Neuroimaging Reveals How LSD Affects the Brain


Since its invention some 80 years ago, LSD has been considered one of the most powerful psychedelic drugs, with a mysteriously high ability to expand the conscious experience beyond the confines of the body. But what does this enigmatic drug actually do inside the brain? Thanks to the first-ever study of LSD with modern brain-imaging techniques, we now have a glimpse of the psychedelic in action.

Robin Carhart-Harris and David Nutt of Imperial College London and their colleagues looked at changes in brain activity patterns during the hallucinatory and consciousness-altering effects of LSD (lysergic acid diethylamide). They found a pattern of communication across the brain that could explain the drug's profound sensory and mind-altering effects. They published their findings today in the journal Proceedings of the National Academy of Sciences.

In the study, divided into two sessions that took place on two days, 20 participants received an IV infusion of either LSD or a salt-water placebo. They then lay in a brain scanner with their eyes shut. During each roughly four-hour session, the participants underwent neuroimaging with multiple techniques, including functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG).

During the session when subjects had LSD in their system, much more of the brain was involved in visual processing compared with the placebo session. Moreover, the visual cortex, the part of the brain involved in processing visual information, showed greater synchronous activity with many areas of the brain. The greater this connectivity, the higher the participants’ reporting of complex visual hallucinations.

Carhart-Harris et al. in PNAS

“What was really intriguing was the magnitude of this expanded visual processing, which was correlated with people's ratings of complex visual hallucinations—the kind of dreamlike visions they describe with psychedelics, involving landscapes and people,” Carhart-Harris told mental_floss.

Meanwhile, as expected, people experienced altered consciousness states as well. One such experience involved a disintegration of the sense of self, or what researchers call ego-dissolution; it was linked with decreased connectivity between two brain regions, the parahippocampus and retrosplenial cortex, suggesting this connection is linked to a sense of self. This was part of a general disruption in the default mode network—a network of brain regions that normally shows a robust pattern of connectivity as people are awake and resting, thinking, remembering the past, and planning for the future.

“The findings are quite consistent with previous findings on psychedelics,” Carhart-Harris said. “We are now getting more confidence in understanding what underlies subjective experience produced by psychedelics.”


Putting together these results with brain imaging findings of other psychedelics points to some general principles, Carhart-Harris said. It seems that LSD breaks the boundaries between well-established brain networks, giving rise to a different, more flexible form of communication among them.

During the development of the brain, neural networks become specialized in the tasks they perform. As these networks become more and more distinct from each other, the communication between them becomes less flexible. “With LSD, these networks in the brain begin to lose their integrity. You see a desegregation of brain systems, where networks start to blend with each other. On the whole, the brain becomes more globally connected, operating in a more flexible way,” Carhart-Harris said. “And this seems to map with some of the fundamental changes in consciousness that you see with LSD.”

"This powerhouse of a study employs a number of cutting-edge human neuroscience techniques to examine the effects of LSD on brain activity,” said Gaurav Patel, a psychiatrist at the New York State Psychiatric Institute at Columbia University Medical Center, who was not involved with the study. The use of multiple techniques in single individuals to study the changes in brain activity helps free the researchers from potential confounds in any one technique, Patel said. “Moreover, the findings were relatively specific, and had high correlations with behavioral measures,” Patel told mental_floss.


For an old drug with such intense effects on the brain, very little is known about LSD. After it was first synthesized by Albert Hofmann in 1938, LSD found its way into psychiatric settings and was in use throughout the 1950s and '60s. The drug also presented an intriguing opportunity for research. Between 1953 and 1973, the U.S. government alone funded more than 100 studies of LSD. But the drug was ultimately banned under the United Nations Convention on Psychotropic Substances, and fell off the radar of researchers due to political and social stigma.

But in recent years, LSD and other psychedelics have gained a renewed interest as potentially untapped resources useful for mental health treatment or studying consciousness. This interest is shared by scientists and nonscientists alike. For the present study, the researchers asked the public to cover the remainder of the cost for finishing the experiment in a crowdfunding campaign last year, ultimately raising £53,390 (about $80,000)—more than double their original goal (the study was also funded by the Beckley Foundation).

