Science Life - A blog of news and ideas in Biomedicine

Linkage 4/15: TEDxUChicago, Chomsky Wrong?, Big Bangs

Posted at 10:31 am CT on April 15, 2011

tedxuchicagoTED Comes to Campus

This weekend, the students of the University of Chicago are putting together a local edition of the renowned TED conference called TEDxUChicago. The theme, “Reinventing the Life of the Mind,” nicely blends the goals of TED and the University, the idea-sharing mission of the conference sutured to the intellectual spirit of our campus. Among the talks taking place at the Reynolds Club this Sunday are a few UChicago scientists: paleontologist and educator Paul Sereno (speaking on the topic of “Art In Science”), psychologist and child language expert Susan Goldin-Meadow (”What Our Hands Can Tell Us About Our Minds”), and student speaking contest winner Bruno Cabral (“The Life of the Mind Lived Through Noise”), an undergraduate working in the laboratory of psychologist Howard Nusbaum. Other speakers include Mark Inglis, the first double amputee to climb Mount Everest, Jonathan Greenblatt, the former CEO of GOOD magazine, and cybernetics expert Kevin Warwick giving probably the talk with the coolest title: “The Last Remaining Hurdles to Cyborg Technology.” Tickets are still for sale on the TEDxUChicago website, but if you can’t make it down to Hyde Park, the talks will be webcast live at the UChicago Facebook page.

The Rules of Language

Last week, the Joseph P. Kennedy Intellectual and Developmental Diabetes Research Center held a symposium called “Variations in Language Learning,” a series of talks about how languages are acquired by children, adults, and cultures. Elissa Newport, a professor of brain & cognitive sciences and linguistics at the University of Rochester, presented fascinating data on the concept of “statistical learning,” the theory that the brain uses mathematical tricks to learn the arcane rules of a new language. To test this idea, Newport and her colleagues played a made-up language of nonsense syllables for 20 minutes (!) to volunteers, showing that combinations of syllables that show up more frequently (such as “dutaba” or “babupu”) are eventually perceived as “words” by the listener. The researchers also went on to show that children are better at this “statistical learning” than adults when confronted with a new language, offering an explanation for why languages are easier to pick up when learned at a younger age.

The idea of a universal foundation for learning and developing language echoes the “universal grammar” theories of Noam Chomsky and others, if peripherally so - Newport’s experiments showing that the same statistical learning can be used for tones and visual sequences implies that it’s a universal learning mechanism, not specific to language. But a new phylogenetic analysis of the world’s languages appearing in Nature this week argues against innate rules for language, demonstrating deep grammatical differences between “families” of languages go against the idea of a universal human grammar. Most linguists seem skeptical or underwhelmed about the result, and the debate smacks of a false dichotomy, with the truth about language development less a battle between cognition and culture than a combination of the two forces. Discover, the LA Times’ Amina Khan, and Ars Technica’s John Timmer all weigh in on the study.

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Posted by - Rob Mitchum

Linkage 11/12: Bacterial Concrete and Ethics Fest

Posted at 11:46 am CT on November 12, 2010
(photo by Lloyd DeGrane)

(photo by Lloyd DeGrane)

Here in Chicago, we’re entering the second of our two seasons: transitioning from “Construction” into “Winter.” The rampant highway repair that happens during warm weather months is largely due to the stresses of the cold weather months, which leave our roads cracked and potholed. But perhaps we’ll be saved from all that misery if a team of Dutch researchers are successful in their efforts to create biologically self-healing concrete. The process embeds calcite-precipitating bacteria into concrete paste, so that when cracks occur, the microorganisms can secrete a mineral that will fill those fractures. It’s a cool example of biology-inspired engineering, and was mentioned as part of the New York Times’ interesting “What’s Next in Science?” feature this week.

Two exciting studies from the other side of the University of Chicago campus came out in this week. In the first, Chuan He in the Department of Chemistry helped characterize the activity of “the most exciting protein family now in biology,” a DNA repair protein called AlkB. In charge of demethylating DNA, AlkB has the power to re-activate silenced genes, a valuable epigenetic function that could someday be harnessed to treat diabetes, obesity, and cancer. The study also utilizes a delightful science word to describe one of the protein’s intermediate states: “zwitterionic,” when an object has a neutral charge, but acts positive or negative when interacting with other objects.

