Examining the ancient technique of "memory palaces" with brain-imaging

A small (51 men aged 24 +/- 3 years) study published in Neuron tasked experimental subjects with practicing the ancient Greek mnemonic technique of "memory palaces" and then scanned their brains with functional magnetic resonance imaging, comparing the scans to scans from competitive "memory athletes" and also measuring their performance on memorization tasks. Read the rest

Brain activity recorded as much as 10 minutes after death

University of Western Ontario researchers examined the electrical activity in several patients before and after their life support was turned off and they were declared clinically dead, when the heart had stopped beating. In one patient, brain waves, in the form of single delta wave bursts, continued for minutes after death.

"It is difficult to posit a physiological basis for this EEG activity given that it occurs after a prolonged loss of circulation," the researchers write in their scientific paper. "These waveform bursts could, therefore, be artefactual in nature, although an artefactual source could not be identified."

This kind of research in the niche field of necroneuroscience is relevant to ethical discussions around organ donation and how the moment of death is defined.

(Neuroskeptic via Daily Grail)

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Can you "hear" flashes of light? Do you have synesthesia? Take a test.

Can you "hear" motion or light flashes? If so, according to new research from City University London, you may be experiencing a not-so-rare form of synaesthesia. Synesthesia is the fascinating neurological phenomenon whereby stimulation of one sense involuntarily triggers another sensory pathway. For example, a synesthete might taste sounds or hear colors. (In this study, 8 out of 40 participants, a very high percentage, were considered to have hearing-motion synaesthesia.) Here is their test for you to take yourself. From The Guardian:

(This new study) suggests that many more of us experience a less intrusive version of (synesthesia) in which visual movements or flashes are accompanied by an internal soundtrack of hums, buzzes or swooshes. Since movements are very frequently accompanied by sounds in everyday life, the effect is likely to be barely discernible.

When tested under laboratory conditions, the “hearing motion” effect appeared to enhance a person’s ability to interpret fine visual movements, but also interfered with the ability to hear real sounds when visual and audio signals were mis-matched.

“These internal sounds seem to be perceptually real enough to interfere with the detection of externally-generated sounds,” said Freeman. “The finding that this ‘hearing-motion’ phenomenon seems to be much more prevalent compared to other synaesthesias might occur due to the strength of the natural connection between sound and vision.”

In a separate study, the team tested for the phenomenon in trained musicians and found that it was much more common in the group. It is not clear if this is due to a natural disposition to link sounds and visual cues or whether thousands of hours of training might have strengthened the neural circuitry behind the effect.

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McGill Neurology will no longer patent researchers' findings, instead everything will be open access

The Neurological Institute at Montreal's McGill University is host to the "Tanenbaum Open Science Institute," endowed by a $20M contribution; since last spring, the unit has pursued an ambitious open science agenda that includes open access publication of all research data and findings, and an end to the practice of patenting the university's findings. Instead, they will all be patent-free and usable by anyone. Read the rest

Gamers blindly navigate a digital maze with input only from brain stimulation

In a new experiment at the University of Washington, test subjects navigated a virtual maze without seeing it. The only input they had were cues delivered in the form of magnetic zaps to the backs of their heads, stimulating particular regions of their brains. From UW Today:

The subjects had to navigate 21 different mazes, with two choices to move forward or down based on whether they sensed a visual stimulation artifact called a phosphene, which are perceived as blobs or bars of light. To signal which direction to move, the researchers generated a phosphene through transcranial magnetic stimulation, a well-known technique that uses a magnetic coil placed near the skull to directly and noninvasively stimulate a specific area of the brain.

“The way virtual reality is done these days is through displays, headsets and goggles, but ultimately your brain is what creates your reality,” said senior author Rajesh Rao, UW professor of Computer Science & Engineering and director of the Center for Sensorimotor Neural Engineering.

“The fundamental question we wanted to answer was: Can the brain make use of artificial information that it’s never seen before that is delivered directly to the brain to navigate a virtual world or do useful tasks without other sensory input? And the answer is yes.”

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Zapping the brain with magnetic pulses boosts libido

In a curious study, researchers at the University of California, Los Angeles showed that transcranial magnetic stimulation (TMS) -- altering brain activity by zapping specific regions with magnetic pulses -- can apparently increase people's libido, at least briefly. Neuroscientist Nicole Prause and her colleagues targeted the left dorsolateral prefrontal cortex (at the left temple), a region involved in reward-seeking. New Scientist explains the curious protocol used by the researchers:

...A vibrator was either connected to a sheath that the penis goes in or a small hood that fits over the clitoris. Electrodes on each participant’s head measured the strength of their brain’s alpha waves, which are weaker when people are more sexually aroused.

During the experiment, 20 people were given TMS for about two minutes, designed to either excite or inhibit the dorsolateral prefrontal cortex. Next, each volunteer was taken to a room where the EEG electrodes were placed on their head. They were then left to attach the vibrator themselves.

