Monday, January 31, 2011

Sunday soundbites: Monday edition

Advances in making an artificial retina.

Why is EEG under-rated? Because there's no pretty brain picture.

Do we need a new enlightenment? I'm not sure, but this is a very cool video.

Thursday, January 27, 2011

What we don't know about cognitive enhancement

The use of prescription drugs such as Ritalin, Adderall and Provigil for increasing attention and work capacity has been controversial. However, in the context of such back and forth fights about the desirability of pharmaceutical cognitive enhancement, we must step back and ask some basic scientific questions:
- Do these drugs enhance brain function in people without ADHD or narcolepsy?
- Do they work equally well in everyone?
- Are there any cognitive trade-offs for using these drugs?

This is why this review by Husain and Mehta is both timely and important. Some of the great points made include:

1. We do not understand cognitive systems well enough to understand the potential trade-offs that may exist from taking a cognitive enhancing drug. There are counter-intuitive findings everywhere. For example, young adults who carry the APOE-4 allele (which has been associated with a higher risk of dementia later in life) actually have better performance on decision making tasks than those carrying the APOE-3 version. Therefore, it is plausible that drugs targeting memory systems might have detrimental effects on decision making tasks.

2. It's difficult to know how well cognitive enhancing drugs work in healthy people in the "real world". Although several studies have shown increased performance for certain laboratory tests of cognitive ability, there is no clear consensus about how these tasks translate into real-world academic or job performance. Furthermore, as most studies show small effect sizes and results in some, but not all tasks, there is a very real possibility that these drugs have no measurable effect outside of the laboratory.

3. A small overall cognitive enhancing effect of a drug can come either from a small effect observed in all participants, or large effects in some participants and no effects in others. Previously, these authors have shown large individual difference in cognitive enhancers (I wrote about this here). In particular, participants with lower working memory capacity seem to have more enhancement from these drugs than those with larger working memories.

4. A common complaint, but relevant nonetheless: the long-term effects of these drugs, taken for enhancement purposes, is unknown.

What I particularly like about this paper is that it both outlines a needed future research plan while staying above the ideological ethical fray.  

Husain M, & Mehta MA (2011). Cognitive enhancement by drugs in health and disease. Trends in cognitive sciences, 15 (1), 28-36 PMID: 21146447

Monday, January 24, 2011

Carrots and sticks, sure but...

The theory of hyperbolic discounting asserts that the farther in the future a consequence (positive or negative), the less it matters to us when compared to an immediate consequence. This is why we abandon our diets in the face of a cupcake: the future hot body just pales in comparison to fatty, sugary goodness right now.

This is why putting clear economic incentives on habits can be so effective. Ian Ayers' Carrots and Sticks is an excellent book detailing how making behavioral contracts can be effective for smoking cessation, weight loss, etc.

So, I'm on board with the method. However, I don't quite understand this motivational structure for working out. Here, a gym membership costs more when you miss a workout. Maybe this is just me (I see my gym time as my favorite time of day), but missing a workout already costs you more because your monthly membership dues means that you're paying more per workout when you work out less.


Sunday, January 23, 2011

Sunday soundbites: I-can-haz-warm-sunshine? edition

Nature reports that one third of grants are rejected for random reasons. Only one third?

The Edge asks "what scientific concept would improve everybody's cognitive toolkit?" Lots of great answers here.

Also in Nature, structured procrastination for the postdoctoral researcher.

Henry Greely has an essay on the ethical ramifications of fetal genotyping from maternal blood samples.

The Royal Society has a nice collection of papers on neuroethics.

Mind Hacks discusses the history of IBM's "Watson" AI project.

The New York Times asks whether consumers should pay their cell phone company to turn off their phones while in a car.

Targeted advertising run amok: Freakonomics blog reports on the use of facial scans to predict what you want to eat!

Neuroskeptic has an excellent post on incidental findings in fMRI research.

Sunday, January 16, 2011

Sunday soundbites: after the blizzard

Two cool visual illusions: here and here.

OK Cupid has a new post on facial attractiveness: it is to your advantage in the dating market to have a split decision about your attractiveness.

[citation needed] has a balanced post about the "ESP paper"

The Neurocritic takes on "neurofacebook".

This is a truly beautiful essay.

Johah Lehrer writes about the cognitive trade-offs of oxytocin.

Science has an article on what it takes to get into the Science Hall of Fame (as determined by Google ngrams). Be sure to watch the video at the bottom - super cool!

Newsweek has a surprisingly good article on cognitive enhancement.

Nature has a piece on detecting mental illness with near-infrared imaging.

Saturday, January 15, 2011

What are you writing that will be read in 10 years?

This was a question asked to an acquaintance during a job interview for a professorship in the humanities. It's one hell of a question, and one that I find unfortunately unasked in the sciences.

In my other life, I submitted a paper this week. It's not a bad paper - it shows something new,  but like too many papers being published today, it's incremental and generally forgettable. It's not something that will be read much in 10 years.

I love reading old papers. They are from a time when authors were under less pressure to produce by volume. They are consequently more theoretical, thoughtful and broad than most papers published today because the authors had the luxurious time to sit and think about the results, and place them in context.

As I've pointed out earlier, the competitive academic environment tends to foster bias in publications: when trying to distinguish oneself amongst the fray of other researchers, one looks for sexy and surprising results. So do the journals, who want to publish things that will get cited the most. And so do media outlets, vying for your attention.