In another study, University of Chicago psychologist Susan Levine found that a child’s early exposure to mathematics can influence later success in the subject. Researchers videotaped interactions between parents and their children when they were between the ages of 14 and 30 months, counting how many “number words” were used by the parents. When the children were given a simple math test at the end of the experiment, those that heard more about math from their parents tended to perform better.

Today and tomorrow, the MacLean Center for Clinical Medical Ethics will hold its 22nd annual conference, a two-day festival of ethical lectures and discussion. Today’s session will expand upon the local, national, and global health disparities theme of the center’s weekly seminar series, while the second day takes a broader approach with topics such as pediatric ethics, palliative care, transplant medicine, and a session dedicated to the memory of faculty member Stephen Toulmin. The schedule is available here (pdf), and we’ll have coverage of the conference next week.

ScienceLife is very excited to have gotten in during the very brief window that registration for Science Online 2011 was open this week. The “unconference,” held in North Carolina in January brings together a dream team of science bloggers for open discussions and workshops on the growing field of internet science journalism. Expect to hear more about it.

Posted by - Rob Mitchum

Linkage 4/16: The Warm Glow of Tax Day

Posted at 10:17 am CT on April 16, 2010

751px-tea_party_sign_-_taxpayer_march_on_washingtonTaxation With Neural Representation

Hopefully, all of you reading remembered that yesterday was that least enjoyable of holidays, the deadline to file taxes. If you didn’t remember, um, sorry. The act of filling out and paying taxes is known anecdotally to produce feelings of nausea, panic, and in some cases, language deficits. But is there any scientific evidence for an actual effect of taxation upon physiology?

Actually, there is! In 2007, University of Oregon scientists in the field of neuroeconomics, a relatively young discipline devoted to studying how financial decisions are encoded by brain activity, published in Science an experiment on how our brains react to taxation vs. donation. Using fMRI to take live images of neural activity, William Harbaugh and colleagues gave subjects $100 and ran them through trials where they either had the choice of donating money to a food bank or were “taxed” in the form of a mandatory donation. People reported that they were 10 percent more satisfied with the voluntary donation compared to the mandatory donation - not a big surprise. But the brain also reflected these different reactions; even though the money went to the same place (the food bank), a voluntary donation more strongly activated brain areas usually associated with reward such as the striatum, nucleus accumbens, and caudate nucleus.

I wrote about the study when it came out for the Chicago Tribune, but focused mostly on the “warm glow” effect of altruism as a potential motivator for the seemingly self-injurious process of donating money. But one could also turn it around the other way and say that the mandatory donation, or taxation, was significantly less rewarding, both in subject’s lower self-reported satisfaction and reduced brain activity. It’s likely that the aversive experience of taxation was even under-measured by this study, where subjects knew where those mandatory taxations were going: to a food bank, hardly a politically controversial cause. Presumably, if money was merely taken away from subjects’ accounts without a subsequent bump in the food bank’s accounts, the response would have been even more negative.

Checking Harbaugh’s site (where you can watch a video of the 3rd James Bond explaining this study), it doesn’t appear that any followup studies have been published as of yet that could better illustrate the brain’s response to taxation. The lessons for real life are also unclear; presumably it would make us all feel better to make voluntary donations rather than have to fill out tax forms every April, but that seems to rely a bit too much on the honor system to keep government services funded. Perhaps the IRS can borrow a portion of the study’s findings and blunt the pain of taxes just a bit by being more clear about where taxes are going - an educated taxpayer may find the experience at least marginally less miserable.

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Posted by - Rob Mitchum

Linkage 4/9: Birdsong Genes & Super Heavy Names

Posted at 11:18 am CT on April 9, 2010

sleeping_bird300dpi1Another species added to the library of sequenced genomes: the zebra finch. Published in Nature and explained in the New York Times, the finchonome could provide answers about the development of language and - most intriguingly - the epigenetic influence of language upon gene expression. Previous studies have shown that gene expression changes in finches that are singing or listening to birdsong, and the Nature study discovers that those expressed proteins, in turn, have effects upon other genes. This cascade effect is very large - the act of singing alone changes the expression of more than 800 genes! Our very own Daniel Margoliash studies birdsong learning in zebra finches, and is no doubt excited to have the entire genome to play with in his research.

