Wednesday 17 November 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge


Jet Lag May Cause Stupidity

Posted: 16 Nov 2010 05:03 PM PST

SAN DIEGO — In addition to making you groggy and dazed, jet lag may make you stupid. A study presented November 15 at the annual Society for Neuroscience meeting finds that hamsters suffering extreme, chronic jet lag had about half the normal rate of new neuron birth in a part of the brain. What's more, these animals showed deficits in learning and memory.

Jet lag poses a serious health threat, said study coauthor Erin Gibson of the University of California, Berkeley. Studies have shown that people with work schedules that require them to frequently change their sleep patterns have higher rates of cardiovascular diseases, diabetes and cancer.

Gibson and colleagues subjected hamsters to jet lag by advancing their day and night schedule by six hours every three days for nearly a month. "It would be like a flight from New York to Paris every three days," Gibson said. The hamsters' total sleep amount didn't change, but the hours spent awake and asleep were completely unrelated to the external environment, like an East Coast businesswoman popping out of bed at 3 a.m. in California.

Jet lag decreases the numbers of new neurons being born in the hippocampus by about 50 percent, the team found. Mental function suffered, too: The jet-lagged hamsters were worse at learning which of two chambers contained a desirable running wheel. Even after 28 days of a back-to-normal schedule, the formerly jet-lagged hamsters still showed learning and memory problems. The mismatch between the internal body clock and the external environment "is having a long-term effect on learning and memory," Gibson said.

It's unclear exactly how these cognitive problems are induced by jet lag. The sleep hormone melatonin, stress and increased cell death are all possible culprits that need to be explored, Gibson said.

 

Image: Flickr/caribb

See Also:

Physicists Tame Bird Songs With Statistics

Posted: 16 Nov 2010 03:07 PM PST

The notoriously complex song of the finch has finally succumbed to statistics. Physicists have developed a model that can map out and predict the notes birds sing in sequence.

The new model is roughly eight times more accurate than previous attempts to unravel complex bird songs. If the scientists can use the same technique to map and predict chatter in other social animals, they could find important clues about the neural origins of complex language, including that of humans.

"We want to gain an understanding of this simplest case, then work our way up in complexity," said physicist Dezhe Jin of Penn State University who led the research, posted Nov. 12 on arXiv.org.

Birdsong originates at the top of a bird's brain in an area called the HVC, or higher vocal center, which is made up of about 40,000 neurons. Networks of thousands of individual neurons there are thought to generate syllables, and these neural networks link up to other areas of the brain to actually vocalize the sounds.

Mapping the sounds and their sequence in a song may help resolve such language-centric brain pathways.

"We think it's like a domino effect, where one syllable cascades into the next to create complex songs," Jin said. "But before neural coordinates can be verified, we need to have robust statistical maps."

 

Jin stuck a Bengalese finch in a soundproof room for six days with a microphone. The bird tweeted more than 25,000 times, sounds that Jin and his team divvied up into 25 groups based on statistical similarity. In total, the finch sang seven distinct song syllables (sounds made very quickly one after the other) and 14 other types of notes.

Unlike previous models, which skyrocket in error when trying to predict more than one note in sequence, the new model factors in the order of previous notes. It also takes into account the fact that different neural networks may produce the same syllable which, Jin says, provides a subtle but crucial detail in correctly mapping and predicting a song's syllables.

No model will ever be able to predict a bird's song with 100 percent accuracy because they improvise as they go, like jazz musicians, Jin said. But they may be able to get close enough to begin to understand what's happening in the bird's brain.

"This is really the beginning of finding how song and language structure originates," Jin says. "We want to further study other species and apply that knowledge to humans."

Images: 1) Spectrograms of song notes (top / a), call notes (middle / b) and a song sequence (bottom / c). Song syllables are marked by letters A-G while call notes are marked by C1, C2, etc. The duration of each sound is listed in milliseconds. Jin et al. 2) A probabilistic map of notes in a bird's song sequence. The pink oval represents the start note while blue ovals represent notes that the bird may end on. 3) A zebra finch, which belongs to the society finch group (the same as Bengalese finches). Flickr/jessi.bryan

Via: Technology Review

See Also:

Follow us on Twitter @davemosher and @wiredscience, and on Facebook.

Earth as Art: Stunning New Images From Space

Posted: 16 Nov 2010 12:39 PM PST

<< Previous | Next >>

Earth is truly beautiful when viewed from space. But add some false color produced by satellite sensors, and the result is stunning.

The U.S. Geological Survey released a new selection of particularly interesting images from the Landsat 5 and Landsat 7 satellites. These space craft have been prolific sources of data for earth scientist, but the new shots were chosen solely based on aesthetics.

