Another installment of news from the world of psychology.
We begin today with a look at why the human brain requires so much energy (adenosine triphosphate) to function -- roughly 20% of the calories we consume.
Why Does the Brain Need So Much Power?
New study shows why the brain drains so much of the body's energy
By Nikhil SwaminathanIt is well established that the brain uses more energy than any other human organ, accounting for up to 20 percent of the body's total haul. Until now, most scientists believed that it used the bulk of that energy to fuel electrical impulses that neurons employ to communicate with one another. Turns out, though, that is only part of the story.
A new study in Proceedings of the National Academy of Sciences USA indicates that two thirds of the brain's energy budget is used to help neurons or nerve cells "fire'' or send signals. The remaining third, however, is used for what study co-author Wei Chen, a radiologist at the University of Minnesota Medical School, refers to as "housekeeping," or cell-health maintenance.
Researchers reached their conclusions after imaging the brain with magnetic resonance spectroscopy (MRS) to measure its energy production during activity shifts. Chen says the technology, which has been around for three decades and is used to track the products of metabolism in different tissues, could prove instrumental one day in detecting brain defects or to diagnose tumors or precursors of neurodegenerative diseases (such as Alzheimer's and Parkinson's) early.Chen and his colleagues used MRS specifically to track the rate of adenosine triphosphate (ATP) production, the primary source of cellular energy, in rat brains. MRS employs a magnetic resonance imaging (MRI) machine programmed to pick up particular elements in the body—in this case, the three phosphorus atoms in each ATP molecule. Their goal: to determine whether ATP production is linked to brain activity by measuring the energy expended during different levels of consciousness.
Sure enough, ATP levels appeared to vary with brain activity. The team noted that when the lab rats were knocked out, they produced 50 percent fewer ATP molecules than when they were mildly anesthetized.The ATP produced when the brain is inactive, says Chen, seems to go mostly toward cell maintenance, whereas the additional ATP found in the more alert animals fueled other brain functions. He speculates that only a third of the ATP produced in fully awake brains is used for housekeeping functions, leaving the rest for other activities.
"Housekeeping power is important for keeping the brain tissue alive," Chen says, "and for the many biological processes in the brain," in addition to neuronal chats. Charged sodium, calcium and potassium atoms (or ions) are continuously passed through the membranes of cells, so that neurons can recharge to fire. ATP supplies the energy required for these ions to traverse cell membranes. Chen says there must be enough energy to maintain a proper ionic balance inside and outside cells; if too many get stuck inside, it can cause swelling, which can damage cells and lead to strokes and other conditions.
He says the team has since used MRS to study energy demands of a cat's brain, which they said also jumped when the kitty was visually stimulated. Next up: humans, which Chen says researchers hope to study "very soon."
So does this mean that more time we spend thinking, the more energy we consume? Can we think ourselves thin?
A recent story making the rounds on all the science and news sites is the finding that selfishness may be an evolutionary partner to altruism.
Selfishness May Be Altruism's Unexpected Ally
Just as religions dwell upon the eternal battle between good and evil, angels and devils, evolutionary theorists dwell upon the eternal battle between altruistic and selfish behaviors in the Darwinian struggle for existence. In a new study published in the Proceedings of the National Academy of Sciences (PNAS), evolutionary theorists at Binghamton University suggest that selfishness might not be such a villain after all.Omar Tonsi Eldakar and David Sloan Wilson propose a novel solution to this problem in their article, which is available in the online Early Edition of PNAS. They point out that selfish individuals have their own incentive to get rid of other selfish individuals within their own group.
Eldakar and Wilson consider a behavioral strategy called "Selfish Punisher," which exploits altruists and punishes other selfish individuals, including other selfish punishers. This strategy might seem hypocritical in moral terms but it is highly successful in Darwinian terms, according to their theoretical model published in PNAS and a computer simulation model published in the Journal of Theoretical Biology. Selfish punishers can invade the population when rare but then limit each other, preventing the altruists from being completely eliminated.
Individuals who behave altruistically are vulnerable to exploitation by more selfish individuals within their own group, but groups of altruists can robustly out-compete more selfish groups. Altruism can therefore evolve by natural selection as long as its collective advantage outweighs its more local disadvantage. All evolutionary theories of altruism reflect this basic conflict between levels of selection.
It might seem that the local advantage of selfishness can be eliminated by punishment, but punishment is itself a form of altruism. For instance, if you pay to put a criminal in jail, all law-abiding citizens benefit but you paid the cost. If someone else pays you to put the criminal in jail, this action costs those individuals something that other law-abiding citizens didn't have to pay. Economists call this the higher-order public goods problem. Rewards and punishments that enforce good behavior are themselves forms of good behavior that are vulnerable to subversion from within.