Finally, each participant carried out a task that involved pressing a button as fast as possible when shapes appeared on a screen. Depending on how quick they were, they were given a genital buzz lasting between half a second and five seconds – but only after a pause.

Their brainwaves were recorded during this waiting period. “They know they’re about to be sexually stimulated, but it hasn’t actually happened yet,” says Prause. It is the closest analogue for measuring desire in the lab, she adds.

As predicted, after excitatory TMS, participants’ alpha waves were weaker – suggesting they were more sexually aroused – than after inhibitory TMS.

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What people with "calendar synesthesia" reveal about how our minds deal with time

Synesthesia is the fascinating neurological phenomenon whereby stimulation of one sense involuntarily triggers another sensory pathway. A synesthete might taste sounds or hear colors. Now, leading synesthesia researcher VS Rakmachandran at the University of California, San Diego is studying "calendar synesthetes" who see very clear images of calendars in their mind's eye when they think about months that have passed or are in the future. For example, according to New Scientist, one participant in the research "sees her months as occupying an asymmetrical “V” shape. Along this V, she sees each month written in Helvetica font." From New Scientist:

The idea that calendars are literally laid out in space for some people suggests that we are all hardwired to some extent to map time in space.

The concepts of time and numbers are something we acquired relatively recently in our evolutionary history, says Ramachandran, but the brain wouldn’t have had time to evolve a specific area to deal with it.

“Given the opportunistic nature of evolution, perhaps the most convenient way to represent the abstract idea of sequences of numbers and time might have been to map them onto a preexisting map of visual space, already present in the brain,” he says.

Indeed, imaging scans show connections between areas of the brain involved in numbers and those involved with mapping the world, memories and our sense of self. The team suggest that when these areas act together, they enable us to navigate mentally through space and time, while being firmly anchored in the present.

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Johns Hopkins psychedelics research keeps finding medical uses

Johns Hopkins is among several institutions challenging a key tenet of outlawing psychedelics: that they have "no medicinal use." Baltimore Magazine examines the progress made by key researchers Roland Griffiths and Bill Richards. Read the rest

Science behind sleeping while you're awake

You may think you're awake but there's a good chance that part of your brain is asleep. And that can cause real problems, especially since you may not even be aware of it. In fact, indivisual neurons and groups of neurons in the cerebral cortex can be independently offline while others are awake. In Scientific American, Christof Koch, president of the Allen Institute for Brain Science, explores the counter-intuitive reality of "Sleeping While Awake:"

A case in point for sleep intruding into wakefulness involves brief episodes of sleep known as microsleep. These intervals can occur during any monotonous task, whether driving long distances across the country, listening to a speaker droning on or attending yet another never-ending departmental meeting. You're drowsy, your eyes get droopy, the eyelids close, your head repeatedly nods up and down and then snaps up: your consciousness lapses....

Perniciously, subjects typically believe themselves to be alert all the time during microsleep without recalling any period of unconsciousness. This misapprehension can be perilous to someone in the driver's seat. Microsleep can be fatal when driving or operating machinery such as trains or airplanes, hour after tedious hour. During a microsleep episode, the entire brain briefly falls asleep, raising the question of whether bits and pieces of the brain can go to sleep by themselves, without the entire organ succumbing to slumber.

Indeed, Italian-born neuroscientists Chiara Cirelli and Giulio Tononi, who study sleep and consciousness at the University of Wisconsin–Madison, discovered “sleepy neurons” in experimental animals that showed no behavioral manifestation of sleep...

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"Self-control" can be switched off with electromagnetic brain stimulation

University of Zurich researchers used transcranial magnetic stimulation, a noninvasive method of inhibiting activity in parts of the brain, to "turn off" people's ability to control their impulses. They focused on the temporoparietal junction, an area of the brain thought to play an important role in moral decisions, empathy, and other social interactions. They hope their research could help inform our understanding of addiction and self-discipline. From Scientific American:

In their study, subjects underwent 40 seconds of disruptive transcranial magnetic stimulation (TMS)—in which a magnetic coil placed near the skull produced small electric currents in the brain that inhibited activity of the posterior TPJ—then spent 30 minutes completing a task. To rule out a placebo effect, a control group received TMS in a different area of the brain. In one task, subjects made a choice between a reward (ranging between 75 and 155 Swiss francs) for themselves or one that was shared equally between themselves and another person, who ranged from their closest confidante to a stranger on the street. In another task subjects were offered an immediate reward of between zero and 160 Swiss francs or a guarantee of 160 Swiss francs after waiting three to 18 months. In a final task, subjects were instructed to take the perspective of an avatar and indicate the number of red dots on a ball that the avatar would see.

Subjects with an inhibited TPJ were less likely to share the money and were more likely to take the money up front rather than delay gratification and wait for a larger prize.

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The coming fight over "nonlethal neuroweapons"

The Chemical Weapons Convention has a giant loophole in that it allows for the stockpiling and use of chemical agents in law-enforcement; with the Eighth Review Conference of the Biological and Toxin Weapons Convention (BTWC) coming up next month, there's an urgent question about whether "neuroweapons" (chemical agents intended to pacify or disperse people) will become tools of law-enforcement and "defensive warfare." Read the rest

What's going on in the brains of people who don't need much sleep?