We've selected our favorites from the USGS's Earth as Art collection in this gallery, which will take you on a tour of the world from the glaciers of Antarctica to the deserts of Algeria.

Images and captions courtesy of the USGS. High resolution images.

Above: Great Salt Desert, Iran

Like poster paints run wild, this image reveals an eclectic montage of landscapes in Iran's largest desert, the Dasht-e Kavir, or Great Salt Desert. The word kavir is Persian for salt marsh. The almost uninhabited region covers an area of more than 77,000 square kilometers (29,730 square miles) and is a mix of dry streambeds, desert plateaus, mudflats, and salt marshes. Extreme heat, dramatic daily temperature swings, and violent storms are the norm in this inhospitable place.

Image taken by Landsat 7 on Feb. 10, 2003

<< Previous | Next >>

 

Images: USGS/NASA

See Also:

Leonid Meteor Shower Peaks Wednesday

Posted: 16 Nov 2010 11:37 AM PST

Wake up early and look up tomorrow: The annual Leonid meteor shower is expected to peak in the hours just before dawn Wednesday and Thursday.

The Leonids come every year in November, when the Earth passes through a cloud of debris trailing the comet Tempel-Tuttle. When the dust Tempel-Tuttle leaves behind smacks into Earth's atmosphere, the specks vaporize and blaze across the sky.

It's hard to predict how intense each shower will be, but astronomers expect this year's Leonids to produce at least 20 meteors an hour. The full moon will set several hours before dawn, so its glare won't interfere with the show.

The Leonids get their name because they appear to fly from the constellation Leo, a backwards-question-mark–shaped collection of stars in the eastern sky.

To check when the best viewing times are in your area, check out this flux calculator applet developed by two meteor hunters at the SETI Institute.

If you want to take photos of the meteor shower, head away from city lights and send us your best shots — if we get enough good ones, we'll compile them into a gallery.

Image: Flickr/Dominic's pics

See Also:

Follow us on Twitter @astrolisa and @wiredscience, and on Facebook.

How Wii and Kinect Hack Into Your Emotions

Posted: 16 Nov 2010 04:00 AM PST

Nintendo's Wii game console may owe some of its extraordinary success to emotions that are triggered by specific movements: It might essentially be using your body to hack into your brain.

A better understanding of which motions trigger which emotions might not only lead to better games, but could one day help improve the iPhone, iPad and other gesture-based and multitouch interfaces as well.

"There's no reason why dealing with a spreadsheet or sorting e-mail couldn't be as wonderful as tai chi," said computer and social scientist Katherine Isbister at NYU's Polytechnic Institute in Brooklyn. "Games are the perfect ecosystems for evolving fun, and hopefully we might be able take those lessons elsewhere."

The Nintendo Wii introduced physical movements to gaming consoles and in just four years became the fastest-selling console of all time. Now Isbister and her colleagues are investigating how Wii games can make us feel by mapping the responses certain movements and gestures evoke.

For example, in "Star Wars: The Force Unleashed," a player can fling an object or a person to the ground, using a hurling motion with the nunchuk part of the Wii controller, creating a feeling of aggression.

"You can make people feel all kinds of ways with movements, which could be the science of what makes the Wii so engaging," Isbister said. "A lot of these games have stumbled upon doing this already without realizing the social science underlying it."

 

Numerous studies have shown that movements or postures generate cues the mind can use to figure out how it feels, a phenomenon dubbed the physical-feedback effect. Wii games might also create emotions between people through "emotional contagion," where the brain can make us feel what we see, hear, read or think others experience.

'Designing interaction as if we did not have any body or emotion is detrimental to what it means to be human.'

The scientists are categorizing motions seen in Wii games using a system developed by famous early 20th-century dance researcher Rudolf Laban, who codified movements based on factors such as whether they were fast or slow, light or heavy.

In addition to experimenting with games that are bestsellers or have the best reviews, as well as the ones recommended by developers, they are also using minigames they devised themselves to test players with specific movements. One such game, which they call Wriggle, examines head wobbling and body tilting. The researchers take video of people while they play, capture their movement data and interview them before and after playing to see if and how their moods change.

Preliminary findings reveal that not only is the type of motion important, but the quality of it can be, too. For instance, while both Boogie Superstar and Wii Cheer involved copying dance moves, participants in tests enjoyed the latter far more than the former, saying they felt constrained and mechanical in Boogie Superstar and flowing and buoyant with Wii Cheer.