Eldakar and Wilson first began thinking about selfish punishment on the basis of a study on humans, which indeed showed that the individuals most likely to cheat were also most likely to punish other cheaters. Similar examples appear to exist in non-human species, including worker bees that prevent other workers from laying eggs while laying a few of their own.
Is selfish punishment really so hypocritical in moral terms? According to Eldakar and Wilson, it can be looked at another way - as a division of labor. Altruists ‘pay’ the selfish punishers by allowing themselves to be exploited, while the selfish punishers return the favor with their second-order altruism. “That way, no one needs to pay the double cost required of an altruist who also punishes others,” says Eldakar. “If so, then the best groups might be those that include a few devils along with the angels.”
If you remember back a while, David Sloan Wilson (along with E.O. Wilson) has been instrumental in helping move evolutionary theory away from a pure reliance on the selfish gene to include group selection as part of the process.
It makes sense that he would be involved in a study that looks at how social pressures (altruism or selfishness) can influence evolutionary natural selection.From an integral perspective, I think we will be seeing more and more about social and cultural pressures on evolution, as well as more about group mind in helping us explain human consciousness.
Many of us have known for a long time that taking a walk in nature can reduce stress and help improve our mood. In fact, more and more psychologists are advocating time in nature as a way of treating mood and personality disorders. Here is another study in that growing literature.
'Forest therapy' taking root: Researchers find that a simple stroll among trees has real benefits
For stressed-out workers, this may someday be a doctor's prescription: Walk around in the woods.Scientists in Japan have been learning a lot in recent years about the relaxing effects of forests and trees on mental and physical health. Based on their findings, some local governments are promoting "forest therapy."
Experience shows that the scents of trees, the sounds of brooks and the feel of sunshine through forest leaves can have a calming effect, and the conventional wisdom is right, said Yoshifumi Miyazaki, director of the Center for Environment Health and Field Sciences at Chiba University.
Japan's leading scholar on forest medicine has been conducting physiological experiments to examine whether forests can make people feel at ease.
One study he conducted on 260 people at 24 sites in 2005 and 2006 found that the average concentration of salivary cortisol, a stress hormone, in people who gazed on forest scenery for 20 minutes was 13.4 percent lower than that of people in urban settings, Miyazaki said.
This means that forests can lower stress and make people feel at ease, he said, noting that findings in other physiological experiments, including fluctuations in heart beats and blood pressure, support this conclusion.
"Humans had lived in nature for 5 million years. We were made to fit a natural environment. So we feel stress in an urban area," Miyazaki said. "When we are exposed to nature, our bodies go back to how they should be."
Taking a walk in a forest, or "forest bathing" as it is sometimes called, can strengthen the immune system, according to Li Qing, a senior assistant professor of forest medicine at Nippon Medical School in Tokyo.
Li conducted experiments to see whether spending time in a forest increases the activity of people's natural killer (NK) cells, a component of the immune system that fights cancer.
In one, 12 men took a two-night trip to a forest in Nagano Prefecture in 2006, during which they went on three leisurely strolls and stayed in a hotel in the woods. Thirteen female nurses made a similar trip to another forest in the prefecture in 2007.
NK activity was boosted in the subjects in both groups, and the increase was observed as long as 30 days later, Li said.
Read the rest, then get thee to a forest. Hmmm . . . . I wonder if cacti work the same magic?
Big-screen superheroes gone wild
The classic superhero is polished, brave and morally righteous. Strong and unerring, he is perfection personified - a superhuman ideal.Not this summer.
Everyday human flaws are the Kryptonite of this year's movie good guys, who deign to suffer the same foibles as those who pay to see them. They may be reclusive, egotistical or intellectually challenged. They may have anger issues or alcohol issues. Some are alienated and lonely.
While the archetypal superhero always has a "weakness," this summer's super problems are more fit for the psychologist's couch than the villain's lair. Such shortcomings make heroes more relatable, says Marvel Comics master Stan Lee, creator of Spider-Man, the Hulk, Iron Man and the Fantastic Four, among sundry others.
"If you can have a good guy who's got hang-ups and flaws and failings, he's more interesting because he not only has to defeat the villain, but he has to defeat and conquer his own flaws and inabilities," Lee says. "It rounds him out and makes the character empathetic."
