music · neuroscience

Listen with your skin

That’s right. We humans listen to music with our skin!

Totally stolen from Not Exactly Rocket Science:

What part of the body do you listen with? The ear is the obvious answer, but it’s only part of the story – your skin is also involved. When we listen to someone else speaking, our brain combines the sounds that our ears pick up with the sight of the speaker’s lips and face, and subtle changes in air movements over our skin. Only by melding our senses of hearing, vision and touch do we get a full impression of what we’re listening to. 
When we speak, many of the sounds we make (such as the English “p” or “t”) involve small puffs of air. These are known as “aspirations”. We can’t hear them, but they can greatly affect the sounds we perceive. For example, syllables like “ba” and “da” are simply versions of “pa” and “ta” without the aspirated puffs. 
If you looked at the airflow produced by a puff, you’d see a distinctive pattern – a burst of high pressure at the start, followed by a short round of turbulence. This pressure signature is readily detected by our skin, and it can be easily faked by clever researchers like Bryan Gick and Donald Derrick from the University of British Columbia.
Gick and Derrick used an air compressor to blow small puffs of air, like those made during aspirated speech, onto the skin of blindfolded volunteers. At the same time, they heard recordings of different syllables – either “pa”, “ba”, “ta” or “da” – all of which had been standardised so they lasted the same time, were equally loud, and had the same frequency.
Gick and Derrick found that the fake puffs of air could fool the volunteers into “hearing” a different syllable to the one that was actually played. They were more likely to mishear “ba” as “pa”, and to think that a “da” was a “ta”. They were also more likely to correctly identify “pa” and “ta” sounds when they were paired with the inaudible puffs.
Read the full post, complete with charts, graphs, and all! 

Large Prehistoric fauna and you

Featured in the New York Times:

Whenever modern humans reached a new continent in the expansion from their African homeland 50,000 years ago, whether Australia, Europe or the Americas, all the large fauna quickly disappeared. [Editorial comment: Hmmm, not exactly true, but I’ll go with it for now]

This circumstantial evidence from the fossil record suggests that people’s first accomplishment upon reaching new territory was to hunt all its all large animals to death. But apologists for the human species have invoked all manner of alternative agents, like climate change and asteroid impacts [I am not one of these, for the record, but I don’t think we were that well coordinated or that large a community to hunt out all the big fauna in North America].

A careful analysis of lake deposits in New York and Wisconsin has brought new data to bear on this heated debate. A team led by Jacquelyn Gill, a graduate student at the University of Wisconsin, has uncovered a critical sequence of events that rules out some explanations for the extinction of the large animals and severely constrains others.

The first event documented by Ms. Gill and her colleagues is the pace of extinction in North America, known from other research to have affected all animal species over about 2,200 pounds and half of those weighing more than about 70 pounds, the weight of a large dog.

Ms. Gill found a clever proxy for these disappearances. A fungus known as Sporormiella has to pass through the digestive system to complete its life cycle, and its spores are found in animal dung. By measuring the number of spores in the lake deposits, the Wisconsin team documented the steady disappearance of large animals from 14,800 years to 13,700 years ago, they reported in Thursday’s issue of Science.

The next clue to emerge from the lake deposits was the pollen of new plants including broad-leaved trees like oak. This novel plant community seems to have emerged because it was released from being grazed by large mammals.

The third clue is a layer of fine charcoal grains, presumably from fires that followed the buildup of wood.

This sequence of events has direct bearing on the megafauna whodunit. First, it rules out as the cause an impact by an asteroid or comet that occurred 12,900 years ago — the animals were dead long before.

It also excludes the standard version of a more popular explanation, that of habitat loss due to climate change. The extinction of large animals occurred before the emergence of the new plant communities. Ms. Gill said that some other aspect of climate, like direct temperature change, could have been involved [so it WAS climate change, then?].

The third suspect to be cleared is the people of the Clovis culture [editorial comment: well, duh!!!!], which first appeared some 13,000 years ago, well after the extinction event. The Clovis people have long been considered the first inhabitants of North America, which they probably reached by trekking across the land bridge that joined Siberia and Alaska during the last Ice Age.

