1 day agookinowasensayyy 8,535 notes
Casual marijuana use linked to brain abnormalities in students

neurosciencestuff:

Young adults who used marijuana only recreationally showed significant abnormalities in two key brain regions that are important in emotion and motivation, scientists report. The study was a collaboration between Northwestern Medicine® and Massachusetts General Hospital/Harvard Medical School.

image

This is the first study to show casual use of marijuana is related to major brain changes. It showed the degree of brain abnormalities in these regions is directly related to the number of joints a person smoked per week. The more joints a person smoked, the more abnormal the shape, volume and density of the brain regions.

"This study raises a strong challenge to the idea that casual marijuana use isn’t associated with bad consequences," said corresponding and co-senior study author Hans Breiter, M.D. He is a professor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine and a psychiatrist at Northwestern Memorial Hospital.

"Some of these people only used marijuana to get high once or twice a week," Breiter said. "People think a little recreational use shouldn’t cause a problem, if someone is doing OK with work or school. Our data directly says this is not the case."

The study will be published April 16 in the Journal of Neuroscience.

Scientists examined the nucleus accumbens and the amygdala — key regions for emotion and motivation, and associated with addiction — in the brains of casual marijuana users and non-users. Researchers analyzed three measures: volume, shape and density of grey matter (i.e., where most cells are located in brain tissue) to obtain a comprehensive view of how each region was affected.

Both these regions in recreational pot users were abnormally altered for at least two of these structural measures. The degree of those alterations was directly related to how much marijuana the subjects used.

Of particular note, the nucleus acccumbens was abnormally large, and its alteration in size, shape and density was directly related to how many joints an individual smoked.

"One unique strength of this study is that we looked at the nucleus accumbens in three different ways to get a detailed and consistent picture of the problem," said lead author Jodi Gilman, a researcher in the Massachusetts General Center for Addiction Medicine and an instructor in psychology at Harvard Medical School. "It allows a more nuanced picture of the results."

Examining the three different measures also was important because no single measure is the gold standard. Some abnormalities may be more detectable using one type of neuroimaging analysis method than another. Breiter said the three measures provide a multidimensional view when integrated together for evaluating the effects of marijuana on the brain.

"These are core, fundamental structures of the brain," said co-senior study author Anne Blood, director of the Mood and Motor Control Laboratory at Massachusetts General and assistant professor of psychiatry at Harvard Medical School. "They form the basis for how you assess positive and negative features about things in the environment and make decisions about them."

Through different methods of neuroimaging, scientists examined the brains of young adults, ages 18 to 25, from Boston-area colleges; 20 who smoked marijuana and 20 who didn’t. Each group had nine males and 11 females. The users underwent a psychiatric interview to confirm they were not dependent on marijuana. They did not meet criteria for abuse of any other illegal drugs during their lifetime.

The changes in brain structures indicate the marijuana users’ brains are adapting to low-level exposure to marijuana, the scientists said.

The study results fit with animal studies that show when rats are given tetrahydrocannabinol (THC) their brains rewire and form many new connections. THC is the mind-altering ingredient found in marijuana.

"It may be that we’re seeing a type of drug learning in the brain," Gilman said. "We think when people are in the process of becoming addicted, their brains form these new connections."

In animals, these new connections indicate the brain is adapting to the unnatural level of reward and stimulation from marijuana. These connections make other natural rewards less satisfying.

"Drugs of abuse can cause more dopamine release than natural rewards like food, sex and social interaction," Gilman said. "In those you also get a burst of dopamine but not as much as in many drugs of abuse. That is why drugs take on so much salience, and everything else loses its importance."

The brain changes suggest that structural changes to the brain are an important early result of casual drug use, Breiter said. “Further work, including longitudinal studies, is needed to determine if these findings can be linked to animal studies showing marijuana can be a gateway drug for stronger substances,” he noted.

Because the study was retrospective, researchers did not know the THC content of the marijuana, which can range from 5 to 9 percent or even higher in the currently available drug. The THC content is much higher today than the marijuana during the 1960s and 1970s, which was often about 1 to 3 percent, Gilman said.

Marijuana is the most commonly used illicit drug in the U.S. with an estimated 15.2 million users, the study reports, based on the National Survey on Drug Use and Health in 2008. The drug’s use is increasing among adolescents and young adults, partially due to society’s changing beliefs about cannabis use and its legal status.

A recent Northwestern study showed chronic use of marijuana was linked to brain abnormalities. “With the findings of these two papers,” Breiter said, “I’ve developed a severe worry about whether we should be allowing anybody under age 30 to use pot unless they have a terminal illness and need it for pain.”

