- You don't have to call them every day, just to let them know you're not fighting.
- You don't have an anniversary--you just sort of "became" best friends.
- When someone calls your girlfriend/boyfriend your "partner" it makes you think of marriage. When they call your best friend your partner, it's more like cops.
- You never have to touch your best friend when it's hot outside, but you can stull huddle close when it's freezing.
- Your parents usually like your best friend.
- Your best friend doesn't care if you get fat, you're ugly, or if you get a bad haircut.
- You don't have to get jealous of "girls only" night or "guys only" night -- You're part of it!
- You can laugh at your best friend with no consequences.
- You can burp/fart in front of your best friend on any occasion.
- You can plan on still having a relationship with your best friend in 20 years.
- Never in your life will you need "space" from your best friend.
- Your best friend won't be mad if you want some time alone, and will only ask you "what's wrong?" once.
- Your best friend is someone you get in trouble with; your boyfriend/girlfriend is someone you get in trouble with if you get in trouble.
- You don't have to get dressed up to go anywhere with your best friend.
- You're allowed to have multiple best friends.
- No one ever spreads rumors or talks about you and your best friend's relationship.
- Your best friend will never refer to you as "the ball and chain," "the old lady/man," or "the whip."
- No one is ever trying to fix you up on blind dates for a new best friend.
- It doesn't matter what your "other" friends think about your best friend.
- Your best frined is the first person you call when you get a new boyfriend/girlfriend, and when you break up with them.
Tuesday, June 29, 2010
20 Reasons Why Best Friends are Better Than Boyfriends/Girlfriends
Saturday, June 26, 2010
Nap vs. Caffeine vs. More Nighttime Sleep?
If a 20-minute nap, a cup of joe, and more shuteye at night were in a cage match, who would win for reducing that classic afternoon "dip"? The answer is: (in order of effectiveness) 1. Nap
2. Caffeine
3. Then more nighttime sleep
A new study just released proves the power of a nap over a jolt of caffeine and even more sleep at night. It's actually the first such study to look at all three methods for combating the afternoon lull that's commonly experienced-and which is a very normal physiological response to the body cycling through its natural rhythms during the day.
Just because you feel sleepy at some point in the afternoon doesn't actually mean you're sleep deprived. About eight hours after you wake up, the body's temperature dips a little, triggering that oh-so-annoying drowsiness after lunch and smack dab in the middle of your attempts to focus and get more done in the late afternoon
2. Caffeine
3. Then more nighttime sleep
A new study just released proves the power of a nap over a jolt of caffeine and even more sleep at night. It's actually the first such study to look at all three methods for combating the afternoon lull that's commonly experienced-and which is a very normal physiological response to the body cycling through its natural rhythms during the day.
Just because you feel sleepy at some point in the afternoon doesn't actually mean you're sleep deprived. About eight hours after you wake up, the body's temperature dips a little, triggering that oh-so-annoying drowsiness after lunch and smack dab in the middle of your attempts to focus and get more done in the late afternoon
• It's easier to over-sleep than you think. Biologically, the body doesn't necessarily need that extra sleep if you force yourself to sleep more at night. (And getting sufficient sleep doesn't mean your body won't go through the dip regardless; it's a natural, physiological phenomenon tied more to your circadian rhythm than to your previous night's sleep and potential sleep debt.)
• Caffeine can wear off (especially if you're so used to it) whereas the benefits of a nap may charge your battery for a longer period of time. No one gets a "high tolerance" to napping.
I've long been an advocate for napping. The best kind? A 20-minute snooze within a 30 minute time period (10 extra minutes to get comfortable and into sleep mode). Or try the Nap-a-latteTM, which is the dynamic duo.
But here's a big caveat: most people would probably choose caffeine over a nap, and ditch the nap entirely. Downing caffeine can be easier, quicker, and socially more acceptable in many ways. Finding a place to nap in the middle of the workday can be a challenge. And studies have also shown that when deciding between a nap and an "attractive wakeful activity," they choose the activity.
Let's face it, coffeehouses have multiple buzzes going on. People. Internet. Connectivity. Social interaction. Exchanges of ideas. And tasty treats beyond the joes and javas. Naps tend to be solitary and, dare I say, not as sexy.
