Thursday, February 7, 2008

Brain Signal Linked to Autism

Imaging the brain during social interaction reveals a deficit that may be tied to a sense of self.

Sensing self: A new brain-imaging study shows that people with a high-functioning form of autism lack a particular brain signal (shown here) linked to a sense of self.
Credit: Tomlin et al., Science, 2006.

By imaging the brains of adolescents with a high-functioning form of autism as they played a social-interaction game, scientists have identified a physiological deficit specific to the disorder. The researchers believe that the change is linked to a diminished sense of self. The findings, recently published in the journal Neuron, could help guide future research into the nature of autism and potentially lead to new ways to diagnose and treat the disorder.

"I think this is an exciting advance," says Uta Frith, a professor at University College London, in England, who wrote a preview of the paper for Neuron. Most studies find only subtle differences in people with high-functioning autism, "so it's quite impressive to find such a big difference," she says.

Autism is a complicated and heterogeneous developmental disorder marked by problems in language and social behavior. No medical tests exist to detect the disorder, so children are typically diagnosed based on doctors' observations. Scientists are avidly searching for more objective markers of autism, but identifying specific brain abnormalities has been a challenge.

Researchers at Baylor College of Medicine, in Houston, believe that they have now identified a specific physiological marker of the disorder. Read Montague, Pearl Chiu, and their colleagues scanned the brains of adolescents with Asperger's syndrome, a high-functioning form of autism, while they played an interactive trust game.

In the game, one person, designated the investor, chooses an amount of money to send to a second player, the trustee. The money is tripled en route, and the trustee must then decide how much to give back to the investor. When played by normal volunteers, the game unfolds in a very characteristic fashion: generous gestures are met with generous responses, while selfish ones inspire selfishness in return.

Brain activity also follows a stereotyped pattern. A study by Montague and his colleagues. published in 2006, imaged the brains of both the investor and the trustee as they played the game. The researchers discovered a specific signal in the cingulate cortex, part of the brain that integrates information from both the cortex and the body, that was detected only when the investor thought about how much money to give the trustee. A second signal was seen only when the investor received his or her return from the trustee. "We see a 'self, other, self, other' pattern," says Montague, director of the Human Neuroimaging Lab at Baylor. "We think that's an unconscious assessment of who the actions should be attributed to."

According to the new findings, people with Asperger's play the game just as a nonautistic person would, but they lack the characteristic "self" signal in the brain. Normal people lack the signal only when they think that they are playing against a computer, suggesting that autistic people view interactions with other people similarly to the way that normal people think about interacting with a computer. "This approach allows a somewhat objective look at something hopelessly subjective--sense of self," says John Gabrieli, a neuroscientist at MIT.

While the findings are clearly intriguing, it's not yet clear what they mean. One popular theory of autism is that people with the disorder lack a normal theory of mind--the ability to imagine the thoughts and actions of others. Identifying a specific deficit linked to thoughts of self could help narrow down what has gone wrong in that process. "People think autism is linked to a lack of understanding of what a partner is doing," says Chiu. "But maybe they don't understand their own role in the social exchange."

Other scientists interpret the results further, suggesting that this signal is linked to a sort of internal reputation assessment in the brain. "If you are a normal person, when you invest money in the game, you are thinking about how you will look in the eyes of your partner," says Frith. "That's precisely what the theory of mind hypothesis would project is wrong with people with autism."

Other autism experts are unwilling to make such a leap. "I'm skeptical about how much [the Baylor College study] tells us about which capacities are intact and engaged in autism," says Matthew Belmonte, a scientist at Cornell University, in Ithaca, NY. "I'm not convinced they have a deficit at all. Maybe they have adopted a different cognitive strategy."