1 day agoneurosciencestuff 608 notes

neverending-fairytale:

Saw my all time favourite dress. Great opportunity to shoot some close-ups!

1 day agoasfarasoneknowsneverending-fairytale 17,079 notes
neurosciencestuff:

Neuroscientists disprove idea about brain-eye coordination 
By predicting our eye movements, our brain creates a stable world for us. Researchers used to think that those predictions had so much influence that they could cause us to make errors in estimating the position of objects. Neuroscientists at Radboud University have shown this to be incorrect. The Journal of Neuroscience published their findings – which challenge fundamental knowledge regarding coordination between brain and eyes – on 15 April.
You continually move your eyes all day long, yet your perception of the world remains stable. That is because the brain processes predictions about your eye movements while you look around. Without these predictions, the image would shoot back and forth constantly. 
Errors of estimationPeople sometimes make mistakes in estimating the positions of objects – missing the ball completely during a game of tennis, for example. Predictions on eye movements were long held responsible for such localization errors: if the prediction does not correspond to the eventual eye movement, a mismatch between what you expect to see and what you actually see could be the result. Jeroen Atsma, a PhD candidate at the Donders Institute of Radboud University, wanted to know how that worked. ‘If localization errors really are caused by predictions, you would also expect those errors to occur if an eye movement, which has already been predicted in your brain, fails to take place at the very last moment.’ Atsma investigated this by means of an ingenious experiment. 
Localizing flashes of lightAtsma asked test subjects to look at a computer screen where a single small ball appeared at various positions at random. The subjects followed the balls with their eyes while an eye-tracker registered their eye movements. The experiment ended with one last ball on the screen, followed by a short flash of light near that ball. The person had to look at the last, stationary ball while using the computer mouse to indicate the position of the flash of light. However, in some cases, a signal was sent around the time the last ball appeared, indicating that the subject was NOT allowed to look at the ball. In other words, the eye movement was cancelled at the last moment. The person being tested still had to indicate where the flash was visible. 
Remarkable findingsEven when test subjects heard at very short notice that they should not look at the ball – in other words when the brain had already predicted the eye movement – they did not make any mistakes in localizing the flash of light. ‘That demonstrates you don’t make localization errors solely on the basis of predictions’, Atsma explained. ‘So far, literature has pretty much suggested the exact opposite. That is why we repeated the experiment several times to be sure.’ 
The findings of the neuroscientists in Nijmegen are remarkable because they challenge much of the existing knowledge about eye-brain coordination. Atsma: ‘This has been an issue ever since we started studying how the eyes function. For the first time ever our experiment offered the opportunity to research brain predictions when the actual eye movement is aborted. Therefore I expect our publication to lead to some lively discussions among fellow researchers.’ 
(Image credit)

neurosciencestuff:

Neuroscientists disprove idea about brain-eye coordination

By predicting our eye movements, our brain creates a stable world for us. Researchers used to think that those predictions had so much influence that they could cause us to make errors in estimating the position of objects. Neuroscientists at Radboud University have shown this to be incorrect. The Journal of Neuroscience published their findings – which challenge fundamental knowledge regarding coordination between brain and eyes – on 15 April.

You continually move your eyes all day long, yet your perception of the world remains stable. That is because the brain processes predictions about your eye movements while you look around. Without these predictions, the image would shoot back and forth constantly.

Errors of estimation
People sometimes make mistakes in estimating the positions of objects – missing the ball completely during a game of tennis, for example. Predictions on eye movements were long held responsible for such localization errors: if the prediction does not correspond to the eventual eye movement, a mismatch between what you expect to see and what you actually see could be the result. Jeroen Atsma, a PhD candidate at the Donders Institute of Radboud University, wanted to know how that worked. ‘If localization errors really are caused by predictions, you would also expect those errors to occur if an eye movement, which has already been predicted in your brain, fails to take place at the very last moment.’ Atsma investigated this by means of an ingenious experiment.

Localizing flashes of light
Atsma asked test subjects to look at a computer screen where a single small ball appeared at various positions at random. The subjects followed the balls with their eyes while an eye-tracker registered their eye movements. The experiment ended with one last ball on the screen, followed by a short flash of light near that ball. The person had to look at the last, stationary ball while using the computer mouse to indicate the position of the flash of light. However, in some cases, a signal was sent around the time the last ball appeared, indicating that the subject was NOT allowed to look at the ball. In other words, the eye movement was cancelled at the last moment. The person being tested still had to indicate where the flash was visible.

