Wednesday, November 05, 2008

Disputed definitions: paradigm shift

NatureNews has an interesting article on words whose definitions get scientists most worked up. Take 'paradigm shift,' for example:
Paradigm shift has a definite origin and originator: Thomas Kuhn, writing in his 1962 book The Structure of Scientific Revolutions, argued against the then prevalent view of science as an incremental endeavour marching ever truthwards. Instead, said Kuhn, most science is "normal science", which fills in the details of a generally accepted, shared conceptual framework. Troublesome anomalies build up, however, and eventually some new science comes along and overturns the previous consensus. VoilĂ , a paradigm shift. The classic example, Kuhn said, is the Copernican revolution, in which Ptolemaic theory was swept away by putting the Sun at the centre of the Solar System. Post-shift, all previous observations had to be reinterpreted.

Kuhn's theory about how science works was arguably a paradigm shift of its own, by changing the way that academics think about science. And scientists have been using the phrase ever since.

In a postscript to the second edition of his book, Kuhn explained that he used the word 'paradigm' in at least two ways (noting that one "sympathetic reader" had found 22 uses of the term). In its broad form, it encompasses the "entire constellation of beliefs, values, techniques and so on shared by the members of a given community". More specifically it refers to "the concrete puzzle-solutions" that are used as models for normal science post-shift.

Scientists who use the term today don't usually mean that their field has undergone a Copernican-scale revolution, to the undying annoyance of many who hew to Kuhn's narrower definition. But their usage might qualify under his broader one. And so usage becomes a matter of opinion and, perhaps, vanity.

The use of the term in titles and abstracts of leading journals jumped from 30 papers in 1991 to 124 in 1998, yet very few of these papers garnered more than 10 citations apiece1. Several scientists contacted for this article who had used paradigm shift said that, in retrospect, they were having second thoughts. In 2002, Stuart Calderwood, an oncologist at Harvard Medical School in Boston, Massachusetts, used it to describe the discovery that 'heat shock proteins', crucial to cell survival, could work outside the cell as well as in2. "If you work in a field for a long time and everything changes, it does seem like a revolution," he says. But now he says he may have misused the phrase because the discovery was adding to, rather than overturning, previous knowledge in the field.

Arvid Carlsson, of the University of Gothenburg in Sweden stands by his use of the phrase. "Until a certain time, the paradigm was that cells communicate almost entirely by electrical signals," says Carlsson. "In the 1960s and '70s, this changed. They do so predominantly by chemical signals. In my opinion, this is dramatic enough to deserve the term paradigm shift." Few would disagree: base assumptions were overturned in this case, and Carlsson's own work on the chemical neurotransmitter dopamine (which was instrumental in this particular shift) earned him the 2000 Nobel Prize in Physiology or Medicine

Unless a Nobel prize is in the offing, it might be wise for scientists to adopt the caution of contemporary historians of science and think twice before using a phrase with a complex meaning and a whiff of self promotion. "Scientists all want to be the scientists that generate a new revolution," says Kuhn's biographer, Alexander Bird, a philosopher at the University of Bristol, UK. "But if Kuhn is right, most science is normal science and most people can't perform that role."

Tuesday, November 04, 2008

A break from watching the election returns....

The psychology of voting - US readers: VOTE TODAY!

An interesting article in today's New York Times Science section by Benedict Carey, on the value of voting beyond politics.

Neuroeconomics - the neural circuitry of overbidding

Delgado et al. offer an interesting article in Science Magazine suggesting that fear of loss may mediate overbidding in auctions. Here is their abstract, followed by comments in a review by Maskin.
We take advantage of our knowledge of the neural circuitry of reward to investigate a puzzling economic phenomenon: Why do people overbid in auctions? Using functional magnetic resonance imaging (fMRI), we observed that the social competition inherent in an auction results in a more pronounced blood oxygen level–dependent (BOLD) response to loss in the striatum, with greater overbidding correlated with the magnitude of this response. Leveraging these neuroimaging results, we design a behavioral experiment that demonstrates that framing an experimental auction to emphasize loss increases overbidding. These results highlight a role for the contemplation of loss in understanding the tendency to bid "too high." Current economic theories suggest overbidding may result from either "joy of winning" or risk aversion. By combining neuroeconomic and behavioral economic techniques, we find that another factor, namely loss contemplation in a social context, may mediate overbidding in auctions.
Maskin's comments are based on followup experiments not mentioned in the abstract:
The fMRI data show that subjects experience a lower blood oxygen level in the striatum in response to losing an auction, but no significant change in reaction to winning one. The authors interpret this result as suggesting that subjects experience "fear of losing" and that this fear accounts for their overbidding. But actually modeling fear explicitly--making it precise--does not seem straightforward.

