Does LSD Induce Synesthesia?


Since Albert Hoffman discovered LSD (lysergic acid diethylamide) in 1938 and hippie culture made it a popular social drug in the 1960s, its psychedelic effects on the brain have been a source of scientific investigation. Anecdotally it’s known to cause visual and auditory hallucinations as well as reports of an individual’s sense of self dissolving and merging with a larger consciousness.

Recent research done at Imperial College London discovered through brain imaging that there is indeed a great deal of activity in the visual cortex of the brain when on LSD, and that it seems to interrupt connections between other brain networks, leading to that ephemeral state of oneness reported by users.

Yet these overlapping sensory experiences also share a lot in common with the brain condition synesthesia, in which an individual’s senses overlap or trigger each other in a way that is atypical. The disorder is rare. Estimates range, but most agree on approximately 1 percent of the population.

A group of researchers at the University of London (UoL) recently set out to study whether the effects of LSD qualified as true synesthesia. Their results, published in Neuropsychologia, suggest that what LSD-users are experiencing is not genuine synesthesia. The researchers say their findings open the door to a better understanding of how we process sensory perceptions.

“Synesthesia is basically understood as … a kind of condition in which a stimulant, known as an inducer, will consistently elicit a secondary experience that is atypical—not something generally experienced in the general population,” Devin Terhune, cognitive neuroscientist at UoL, tells mental_floss.

While every synesthete’s experience is unique, Terhune says there are some commonalities. For instance, many report seeing the letter B as blue, zero as white, and one as black. The most common instances of synesthesia are sound/color pairings (where the sound of a doorbell may evoke a green aura, for example) and color/grapheme pairings (where a particular letter or part of a word may appear in a specific color and even shape, like a blob or spiny edges).

To be considered congenital synesthesia, however, the response must be confirmed by consistency and specificity—that is, the same inducer must produce the same reaction every time.

For the placebo-controlled study, 10 physically and psychologically healthy participants were injected with saline solution for their first session, then they completed psychological tests to measure synesthesia-like experiences: a grapheme-color association test and a sound-color association test. After five to seven days, they were injected with 40-80 micrograms of LSD, and the tests were repeated.

While the participants said they had spontaneous synesthesia-like experiences while on LSD, they didn't report specific color experiences with graphemes and sounds, and sounds and colors were no more consistent on LSD than with the placebos. These results suggest that whatever is happening while under the influence of LSD, it isn't “true” synesthesia.

Given such anecdotal associations of color hallucinations in the existing literature about LSD, Terhune says he was surprised to find that “the color experiences effect was not even statistically significant.”

Terhune says the small sample size of 10 participants may have something to do with the weakness of the results. Another factor may have been the laboratory setting itself. Most people who take LSD aren't experiencing the drug's effects in a lab environment. “Factors like novelty and exposure to stimuli may be more critical,” he says. “Congenital synesthesia is really known as a stimulant-specific phenomenon—that something in your environment triggers your experience, reliably and automatically.”

He suggests future studies could be designed that would follow people taking LSD “out in the field” and ask them at various times, using an app, to report what they’ve been experiencing. This could yield a wider range of data.

Another question for future researchers is whether there is a “fundamental distinction between spontaneous forms of synesthesia and the inducer-specific experiences that congenital synesthetes’ experience,” Terhune says.

There may be genetic underpinnings to the disorder, which seems to be inherited in families. There are several working theories on its origins. One is the immune hypothesis, which considers that the genes responsible for normal cortical development are also involved in the development of synesthesia. The hyperconnectivity theory suggests that synesthetes, whose brains have been shown to have extra-developed myelin along sensory pathways, may experience a collaboration of senses resulting in synesthesia. Other theories consider the influence of the childhood environment or potentially higher levels of serotonin in the brains of synesthetes.

While the results of this study may not appear to have immediate implications—and no researcher is out to “cure” synesthesia—Terhune says that one motivation for his work is to understand the neurochemicals involved in the phenomenon. Plus, there is research to suggest that synesthetes with grapheme-color synesthesia have enhanced recognition memory compared to the average person, which could be of benefit to cognitive research.