Earlier this week, scientists in Russia and the US plugged a hole in the periodic table with the discovery of element 117, a super-heavy element which flashed into existence for a total of 78 milliseconds. The element currently bears the placeholder name of ununseptium - fancy Latin for element #117 - so the fun part now comes in naming the particle. Recent element naming has gotten creative, with names like Copernicium, Promethium, and the rather presumptuous Nobelium, so everyone’s got an idea for #117: see the naming suggestions on twitter for a funny read. My personal submission evokes the element’s super-heaviness: Sabbathium.

Daniel Levitin reviews Nature editor Philip Ball’s new book, The Music Instinct: How Music Works and Why We Can’t Do Without It, and nails a succinct answer for the question in the title:

The secret to composing a likeable song is to balance predictability and surprise. Because most music has a beat and is based on repetition, we know when the next musical event is likely to happen, but we don’t always know what it will be. Our brains are working to predict what will come next. The skillful composer rewards our expectations often enough to keep us interested, but violates those expectations the rest of the time in interesting ways.

Cool news from the other side of campus: the University of Chicago Oriental Institute has uncovered an 8,000-year-old city in Syria, one of the oldest civilizations ever discovered. Called Tell Zeidan, the site is expected to yield decades of data about what life was like in the 5,000s and 4,000s BC - Oriental Institute director Gil Stein told the New York Times, “I figure I’m going to be working there till I retire.” It’s enough to make a biologist jealous.

I am pro-stem cell research, of course, but am still slightly creeped out by the anthropomorphic stem cells in this children’s book, Super Stemmys: Doris and the Super Cells, which has drawn mixed reviews from scientists according to, er, The Scientist.

More cool things happening at Argonne that I barely understand: a green way for making the decidedly un-green-sounding chemical propylene oxide (money quote: “This is basically a holy grail reaction.”) and a venus fly-trap for radioactive waste, gamely tackled by Ted Gregory of the Chicago Tribune.

With good timing for Masters week, Jonah Lehrer talks to University of Chicago associate professor of psychology Sian Beilock about her studies on clutch performance in golfers.

Posted by - Rob Mitchum

Bird Sleep & Human Memory (Video)

Posted at 11:41 am CT on January 13, 2010

starling2If we’re lucky, we spend about one-third of our lives sleeping, a fact that appears on its face to be a colossal waste of time. Wouldn’t us humans  be able to get so much more done if we weren’t required to shut down for 8 hours a night? But the fact that the need for sleep is shared across the majority of animal species indicates that there must be some important role that the behavior plays, otherwise evolution would have likely done away with it millions of years ago.

The laboratories of Daniel Margoliash and Howard Nusbaum at the University of Chicago focus on how birds and humans learn to use language. But over the past decade, their research has also discovered some pretty interesting things about the role that sleep plays in language learning. In Margoliash’s laboratory, studies of juvenile zebra finches learning to sing found that the brains of birds will “replay” in sleep the symphony of neural activity that was present during the day when they listened to song. Separate human studies by Margoliash and Nusbaum found that sleep helped stabilize the learning of a language perception task - college students learning to comprehend computer-generated speech similar to heavily-accented English performed better on the task after a night’s sleep.

The latter experiment tested the principle of memory consolidation, the process by which short-term memories are stabilized into long-term storage. Sleep’s role in facilitating consolidation has been studied in many different ways in humans, including a 2008 paper by Timothy Brawn and Kimberly Fenn with Margoliash and Nusbaum that found that sleep enhanced people’s ability to learn how to play a first-person shooter video game. But despite accumulating evidence in humans that sleep-dependent consolidation was a real phenomenon, a true animal model had not yet been established. So Brawn once again used the unique partnership between Margoliash and Nusbaum to demonstrate that the stabilization of memories through sleep was not a uniquely human characteristic, but was also present in a bird species, the starling.

In the video below, you can hear Brawn, Margoliash and Nusbaum talk about the experiment, which was published today in The Journal of Neuroscience. You can also watch one of the experimental subjects - a starling - perform the learning task that was used in the experiment, called a “go-nogo” task. After a day of learning what birdsong cue signaled them to poke their beaks into a hole to receive food, and what cue meant to avoid poking, the starlings were tested before and after a period of sleep. As in humans, sleep improved the starlings’ performance of the task, suggesting that sleep-dependent consolidation is a common feature of at least two species.

“We really wanted to behaviorally show that these types of sleep-dependent memory benefits are occurring in animals,” Brawn said. “What was remarkable was that the pattern here looks very similar to what we see in humans. There wasn’t anything that was terribly different.”

