Sunday, November 28, 2010

Sunday soundbites

The Neuroskeptic has the 9 circles of academic hell.

Speaking of academic hell, it looks like the 2011-2012 science funding prospects are very slim, especially with the latest tea-party-style Republicans.

Also, the Neuroskeptic has an excellent post on the rise of fMRI research with 7-Tesla magnets. Now, we  have more power to detect artifacts!

NPR wonders why people can't walk straight. Apparently, the problem isn't limited to post-alcohol consumption walking.

"Your brain has more connections than every computer on Earth combined" claims Gizmodo.

Over at Science is a review of a paper claiming that these connections are the latest reason that human brains are "special".

Does early exposure to pornography turn people into porn addicts? Barking up the Wrong Tree reviews a new study saying "No".

Jonah Lehrer has a timely piece on overeating in the Wall Street Journal.

For the statistically obsessed, this will keep you busy for hours.

Sunday, November 21, 2010

Sunday soundbites

In defense of perfectionism.

Over at Nature, Melanie Stefan argues that scientists should keep a CV of failures. You know, to keep perspective. The perspective of wanting to drink heavily at 10am?

On the other hand, Frank Furedi argues that civic-minded activities should be recognized as accomplishments on one's CV.

Freakonomics blog has a review of a new novel on romance and data mining. Sounds like my kind of book!

A great description of a very depressing study on the media's representation of female scientists.

Also in the category of gender inequality, the recommendation letters women receive might do more harm than good.

Excellent article on the "privatization of neuroscience" and the shift away from basic research.

OK. Now to solve your depression from the previous links.

OK. Enough feeling good. Big Pharma really is as evil as you think they are.

Friday, November 19, 2010

Ah, the magic of.... placebo

Placebos are incredibly neat. This is why I am disappointed that they are typically described in undergraduate classrooms simply as a type of control. While they are certainly critical research controls, they are also a powerful example of how the brain, as much as the external world, creates our reality.

Work on placebos started after World War II, primarily from the work of Henry Beecher. Beecher, who had tended to wounded soldiers during the war, had witnessed saline solutions providing powerful pain relief to wounded soldiers during times when morphine supplies had run out.

Generally, we know that a placebo can provide relief from a variety of symptoms, including pain, Parkinson’s symptoms, ADHD, depression, allergies, epilepsy and more.  The relief from placebo isn’t just from patients telling doctors what they want to hear –when naloxone, a drug that blocks opiate receptors, is given to people who are taking a placebo pain reliever, the pain relief vanishes, suggesting that the placebo was activating some of the same neural systems activated when “real” drugs are taken. Similarly, dopamine is released during a placebo treatment for Parkinson’s, just as with the active treatment. An excellent summary of the neurobiology of placebo research can be found here.

Of course, not all placebos are created equal. For example, placebos that are injected are more effective than pills, and among pills, gelatin capsules are more effective than tablets. The price of the placebo also seems to alter its effectiveness. For example, in a clever 2008 study from Dan Ariely’s research group, participants were given mild electric shocks to their wrists before and after taking a drug they were told was an experimental pain killer that is similar to codeine. The “drug” was, of course, a placebo. Critically, half of the participants were told that the pills cost $2.50 each, while the other half of participants were told that each pill had been discounted to $0.10 each. It turns out that over 85% of participants in the high-priced drug condition experienced pain relief while only 60% of participants in the low-priced drug did.

To further complicate matters, not all people respond to a placebo to the same degree. In general, the more willing you are to expect a good outcome, the more of a placebo effect you will have. This is why children have more of an effect than adults (I mean, they believe in the Tooth Fairy, too!), and severely depressed patients have very little of a placebo effect.

It is crucial to consider studies such as these when considering clinical trials for new drugs. The gold standard for such trials is to compare the new drug to a placebo. If the drug has a greater effect than placebo and has an acceptable level of negative side effects, then it is typically approved by the FDA. While it is unlikely that clinical researchers are making their placebos intentionally less effective by making them less believable (these studies are done “double blind” meaning that the researchers don’t know which participants are on the drug, and which are on the placebo until the end of the study, so doing this would make the drug less effective too), we do need to consider that the effect size of the same drug is going to vary widely as a function of the placebo used, and the type of participants in the study.

