light

Dear EarthTalk: Can those energy-efficient compact fluorescent light bulbs that are popular now cause headaches because of the flickering they do? I converted my whole house over last fall and both my kids were complaining of headaches on and off.
-- Sandy, Eugene, OR

With a switch to energy efficient compact fluorescent (CFL) light bulbs already in full swing in the U.S. and elsewhere—Australia has banned incandescents, Britain will soon, and the U.S. begins a phase-out of incandescents in 2012—more and more complaints have arisen about the new bulbs causing headaches.

Many experts say that the issue is being overblown, however, that there is no scientific evidence that the bulbs cause headaches and that a kind of hysteria has grown out of a small number of anecdotal reports.http://ljsheehan.livejournal.com

Industry experts acknowledge that day-to-day exposure to older, magnetically ballasted long tube fluorescent bulbs found mostly in industrial and institutional settings could cause headaches due to their noticeable flicker rate. The human brain can detect the 60 cycles per second such older bulbs need to refresh themselves to keep putting out light.

However, modern, electronically ballasted CFLs refresh themselves at between 10,000 and 40,000 cycles per second, rates too fast for the human eye or brain to detect. “As far as I’m aware there is no association between headaches and the use of compact fluorescent lamps,” says Phil Scarbro of Energy Federation Incorporated (EFI), a leading distributor of energy efficiency-related products—including many CFLs.

But Magda Havas, an Environmental & Resource Studies Ph.D. at Canada’s Trent University, says that some CFLs emit radio frequency radiation that can cause fatigue, dizziness, ringing in the ears, eyestrain, even migraines. You can test to see if CFLs in your home give off such radiation, she says, by putting a portable AM radio near one that’s on and listening for extra static the closer you get. She says that such electromagnetic interference should also be of concern to people using cell phones and wireless computers.http://louis-j-sheehan.info

Sometimes headaches are due to eyestrain from inadequate lighting. When replacing an incandescent bulb with a CFL, pay attention to the lumens, which indicate the amount of light a bulb gives out (watts measure the energy use of a bulb, not the light generated). A 40-watt incandescent bulb can be replaced by an 11-14 watt CFL because the lumen ouput is approximately the same (490); a 100-watt incandescent can be replaced by a 26-29 watt CFL, both providing about 1,750 lumens. If you’re still skeptical, replace a 40-watt incandescent with a 60-watt equivalent 15-19 watt CFL, which will boost lumens to 900.

Another consideration is color temperature (measured in degrees “Kelvin”). CFLs rated at 2,700 Kelvin give off light in the more pleasing red/yellow end of the color spectrum, closer to that of most incandescents. Bulbs rated at 5,000 Kelvin and above (usually older ones) give off a less pleasing white/blue light.

The Environmental Defense website provides a handy chart comparing the watts and lumens of incandescents versus CFLs, along with further discussion about color temperature.

testing

A brief course on how to pay attention boosts children's scores on either intelligence or attention tests, depending on their age, a new study finds.

The training may quicken normal brain development, says a team of neuroscientists led by Michael I. Posner of the University of Oregon in Eugene. Earlier research had indicated that brain areas involved in controlling attention in the presence of conflicting information develop rapidly between ages 4 and 6.

Over 2 to 3 weeks, Posner's team administered five training sessions to 4-year-olds and 6-year-olds. The younger kids showed higher IQ boosts—and the older ones, greater attention gains—than untrained kids did, the researchers report in an upcoming Proceedings of the National Academy of Sciences.

The researchers also note that their study showed enhanced electric signaling in the brains of the children who received the training. Genetic differences, which the researchers analyzed in the 6-year-olds, influenced training effects too. http://Louis2J2Sheehan2Esquire.US

Attention training "could potentially lead to better intervention strategies for children with attention and other behavior problems," according to Karla Holmboe and Mark H. Johnson, both neuroscientists at the University of London in England, in a comment published with the new study.

Posner and his colleagues recruited 49 kids in the younger group and 24 in the older group. The children received intelligence and attention testing while most of them wore sensor nets on their heads to measure electrical signals on the brain's surface. Then, the children were randomly assigned to receive attention training or no training.

The training was adapted from tasks that increase attention control in monkeys. For example, children moved a cartoon cat across a computer screen using a joystick to keep the cat out of expanding muddy areas. http://Louis2J2Sheehan2Esquire.US

After training, all the children were again tested on intelligence and attention.