So, do the new data exculpate humans of the murder of the North American mammoth? Not exactly. Butchered mammoth bones some 14,500 years old have been found in Wisconsin. There were evidently pre-Clovis people in North America, and they could have hunted the large animals to death. [no, no, look at frequency, not presence/non-presence of scraping on bones. Humans are also scavengers and opportunistic meat eaters]

But Ms. Gill is not yet willing to declare people guilty. “At this stage it’s too early to completely eliminate climate change,” she said.

Nor is it clear that the pre-Clovis people had the technology to take down large game like mammoths. [you can take down mammoth by driving them off a cliff, but I’ll go with this for now]. Ms. Gill plans to analyze many more lake bottoms before rendering any final verdict.

Am I just being grumpy here, or does this article sort of miss the point, or try to keep the “mystery alive” just for a good story? Interesting research, however.


Why chimps don’t talk?

All the news came out last week about the FOXP2 gene, but I can’t help and post it here a week late anyway:

Chimps, our nearest relative, don’t talk. We do. Now scientists have pinpointed a mutation in a gene that might help explain the difference.

The mutation seems to have helped humans develop speech and language. It’s probably not the only gene involved, but researchers found the gene looks and acts differently in chimps and humans, according to a study published online Wednesday by the journal Nature.

Lab tests showed that the human version regulated more than 100 other genes differently from the chimp version. This particular gene — called FOXP2 — mutated around the time humans developed the ability to talk.

“It’s really playing a major role in chimp-human differences,” said the study’s author, Daniel Geschwind, a professor of neurology, psychiatry and human genetics at the University of California, Los Angeles. “You mutate this gene in humans and you get a speech and language disorder.”

This tells you “what may be happening in the brain,” he said.

Read the full Associated Press story.


Mummies had clogged arteries

A recent study of mummies found a significant number of the elite mummies (which most were) had clogged arteries, calcification of vessels, and other symptoms of heart disease and obesity.

This has been found before, but this is the largest study so far.

The BBC article I read suggested it was caused by the supposed large amounts of fatty meats being eaten by the elite.

However, as I suspected he might, Rafe said “There’s currently a bit of discussion on GNXP (Gene Expression). Michael Eades, auther of Protein Power, has published in the past showing that the Egyptian elite were in fact obese quite regularly, and attributes it to a diet that was very high in grains combined with a sedentary lifestyle, not the high in meat diet proposed in the BBC article.”

Quoted from Science Daily: “UC Irvine clinical professor of cardiology Dr. Gregory Thomas, a co-principal investigator on the study, said, ‘The findings suggest that we may have to look beyond modern risk factors to fully understand the disease.'”


children · gender · play

Effects of prenatal exposure of phthalates in boys

First came across this in Discover Magazine:

A new study in the International Journal of Andrology has raised a storm of concern that prenatal exposure to these chemicals could make boys less masculine in their play preferences.

Phthalates, which block the activity of male hormones such as androgens, could be altering masculine brain development, according to Shanna H. Swan, a professor of obstetrics and gynecology at the University of Rochester Medical Center and lead author of the new report [Los Angeles Times]. To test whether that link extended into behavior, Swan’s team tested women for phthalate levels midway through their pregnancy and then checked back in on the children four to seven years later.

The researchers asked parents to report their children’s patterns of play, but they knew they also had to separate any potential phthalate effect from the “nuture ” side of question. To determine how parental views might sway behavior, parents completed a survey that included questions such as, “What would you do if you had a boy who preferred toys that girls usually play with?” They were asked to respond with whether they would support or discourage such behavior, and how strongly [TIME].

