confirmed my suspicions:

Runners report that they say "hi" to walkers 57.1 percent of the time. But looking back at the other graph, walkers claim runners only say "hi" only 31 percent of the time. That's a massive difference -- a statistically significant one. A similar -- and also significant -- disparity holds for bikers and walkers.

But there were some unanswered questions back then. Are the people who answered our survey just friendlier than average? It's possible that they were telling the truth about how often they say "hi" and that others aren't so friendly.

This time around, we have a larger sample (415 responses), and we've asked a few additional questions that may help us determine if our respondents self-selected, or if we really do just misrepresent how often we say "hi." Clearly there is some self-selection going on, because we had many fewer responses than we normally get. I'm guessing this is because a lot of our readers simply don't go outside to do their exercise. Let's see if we can confirm that with a quick poll:

Now, let's take a look at the results of the new study. As before, respondents indeed report saying "hi" more often than people say "hi" to them:

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In which I resist writing the obvious headline

Wed, 14 Oct 2009 13:58:12 -0500

I've just read an engrossing report about some very promising research in a an exciting field. The researchers combined fMRI research with genetic analysis to see if they could identify a genetic basis for anger. And they actually found something quite interesting.

If I was writing for the New York Times, the headline might read something like this: "Researchers identify gene responsible for regulating anger." For the Washington Post, it could be "Is there an anger gene?" For the New York Post, perhaps simply "RAGE GENE FOUND."

But those headlines, while they are in some ways accurate, don't really tell the whole story. A team led by Martin Reuter was intrigued by findings linking the gene for a protein, DARPP-32, with antisocial and addictive behaviors. DARPP-32 is involved in regulating the dopamine signaling pathway in the brain. When the brain has elevated dopamine levels, it has a lower threshold for anger and aggression, so DARPP-32 may be the key to understanding why some people are quicker to anger than others.

The gene that encodes DARPP-32 has been fully sequenced, and a variation in just one tiny section of the gene, it turns out, may have a direct impact on human behavior. A gene sequence is simply a string of nucleotides. There are four possible nucleotides, represented by the letters C, T, A, and G. In DARPP-32, just two nucleotides are related to the antisocial and addictive behaviors. Out of a long string of nucleotides, it turns out, it matters a lot whether one set of two particular elements is CC, CT, or TT. But does it directly affect anger?

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