This speaks directly to the recent controversy over the effectiveness of anti-depressant medication. The media creates headlines such as “The depressing news about anti-depressants”, which hide a rather nuanced issue: if the severity of depression affects the strength of the placebo effect, then not all studies of depressed patients will show a statistically significant effect of anti-depressants. This is shown graphically in this figure from a 2008 meta-analysis of antidepressant effects: while the effect size of the anti-depressants (red triangles) were more or less constant over a wide-range of depression levels, the effect size of the placebo (gray circles) decreased as the severity of depression increased. This means that in only the most depressed patients is there a significant effect of the antidepressant, but not because the drug is less effective in less depressed people.

…And placebos are not just limited to drugs. It turns out that most building thermostats and city street crosswalk buttons don’t actually do anything other than give you a sense of control! And I’m just about the biggest jerk on the planet as the placebo effect goes away once you know about it, so you can blame me when you are sitting in your office freezing and knowing that you can’t do a thing about it! Sorry.

EDIT: 1-1-11
And the movement of your progress bar might also be another placebo!

Sunday, November 14, 2010

Sunday soundbites

Should be get rid of university libraries?  Um.... hell no!

How will the US elections affect science funding? According to Nature, the outlook is a little grim. See also the analysis in Science.

Virtual Mentor has a fairly lucid article on potential concerns of using fMRI to determine the reliability of eye-witness testimony.

The Dana Foundation is updating its list of great books about the brain.

A great example of bad science journalism criticism can be found here, writing about media's response to new "computational marathoning" paper.

The Neurocritic sets the record straight on the Tetris-as-PTSD-prevention garbage.

Beautiful brain pictures over at The New Scientist.

Wired is "celebrating" the 75th anniversary of the lobotomy.

Thursday, November 11, 2010

More on what makes you happy

One problem that has previously limited happiness research is that asking people to imagine how happy they are doing something might not yield the same results as asking them how happy they are when they are actually doing this activity. However, a paper in today’s Science shows just this kind of data. The authors developed an iPhone application that would randomly “ping” participants and ask them what they were doing, how happy they were doing it, and whether they were currently thinking about what they were doing or something else. After getting over a quarter of a million responses from over 2000 participants, they noticed the following trends:

-         Except for when you are having sex, your mind is often on 
      something other than what you are doing. Nearly half of the samples reported mind wandering.
-         You are generally more unhappy when your mind is wandering, 
      albeit less so when you are thinking pleasant thoughts.
-         Happiness was better predicted from what you are thinking about than what you are doing.

I also really like their data representation: the location of the bubble 
indicates how happy you are (unhappy on the left to happy on the right), 
and the size of the bubble shows how many samples were from each activity. From this, I conclude that we consistently under-rate how happy exercise makes us, and that we need to have more sex!

Killingsworth, M., & Gilbert, D. (2010). A Wandering Mind Is an Unhappy Mind Science, 330 (6006), 932-932 DOI: 10.1126/science.1192439

Tuesday, November 9, 2010

Electrical enhancement of mathematical ability

Mathematical ability is highly linked to earning power and career success.  A new paper  in Current Biology demonstrates that six days of 20 minute sessions of electrical stimulation over the parietal lobe can increase some numerical literacy tasks, even six months after the stimulation was applied!

The electrical stimulation is called transcranial direct-current stimulation (TDCS). In this paradigm, electrodes are placed on the scalp as in EEG, and then a small amount of current (1-2 mA) is applied. In this paper, electrodes were applied to the parietal lobe as injuries to this region can lead to numerical difficulties. Three groups of participants were tested: two experimental groups who received stimulation, with the current going in each direction, and a control group who had electrodes applied, but without electrical stimulation (sham stimulation).

During the stimulation, participants were presented with pairs of novel symbols that stood for digits. Participants would learn the value of these symbols by indicating which symbol represented the larger value.

 As you can see from this figure, all three groups learned the task over the six experimental sessions.