Brain regions activated in the 4-year-olds by attention training overlapped with those previously tied to IQ (SN: 7/29/00, p. 72: Available to subscribers at http://www.sciencenews.org/articles/20000729/note12.asp), Posner says. That neural intermingling toward the front of the brain could explain why average intelligence scores rose 6 points among 4-year-olds after attention training, compared with a 1-point increase for untrained 4-year-olds, he suggests. Trained 4-year-olds displayed a much narrower advantage on an attention test.

Among 6-year-olds, training yielded a slight IQ-score advantage but a marked gain in attention control, also called executive attention. During testing, trained kids in this group showed strong neural responses toward the back of the brain, whereas untrained kids displayed predominantly frontal-brain activity, perhaps reflecting conscious effort.

DNA testing examined a gene that influences transmission of the chemical messenger dopamine. Posner's findings indicated that 6-year-olds bearing one form of the gene displayed the poorest attention control before the training and the most improvement with training. The gene variant had been previously linked to an outgoing temperament.

Attention training engages brain networks that unconsciously orchestrate executive attention, propose Holmboe and Johnson. Untrained individuals devote considerable conscious effort to attention tasks and thus invoke other brain areas.

Posner's team is now studying attention training with preschoolers who have symptoms of attention-deficit hyperactivity disorder.

adhd

Brain maturation in children with attention-deficit hyperactivity disorder (ADHD) lags several years behind that of children with no psychiatric or neurological ailments, according to a new brain-imaging study. http://louisejesheehan.blogspot.com

Developmental delays in ADHD hit a peak of 5 years in regions at the front of the brain's outer layer, or cortex, say psychiatrist Philip Shaw of the National Institute of Mental Health in Bethesda, Md., and his colleagues. http://louisejesheehan.blogspot.com These areas assist in controlling attention and in planning upcoming actions.

Kids with ADHD display the same sequence of brain development as healthy youngsters do, the researchers find. Sensory and motor areas attain maximum thickness first, before a thinning-out process begins. Regions that integrate information from different neural sources then do the same. These findings indicate that ADHD involves a slowing, rather than a derailing, of brain maturation, Shaw argues.

A slight developmental speedup occurs in the motor cortex of children with ADHD, the researchers note. A neural mismatch between an early-maturing motor cortex and a late-maturing frontal cortex might account for the restlessness and fidgety behavior seen in ADHD, they propose.

Shaw's group used magnetic resonance imaging to gauge the thickness of neural tissue at more than 40,000 sites throughout the cortex. The researchers scanned 223 youths with ADHD and 223 typically developing children, whose ages ranged from around 7 to 13 at the study's start.

Among youngsters with ADHD, much of the cortex reached maximum thickness at an average age of 10.5, compared to age 7.5 for the others. Shaw's investigation will appear in the Proceedings of the National Academy of Sciences. http://louisejesheehan.blogspot.com

adhd

Brain maturation in children with attention-deficit hyperactivity disorder (ADHD) lags several years behind that of children with no psychiatric or neurological ailments, according to a new brain-imaging study. http://louisejesheehan.blogspot.com

Developmental delays in ADHD hit a peak of 5 years in regions at the front of the brain's outer layer, or cortex, say psychiatrist Philip Shaw of the National Institute of Mental Health in Bethesda, Md., and his colleagues. http://louisejesheehan.blogspot.com These areas assist in controlling attention and in planning upcoming actions.

Kids with ADHD display the same sequence of brain development as healthy youngsters do, the researchers find. Sensory and motor areas attain maximum thickness first, before a thinning-out process begins. Regions that integrate information from different neural sources then do the same. These findings indicate that ADHD involves a slowing, rather than a derailing, of brain maturation, Shaw argues.

A slight developmental speedup occurs in the motor cortex of children with ADHD, the researchers note. A neural mismatch between an early-maturing motor cortex and a late-maturing frontal cortex might account for the restlessness and fidgety behavior seen in ADHD, they propose.

Shaw's group used magnetic resonance imaging to gauge the thickness of neural tissue at more than 40,000 sites throughout the cortex. The researchers scanned 223 youths with ADHD and 223 typically developing children, whose ages ranged from around 7 to 13 at the study's start.