“I don’t think synesthesia is going to reveal the really deep insights into different psychological phenomena,” Terhune concludes, “but it can provide us with some useful insights and potentially interesting models for things such as memory, imagery, and other cognitive functions.”

6 Signs You're Getting Hangry

Hangry (adjective): Bad-tempered or irritable as a result of hunger. This portmanteau (of hungry and angry) is not only officially recognized as a word by the Oxford English Dictionary, but it's also recognized by health experts as a real physiological state with mood-altering consequences.

That hangry feeling results from your body's glucose level dropping, putting you into a state of hypoglycemia, or low blood sugar. Glucose is the body's primary source of energy, so when you don't have enough, it affects your brain and other bodily functions, including the production of the hormones insulin and glucagon, which help regulate blood sugar. Check out the symptoms below to see if you've crossed over into the hanger danger zone.


A woman naps at her desk

Glucose equals energy, so when your blood sugar levels are low, you may start wishing you were back in bed with the shades drawn. If you start feeling sluggish or tired even though you’re well-rested, you might just need to eat something.


It’s hard to concentrate when all you can think about is whether you're going to order the fish or beef tacos for lunch. The distraction goes beyond fantasies about food, though. The brain derives most of its energy from glucose, so when it's low on fuel, a serious case of brain fog can set in. Confusion and difficulty speaking are among the more serious symptoms you may experience when you're hangry.


Blame this on brain fog too. The gray matter in your noggin goes a little haywire when blood sugar is in short supply. That's why you may start stuttering or slurring your words. You might also have difficulty finding your words at all—it can feel like your mouth and brain are disconnected.


Tremors and dizziness are both signs that you should pay closer attention to your body, which is screaming, "Feed me!" Once again, low blood sugar is often the culprit of trembling hands and feeling faint, and exhaustion and stress make the symptoms worse.


A woman looking frustrated at work

You’re tense and irritable, and it’s starting to show. Hunger causes your body to release cortisol and adrenaline, the same hormones responsible for stress. This can put you on edge and lower your tolerance for other people’s quirks and irksome habits, which suddenly seem a lot less bearable.


A couple arguing in their kitchen

Not only are you irritable, but you’re more likely to lash out at others because of it. The doses of adrenaline and cortisol in your body can induce a fight-or-flight response and make you go on the attack over matters that—if you had some food in you—would seem unimportant.

So what should you do if these descriptions sound all too familiar? Eat a snack, pronto—one with complex carbohydrates, lean protein, and healthy fats. The first one brings up your blood sugar level, and the other two slow down how fast the carbohydrates are absorbed, helping you to avoid a sugar crash and maintain a normal blood sugar level. Eating small meals every few hours also helps to keep hanger at bay.

Astronomers Discover 12 New Moons Around Jupiter

As the largest planet with the largest moon in our solar system, Jupiter is a body of record-setting proportions. The fifth planet from the Sun also boasts the most moons—and scientists just raised the count to 79.

A team of astronomers led by Scott S. Sheppard of the Carnegie Institute for Science confirmed the existence of 12 additional moons of Jupiter, 11 of which are “normal” outer moons, according to a statement from the institute. The outlier is being called an “oddball” for its bizarre orbit and diminutive size, which is about six-tenths of a mile in diameter.

The moons were first observed in the spring of 2017 while scientists looked for theoretical planet beyond Pluto, but several additional observations were needed to confirm that the celestial bodies were in fact orbiting around Jupiter. That process took a year.

“Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant solar system objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our solar system,” Sheppard said in a statement.

Nine of the "normal" moons take about two years to orbit Jupiter in retrograde, or counter to the direction in which Jupiter spins. Scientists believe these moons are what’s left of three larger parent bodies that splintered in collisions with asteroids, comets, or other objects. The two other "normal" moons orbit in the prograde (same direction as Jupiter) and take less than a year to travel around the planet. They’re also thought to be chunks of a once-larger moon.

The oddball, on the other hand, is “more distant and more inclined” than the prograde moons. Although it orbits in prograde, it crosses the orbits of the retrograde moons, which could lead to some head-on collisions. The mass is believed to be Jupiter’s smallest moon, and scientists have suggested naming it Valetudo after the Roman goddess of health and hygiene, who happens to be the great-granddaughter of the god Jupiter.


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