But for what it's worth, hail to the nap.
Sweet Dreams,
July 20, 2009, Sleep
Which is better: coffee, 20 min. nap, or more sleep?
Published on July 20, 2009
Michael J. Breus, PhDThe Sleep DoctorTM
A Woman's Touch...

We all know the value of human touch. It’s one of the defining cornerstones of our existence since our birth — the connection between mother and infant. The importance of maternal physical contact and nurturing has been demonstrated time and time again in previous research.
But what we don’t always realize is the impact simple human touch has on another person. A handshake, a touch of the shoulder — these things matter in more ways than we may realize. Could human touch increase our sense of security, as prior studies have suggested, which in turn could make us to make more risky decisions?
That’s what two researchers (Levav & Argo, 2010) set to find out in a series of three experiments…
The main hypothesis we tested is that certain forms of physical contact will evoke a sense of security in experimental participants, and that this sense of security, in turn, will increase their willingness to make risky financial decisions.
Subjects were undergraduate students at an American university and participated in three different experiments that explored their risk-taking in financial decisions. Subjects selected more risky investments when they received a light pat on the shoulder from a female researcher while getting instructions for the experiment. Those investments were more risky than those chosen by subjects who were not touched by the female researcher.

The researchers suggest that subtle physical contact by a female increased participants’ feelings of security, which may have resulted in a greater willingness to take risks.
The three experiments we have reported demonstrate an association between certain kinds of physical contact and financial risk taking. This association was observed despite the subtlety of the manipulation: a momentary touch on the shoulder.
We suggest that a simple pat on the back of the shoulder — by a female — in a way that connotes support may evoke feelings that are similar to the sense of security afforded by a mother’s comforting touch in infancy. Although the comfort in the case of our studies was illusory, the data indicate that our participants perceived a real sense of security and that it led them to take greater financial risk than untouched participants did.
More generally, our findings suggest that minimal physical contact can exert a strong influence on decision making and risk preferences of adults, possibly also outside the financial domain.
Limitations of this study include the usual limitations we find from many of the journal articles published in Psychological Science — it was done on undergraduate college students in an artificial, contrived laboratory setting.
College students are not representative of the population in general. It may be that younger people are more sensitive and susceptible to touch than older, more experienced individuals. Artificial laboratory settings don’t always translate to the real world when real money and real risk-taking decisions have a real impact on our everyday lives. It remains to be seen whether these findings translate to outside the lab, and to a more diverse population (Oddly, the journal article makes absolutely no mention of limitations of the current research).
By John M Grohol PsyD
Reference:
Levav, J. & Argo, J.J. (2010). Physical Contact and Financial Risk Taking. Psychological Science. DOI: 10.1177/0956797610369493
Friday, June 25, 2010
Porn sites get their own domain: '.xxx'

(CNN) -- It's a big day for the porn industry.
On Friday, ICANN, the not-for-profit corporation that coordinates the internet's naming system, voted to allow the application of the controversial ".xxx" top-level domain name for sites that display adult content.
The domain, which would need further approval before going live on the internet, would be applied to adult entertainment sites just as ".com" is now.
The .xxx internet suffix, which was first proposed six years ago by ICM Registry, a group that sells domain names, "will provide a place online for adult entertainment providers and their service providers who want to be part of our voluntary self regulatory community," according to that company's news release.
Adopting .xxx will be optional. However, some tech blogs speculate a push to make the domain mandatory for adult-only sites.
ICM Registry has already taken 110,000 pre-reservations for the domain, which could be available in early 2011, if not sooner, its news release states.
While the company says labeling adult content online "will allow for simple and effective filtering for those who wish to do so," not everyone is pleased with ICANN's decision to approve the domain.
Some people involved in the industry are hesitant to accept the domain, "fearing it will lead to censorship, as it would be very easy to block the entire domain instead of individual sites," Rick Johnson of Portfolio.com wrote Thursday.
On the other hand, "some religious groups are against the creation of the domain, as it would lend more legitimacy to the adult entertainment industry," he wrote.