“The response was amazing,” said Carhart-Harris, who sees this as evidence of a genuine intellectual interest among the public for understanding the curious effects of the drug.

Screenshot from a crowdfunding video describing the researchers' LSD project 

Carhart-Harris and colleagues previously studied psilocybin, the active compound in psychoactive mushrooms. They found psilocybin allowed for bypassing the brain's normal control, lifting the typical limits on our perception—an idea reminiscent of what Aldous Huxley suggested in his 1954 book on psychedelics, The Doors of Perception.

The new findings on LSD, too, suggested the drug disrupts the normal pattern of activity in important brain networks, allowing the brain to operate in a more flexible, fluid way, Carhart-Harris said. 

The researchers suggest this modification of normal brain communication underlies ego-dissolution. There isn’t a clear definition of this phenomenon yet, but Carhart-Harris describes it as a feeling of becoming less sure of the self, identity, and personality. “You begin to see your ‘self’ more as something objective as opposed to subjective," he said. "This often is accompanied by certain insights about oneself, one's background and relationships with others and with the world in general. And actually it often goes hand-in-hand with feelings of a spiritual and mystical nature.”


In another article published online in the May issue of Psychological Medicine, the team detailed the findings on psychological effects of LSD. One paradoxical effect of the drug, the team said, was that it includes psychosis-like symptoms when it’s taken—yet seems to improve psychological well-being afterward. It is possible that LSD increases cognitive flexibility and leaves a residue of “loosened cognition” that leads to improved psychological well-being, the researchers said.

A few other studies, too, have explored the possible positive effects of LSD or other psychedelics on mental health. A 2014 study with 12 people with life-threatening diseases, for instance, found LSD useful for easing anxiety. And when researchers followed up with nine of the people a year later, they found the effects to be long-lasting.

Studying how psychedelics affect the brain can reveal new insights about how the brain works, in both health and disease.

“In psychiatric research, we struggle with understanding how the brains of individuals may or may not be different from what they could have been if healthy,” Patel said. “Here, we get to see how psychiatric-like symptoms correlate with circuit-level changes in brain activity. It is rare to see a study of this nature performed so rigorously, and to have found such clean results.”

This Just In
Yes, Parents Do Play Favorites—And Often Love Their Youngest Kid Best

If you have brothers or sisters, there was probably a point in your youth when you spent significant time bickering over—or at least privately obsessing over—whom Mom and Dad loved best. Was it the oldest sibling? The baby of the family? The seemingly forgotten middle kid?

As much as we'd like to believe that parents love all of their children equally, some parents do, apparently, love their youngest best, according to The Independent. A recent survey from the parenting website Mumsnet and its sister site, the grandparent-focused Gransnet, found that favoritism affects both parents and grandparents.

Out of 1185 parents and 1111 grandparents, 23 percent of parents and 42 percent of grandparents admitted to have a favorite out of their children or grandchildren. For parents, that tended to be the youngest—56 percent of those parents with a favorite said they preferred the baby of the family. Almost 40 percent of the grandparents with a favorite, meanwhile, preferred the oldest. Despite these numbers, half of the respondents thought having a favorite among their children and grandchildren is "awful," and the majority think it's damaging for that child's siblings.

Now, this isn't to say that youngest children experience blatant favoritism across all families. This wasn't a scientific study, and with only a few thousand users, the number of people with favorites is actually not as high as it might seem—23 percent is only around 272 parents, for instance. But other studies with a bit more scientific rigor have indicated that parents do usually have favorites among their children. In one study, 70 percent of fathers and 74 percent of mothers admitted to showing favoritism in their parenting. "Parents need to know that favoritism is normal," psychologist Ellen Weber Libby, who specializes in family dynamics, told The Wall Street Journal in 2017.

But youngest kids don't always feel the most loved. A 2005 study found that oldest children tended to feel like the preferred ones, and youngest children felt like their parents were biased toward their older siblings. Another study released in 2017 found that when youngest kids did feel like there was preferential treatment in their family, their relationships with their parents were more greatly affected than their older siblings, either for better (if they sensed they were the favorite) or for worse (if they sensed their siblings were). Feeling like the favorite or the lesser sibling didn't tend to affect older siblings' relationships with their parents.