Among youngsters with ADHD, much of the cortex reached maximum thickness at an average age of 10.5, compared to age 7.5 for the others. Shaw's investigation will appear in the Proceedings of the National Academy of Sciences. http://louisejesheehan.blogspot.com

leeds

Call it a happy accident: Phytoplankton in tropical areas of the Atlantic Ocean may be helping to break down greenhouse gases. http://Louis2J2Sheehan2Esquire.US

After analyzing data gathered by airplane and in a lab at Cape Verde, a chain of Atlantic islands not far from West Africa, a team of British researchers was pleased but puzzled to find that ozone in the atmosphere near the islands had decreased 50 percent more than climate modelers had predicted. The reason, they think, is that phytoplankton produce chemicals like bromine monoxide and iodine monoxide that get pulled up into the atmosphere by all the water vapor that evaporates in a hot climate like Cape Verde. Once aloft in the low atmosphere, these chemicals can break apart ozone molecules. Not only that, says Alastair Lewis, of the U.K.’s National Centre for Atmospheric Science, but the byproducts of that first chemical reaction then broke down methane, a much worse greenhouse gas than carbon dioxide, into non-harmful components.

Ozone is three atoms molecules of oxygen, O₃, but some chemicals can break up that trio and steal one oxygen atom, leaving O₂, which is just plain old atmospheric oxygen. That’s how CFCs harm the ozone layer, and why the Montreal Protocol of 1987 phased them out. http://Louis2J2Sheehan2Esquire.US The plankton-produced chemical in this study might be destroying ozone in the same way, Lewis says, but helping us instead of hurting. While ozone high up in the ozone layer protects us from the sun’s ultraviolet radiation, ozone in the lower atmosphere is a greenhouse gas contributing to global warming.

The study brings good news, Lewis says, but he wants to keep it in perspective—if the amount of fossil fuel-created nitrogen oxides coming to the Cape Verde area increased slightly, it could offset this greenhouse reduction. But it’s nice to hear some good climate news for a change, however small. And John Plane from the University of Leeds, another study participant, said that ozone destruction over the ocean could be happening in other parts of the world. http://Louis2J2Sheehan2Esquire.US

So this study represents a win and a loss: We still have a long way to go in understanding the working of the atmosphere, but at least somewhere in the world the greenhouse gas concentrations aren’t going up.

street

MAY 15TH.—Clouds, sunshine, and showers.

The tremendous cannonading all day yesterday at Drewry’s Bluff was merely an artillery duel—brought on by the heavy skirmishing of pickets. The batteries filled the air with discordant sounds, and shook the earth with grating vibration. http://louis6j6sheehan.blogspot.comPerhaps 100 on each side were killed and wounded—”not worth the ammunition,” as a member of the government said.

Gen. Lee’s dispatches to the President have been withheld from publication during the last four days. The loss of two trains of commissary stores affords the opportunity to censure Lee; but some think his popularity and power both with the people and the army have inspired the motive.

I saw to-day some of our slightly wounded men from Lee’s army, who were in the fight of Thursday (12th inst.), and they confirm the reports of the heavy loss of the enemy. They say there is no suffering yet for food, and the men are still in good spirits.

Both the Central and the Fredericksburg Roads are repaired, and trains of provisions are now daily sent to Gen. Lee.

The Danville Road was not materially injured; the raiders being repulsed before they could destroy the important bridges. Supplies can come to Petersburg, and may be forwarded by wagons to the Danville Road, and thence to Lynchburg, etc. http://louis6j6sheehan.blogspot.com

Fresh troops are arriving from the South for Beauregard; but he is still withheld from decisive operations.

The Departmental Battalion is still out; the enemy still menacing us from the Chickahominy.

During the last four days correspondence has ceased almost entirely, and the heads of bureaus, captains, majors, lieutenant-colonels, adjutants, quartermasters, and commissaries, have nothing to do. They wander about with hanging heads, ashamed to be safely out of the field—I mean all under 50 years of age—and look like sheep-stealing dogs. Many sought their positions, and still retain them, to keep out of danger. Such cravens are found in all countries, and are perhaps fewer in this than any other. However, most of the population of the city between 17 and 50 are absent from the streets; some few shopkeeping Jews and Italians are imprisoned for refusing to aid in the defense, and some no doubt are hidden.

Most of the able-bodied negro men, both free and slave, have been taken away—in the field as teamsters, or digging on the fortifications. Yet those that remain may sometimes be seen at the street corners looking, some wistfully, some in dread, in the direction of the enemy. There is but little fear of an insurrection, though no doubt the enemy would be welcomed by many of the negroes, both free and slave.

At 1 P.M. to-day a train arrived from Guinea’s Station with 800 of our wounded, in Sunday’s and Thursday’s battles.