By Stephanie Goldberg, Special to CNN June 25, 2010 2:42 p.m. EDT | Filed under: Web |
Wednesday, June 23, 2010
Greater Risk Of Drunken Violence In Those Who Suppress Anger
A study published in the journal Addiction reveals that drunkenness increases the risk for violent behaviour, but only for individuals with a strong inclination to suppress anger.
The two authors, Thor Norström and Hilde Pape, applied an approach that reduces the risk of drawing erroneous conclusions about cause and effect. They conclude that their study adds to the body of evidence suggesting that drinking may in fact inflict physical aggression. The authors elaborate this conclusion: "Only a tiny fraction of all drinking events involve violence and whether intoxicated aggression is likely to occur seems to depend on the drinkers' propensity to withhold angry feelings when sober."
The study is based on self-reported data from a general population survey of young people in Norway. Nearly 3000 individuals were assessed twice, first at 16-17 years of age and again at ages 21-22. The participants were divided into 3 equally large groups with respect to anger suppression. Among individuals who reported a high inclination to suppress feelings of anger, a 10% increase in drinking to the point of intoxication was associated with a 5% increase in violence. Researchers observed no such association among those who did not habitually suppress their angry feelings.
Notes:
Norström T. and Pape H.
Alcohol, suppressed anger and violence.
Addiction 2010; 105: 10.1111/j.1360-0443.2010.02997.x
Source:
Amy Molnar
Wiley-Blackwell
The two authors, Thor Norström and Hilde Pape, applied an approach that reduces the risk of drawing erroneous conclusions about cause and effect. They conclude that their study adds to the body of evidence suggesting that drinking may in fact inflict physical aggression. The authors elaborate this conclusion: "Only a tiny fraction of all drinking events involve violence and whether intoxicated aggression is likely to occur seems to depend on the drinkers' propensity to withhold angry feelings when sober."
The study is based on self-reported data from a general population survey of young people in Norway. Nearly 3000 individuals were assessed twice, first at 16-17 years of age and again at ages 21-22. The participants were divided into 3 equally large groups with respect to anger suppression. Among individuals who reported a high inclination to suppress feelings of anger, a 10% increase in drinking to the point of intoxication was associated with a 5% increase in violence. Researchers observed no such association among those who did not habitually suppress their angry feelings.
Notes:
Norström T. and Pape H.
Alcohol, suppressed anger and violence.
Addiction 2010; 105: 10.1111/j.1360-0443.2010.02997.x
Source:
Amy Molnar
Wiley-Blackwell
Friday, June 18, 2010
Tuesday, June 15, 2010
I know it like the back of my hand....
Distorted body image means people don't know the back of their own hands
A study suggests our brains have highly distorted representations of the size and shape of our own hands. The distortion may extend to other body parts, skewing body image
- Alok Jha, science correspondent
- guardian.co.uk,

You may think you know the back of your hand like, well, the back of your hand. But think again. Scientists have found that our brains contain highly distorted representations of the size and shape of our hands, with a strong tendency to think of them as shorter and fatter than they really are.
The work could have implications for how the brain unconsciously perceives other parts of the body and may help explain the underpinnings of certain eating disorders in which people's body image becomes distorted.
In the study, neuroscientists at University College London asked more than 100 volunteers to place their left hand palm-down on a table. The researchers covered the volunteers' hands with a board and then asked them to indicate on it where they thought landmarks such as fingertips and knuckles lay underneath. This data was used to reconstruct the "brain's image" of the hand.
The results, published today in the Proceedings of the National Academy of Sciences, showed a consistent overestimation of the width of the hand. Many of the volunteers estimated their hand was around 80% broader than it really was.
"It's a dramatic and highly consistent bias," said Matthew Longo of UCL's Institute of Cognitive Neuroscience, who led the work. "It was the same with estimation of finger lengths," he said, where the bias was to judge them as shorter than the reality: "When you get to the ring finger, with the largest bias, it's 30-40% underestimation."
The brain uses several ways to work out the location of different parts of the body. This includes feedback from muscles and joints and also some sort of internal model of the size and shape of each body part.
"Previously it has been assumed that the brain uses a perfectly accurate model of the body and it's not mysterious where that might come from," said Longo. "We see our body all the time and it wouldn't be surprising if the brain had developed an accurate representation of the body."