However, the author of that study, Brigham Young University professor Alex Jensen, noted in a press release at the time that whether or not favoritism affects children tends to depend on how that favoritism is shown. "When parents are more loving and they're more supportive and consistent with all of the kids, the favoritism tends to not matter as much," he said, advising that “you need to treat them fairly, but not equally.” Sadly for those who don't feel like the golden child, a different study in 2016 suggests that there's not much you can do about it—mothers, at least, rarely change which child they favor most, even over the course of a lifetime.

[h/t The Independent]

15 Scientific Reasons Spring Is the Most Delightful Season

Summer, winter, and fall may have their fans, but spring is clearly the most lovable of the four seasons. Not convinced? Here are 15 scientific reasons why spring is great:


road and field on a sunny day

Spring marks the end of blistering winter and the transitional period to scorching summer. In many places, the season brings mild temperatures in the 60s and 70s. People tend to be most comfortable at temperatures of about 72°F, research shows, so the arrival of spring means you can finally ditch the heavy winter layers and still be comfortable.


sunny sky

Following the spring equinox, days begin lasting longer and nights get shorter. Daylight Saving Time, which moves the clock forward starting in March, gives you even more light hours to get things done. Those extra hours of sun can be a major mood-booster, according to some research. A 2016 study of students in counseling at Brigham Young University found that the longer the sun was up during the day, the less mental distress people experienced.


blue bird on branch

Many animals migrate south during the winter, then head north as temperatures rise. For relatively northern regions, there is no better indicator of spring than birds chirping outside your window. Their northward migration can start as early as mid-February and last into June, meaning that throughout the spring, you can expect to see a major avian influx. In addition to the satisfaction of marking species off your bird-watching checklist, seeing more of our feathered friends can make you happy. In 2017, a UK study found that the more birds people could see in their neighborhoods, the better their mental health.


Baby squirrels

Many animals reproduce in the spring, when temperatures are warmer and food is plentiful. Baby bunnies, ducklings, chipmunks, and other adorable animals abound come spring. Studies have found that seeing cute animals can have positive effects on humans. For instance, one small study in 2012 found that when college students looked at cute images of baby animals, they were better at focusing on a task in the lab. Being able to watch fluffy baby squirrels frolic outside your office window might make spring your most productive season of the year.


flowers hanging outside of a house

In 2015, a pair of public policy researchers discovered a hidden upside to "springing forward" for Daylight Saving Time. It reduced crime. When the sun set later in the evening, the study published in the Review of Economics and Statistics found, robbery rates fell. After Daylight Saving Time started in the spring, there was a 27 percent drop in robberies during that extra hour of evening sunlight, and a 7 percent drop over the course of the whole day.


child with rainbow umbrella jumping in puddle

Warmer temperatures mean you can spend more time outside without freezing your feet off, which is great for mental health. Across the seasons, research has found that taking walks in nature slows your heart rate and makes you more relaxed, but some research indicates that there is something special about spring's effect on your brain. A 2005 study from the University of Michigan linked spending 30 minutes or more outside in warm, sunny spring weather to higher mood and better memory. But the effect reverses when spring ends, since being outside in the warmest days of summer is usually pretty uncomfortable.


woman writing in a park

That same University of Michigan study found that spending time outside in the sunny spring weather isn't just a mood booster, it actually can change the way people think. The researchers found that being outdoors broadened participants' minds, leaving them more open to new information and creative thoughts.


leaves budding in spring

Spring brings green growth back to plants and trees. Depending on where you live, trees may begin sporting new leaves as early as mid-March. That successful spring leaf growth ensures a cool canopy to relax under during the hot summer—a hugely important factor in keeping cities comfortable. According to researchers, vegetation plays a big role in mitigating the urban heat island effect. When trees release water back into the air through evapotranspiration, it can cool down the areas around them by up to 9°F, according to the EPA.