The following prices are now paid in this city : boots, $200; coats, $350; pants, $100; shoes, $125; flour, $275 per barrel; meal, $60 to $80 per bushel; bacon, $9 per pound; no beef in market; chickens, $30 per pair; shad, $20; potatoes, $25 per bushel; turnip greens, $1 per peck; white beans, $4 per quart, or $120 per bushel; butter, $15 per pound; lard, same; wood, $50 per cord. What a change a decisive victory—or defeat—would make! http://louis6j6sheehan.blogspot.com

lie

FALSE beliefs are everywhere. http://louis-j-sheehan.comEighteen percent of Americans think the sun revolves around the earth, one poll has found. Thus it seems slightly less egregious that, according to another poll, 10 percent of us think that Senator Barack Obama, a Christian, is instead a Muslim. http://louis-j-sheehan.comThe Obama campaign has created a Web site to dispel misinformation. But this effort may be more difficult than it seems, thanks to the quirky way in which our brains store memories — and mislead us along the way.

The brain does not simply gather and stockpile information as a computer’s hard drive does. Facts are stored first in the hippocampus, a structure deep in the brain about the size and shape of a fat man’s curled pinkie finger. http://louis-j-sheehan.comBut the information does not rest there. Every time we recall it, our brain writes it down again, and during this re-storage, it is also reprocessed. In time, the fact is gradually transferred to the cerebral cortex and is separated from the context in which it was originally learned. For example, you know that the capital of California is Sacramento, but you probably don’t remember how you learned it.

This phenomenon, known as source amnesia, can also lead people to forget whether a statement is true. Even when a lie is presented with a disclaimer, people often later remember it as true.

With time, this misremembering only gets worse. A false statement from a noncredible source that is at first not believed can gain credibility during the months it takes to reprocess memories from short-term hippocampal storage to longer-term cortical storage. As the source is forgotten, the message and its implications gain strength. This could explain why, during the 2004 presidential campaign, it took some weeks for the Swift Boat Veterans for Truth campaign against Senator John Kerry to have an effect on his standing in the polls.

Even if they do not understand the neuroscience behind source amnesia, campaign strategists can exploit it to spread misinformation. They know that if their message is initially memorable, its impression will persist long after it is debunked. In repeating a falsehood, someone may back it up with an opening line like “I think I read somewhere” or even with a reference to a specific source.

In one study, a group of Stanford students was exposed repeatedly to an unsubstantiated claim taken from a Web site that Coca-Cola is an effective paint thinner. Students who read the statement five times were nearly one-third more likely than those who read it only twice to attribute it to Consumer Reports (rather than The National Enquirer, their other choice), giving it a gloss of credibility.

Adding to this innate tendency to mold information we recall is the way our brains fit facts into established mental frameworks. We tend to remember news that accords with our worldview, and discount statements that contradict it.

In another Stanford study, 48 students, half of whom said they favored capital punishment and half of whom said they opposed it, were presented with two pieces of evidence, one supporting and one contradicting the claim that capital punishment deters crime. Both groups were more convinced by the evidence that supported their initial position.

Psychologists have suggested that legends propagate by striking an emotional chord. In the same way, ideas can spread by emotional selection, rather than by their factual merits, encouraging the persistence of falsehoods about Coke — or about a presidential candidate.

Journalists and campaign workers may think they are acting to counter misinformation by pointing out that it is not true. But by repeating a false rumor, they may inadvertently make it stronger. In its concerted effort to “stop the smears,” the Obama campaign may want to keep this in mind. Rather than emphasize that Mr. Obama is not a Muslim, for instance, it may be more effective to stress that he embraced Christianity as a young man.

Consumers of news, for their part, are prone to selectively accept and remember statements that reinforce beliefs they already hold. In a replication of the study of students’ impressions of evidence about the death penalty, researchers found that even when subjects were given a specific instruction to be objective, they were still inclined to reject evidence that disagreed with their beliefs.

In the same study, however, when subjects were asked to imagine their reaction if the evidence had pointed to the opposite conclusion, they were more open-minded to information that contradicted their beliefs. Apparently, it pays for consumers of controversial news to take a moment and consider that the opposite interpretation may be true.

In 1919, Justice Oliver Wendell Holmes of the Supreme Court wrote that “the best test of truth is the power of the thought to get itself accepted in the competition of the market.” Holmes erroneously assumed that ideas are more likely to spread if they are honest. Our brains do not naturally obey this admirable dictum, but by better understanding the mechanisms of memory perhaps we can move closer to Holmes’s ideal.lier