Instead, Longo's work shows that the brain's internal models can be hopelessly wrong. The errors could partly be explained because of the way the brain allocates its processing capacity, said Longo. Regions of high sensitivity in the skin, such as the fingertips and the lips, get a correspondingly larger proportion of the brain's territory.
Longo said that this sensitivity was mirrored in the relative size of the fingers in the maps of perceived positions. "You find the least underestimation for the thumb and more underestimation as you go across to the little finger. You see the same pattern if you measure tactile sensitivity."
The research was carried out on the hand because there were obvious landmarks for the volunteers to point out, which could then be used by the researchers to draw the brain's image of the hand. But the results might be applicable across the body.
"It would be very surprising if there was a distorted representation of the hand but an accurate representation of the complete rest of the body. That would be a bizzare finding, so my guess is that there would be similar sorts of biases, perhaps bigger ones, on other parts of the body," said Longo.
He said the research showed how the brain's ability to distort its representation of the body might underlie certain psychiatric conditions involving body image such as anorexia nervosa.
"It's interesting to note that what we find for the hand is that the representation seems to be 'too fat'. If there's an implicit default representation of the brain to perceive the body as overly wide, then that could potentially account for the pattern you get with eating disorders."
He added: "Our healthy participants had a basically accurate visual image of their own body, but the brain's model of the hand's underlying position sense was highly distorted. This distorted perception could come to dominate in some people, leading to distortions of body image as well, such as in eating disorders."
Why Would I Not Be Suprised if He Hates Twilight...
Robert Pattinson Not a 'Twihard,' Saw 'Twilight' for The First Time 'A Few Days Ago'
by Joe Lynch · June 14, 2010
Yep, "Twilight" antihero, Robert Pattinson has admitted that, until quite recently, he was among the few who've managed to avoid seeing the movie that made him famous.
"I just saw 'Twilight' on TV for the first time a few days ago," Pattinson revealed during a press conference for 'Eclipse' this past weekend. Although he had seen bits and pieces of the film while doing the DVD commentary, he said had never actually sat through the whole thing.
What were his impressions of the $408 million blockbuster he starred in two years ago? "Now that I've seen it, [I realize] you do need to read the book to get it," Pattinson said while laughing. "I was like, 'What?!' and I'm in it."
Pattinson also confessed that he freaked out a bit upon hearing his own song in the first 'Twilight' movie. "I was thinking, 'That is so bizarre,'" he told reporters when asked whether he would pen any more Twilight ditties. "It really shows how none of us thought it was going to be so massive. I never thought people would buy the soundtrack or anything, so it's a little more nerve-wracking now."
What next on the agenda for R-Pattz? Reading "Breaking Dawn," for one. Back-to-back filming for the final two movies begins this fall and so far Pattinson only has a vague idea of what happens in the final book. A spoiler for Pattinson and other non-Twihards: it's the one where Bella (Kristen Stewart) gives birth to Edward's child in a bizarre sequence.
"I didn't intend to not read it until now," Pattinson said with a laugh. "I just heard brief rumors about what happens in the story, but I don't really know what happens at all."
As for "Eclipse," Pattinson says the third movie stands on its own more easily than the past two did and appeals to a broader crowd.
"I guess in terms of the violence and stuff.... that makes it a bit more grown-up," he said during a separate panel. "Also I think it's just a more accessible storyline. The sort of love triangle thing -- being torn between two lovers doesn't really happen when you're eight. So yeah, I guess it's a bit more grown-up in that respect."
Also somewhat more mature in this installment: the liplocking between the two main "Twilight" characters (a practice for which Pattinson and his co-star, Kristen Stewart, just won an MTV Movie Award.)
"It was kind of the ultimate movie kiss," the 24-year-old heartthrob said at an "Eclipse" press junket. "We were on top of this mountain. There was a beautiful background. The camera is circling around us. And there we are kissing. It was good -- I'm glad Jacob had the opportunity to get his kiss in there."
Fugitive hid 40 years in plain sight
By MATT GOURAS, Associated Press Writer Matt Gouras, Associated Press Writer
–
Tue Jun 15,
5:55 am ET
HELENA, Mont. – The aging Frank Dryman, a notorious
killer from Montana's past, had hidden in plain sight for so long that
he forgot he was a wanted man.