Following the learning task, participants would then be given a "numerical Stroop" task to determine the automaticity of the symbol-value relationships. In this task, pairs of symbols are presented with one larger than the other. The larger symbol could be the symbol representing the larger value (congruent condition), could be the same value as the smaller value (neutral condition), or the larger symbol could represent the smaller value (incongruent condition). If the newly learned symbols were being processed as numbers, then the reaction times in the incongruent condition should be longer than neutral while congruent trials should lead to faster reaction times.

 It turns out that the stimulation did lead to an increased congruity effect, but only when the current was going in one direction (right-annode, left-cathode). In fact, current in the opposite direction seemed to decrease the learning of the symbols!

As illustrated in the left-hand figure, sham stimulation led to a ~65ms congruency effect (because even without stimulation, the participants were still learning the task). However, in the right-annode, left-cathode stimulation, the effect was about twice as large, while the opposite stimulation provided no learning at all.

Over at Practical Ethics, this paper is being discussed in terms of the societal benefit that could come from increased mathematical ability. Indeed, increasing numerical literacy could indeed decrease poverty and lead to increased innovation as they suggest. I also agree with their general unease about the possibility of "anti-enhancement" of mathematical abilities that is suggested from the right-cathode stimulation condition.

Cohen Kadosh, R., Soskic, S., Iuculano, T., Kanai, R., & Walsh, V. (2010). Modulating Neuronal Activity Produces Specific and Long-Lasting Changes in Numerical Competence Current Biology DOI: 10.1016/j.cub.2010.10.007

Sunday, November 7, 2010

Sunday soundbites

Will my neurotic personality negatively affect my career? No, but my current academic salary will not decrease my neuroticism over time.

Is the university dead? We have no idea. In other depressing news, here's the state of tenure according to Nature.

Also in Nature are the results on one journal's experiment with making peer review transparent.... followed by some hand-wringing about its high rate of retractions.

The Simpson's take on grad students and PhDs.

The ability to imagine the future seems independent of the hippocampus.

An excellent review of the (in)famous Little Albert experiment over at The History of Psychology.

More good history: Bering in Mind has a great article on the history of obesity.

The great Facebook Oracle of data mining can predict when romantic breakup are most likely to happen.

Vogue-it til you make it: power posing your way to success.

Wednesday, November 3, 2010

Data-driven dieting

The interesting thing about dieting is that while everyone knows what you need to do to lose weight (eat less and move more), very few people know much about how to get yourself to do these things.

So, how do you increase your willpower? 

1. Don’t get too hungry.
It seems that there is a link between blood sugar and self control. For example, this study showed that when you perform an act requiring self-control, your blood sugar drops, and that when you have low blood sugar, your performance on subsequent self-control tasks decreases. This is a good reason to heed the oft-quoted diet advice to eat small meals 5-6 times a day as this stabilizes the blood sugar and keeps the cookie monster at bay.

2. Use your imagination.
Tempting treats are nearly everywhere around us at this time of year: leftover Halloween candy, holiday parties, home-baked treats, etc. How should you respond to a tempting, but fattening treat in your vicinity? According to this study, try to imagine it in non-food context. Instead of seeing brownies, see chocolate door stops. Instead of candies, checkers pieces. Just try to think of as many non-food uses for the item. Researchers found that subjects who were told to think of non-food uses for tempting chocolate rated chocolate as less appealing than those who were instructed to think of chocolate as delicious.

3. Adjust your mental model.
Earlier, I wrote about a recent paper refuting a long-held model of self-control that asserted that self-control is a limited resource that gets depleted with use. This paper demonstrated that not believing in this model led to higher performance on a self-control task.

Gailliot, M., Baumeister, R., DeWall, C., Maner, J., Plant, E., Tice, D., Brewer, L., & Schmeichel, B. (2007). Self-control relies on glucose as a limited energy source: Willpower is more than a metaphor. Journal of Personality and Social Psychology, 92 (2), 325-336 DOI: 10.1037/0022-3514.92.2.325

Hofmann, W., Deutsch, R., Lancaster, K., & Banaji, M. (2009). Cooling the heat of temptation: Mental self-control and the automatic evaluation of tempting stimuli European Journal of Social Psychology DOI: 10.1002/ejsp.708