Now that the similarities between birds and humans have been proven for this phenomenon, the story is just beginning. Further experiments in the starlings will look for the mechanisms of how sleep-dependent consolidation occurs, offering clues to how memories are stabilized in the brain that would be difficult or impossible to gather from human studies alone.

“The result suggests this is a very broad, general phenomenon that might be shared across a great many vertebrates,” Margoliash said. “It was quite important to show that and it now opens the possibility for mechanistic and behavioral experiments in animals that are difficult to do in humans.”

Posted by - Rob Mitchum

The Hopeful Monster of Human Language

Posted at 8:41 am CT on November 12, 2009
A sleeping zebra finch (image courtesy of Margoliash lab)

A sleeping zebra finch (courtesy of Margoliash lab)

One of the repeated themes of the Darwin/Chicago 2009 meeting two weeks ago was the history of the anti-evolution movement, a resistance that has actually changed form, even *cough* evolved, quite a bit since The Origin of the Species. At the opening night event in Rockefeller Chapel, science historian Ronald Numbers talked about differences between the anti-Darwinists led by William Jennings Bryan in the 1920’s (immortalized in the Scopes Monkey Trial and Inherit the Wind) and today’s intelligent design supporters and creationists. Surprisingly, Bryan and his followers were considerably less extreme than today’s anti-evolutionists, as Numbers explained that most who railed against Darwinism in the early 20th century were fine with the evolution of animals over billions of years, they merely could not abide that humans also evolved.

The evolution vs. creation debate has obviously become a lot more complicated since then, but Bryan’s primary objection has lingered - the core of most people’s opposition to evolution is the idea that humans must be somehow separate and different from the rest of the natural world. One “proof” of this uniqueness is the complexity of human language, a form of communication that, to the casual observer, appears in an entirely different league from the songs, gestures, or simple noises that animals use to share information. The assumption that the more complex forms of human language are unique is even held by some in the field of linguistics and psychology, including the legendary Noam Chomsky, who argued as much in a 2002 Science paper with cognitive psychologist (and Darwin/Chicago speaker) Marc Hauser.

That assumption is a handicap to the study of language, argue University of Chicago’s Daniel Margoliash and Howard Nusbaum in a recent issue of the journal Trends in Cognitive Science. The idea that human language is biologically unique, and thus the kind of “hopeful monster” geneticist Richard Goldschmidt coined to describe the sudden appearance of a new feature in evolutionary history, walls off language from the world of biology. Perceiving human language in its proper evolutionary context, and thus exposing it to the tools of comparative biology, will allow scientists to fully understand how language works and where it originated, Margoliash and Nusbaum conclude.

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Posted by - Rob Mitchum

Hockey, Language and the Brain

Posted at 4:43 pm CT on August 17, 2009
Hockey players conducting hands-on research

Hockey players conducting hands-on research

If you had to pick a group of researchers who would be interested in hockey, you’d probably first think of dentists, not psychologists. Certainly you wouldn’t consider hockey players an ideal subject pool for mapping the brain’s language pathways, unless you were uniquely interested in the comprehension of French-Canadian slurs.

But hockey players and their brains were perfectly suited for the lab of Sian Beilock, a University of Chicago psychologist looking to study whether experts in an action-based field - such as one involving pucks, sticks and skates - process language differently than those with little experience in the field. Professional and college hockey players, as well as hockey fans and hockey novices, sat in MRI machines while they heard sentences about hockey (“The hockey player knocked down the net.”) or more mundane topics (“The individual closed the book.”). The resulting images revealed that people who play hockey for a living exhibit a unique pattern of brain activation when they hear sentences about their sport, suggesting that experience can shape the way humans comprehend language at its most basic level.

It may not be surprising that people who spend dozens of hours a week practicing slap-shots and fore-checking have a deeper understanding of their sport’s terminology than someone who thinks a hat trick is a Charlie Chaplin bit. But Beilock, an associate professor of psychology at U. of C., said nobody previously had viewed modulation of language pathways as a function of an individual’s motor expertise. In fact, psychologists long considered language and one’s ability to shoot a puck to be unrelated processes in the brain, never sharing information.

“People used to often talk about language as being a very specific cognitive activity in a very specific part of the brain,” Beilock said. “What we’re showing is that people with experience in acting out things they might read, hear or talk about seem to call upon not just traditional language areas when hearing information, but seem to call upon areas involved with acting out things the language depicts.”

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Posted by - Rob Mitchum