In an exclusive jailhouse interview with The Associated
Press, Dryman detailed how he invented a whole new life, with a new
family, an Arizona wedding chapel business — and even volunteer work for
local civic clubs.
"They just forgot about me," said Dryman, in his
first interview since being caught and sent back to the prison he last
left in the 1960s. "I was a prominent member of the community."
That is, until the grandson of the man he shot six
times in the back came looking.
Dryman had been one step ahead of the law since 1951
when he avoided the hangman's noose, a relic of frontier justice still
in use at the time.
Less than 20 years later he was out on parole. Not
content with that good fortune, he skipped out and evaded authorities
for four decades. After a while he even forgot about hiding and signed
up for V.A. benefits from his days in the Navy in 1948.
Now the 79-year-old Dryman is back behind bars, likely for what remains of
his life.
He was caught only after his long-ago victim's
grandson got curious and started poking around.
Dryman was hitching a ride from Shelby cafe owner
Clarence Pellett on a cold and snowy day in 1951 when he pulled a gun
and ordered Pellett out of his own car and began firing.
Dryman does not deny the crime — just that he's not
the same man today. He has been Victor Houston for decades. At the time of the murder,
and after being discharged from the Navy for mental issues, he was
going by yet another name: Frank Valentine.
"That kid, Frank Valentine, he just exploded," Dryman
says of his crime. "I didn't shoot that man in the back. That wild kid
did. That's not me.
"Victor Houston tried to make up for it by being an
honor citizen."
Dryman says he served his time, which he did until
paroled. But a Montana Parole Board not accustomed to leniency on
those who walk away from supervision was not impressed with Dryman's
subsequent good deeds. Last month the board sent him back behind bars to
serve what remains of his life sentence.
Dryman said he disappeared from parole in California
to get away from a wife he didn't like. He said he's not sure why he
just didn't leave the wife and remain on parole.
But once gone, he said, he didn't look back. His new
wife and family knew nothing of his past. He put down roots in Arizona
City painting signs, a trade learned in prison, and performing weddings.
"I never thought I was a parole violator. I was
Victor Houston. I never looked over my shoulder," Dryman said. "I just
forgot about it."
On his birthday he used to get two cards from his
brother: one for Houston and one for Valentine.
"I thought it was cute. I had no fear," Dryman said.
He said the details of his past are just coming back: the shooting, his
original sentence and the cause he became for opponents of the death
penalty, and his first stint in prison.
"Only since I have been back here did I start to think about it," said
Dryman. "To be honest, I didn't even remember the victim's name."
Dryman understands he is not likely to get out again now. And he is not
kindly disposed to the victim's grandson, the Bellevue, Wash., oral
surgeon who became intensely interested in a piece of family history he
knew nothing about. Clem Pellett compiled reams of old documents and
tracked down his grandfather's killer with the help of a private
investigator.
"I can't blame him for what he did," Dryman said. "But I think it was so
wrong he spent so much money getting me here. I feel it is unfair."
Many in the Pellett family do remember the murder. A dozen descendants
showed up at the parole hearing when Dryman was rearrested to testify
against his release, saying the killing had forever changed the history
of the family.
They said as kids they lived in fear of hitchhikers — even in fear of
Dryman. Some remembered Dryman's courtroom outburst at his first trial
that resulted in conviction and a hanging sentence.
"He turned to the judge and said, 'I'm going to kill you,' he turned to
the jury and said 'I am going to kill you' and he turned to the crowd
and said some stuff like that," said Clem Pellett. "He was an angry
young man who felt powerless."
Pellett only learned the details of the case last year after cleaning out
boxes of old newspaper clippings. His own parents never talked about the
murder. He had never even really known the Montana side of his family,
where the pain of the killing still lingers.
Pellett, without even talking to those relatives, began a quest to learn
more, compiling old records, court transcripts, ancient arrest records
for Dryman's petty crimes prior to the shooting — all
of which he used to track down his grandfather's killer.