Flawed heroes are also a sign of the times, says "Iron Man" director Jon Favreau.
"Complicated times demand for escapist entertainment," he says. "These characters are facing the same types of problems we are. They're a proxy for us."
"Iron Man," which opens Friday, stars Robert Downey Jr. as Tony Stark, a pompous, womanizing, hard-drinking genius whose superpowers come solely from a supercharged, weapons-filled suit he created from scratch. Without it, Stark is just another guy with issues - not much of a stretch for the actor who's a veteran of both big screen and blotter.
After many nods to that effect throughout the film, Downey (as Stark) acknowledges at its conclusion that he's "not the hero type, with these character defects and all."
Indiana Jones is another "real guy," says creator George Lucas. The archaeologist-adventurer played by Harrison Ford returns to theaters May 22 with "Indiana Jones and the Kingdom of the Crystal Skull."
"He makes lots of mistakes. He kind of goofs up. He has the same kind of thinking that we have," Lucas says. "It's like he's not a superhero. He's just an average Joe that's always in over his head that somehow seems to get through it."
June will bring three more unlikely superheroes: Bruce Banner, Maxwell Smart and Zohan.
After a gamma-radiation accident, Banner (Ed Norton) discovers he involuntarily transforms into a monstrous mass in "The Incredible Hulk." Fearful and emotionally withdrawn, Banner is "blind to his heroic potential," says Kevin Feige, president of production for Marvel Studios.
Many of us have had dreams that seem more than a little bizarre. Perhaps even psychotic? Turns out that dreams and psychotic thoughts have some things in common.
Mondo BizarroAlthough the researchers suggest that the absence of paranoia and delusions of grandeur make dreams and psychosis different, I wonder if it is just a matter of degrees, or maybe even that while waking the mind is forced to justify the psychotic elements with the external world. While that obviously isn't working so well for the psychotics, the brain could still be trying to make sense of the lack of external information and the surplus of emotions -- and in doing so creates scenarios in which the individual is at the center of the narrative.Researchers identify similarities between dreams and psychotic thoughtsDreams and psychotic ruminations have certain strange features in common, and psychiatrists have now measured the degree of similarity.
Both dreams and waking psychotic moments share cognitive bizarreness — a well-defined term in psychology. It consists of impossible plots, characters and actions: flying over Elvis’ first concert or conversing with Fido the dog. It also includes discontinuity or uncertainty in time and place: stepping outside your house, which is really your aunt’s house, and onto Mars, the day before.
“We are not talking about hallucinations,” says Silvio Scarone of the University of Milan in Italy, “but rather the organization of thinking.” When awake, normal people don’t have bizarre fantasies, he says. But when asleep, their dreams are as bizarre as a schizophrenia patient’s waking fantasies.
To examine these fantasies, Scarone and his team instructed normal people and schizophrenia patients to tell a fantastic tale about a given image. The stories were systematically scored according to how bizarre the tales were. Normal people’s plotlines contained few signs of bizarreness, whereas the plotlines of schizophrenia patients contained as many bizarre, illogical jumps as dreams do. The researchers also scored people’s descriptions of their dreams. Normal people and those with schizophrenia showed similar levels of cognitive bizarreness in their dreams, the researchers report in the May issue of Schizophrenia Bulletin.
By understanding the organization of schizophrenic thought, psychiatrists might be better able to communicate with their patients, Scarone says.
Bizarreness appears to arise when sensory information from the outside world is blocked, and when thoughts are heavily influenced by an excess of emotion, says Harvard Medical School psychiatrist J. Allan Hobson, another researcher on the study. A predominance of the inner world characterizes a variety of mental illnesses. Likewise, the dreaming mind cuts off outside stimuli. “It’s not just a dull waking state,” Hobson says. “It’s an entirely different state of consciousness.”
But bizarreness isn’t the only thing that lurks beneath madness. Other elements of psychotic episodes include delusions of grandeur and paranoia. Dreams, however, generally don’t exhibit these qualities. Normal dreamers rarely imagine being chased by the KGB, Scarone says. This difference may indicate that the two erratic modes of logic, bizarreness and delusion, occur by separate mechanisms.
Still other researchers think the gap between psychosis and dreaming is wider. G. William Domhoff of the University of California, Santa Cruz expresses skepticism about any connection at all. “Dreams are far more coherent, far more consistent over time and far more continuous with waking conceptions and concerns,” he says.
I'm just thinking out loud -- this is an interesting avenue of research. I wonder what fMRI images might show of both dreamers and psychotics.
Thanks for sharing these.
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