Regardless of the deeper meaning of their findings, Montague and his team ultimately hope to develop the brain-imaging results into a diagnostic test. They have converted the activity signal from the cingulate cortex into a simple numerical score, which correlates well with a clinical test for the severity of autism. Eventually, they hope to be able to show, for example, "that if you get a 3 rather than a 14, you are 80 percent more likely to be a high-functioning autistic," says Montague. Such a tool could potentially also be used to test the effectiveness of new behavioral treatments, he says.

However, much work remains to be done before such a test could be used in a doctor's office. "We need to make it simpler and test people with a wider range of IQs," says Montague. The Asperger's volunteers in the current study had an above-average IQ.

The Future of Clean Coal

The DOE's decision to abandon FutureGen could accelerate clean-coal technology.

Clean dream: FutureGen was the Bush administration’s showcase project to produce carbon-free power and hydrogen from coal. The plant was to burn hydrogen gas produced from coal in high-temperature gasification vessels while carbon dioxide from the coal was sequestered deep underground.
Credit: U.S. Dept. of Energy

When it was first announced in 2003, FutureGen was billed as a $1 billion prototype for the coal-burning power plant of the future, combining electricity and hydrogen production with the near elimination of harmful emissions. So the U.S. Department of Energy's (DOE) decision late last month to back out of the project, which was meant to build an advanced coal-gasification plant designed to sequester its carbon dioxide emissions underground, is once again fueling debate over the future of clean-coal technology in the United States.

Some energy-policy analysts say that technology development and changing priorities have simply made FutureGen obsolete. In fact, they say that the DOE's plans to instead finance carbon-capture equipment at commercial power plants could actually accelerate the implementation of the clean-coal vision that FutureGen once represented. "The fact that the [FutureGen] project was cancelled reflects budgetary issues more than a lack of confidence in the technology," says Alex Klein, a senior analyst tracking developments in power generation for the consultancy Emerging Energy Research, based in Cambridge, MA. "If the government does, in fact, concentrate its efforts on capture and sequestration, it will be just as significant a development for the industry as if FutureGen went forward."

In a statement released last week, U.S. secretary of energy Samuel Bodman explained that FutureGen had become too expensive. Indeed, FutureGen's predicted price tag has gone from $950 million in 2003 to $1.5 to $1.8 billion today. The DOE had agreed to foot 74 percent of the bill, leaving just over a quarter to the FutureGen Alliance, a consortium of primarily coal-fired utilities.

FutureGen was also overtaken by public concern over rising greenhouse-gas emissions and the emergence of rival commercial projects. Utilities have proposed more than 50 Integrated Gasification Combined Cycle (IGCC) power plants, which are similar in design to FutureGen. Both technologies convert coal into a mixture of hydrogen and carbon monoxide. The commercial IGCC plants burn the mixed gases, producing a more concentrated (and thus easier to capture) stream of carbon dioxide than conventional power plants do. In contrast, FutureGen's design would remove the carbon before the combustion of pure hydrogen in more efficient but as yet unproven ultrahigh-temperature turbines, further reducing the energy penalty caused by carbon capture.

Since the commercial plants are based on existing equipment, they are considerably cheaper to build than FutureGen would have been. For example, utility giant American Electric Power estimates that the 629-megawatt IGCC plants that it wants to build in Ohio and West Virginia would cost about $2.5 billion each, including carbon capture, which is at least 27 percent cheaper per megawatt of power produced than projected costs for FutureGen.

In his statement, Bodman said that restructuring the FutureGen effort will leave IGCC plants to the private sector but will provide funding to coal-fired power plants to help them capture and sequester carbon dioxide. "After the restructuring, funding will be available to equip multiple new clean-coal power plants with advanced [carbon-capture and storage] technology--instead of just one demonstration plant," he said. "These commercial plants ... should each sequester at least one million metric tons of carbon dioxide annually."

However, FutureGen supporters question the DOE's motives, and they vow to fight on. Illinois governor Rod Blagojevich released a statement calling the DOE's decision politically motivated: "Only after it became clear that an Illinois site would be chosen over a Texas site, the Department suggested the project be delayed and now, that it be dismantled."