Pellett said he was driven by an intense curiosity, and would now like
to meet with Dryman to fill in holes in the story that he may chronicle
in a book.
Dryman doesn't think he will agree to the meeting.
He also denounces the allegation that he made a courtroom death threat,
which Clem Pellett said was confirmed through his research.
Dryman lives in a low security wing of the Montana State Prison, wears
prison-issue clothing and due to failing eyesight walks with a cane to
avoid tripping. Being interviewed in the same parole board room where
was he returned to prison for life, Dryman said of Clem Pellett, "He's
already got me here, he should be happy. I think they got their pound of
flesh, and I accept it."
One of the original prosecutors in the case also never forgot about
Dryman.
"It was a very notorious case, perhaps the biggest of the time," said
John Luke McKeon, now 85.
McKeon, a very young assistant attorney general assigned to the case
despite his own opposition to the death penalty, said the Montana Supreme Court threw out the hanging
sentence amid some of the most intense arguments over the death penalty
the state had seen.
McKeon wrote a letter to the parole board in late May asking for
leniency, telling the board he thinks Dryman has paid for his crime. But
it got there after the board made its decision.
The former prosecutor doesn't see any way out for Dryman this time.
"I don't think the governor's going to give him exoneration," he said.
"I think he is going to die in prison."
Suger ≠ Focus
Sugar Does Not Help Self-Control, Willpower
By Rick Nauert PhD Senior News Editor
Reviewed by John M. Grohol, Psy.D. on June 14, 2010
Put aside the candy bar as a self-management tactic to infuse energy, improve attention and help you get down to business.
A new interpretation of a 2007 study challenges the idea that glucose is used to manage self-control and that humans rely on this energy source for willpower.
The investigation by University of Pennsylvania psychologist Robert Kurzban is published in the current issue of the journal Evolutionary Psychology.
The new analysis contradicts results published in the Journal of Personality and Social Psychology based on “resource” models of self-control, suggesting that when people exert self-control — by, for example, carefully focusing their attention — a resource is “depleted,” leaving less of it for subsequent acts of self-control. This study identified glucose as this resource that gets depleted.
“For this model to be correct, it obviously must be the case that performing a self-control task reduces glucose levels relative to pre-task levels,” Kurzban said.
“Evidence from neurophysiology research suggests that this is unlikely, and the evidence for it is mixed at best.”
By analyzing the portion of the data made available by prior researchers, Kurzban discovered that, in the studies reported, glucose levels did not decrease among subjects who had performed self-control tasks. In short, his reanalysis shows that the researchers’ own data undermine the model they advance in their paper.
Kurzban’s new analysis is consistent with the neuroscience literature, which strongly implies that the marginal difference in glucose consumption by the brain from five minutes of performing a “self-control” task is unlikely in the extreme to be of any significant size.
Further, research on exercise shows that burning calories through physical activity, which really does consume substantial amounts of glucose, in fact shows the reverse pattern from what the model would predict: People who have recently exercised and burned glucose are better, not worse, on the sorts of tasks used in the self-control literature.
“The failure to find the effect predicted by the glucose model of self-control is not surprising given what is known about brain metabolism,” Kurzban said.
“Even very different computational tasks result in very similar glucose consumption by the brain, which tends to metabolize glucose at similar rates independent of task.”
Furthermore, even if exerting self-control did reduce levels of glucose, the cause of the reduction could be factors such as increased heart rate when people perform certain kinds of tasks, rather than consumption by the brain.
Glucose levels are probably influenced, Kurzban said, by a cascade of physical and psychological mechanisms that mediate glucose levels throughout the body.
“The weight of evidence implies that the glucose model of self-control in particular –- and perhaps the resource model in general –- ought to be carefully rethought,” he said.
“From a computational perspective, a ‘resource’ account is the wrong kind of explanation for performance decrements to begin with. No one whose computer is performing slowly would think that the fault lies in not having sufficient electricity –- or that running Excel for five minutes will drain the battery and so make Word slow down –- even though no one would deny that electricity is necessary for computers.”
One way to put the prior data in context, according to Kurzban, is to consider the data in terms of the familiar unit of calories. The brain as a whole consumes about one quarter of one calorie per minute. Obviously, the consumption rate for just the fraction of the brain involved in “self-control” must, logically, be much smaller than .25 calories per minute.