Jonah Lehrer's new piece on the "decline effect" in the New Yorker almost gets it right. The decline effect, according to Lehrer, is the phenomenon of a scientific finding's effect size decreasing over time. Lehrer dances around the statistical explanations of the effect (regression to the mean, publication bias, selective reporting and significance fishing), and seems all-too-willing to dismiss these over a more "magical" and "handwave-y" explanation:

"This is largely because scientific research will always be shadowed by a force that can’t be curbed, only contained: sheer randomness" 

But randomness (along with the sheer number of experiments being done) is the underlying basis of the other effects he wrote about and dismissed. The large number of scientists we have doing an even larger number of experiments is not unlike the proverbial monkeys randomly plunking keys on a typewriter. Eventually, some of these monkeys will produce some "interesting" results: "to be or not to be" or "Alas, poor Yorick!" However, it is unlikely that the same monkeys will produce similar astounding results in the future.

Like all analogies, this one is imperfect as I am not trying to imply that scientists are only shuffling through statistical randomness. What I am saying is that given publication standards of large, new, interesting and surprising results, it is very likely that any experiment meeting these standards is an outlier and that its effect size will regress to the mean. This cuts two ways: although some large effects will get smaller, some experiments that were shelved for having small effects will probably have larger effect sizes if repeated in the future.

 This gets us back to my penchant for old papers. With more time, a researcher could do several replications of the study, and find the parameters under which the effects could be elicited. And often, these papers are from the pre-null-hypothesis significance testing days, so the effects tend to be larger as they need to be visually obvious from a graph. (A colleague once called this the JFO statistical test for "just f-ing obvious". It's a good standard) This standard guards against many of the statistical sins outlined by John Ioannidis.

This is also why advances in bibiometrics are going to be key for shaping science in the future. If we can formalize what makes a paper good, and what makes a scientist's work "good", then (hopefully) we can go about doing good, rather than voluminous, science.

Sunday, January 9, 2011

Sunday soundbites

It's a good week for science - the already-retracted Wakefield autism-MMR paper was shown to also be a complete fraud.

Brains have decreased in size over human evolution, according to NPR. I say it's not the size, but how you use it. :)

The New York Times describes the brave new world of computer vision.

More on this from Wired.

Also in the New York Times: how to best deal with grade inflation?

How long does it take for a conversational silence to become awkward? About 4 seconds, reports Time magazine.

There were visual illusions in Paleolithic cave drawings! Super cool report by Natgeo.

Nature examines whether university rankings should be determined by more than just citations.

A successful "cocaine vaccine" was produced (at least for mice), according to io9.

Female tears reduce male testosterone and libido.

Mind Hacks points out that the mapping of tastes to different tongue real-estate is without evidence.

Slate has an excellent article on the statistical difficulties involved in both the DSM-V and graduate school rankings.

Science Daily reports that female faculty who understand the social network of the university do better than those who don't. Seems to be a gender-neutral skill to me, though.

Friday, January 7, 2011

"Hooking up" and depression

Do attachment-free sexual encounters increase or decrease depression? Let me quote from this abstract:

"Young adults who reported more depressive symptoms and feelings of loneliness at Time 1 and subsequently engaged in penetrative hook ups reported fewer depressive symptoms and lower feelings of loneliness at Time 2 as compared to young adults who did not hook up. However, young adults who reported fewer depressive symptoms and were less lonely at Time 1 and engaged in penetrative hook ups over the 4 month period reported more depressive symptoms and greater feelings of loneliness at Time 2 as compared to young adults who did not hook up."

Holy regression to the mean, batman!

Monday, January 3, 2011

Is it time to question a lack of free will?

In the early 1980s, psychologist Benjamin Libet conducted a relatively simple experiment that critically shaped the way we think about free-will. Participants sat facing a clock, keeping a finger on a button, and were instructed to lift the finger whenever they pleased, remembering the clock time corresponding to the time when they decided to move the finger. All the while, EEG was being recorded. Libet found that 300-500 msec before participants moved (and about 150 msec before reporting that they decided to move), that a strong negative signal was found in the EEG waveforms. If the brain "knows" you are going to move before you do, do you really have conscious control over your own behavior?

The Libet experiment has been replicated, if not uncontroversial among philosophers. However, a new paper in Psychological Science questions whether the readiness potential is an artifact of observing a moving clock.

In the new study, Jeff Miller and colleagues presented participants with two decision-making conditions: a clock condition, similar to that of Libet, and a condition without the clock. If the time between the decision and the movement is constant, then one can look at the EEG from the time to move, with or without the clock. The authors found that participants in the clock condition showed the readiness potential, but the participants in the no-clock condition did not, suggesting that the act of monitoring the clock modulated the EEG signal, not the preparation for making a decision.

I think that this study is innovative as we need new methods to study the time course of decision making. I do think it asks more questions than it answers, though. For example, there are differences between the clock and no-clock groups that go beyond the presence of a clock: being asked to keep a time in mind provides a load to working memory that the no-clock participants did not have.

Is it time to give up on Libet? I'm not so sure. Is it time to reconsider with new methods? Absolutely!

Miller J, Shepherdson P, & Trevena J (2010). Effects of Clock Monitoring on Electroencephalographic Activity: Is Unconscious Movement Initiation an Artifact of the Clock? Psychological science : a journal of the American Psychological Society / APS PMID: 21123855

Sunday, January 2, 2011

Sunday Soundbites: Happy New Year!

Is peer review better than chance? A new study says "maybe not".

Who is more likely to be prescribed a cognitive enhancer, me or my father? A new study in PLoS says it's Dad.

Confused about what is and is not a mental disorder according to the DSM-V? So are most experts, says NPR.

This is the smartest thing I've read about "neurobabble" all week.

The ever-excellent Dan Ariely has a post about money and cognitive heuristics.

Bora Zivkovic has an excellent article on the history of scientific discourse, and the links between scientific and journalistic writing.

Can Google's new Ngram toy show which science is fad and which is legit? Big Think says yes. I'm not so sure, but they have cool graphs.

People who believe in free will have better job performance, reviewed by Barking up the Wrong Tree.