tDCS in the Press

Nature News is running a piece on transcranial direct current stimulation (tDCS):

Allan Snyder, director of the Centre for the Mind at the University of Sydney in Australia, hopes to develop "a thinking cap", a tDCS device that corporate executives or advertising copywriters might use to bump up their creativity before walking into a brainstorming meeting. Snyder is cagey about how far he is in product development — but his latest demonstration, published this February¹⁴, garnered plenty of attention. Snyder claims to have boosted people's flair for sudden insight by stimulating their anterior temporal lobes. People who received tDCS were two to three times more likely than those receiving sham stimulation to solve a creativity problem in which they raced against the clock to spell out maths equations with matchsticks.

I've posted previously about Snyder's research. Any tech that makes humans smarter is hugely exciting to me, and doubly so when it is cheap and nearly ubiquitous. tDCS probably qualifies as low-hanging fruit, so long as efficacy and safety can be demonstrated with chronic use.

Cancer Complexity

This, from the always excellent Derek Lowe:

A new study, one of those things that could only be done with modern sequencing techniques, has given us the hardest data yet on the genomic basis of cancerous cells. This massive effort completely sequenced the tumors from 50 different breast cancer patients, along with nearby healthy cells as controls for each case.

Over 1700 mutations were found - but only three of them showed up in as many as 10% of the patients. The great majority were unique to each patient, and they were all over the place: deletions, frame shifts, translocations, what have you. The lead author of the study told Nature News that the results were "complex and somewhat alarming", and I second that, only pausing to drop the "somewhat". I add that qualification because these patients were already more homogeneous than the normal run of breast cancer cases - they were all estrogen-receptor positive, picked for trials of an aromatase inhibitor.

Astonishing. I had encountered the "cancer is not a single disease" idea before, but these new findings are way beyond what I had imagined. Personalized treatment for all but the earliest stage cancers may be a dead end.

On a larger scale, I think public education is a huge problem. Most folks still think of cancer as a singular disease, and one that must have a cure. While this may be technically correct, I doubt that the average person is thinking of advanced molecular nanotechnology when he or she considers charities to cure cancer.

The Representativeness Heuristic Strikes Again

Researchers at Brown University have demonstrated that people given weak positive evidence may judge a statement as less likely than people given no evidence at all. The experimenters provided some participants with weak evidence (the "conditional" condition), and gave other participants no evidence (the "marginal" condition):

Participants were [...] randomly assigned to one of the conditions. In the conditional condition they read the following:

Mid-term elections for the House of Representatives are coming up in November. Recently, Ryan Frazier, a Republican candidate in Colorado’s hotly contested 7th district House race won the endorsement of the Denver Post, Colorado’s largest newspaper.

They were then asked to judge the likelihood that the ‘‘Republicans will win control of the House of Representatives’’ on a 0–100 scale. After making the likelihood judgment, they were asked to choose whether they wanted to gamble on the Republicans winning the House as below:

Please Choose One Option:

1. You get 10 dollars no matter what happens.
2. You get 30 dollars if the Republicans win control of the House of Representatives in mid-term elections.

The order of response options was randomized. The marginal condition was identical except that the sentence about the newspaper endorsement was omitted.

The results are fairly horrific. The people who had evidence in support of the wager were far less likely to take the wager than those who had no evidence:

The researchers are calling this the "weak evidence effect". The likely cause of the bizarre inversion is the representativeness heuristic. In this case, I think the heuristic is causing us to conflate weak evidence with a weak hypothesis.

Cognition, 2011. DOI: 10.1016/j.cognition.2011.01.013