There are many directions the researchers could explore with the Wii, Isbister noted. For instance, they are developing mini-games to analyze movement's social effects, such as Torch, where partners collaborate to pass a flame from one pillar to another. "Physically being in sync can lead to feelings of liking or trust. You can make people feel more connected." Isbister said. "On the whole, cooperative game mechanics seem underdeveloped on the Wii so far, and so could be an open area of opportunity."

Future work could also integrate motions more deeply into a game's story, Isbister suggested. "One really wonderful thing you can do with games is identify with protagonists, to go on the hero's journey, and imagine how much one could feel what they feel if players learned to stand and move the same way — to go, say, from a hesitant posture to a confident one," she explained.

In addition to such work potentially influencing interactions with current multitouch and gesture-based interfaces, the researchers also are looking forward to studying new systems such as Microsoft's Kinect, which tracks player motions with a camera rather than a remote. That system may more-easily incorporate whole-body motions into games, which could be more engaging than just moving parts of the body. Also, the Kinect could recognize moods such as frustration, by looking at body posture and adjust games to be easier, suggested researcher Ulf Schwekendiek at NYU-Poly.

Isbister's research will naturally help in the design of movement-based games, "an area that has been and will continue to grow over the years to come," human-computer interaction researcher Kristina Höök at Stockholm University in Sweden wrote in an e-mail. "But given the development in mobile and ubiquitous technology, we will see more and more full-body interaction and gestures used also in other kinds of applications — social and emotional communication between users, interaction with services built into our environment, playful applications outside the games realm, interactive art, and creative tools for end-user TV-production using only mobiles."

"We already swipe our prepaid subway card over the RFID reader — that movement should be made pleasurable and not only functional," Höök said. "We tilt our mobile to change the direction of the screen. We place sensors in our sports shoes. All these kinds of interactions needs design knowledge of how movement feels — otherwise, interaction will feel awkward, misplaced and tedious to perform in the long run."

"Designing interaction as if we did not have any body or emotion is detrimental to what it means to be human," Höök said. "Isbister's work is at the heart of what it means to be human."

Isbister and her colleagues will detail their findings in a chapter in the book Whole Body Interaction late this year or early next, and will also present their work at the CHI conference in May 2011 and at the Foundations of Digital Games conference in June and July of 2011.

Image: Flickr/Ted Van Huisen

See Also:

Movie Soundtracks Mimic Primordial Sounds of Animal Distress

Posted: 16 Nov 2010 03:00 AM PST

Without even knowing it, movie soundtrack makers appear to mimic the sounds of animals in distress.

Biologists analyzed sound patterns in movies of war, horror, action and old-fashioned drama in a study to be published in Biology Letters. They compared the noises to what animal-communication researchers know as "nonlinear vocalizations."

That technical term spans what bioacousticians describe in terms of "noise and deterministic chaos, sidebands and subharmonics, and abrupt amplitude and frequency transitions," and most anyone else refers to as screeches of alarm. (In particular, lovers of "Meerkat Manor" and bioacousticians alike appreciate those animals' unique calls.)

The harshness and unpredictability of these sounds is thought to be a vocal adaptation fine-tuned for quickly capturing a listener's attention. And if that's true, then "we might expect them to be also used by film-score composers and audio engineers to manipulate the emotions of those watching a film," hypothesized University of California, Los Angeles biologist Daniel Blumstein and his Biology Letters co-authors.

Guided by best-of polls from various internet film sites, Blumstein's team extracted the soundtrack of pivotal scenes in 102 classic movies, from Lawrence of Arabia to Aliens. They fed the recordings into analytical tools designed by bioacousticians at the Cornell Lab of Ornithology.

 

When all the diegetic noise and abrupt amplitude fluctuations and changes in tonal frequency bands were added up, the soundscapes of those key scenes resembled animal alarm calls.

"The use of these simulated nonlinearities is not random, but rather appears to be specifically used to enhance the emotional impact of scenes," wrote the researchers, noting the non-linear attributes of distorted electronic electronic guitar and flutter-tongued flutes. Of course, directors often borrow directly from the sounds of animals, a la King Kong's roars. Though perhaps the most horrifying animal sound of all, the eponymous language of Alfred Hitchcock's The Birds, was generated entirely on the Trautonium.

The researchers do not directly address whether non-linear vocalization analogues became part of the cinematic vernacular through conscious emulation of the animal world, or because it just felt right. Even at our most refined, an ancient nature seeps through.

Image: Monkeysox/Flickr.

See Also:

Citation: "Do film soundtracks contain nonlinear analogues to influence emotion?" By Daniel T. Blumstein, Richard Davitian and Peter D. Kaye. Biology Letters, Vol. 6 No. 6, December 23, 2010.

Brandon's Twitter stream, reportorial outtakes and citizen-funded White Nose Syndrome story; Wired Science on Twitter.