Remarkable findings
Even when test subjects heard at very short notice that they should not look at the ball – in other words when the brain had already predicted the eye movement – they did not make any mistakes in localizing the flash of light. ‘That demonstrates you don’t make localization errors solely on the basis of predictions’, Atsma explained. ‘So far, literature has pretty much suggested the exact opposite. That is why we repeated the experiment several times to be sure.’

The findings of the neuroscientists in Nijmegen are remarkable because they challenge much of the existing knowledge about eye-brain coordination. Atsma: ‘This has been an issue ever since we started studying how the eyes function. For the first time ever our experiment offered the opportunity to research brain predictions when the actual eye movement is aborted. Therefore I expect our publication to lead to some lively discussions among fellow researchers.’

(Image credit)

1 day agoneurosciencestuff 201 notes

internetboredom:

I apparently was in 101 Dalmatians 

1 day agocmtothemcanightmarefantasmic 163,580 notes

shrekmin:

accidentally in love / shrekmin au

shrek and armin meet over the summer. it feels like the perfect love. they both get each other completely. but as summer comes to an end, will they be able to keep their romance alive? or will it sizzle out with the summer sun?

1 day agovincecartersshrekmin 8,717 notes

wetheurban:

SPOTLIGHT: New Banksy Mural On Love in the Digital Era

Oh, Banksy, we love how you never seem to miss a beat. Painted on a quaint stone wall on Clement Street in Bristol, United Kingdom is a new mural from the famed artist depicting a scenario thats becoming all too familiar in this ever-so saturated digital world. 

Read More

1 day agowetheurban 3,201 notes
hckeys:

fearrs:

metalite:

vicsecretmodels:

supermodelgif:

Karlie Kloss @ Jean Paul Gaultier SS 2014

The walk! 

I WAS WAITING FOR THIS GIF

fucking slay me

my QUEEN

hckeys:

fearrs:

metalite:

vicsecretmodels:

supermodelgif:

Karlie Kloss @ Jean Paul Gaultier SS 2014

The walk! 

I WAS WAITING FOR THIS GIF

fucking slay me

my QUEEN

1 day agopuree-passionsupermodelgif 19,093 notes
amischiefofmice:

orfs:

averyterrible:

thisplaceisdespair:

flatluigi:

stormingtheivory:

So can we talk about the absolutely stunning duplicity going on here?

holy shit

ok, why the fuck is the graph upside down. that is incredibly misleading

Because its from the Florida Department of Justice, and they have a mandate here.

for those who have trouble inverting it in their head, ftfy:


this is some of the most blatant twisting of info i have ever seen holy shit

amischiefofmice:

orfs:

averyterrible:

thisplaceisdespair:

flatluigi:

stormingtheivory:

So can we talk about the absolutely stunning duplicity going on here?

holy shit

ok, why the fuck is the graph upside down. that is incredibly misleading

Because its from the Florida Department of Justice, and they have a mandate here.

for those who have trouble inverting it in their head, ftfy:

image

this is some of the most blatant twisting of info i have ever seen holy shit

1 day agookinowastormingtheivory 35,491 notes

vivianvivisection:

jonesdavid813:

h0llo:

Putting on makeup is such a spiritual experience I watch myself go from a 3 to a 9 right in front of my mirror I love it

no, if you are putting on makeup, I don’t care who you are or what you look like, you go from about a 10 to 1

keep talking shit you gonna go from a basic ass 2 to a 6-feet-under

2 days agocmtothemch0llo 341,322 notes
2 days agocmtothemcbitch-imbarbz 245 notes

Amy Poehler: Mean Girls - Mrs. George (2004) vs. Parks & Recreation - Leslie Knope (2014)

2 days agopalmistmcdonald-s 68,845 notes
petal-girl:

i have reblogged this like 10 times and am tempted to print off some copies and stick them on my wall/in my sketchpad/on my art teacher’s face

petal-girl:

i have reblogged this like 10 times and am tempted to print off some copies and stick them on my wall/in my sketchpad/on my art teacher’s face

2 days agoottermaticfutonpixytrixx 560,805 notes

cmtothemc:

kenobi-wan-obi:

poeticdarkbeauty:

ratchetivity:

ebbaliciousz:

awkwardexcellence:

blkmartian:

Gems of wisdom

😂😂😭

LOL

Lmfaooo

LMAOO “Bye Tyrone” haha

lmaoooo nooooo

Maya is a bad bitch

2 days agocmtothemcblkmartian 10,085 notes

skippyjif:

We HAVE to do this version this summer, I decree it.

3 days agothesugarrayskippyjif 49,676 notes
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