Science Digest

MIT Model Predicts Accelerating Warming Trends

Who was that masked man? People of a certain age and a certain talent might recognize Clayton Moore decades after his role as the Lone Ranger. Research suggests that some have a heightened ability to recognize faces.
Who was that masked man? People of a certain age and a certain talent might recognize Clayton Moore decades after his role as the Lone Ranger. Research suggests that some have a heightened ability to recognize faces. (Associated Press)
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Monday, May 25, 2009

Hotter and Hotter

If an unusually detailed computer simulation at the Massachusetts Institute of Technology has it right, global warming in this century is on track to be about twice as bad as predicted six years ago.

The MIT model is said to be the only one that incorporates among its variables possible changes in economic growth and other human activities and draws on peer-reviewed science on the climatic effects of atmospheric, oceanic and biological systems.

After running the model 400 times with slight variations in the inputs, the new predictions are for surface temperatures to warm by 6.3 to 13.3 degrees Fahrenheit. The prediction is for a 9.4-degree increase in the median temperature, more than double the 4.3 degrees predicted in a 2003 simulation.

Ronald Prinn, co-author of a paper in the Journal of Climate describing the results, said the higher numbers are due to several factors, including better economic modeling, new data showing a lower probability of low-emission scenarios in the future, and better accounting for the effects of past volcanoes and soot emissions.

The simulations also examined what is likely to happen under various policy scenarios. Without strong policies to curb greenhouse gas emissions, the changes in the computer model "stacked up so they caused more projected global warming," Prinn said in a statement. With drastic steps to curb emissions buildup, however, there was less change from the earlier projections.

-- Nils J. Bruzelius

Toned Up, Tuned In

Mozart, Frank Sinatra and Jimi Hendrix supposedly all had perfect pitch -- the ability to identify or reproduce a musical note without any reference notes. The rare skill is often thought of as a mysterious genetic gift, but researchers at the University of California at San Diego have found that perfect pitch is significantly more common among fluent speakers of Mandarin, Cantonese, Vietnamese and other languages that use tone to distinguish between words.

In a study published in the Journal of the Acoustical Society of America and presented at an ASA meeting last week in Portland, Ore., UCSD researchers tested 203 music students at the University of Southern California for perfect pitch by asking them to identify 36 piano notes. The students self-reported their musical education and ethnicity, and which languages they spoke and how fluently.

More than 90 percent of students who began musical training between ages 2 and 5 and spoke an East Asian tonal language very fluently had perfect pitch, compared with less than 30 percent of Caucasian speakers of non-tonal languages who started to learn music at the same ages. Within that early-onset musical training age group, the "very fluent" tonal language group also blew away those who spoke East Asian languages "fairly fluently" and "non-fluently."

Because the East Asian non-fluent tonal speakers and the Caucasian non-tonal speakers had similar test results, the researchers concluded that their performance was based on language skills rather than ethnicity.

"It also raises the interesting question: What other exceptional abilities might be latent in an infant that we could bring out if we only knew what buttons to push?" said the study's lead author, Diana Deutsch, who has perfect pitch.

-- Rachel Saslow

Never Forget a Face?

About one in 50 human beings suffers from a condition known as prosopagnosia, a diminished ability to recognize faces. Scientists had long assumed that the world was divided into two groups -- those with normal abilities to recognize a face and those unable to do so because of the disorder.

But in research being published in Psychonomic Bulletin and Review, Harvard psychologist Richard Russell and his colleagues have shown that there is a third group of people whose face-recognition skills are unusually good -- people whose powers of face recognition seem to be as enhanced as the face-recognition powers of those with prosopagnosia are diminished.

"There has been a default assumption that there is either normal face recognition, or there is disordered face recognition," Russell said in a statement. But the existence of people with unusual powers to remember faces, he added, suggested that these abilities may fall along a spectrum that ranges from the very poor to the very good.

Russell and his colleagues studied four people with the unusual face-recognition skills, who reported being able to remember faces of strangers they had seen months earlier. Experiments showed that these people could recognize faces even if the features had been changed or distorted, and that they were significantly better at such tasks than average people. Volunteers who were average at face-recognition tasks, in turn, did significantly better at such tasks than those with prosopagnosia.

-- Shankar Vedantam

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