tulip bulbs

It's amazing what a little sun can do for plants and grass. Through photosynthesis, plants convert sunlight, carbon dioxide, and water into food, releasing oxygen in the process. That means as plants start to grow in the spring, they pull carbon out of the atmosphere, providing an important environmental service. Plants take in roughly 25 percent of the carbon emissions humans produce, absorbing more than 100 gigatons of carbon through photosynthesis each growing season. Because of this, the amount of carbon dioxide in the atmosphere drops each spring and summer. (Unfortunately, it rises in the winter, when most plants aren't growing.)


wooden box full of fresh produce

Many vegetables and some fruits are harvested in the spring. 'Tis the season to get your local asparagus, greens, peas, rhubarb, and other fresh produce. Getting more fruits and vegetables into your diet isn't just good for the body; it's good for the soul. A 2016 study of more than 12,000 Australians found that when people increased the amount of fruits and vegetables in their diet, they felt happier and had higher rates of life satisfaction. If they increased their intake by eight portions a day (a tall order, we know) the psychological gains were equivalent to the change in well-being people experience when they go from being unemployed to having a job, the researchers found.


Flowers in a vase

After months spent conserving energy, flowers bloom in the spring, once they sense that the days have grown longer and the weather has turned warmer. That's good for humans, because several studies have shown that looking at flowers can make you happy. A 2008 study of hospital patients found that having flowers in the room made people feel more positive and reduced their pain and anxiety [PDF]. Another study from Rutgers University found that when participants were presented with a bouquet of flowers, it resulted in what scientists call a "true smile" a full 100 percent of the time. Seeing flowers had both "immediate and long-term effects" that resulted in elevated moods for days afterward, according to the researchers [PDF].


woman tying shoes in flower field

While it's important to keep moving no matter what the weather, research shows that working out can be more beneficial if you do it outside. A 2011 study found that, compared with an indoor workout, exercising outdoors in nature increased energy levels, made people feel revitalized, and decreased tension, among other positive effects. People who worked out in the fresh air also tended to say they enjoyed the experience more and would be likely to repeat it, suggesting that using nature as your gym might help you stick with your exercise regimen. While those benefits probably extend to winter, too, it's a whole lot easier to stomach the idea of a run once the weather warms up.


dew on grass and a daisy

Flu season in the U.S. typically lasts through the fall and winter, usually peaking between December and February and tapering off during the spring. The seasonal change is in part because of dry air. Cold temperatures mean a drop in humidity, and indoor heating only makes the air drier. This lack of moisture in the air can dry out your skin and the nasal cavities, leading to nose bleeds, irritated sinuses, and a greater risk of getting sick. Since the mucus in your nose is designed to trap viruses, when it dries up, you're more likely to catch something nasty, like the flu. As the weather warms up and becomes more humid throughout the spring, that mucus comes back. As the season wears on, not only can you lay off the body lotion, but you can probably put away the tissues—if you don't have spring allergies, that is.


windows open on a red house

Temperate weather makes it easier to get the fresh air you need. Opening your windows and allowing the breeze in serves as an important way to ventilate indoor spaces, according to the EPA. A lack of ventilation can lead to an unhealthy concentration of indoor pollutants from sources like cleaning product fumes, certain furniture and building materials, and stoves (especially gas ones), posing a threat to your health and comfort. Winter brings the highest rates of indoor pollutants like nitrogen oxide, a 2016 study of unventilated stove use in homes found. Spring brings the perfect opportunity to throw open those windows and doors and get the air moving again.


woman enjoying sitting in the sun

Sunlight triggers your body to produce the vitamin D, which keeps your bones strong. At northern latitudes, it's extremely difficult to get enough sun exposure naturally to maintain healthy vitamin D levels during the winter—even if you did want to expose your skin to the elements—but that starts to change during the spring. One Spanish study found that in Valencia (which shares a latitude with Philadelphia, Denver, Baltimore, Kansas City, and several other major U.S. cities), people only need 10 minutes outside with a quarter of their bodies exposed to the spring sunshine to get an adequate daily dose of vitamin D.

A version of this story originally ran in 2014.


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