A natural modeling device would be simply to subtract something from the subject's payoff when she loses. However, such a modification would not accord with the authors' findings in their subsequent experiment. In the follow-up, there were two treatments: one in which a subject is initially given a bonus sum of money S but told that she has to return it if she loses the auction; the other in which the subject is promised that if she wins she will get S. The two treatments are, ex post, identical: In both cases, the subject ends up with the bonus if and only if she wins. However, in practice, subjects bid more in the former treatment than the latter. Such behavior sharply contradicts the "payment subtraction" hypothesis, under which behavior in the two treatments would be the same. Moreover, it seems difficult to find a natural alternative formulation of the "fear of losing" idea that explains the results simultaneously from both Delgado et al. experiments. Even so, there is a well-known principle that could account for the behavioral discrepancy between the two treatments in the follow-up experiment: the "endowment" effect. When a subject is given a bonus S at the outset, she may become possessive and so move more aggressively to retain it than she would act to obtain a contingent bonus at the end of the experiment.

As for why subjects overbid, perhaps the answer is that high-bid auctions are just too complex for a typical buyer to analyze completely systematically. The buyer will easily see that she has to shade her bid (bid strictly below v) to get a positive payoff. Still, she won't want to shade too much because shading reduces her probability of winning. A simple rule of thumb would be to shade just a little. But this leads immediately to overbidding, because risk-neutral equilibrium bidding entails a great deal of shading: A buyer will bid only one-half her valuation.

The behavioral revolution in economics

In light of the work by Delgado et al. mentioned in today's other posting, I thought it appropriate to pass on this NY Times Op-Ed piece by David Brooks, on the decline of economic models that presume that people are mostly engaged in rationally calculating and maximizing their self-interest. Rather, people put great energy in perceiving things that aren't true. Brooks emphasizes the work of Taleb:
Taleb believes that our brains evolved to suit a world much simpler than the one we now face. His writing is idiosyncratic, but he does touch on many of the perceptual biases that distort our thinking: our tendency to see data that confirm our prejudices more vividly than data that contradict them; our tendency to overvalue recent events when anticipating future possibilities; our tendency to spin concurring facts into a single causal narrative; our tendency to applaud our own supposed skill in circumstances when we’ve actually benefited from dumb luck.

And looking at the financial crisis, it is easy to see dozens of errors of perception. Traders misperceived the possibility of rare events. They got caught in social contagions and reinforced each other’s risk assessments. They failed to perceive how tightly linked global networks can transform small events into big disasters.

Monday, November 03, 2008

Explanatory Neurophilia - seduction without cause

Trout discusses the work of Weinberg (mentioned in a previous post) who has shown in a series of experiment how non-expert consumers of behavioral explanations assign greater standing to explanations that contain neuroscientific details, even if these details provide no additional explanatory value. He discusses the part that this ‘placebic’ information might play in producing a potentially misleading sense of intellectual fluency and, consequently, an unreliable sense of understanding. I'm passing the article on to you here.

Happiness, Eudaimonia, etc.

As I was doing some homework in preparation for a gig as a talking heading ‘expert’ on a web radio show called “Make Me Happy” I ran across this 2002 article, “Pleasure, Meaning & Eudaimonia” by Martin Seligman.
So the core thesis in Authentic Happiness is that there are three very different routes to happiness. First the Pleasant Life, consisting in having as many pleasures as possible and having the skills to amplify the pleasures. This is, of course, the only true kind of happiness on the Hollywood view. Second, the Good Life, which consists in knowing what your signature strengths are, and then recrafting your work, love, friendship, leisure and parenting to use those strengths to have more flow in life. Third, the Meaningful Life, which consists of using your signature strengths in the service of something that you believe is larger than you are.

Sunday, November 02, 2008

MindBlog as election worker...

I got a call from the Obama campaign asking if I would work as a poll watcher at an election polling site on Tuesday. I said yes, went to the training session yesterday (shown at left), and came away in awe of the micro-analytical detail and power of the Obama ground effort. Our main job is to be sure people make it through the long waiting lines, give out registration information and assistance, be alert for any signs of voter intimidation. Another class of poll worker, designated a "Houdini", records the identity of every voter, and at 30 min- 1hr intervals calls in the information to command central, which takes those names off the canvass and phone lists to reallocate resources in real time towards getting out the people who haven't voted.

What is the difference between a 40 and a 70 year old brain...

A piece by Dr. Robert Epstein relevant to the current presidential election.

Friday, October 31, 2008

A question to readers... MindBlog podcasts?

Blog reader Patrice responded to the previous posting in a comment asking about the possibly of my doing podcasts on some mindblog topics. Another friend has mentioned this, yet I haven't thought much about it because I've never really gotten into listening to podcasts myself. When I am driving I usually listen to music. However, I am an experienced university lecturer, and actually sort of miss the more spontaneous and improvisational energy of talking versus writing. So, I'm curious to know how many of you might actually find occasional podcasts useful. And if so, do you have opinions about optimal length and subjects that are most interesting to you? I would appreciate responses, either to this posting, or by email to mdbownds@wisc.edu.