The study of about 150 kids found that while girls were mostly unaffected, boys who had been exposed to the highest phthalate levels showed a lower likelihood than other boys to participate in what we consider typical rough-and-tumble male recreation—play fighting, pretending to play with guns, and so on. But the research might not imply the national masculinity crisis that some headlines suggest. Play in the most highly phthalate-exposed boys wasn’t “feminized,” Swan explains, since these kids didn’t preferentially play with dolls or don dresses. Rather, she says, “we’d describe their play as less masculine” [Science News]. Rather than play-fighting, she says, those boys tended toward “gender neutral” play like putting puzzles together or competing in sports.

Read full article here.



I know this is OLD news at this point, but it is still so cool! This comprehensive (I think) compared vocalizations made by different apes, including us, and found them to be all pretty similar.

Ha ha!

And, some new research on rats being tickled: The Woody Allen/Eeyore type rats of the world don’t like being tickled (yikes, I hate being tickled, so what does that say about me? That I’m an Eeyore of the people world?)

disease · school

Oh sure, blame the primates

Poor guys get in trouble for everything.

First a new strand of AIDS found in Gorillas (and a woman in Cameroon), and now the poor chimps are getting blamed for Malaria.

Seriously, people, can’t we take a little responsibility?
(total side note, but I mean it! Some student is suing her college because she can’t find a job. In a recession. After less than three months of searching. Grow up!)


Update on Baboon buddies

So my last post dealt with baboons making male/female relationships. The authors of the paper basically said because the dudes weren’t getting sex out of the females they didn’t see what the males were getting out of it. The females did get harassed less.

WELL, I just happened to be listening to an archived episode of Radiolab, probably a couple of years old, and they interviewed Robert Sapolsky, author of Why Zebras Don’t Get Ulcers and a studier of all things stressful. Sapolsky primary animal of study is baboons. In this interview, Sapolsky discussed this same phenomenon, where males will hang out with females, not for sex, just for companionship. Sapolsky actually seemed to imply that the males got more out of the relationships than the femmes. Why:

1. The males WERE in fact having sex more frequently with females in this troop of baboons.
2. When a dominant male gets old and loses his status, he is in essence drummed out of the troop, about half the time fleeing to a new troop where he is still lower on the totem pole but less harassed overall. HOWEVER, the half that don’t leave the troop are the ones who formed friendships with the females.

Ha ha! Having females as your allies is a political and evolutionary good idea for baboons. So it works out well for everyone involved.

There are probably different cultures of baboon troops, but it’s nice to know that at least for some male baboons it pays to have female friends.


Assembling Bodies

From my other blog, Art of Science:

From Material World:

Details of some of the objects shown in Assembling Bodies. © MAA.

How do we know and experience our bodies? How does the way we understand the human body reflect and influence our relations with others?

Assembling Bodies: Art, Science & Imagination is a major interdisciplinary exhibition at the Museum of Archaeology and Anthropology (MAA) University of Cambridge, open from March 2009 to November 2010. Curated by Anita Herle, Mark Elliott and Rebecca Empson, the exhibition explores some of the different ways that bodies are imagined, understood and transformed in the arts, social and biomedical sciences. They displays showcase Cambridge’s rich and diverse collections, complemented by loans from national museums and exciting contemporary artworks. It brings together a range of remarkable and distinctive objects, including the earliest stone tools used by human ancestors, classical sculptures, medieval manuscripts, anatomical drawings, scientific instruments, the model of the double helix, ancestral figures from the Pacific, South African body-maps and kinetic art.

The idea of assembly evokes two distinct but overlapping themes that underlie the exhibition. Jim Bond’s kinetic sculptures illuminate one notion of assembly – the process of putting something together, of creating something new from component parts. Positioned at the entrance to the gallery, Atomised (2005) (below) is triggered by the movement of visitors into the gallery. An openwork human figure is pulled apart and put together by external telescopic ‘arms’.

Read full post and see more pictures at Material World.

Atomised. Jim Bond. Animated Sculpture, 2005


How to make your own primordial soup

A team discovered how to get RNA molecules to not only replicate, but how to grab other useful pieces of RNA, attach them to their string, and replicate themselves with the new pieces. This in effect mirrors how DNA started replicating itself and getting more complicated, thereby creating a primordial noodle dish. Bon Appetite!