Many people claim that they don't need much sleep, insisting that even five hours a night is enough shuteye for them to feel rested. According to new scientific research, "habitual short sleepers" may actually be handling the brain tasks that most of us deal with during the night, like memory consolidation. From Medical Xpress:

Both groups of short sleepers exhibited connectivity patterns more typical of sleep than wakefulness while in the MRI scanner. (University of Utah radiologist Jeff) Anderson says that although people are instructed to stay awake while in the scanner, some short sleepers may have briefly drifted off, even those who denied dysfunction. "People are notoriously poor at knowing whether they've fallen asleep for a minute or two," he says. For the short sleepers who deny dysfunction, one hypothesis is that their wake-up brain systems are perpetually in over-drive. "This leaves open the possibility that, in a boring fMRI scanner they have nothing to do to keep them awake and thus fall asleep," says (Utah neurologist Chirstopher) Jones. This hypothesis has public safety implications, according to Curtis. "Other boring situations, like driving an automobile at night without adequate visual or auditory stimulation, may also put short sleepers at risk of drowsiness or even falling asleep behind the wheel," he says.

Looking specifically at differences in connectivity between brain regions, the researchers found that short sleepers who denied dysfunction showed enhanced connectivity between sensory cortices, which process external sensory information, and the hippocampus, a region associated with memory. "That's tantalizing because it suggests that maybe one of the things the short sleepers are doing in the scanner is performing memory consolidation more efficiently than non-short sleepers," Anderson says.

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Bad trips may be good for you

A "bad trip" on psychedelic mushrooms may lead to "enduring increases in well-being," according to a new study from Johns Hopkins University School of Medicine. Neuroscientist Roland Griffiths and colleagues surveyed nearly 2,000 adults about their psilocybin experiences. Those who experienced bad trips had taken, on average, a powerful dose of 4 grams. From Psypost:

A majority of the participants — 62 percent — said their bad trip was among the top 10 most psychologically difficult situations of their lives. Eleven percent said it was their number one most difficult experience.

But 34 percent of participants said the bad trip was among the top five most personally meaningful experiences of their life and 31 percent said it was the among the top five most spiritually significant. And 76 percent said the bad trip had resulted in an improved sense of personal well-being or life satisfaction. Forty-six percent said they would be willing to experience the bad trip all over again.

"Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences" (Journal of Psychopharmacology) Read the rest

Brain's "reward system" also tied to sleep-wake states

According to Stanford University researchers, a primary circuit in the brain's reward involving the chemical "feel-good" chemical dopamine, is also essential for controlling our sleep-wake cycles.

“Insomnia, a multibillion-dollar market for pharmaceutical companies, has traditionally been treated with drugs such as benzodiazepines that nonspecifically shut down the entire brain," says psychiatry and behavior science professor Luis de Lecea "Now we see the possibility of developing therapies that, by narrowly targeting this newly identified circuit, could induce much higher-quality sleep.”

From Stanford:

It makes intuitive sense that the reward system, which motivates goal-directed behaviors such as fleeing from predators or looking for food, and our sleep-wake cycle would coordinate with one another at some point. You can’t seek food in your sleep, unless you’re an adept sleepwalker. Conversely, getting out of bed is a lot easier when you’re excited about the day ahead of you...

The reward system’s circuitry is similar in all vertebrates, from fish, frogs and falcons to fishermen and fashion models. A chemical called dopamine plays a crucial role in firing up this circuitry.

Neuroscientists know that a particular brain structure, the ventral tegmental area, or VTA, is the origin of numerous dopamine-secreting nerve fibers that run in discrete tracts to many different parts of the brain. A plurality of these fibers go to the nucleus accumbens, a forebrain structure particularly implicated in generating feelings of pleasure in anticipation of, or response to, obtaining a desired objective.

“Since many reward-circuit-activating drugs such as amphetamines that work by stimulating dopamine secretion also keep users awake, it’s natural to ask if dopamine plays a key role in the sleep-wake cycle as well as in reward,” Eban-Rothschild said.

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Thought-controlled nanorobots in your body

A team of Israeli scientists devised a system by which a person can use their thoughts alone to trigger tiny DNA-based nanorobots inside a living creature to release a drug.

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Why did it take a private foundation to do public science right?

Microsoft co-founder Paul Allen funded the Allen Brain Observatory, a detailed, rich data-set derived from parts of a mouse-brain: what's striking is that the Allen Institute released all the data into the public domain, at once, as soon as it was available, which is exactly what you'd want the publicly funded alternatives to do, and what they almost never do. Read the rest

Study confirms a physical correlate to PTSD: "brown dust" in the brain

Since WWI, doctors have speculated that PTSD's underlying cause was some sort of physical damage caused by blast-waves from bombs, which literally shook loose something important in the brains of sufferers. Read the rest

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