Fan Mail

Although I feel totally immodest about doing this, I have to pass on this text of a email today from a reader of this blog in Tasmania, Australia. Whenever I question how worthwhile this effort is, a statement like this really warms me up:
Just a quick appreciation: I love your blog. I don’t know how you do it but just about every day there’s something that I really want to read. You appear to write a blog that is bang on some of my interests, in particular, building the full - crazy, intelligent, imaginative, smart, musical, superstitious, religious, even - human from biology. We appear to be living in a very exciting time where a lot of stuff that was in what I’d call the realm of superstition – is being dusted off and actually inspected. Maybe it’ll go on like this forever, but I can’t imagine that we won’t run out of things pretty soon at the current rate.

Psychology of the electorate

I point to two interesting articles in the New York Times. Dewan and Brown discuss how the work of psychologist Drew Westen (mentioned in three - previous - posts) has shaped the message delivery of democratic candidates so thoroughly that the rhetorical dominance enjoyed by republican for years has been completely reversed. Kristof deals again with the issue of unconscious bias in voters, and links in his article direct you to online tests for your own unconscious biases.

Emergent properties of human groups

Just as ants interact to form elaborate colonies and neurons interact to create structured thought, groups of people interact to create emergent organizations that the individuals may not understand or even perceive. I recently went to an interesting seminar on this topic in the Psychology Department at Univ. Wisc. given by Robert Goldstone at Indiana Univ. He has set up an interesting web based experiment to test agent based models of emergent properties of human groups. You can read about and also become a subject in the experiments here.

Thursday, October 30, 2008

Religion: Bound to believe?

I pass on clips from an article by Pascal Boyer that explains why a slew of cognitive traits shared by humans will always make atheism a hard sell.
In the past ten years, the evolutionary and cognitive study of religion has begun to mature. It does not try to identify the gene or genes for religious thinking. Nor does it simply dream up evolutionary scenarios that might have led to religion as we know it. It does much better than that. It puts forward new hypotheses and testable predictions. It asks what in the human make-up renders religion possible and successful. Religious thought and behaviour can be considered part of the natural human capacities, such as music, political systems, family relations or ethnic coalitions. Findings from cognitive psychology, neuroscience, cultural anthropology and archaeology promise to change our view of religion.

Unlike other social animals, humans are very good at establishing and maintaining relations with agents beyond their physical presence; social hierarchies and coalitions, for instance, include temporarily absent members. This goes even further. From childhood, humans form enduring, stable and important social relationships with fictional characters, imaginary friends, deceased relatives, unseen heroes and fantasized mates. Indeed, the extraordinary social skills of humans, compared with other primates, may be honed by constant practice with imagined or absent partners.

It is a small step from having this capacity to bond with non-physical agents to conceptualizing spirits, dead ancestors and gods, who are neither visible nor tangible, yet are socially involved. This may explain why, in most cultures, at least some of the superhuman agents that people believe in have moral concerns.

In addition, the neurophysiology of compulsive behaviour in humans and other animals is beginning to shed light on religious rituals. These behaviours include stereotyped, highly repetitive actions that participants feel they must do, even though most have no clear, observable results, such as striking the chest three times while repeating a set formula. Ritualized behaviour is also seen in patients with obsessive-compulsive disorders and in the routines of young children. In these contexts, rituals are generally associated with thoughts about pollution and purification, danger and protection, the required use of particular colours or numbers or the need to construct a safe and ordered environment.

So is religion an adaptation or a by-product of our evolution? Perhaps one day we will find compelling evidence that a capacity for religious thoughts, rather than 'religion' in the modern form of socio-political institutions, contributed to fitness in ancestral times. For the time being, the data support a more modest conclusion: religious thoughts seem to be an emergent property of our standard cognitive capacities.

Religious concepts and activities hijack our cognitive resources, as do music, visual art, cuisine, politics, economic institutions and fashion. This hijacking occurs simply because religion provides some form of what psychologists would call super stimuli. Just as visual art is more symmetrical and its colours more saturated than what is generally found in nature, religious agents are highly simplified versions of absent human agents, and religious rituals are highly stylized versions of precautionary procedures. Hijacking also occurs because religions facilitate the expression of certain behaviours. This is the case for commitment to a group, which is made all the more credible when it is phrased as the acceptance of bizarre or non-obvious beliefs.

Some form of religious thinking seems to be the path of least resistance for our cognitive systems. By contrast, disbelief is generally the result of deliberate, effortful work against our natural cognitive dispositions — hardly the easiest ideology to propagate.