FutureGen Alliance executive director Michael Mudd says that his group will seek Congressional support to reverse the DOE's decision. He believes that FutureGen is needed to make the next generation of IGCC plants more energy efficient and cost effective. "Right now, the [energy penalty] to add carbon capture and storage to a coal plant, whether it's IGCC or [conventional] coal, is huge," he says. "FutureGen is about trying to find a way to reduce that."

Beyond Search and Advertising

If Microsoft purchases Yahoo, the popular Internet property would contribute a lot more than ad revenue.
Credit: Kenn Kiser (foreground) / Technology Review

Last week, Microsoft made an unsolicited $44.6 billion offer to buy Yahoo. According to its website, Yahoo is still reviewing the bid, and the offer has generated a flurry of speculation about the possible results, including a statement from Google that raises the possibility that a Microsoft purchase of Yahoo could lead to unfair competition. Some experts say that Microsoft is after more than just the obvious--increased market share in online search and advertising--and point to other assets in the Yahoo portfolio.

Charlene Li, an analyst with Forrester Research, thinks that, in addition to Yahoo's search and advertising capabilities, its social and mobile technologies play "a significant role" in Microsoft's interest. She points especially to Yahoo's ownership of social-computing powerhouses Flickr, a popular photo-sharing site, and, which started a trend of social bookmarking. "These are great brands, and centerpieces for how people interact with each other," Li says. She adds that part of the appeal of is the social search it empowers, since tags that users add to pages give an additional way of determining those pages' relevancy. "It's a democratization of [key Google ranking software] PageRank in many ways," she says. Li also notes that Yahoo's Go Internet portal for mobile phones could be appealing to Microsoft. The Yahoo interface might complement Microsoft's Windows Mobile operating system, she says, which, in her opinion, still lacks a good user interface.

Lawrence Ricci, an industry consultant who specializes in embedded systems, says that he thinks Yahoo properties like Flickr are attractive to Microsoft in part because they could be closely integrated with devices such as digital cameras that use Microsoft's Windows Embedded operating system. "I suspect that one of their motivations is, they want to make sure that everyone who has a Microsoft embedded device will have access to the services that they need to make that device come alive," he says.

Rob Koplowitz, who is, like Li, an analyst with Forrester Research, says that some of Yahoo's technological expertise could help Microsoft keep its Office products competitive. Challenges to Microsoft's flagship product have come recently from Web-based productivity services such as Google Docs and IBM's Lotus Symphony, offered either free or at extremely low cost. At the recent Lotusphere conference in Orlando, FL, Michael Rhodin, general manager of IBM's Lotus division, said that the company plans to compete in part by changing how it develops software. "We will be very aggressive as to how our services are priced," he said at a press conference. He added that Lotus would provide small-business services such as Symphony, "so people won't have to spend $400 a user on a word processor."

Although competitors have yet to take a significant part of Microsoft's market share, Koplowitz says that the company has begun moving to protect its lucrative Office products. "It's a core strength of Microsoft, how seriously they take their competition," he says. The company has started adding online services to Office, in an attempt to take advantage of the benefits of online services while maintaining the comfort of the desktop for its longtime users. Yahoo's engineers, Koplowitz says, could bring extensive experience at delivering Web-based services to bear on the problem, as well as their expertise at building efficient data centers. "If we're really moving to a model where more and more software is being delivered through the cloud, it's probably not going to be a high-margin business," he says. "The ability to do it efficiently at every level will be a differentiator."

Li notes that, even if the offer goes through, the deal is unlikely to close before the final part of this year, at the earliest. She says that it's likely that the companies would focus initially on advertising and search, followed by easy integrations such as combining instant-messaging clients and the two companies' news coverage. She thinks that Microsoft would only be able to focus on properties such as once those earlier matters were resolved.