A 1 percent increase across the entire brain would, over the course of a five-minute task, consume .0125 calories. If one assumes an order of magnitude greater effect, a 10-percent increase, the amount of energy consumed would still be much less than a single calorie.
“Even with these extreme assumptions, potentially off by orders of magnitude, the caloric cost would still be well less than .2 calories,” Kurzban said.
“The brains of subjects categorized as ‘depleted’ in this literature, have, relative to controls, used an additional amount of glucose equal to about 10 percent of a single Tic Tac.”
Source: University of Pennsylvania
By Rick Nauert PhD Senior News Editor
Reviewed by John M. Grohol, Psy.D. on June 14, 2010
Put aside the candy bar as a self-management tactic to infuse energy, improve attention and help you get down to business.
A new interpretation of a 2007 study challenges the idea that glucose is used to manage self-control and that humans rely on this energy source for willpower.
The investigation by University of Pennsylvania psychologist Robert Kurzban is published in the current issue of the journal Evolutionary Psychology.
The new analysis contradicts results published in the Journal of Personality and Social Psychology based on “resource” models of self-control, suggesting that when people exert self-control — by, for example, carefully focusing their attention — a resource is “depleted,” leaving less of it for subsequent acts of self-control. This study identified glucose as this resource that gets depleted.
“For this model to be correct, it obviously must be the case that performing a self-control task reduces glucose levels relative to pre-task levels,” Kurzban said.
“Evidence from neurophysiology research suggests that this is unlikely, and the evidence for it is mixed at best.”
By analyzing the portion of the data made available by prior researchers, Kurzban discovered that, in the studies reported, glucose levels did not decrease among subjects who had performed self-control tasks. In short, his reanalysis shows that the researchers’ own data undermine the model they advance in their paper.
Kurzban’s new analysis is consistent with the neuroscience literature, which strongly implies that the marginal difference in glucose consumption by the brain from five minutes of performing a “self-control” task is unlikely in the extreme to be of any significant size.
Further, research on exercise shows that burning calories through physical activity, which really does consume substantial amounts of glucose, in fact shows the reverse pattern from what the model would predict: People who have recently exercised and burned glucose are better, not worse, on the sorts of tasks used in the self-control literature.
“The failure to find the effect predicted by the glucose model of self-control is not surprising given what is known about brain metabolism,” Kurzban said.
“Even very different computational tasks result in very similar glucose consumption by the brain, which tends to metabolize glucose at similar rates independent of task.”
Furthermore, even if exerting self-control did reduce levels of glucose, the cause of the reduction could be factors such as increased heart rate when people perform certain kinds of tasks, rather than consumption by the brain.
Glucose levels are probably influenced, Kurzban said, by a cascade of physical and psychological mechanisms that mediate glucose levels throughout the body.
“The weight of evidence implies that the glucose model of self-control in particular –- and perhaps the resource model in general –- ought to be carefully rethought,” he said.
“From a computational perspective, a ‘resource’ account is the wrong kind of explanation for performance decrements to begin with. No one whose computer is performing slowly would think that the fault lies in not having sufficient electricity –- or that running Excel for five minutes will drain the battery and so make Word slow down –- even though no one would deny that electricity is necessary for computers.”
One way to put the prior data in context, according to Kurzban, is to consider the data in terms of the familiar unit of calories. The brain as a whole consumes about one quarter of one calorie per minute. Obviously, the consumption rate for just the fraction of the brain involved in “self-control” must, logically, be much smaller than .25 calories per minute.
A 1 percent increase across the entire brain would, over the course of a five-minute task, consume .0125 calories. If one assumes an order of magnitude greater effect, a 10-percent increase, the amount of energy consumed would still be much less than a single calorie.
“Even with these extreme assumptions, potentially off by orders of magnitude, the caloric cost would still be well less than .2 calories,” Kurzban said.
“The brains of subjects categorized as ‘depleted’ in this literature, have, relative to controls, used an additional amount of glucose equal to about 10 percent of a single Tic Tac.”
Source: University of Pennsylvania
Saturday, June 12, 2010
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