Fair and Balanced - measuring media bias

One hears charges from both left and right about media bias, with FOX News frequently cited as the most extreme case. Tim Groeling has done interesting work to objectively measure the bias shown by television media, in a paper (PDF here) to be published in the December issue of Presidential Studies Quarterly. He simply collected the in-house presidential approval polling by ABC, CBS, NBC and FOX News and compared these with the actual broadcasts of such polls on evening news shows from 1997 to early 2008. As an example, CBS was 35 percent less likely to report a five-point drop in approval for Bill Clinton than a similar rise in approval and was 33 percent more likely to report a five-point drop than a rise for George W. Bush. FOX News was 67 percent less likely to report a rise in approval for Clinton than a decrease and 36 percent more likely to report an increase rather than a decrease for Bush.

Wednesday, October 29, 2008

Watching the amygdala signal the good and the bad

An interesting piece in Jour. of Neuoscience by Belova et al., in which recordings from single cells in the monkey amygdala indicate their division into those that track either positive state or negative states:
As an organism interacts with the world, how good or bad things are at the moment, the value of the current state of the organism, is an important parameter that is likely to be encoded in the brain. As the environment changes and new stimuli appear, estimates of state value must be updated to support appropriate responses and learning. Indeed, many models of reinforcement learning posit representations of state value. We examined how the brain mediates this process by recording amygdala neural activity while monkeys performed a trace-conditioning task requiring fixation. The presentation of different stimuli induced state transitions; these stimuli included unconditioned stimuli (USs) (liquid rewards and aversive air puffs), newly learned reinforcement-predictive visual stimuli [conditioned stimuli (CSs)], and familiar stimuli long associated with reinforcement [fixation point (FP)]. The FP had a positive value to monkeys, because they chose to foveate it to initiate trials. Different populations of amygdala neurons tracked the positive or negative value of the current state, regardless of whether state transitions were caused by the FP, CSs, or USs. Positive value-coding neurons increased their firing during the fixation interval and fired more strongly after rewarded CSs and rewards than after punished CSs and air puffs. Negative value-coding neurons did the opposite, decreasing their firing during the fixation interval and firing more strongly after punished CSs and air puffs than after rewarded CSs and rewards. This representation of state value could underlie how the amygdala helps coordinate cognitive, emotional, and behavioral responses depending on the value of one's state.

Happiness and the 'prosperoscope'

The random samples section of Science Magazine discusses the latest prosperity or 'happiness index' report of the Legatum Institute:
The results are in: Australia is the most prosperous country in the world; Yemen drags at the bottom of the list. But it's not just wealth that makes a country prosperous, according to the 2008 prosperity index, also known as the "happiness index," published last week by the Legatum Institute (LI) in Dubai (see www.prosperity.com). The institute based its rankings on surveys of economic competitiveness and comparative livability from 140 countries, including factors such as capital investment and the degree of social equality.

This year, for the first time, countries' environmental efforts counted toward their scores, says LI Senior Vice President William Inboden. The institute selected an objective measurement--the ratio of developed land to land remaining in its natural state in each country--and added questions about how respondents felt about their country's environmental policies. Depending on a country's wealth, the environmental measures could count for as much as 4% of a country's prosperity score. Although Australia was the most prosperous country overall, New Zealand topped the environmental measures. The most environmentally unhappy people were Ukrainians, who particularly dislike their air quality.
You might enjoy playing with the 'prosperiscope' on the site.
"The Legatum Prosperiscope™ is a powerful interactive online tool that allows users to customise analyses across 104 countries using 22 different factors. Users can also compare countries against each other to identify their relative strengths and weaknesses. Follow the simple steps on the right to start using the Prosperiscope."

Tuesday, October 28, 2008

Instinctual math

Natalie Angier does an interesting article on our instinctual intuitive math versus our more analytical learned number crunching, and the relationship between them. Apparently our evolutionarily endowed sense of approximation is related to how good we are at formal math. The article contains a neat interactive demonstration of our non verbal intuitive math abilities.
Brain imaging studies have traced the approximate number sense to a specific neural structure called the intraparietal sulcus, which also helps assess features like an object’s magnitude and distance. Symbolic math, by contrast, operates along a more widely distributed circuitry, activating many of the prefrontal regions of the brain that we associate with being human. Somewhere, local and global must be hooked up to a party line.

...open questions include how malleable our inborn number sense may be, whether it can be improved with training, and whether those improvements would pay off in a greater appetite and aptitude for math. If children start training with the flashing dot game at age 4, will they be supernumerate by middle school?

Views of the presidential candidates on science

Here is the PDF from Science Magazine.

Monday, October 27, 2008

Poulenc Novelette in C major for a Monday morning

Recorded 10/25/08 on the Steinway B in my home on Twin Valley Road in Middleton, Wisconsin.