brain

‘An artist cannot endure reality.’ –Nietzsche

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When he was two years old, Ben stopped seeing out of his left eye. His mother took him to the doctor and soon discovered he had retinal cancer in both eyes. After chemotherapy and radiation failed, surgeons removed both his eyes. For Ben, vision was gone forever.

But by the time he was seven years old, he had devised a technique for decoding the world around him: he clicked with his mouth and listened for the returning echoes. This method enabled Ben to determine the locations of open doorways, people, parked cars, garbage cans, and so on. He was echolocating: bouncing his sound waves off objects in the environment and catching the reflections to build a mental model of his surroundings.

Echolocation may sound like an improbable feat for a human, but thousands of blind people have perfected this skill, just like Ben did. The phenomenon has been written about since at least the 1940s, when the word “echolocation” was first coined in a Science article titled “Echolocation by Blind Men, Bats, and Radar.” […]

Neuroscience used to think that different parts of the brain were predetermined to perform specific functions. But more recent discoveries have upended the old paradigm. One part of the brain may initially be assigned a specific task; for instance, the back of our brain is called the “visual cortex” because it usually handles sight. But that territory can be reassigned to a different task. There is nothing special about neurons in the visual cortex: they are simply neurons that happen to be involved in processing shapes or colors in people who have functioning eyes. But in the sightless, these same neurons can rewire themselves to process other types of information. […]

we refer to the brain’s plasticity as “livewiring” to spotlight how this vast system of 86 billion neurons and 0.2 quadrillion connections rewires itself every moment of your life. […]

In Ben’s case, his brain’s flexible wiring repurposed his visual cortex for processing sound. As a result, Ben had more neurons available to deal with auditory information, and this increased processing power allowed Ben to interpret soundwaves in shocking detail. Ben’s super-hearing demonstrates a more general rule: the more brain territory a particular sense has, the better it performs. […]

Recent decades have yielded several revelations about livewiring, but perhaps the biggest surprise is its rapidity. Brain circuits reorganize not only in the newly blind, but also in the sighted who have temporary blindness. In one study, sighted participants intensively learned how to read Braille. Half the participants were blindfolded throughout the experience. At the end of the five days, the participants who wore blindfolds could distinguish subtle differences between Braille characters much better than the participants who didn’t wear blindfolds. Even more remarkably, the blindfolded participants showed activation in visual brain regions in response to touch and sound. When activity in the visual cortex was temporarily disrupted, the Braille-reading advantage of the blindfolded participants went away. In other words, the blindfolded participants performed better on the touch- related task because their visual cortex had been recruited to help. After the blindfold was removed, the visual cortex returned to normal within a day, no longer responding to touch and sound.

But such changes don’t have to take five days; that just happened to be when the measurement took place. When blindfolded participants are continuously measured, touch-related activity shows up in the visual cortex in about an hour. […]

In the ceaseless competition for brain territory, the visual system has a unique problem: due to the planet’s rotation, all animals are cast into darkness for an average of 12 out of every 24 hours. (Of course, this refers to the vast majority of evolutionary time, not to our present electrified world.) Our ancestors effectively were unwitting participants in the blindfold experiment, every night of their entire lives.

So how did the visual cortex of our ancestors’ brains defend its territory, in the absence of input from the eyes?

We suggest that the brain preserves the territory of the visual cortex by keeping it active at night. In our “defensive activation theory,” dream sleep exists to keep neurons in the visual cortex active, thereby combating a takeover by the neighboring senses. […]

In humans, sleep is punctuated by rapid eye movement (REM) sleep every 90 minutes. This is when most dreaming occurs. (Although some forms of dreaming can occur during non-REM sleep, such dreams are abstract and lack the visual vividness of REM dreams.)

REM sleep is triggered by a specialized set of neurons that pump activity straight into the brain’s visual cortex, causing us to experience vision even though our eyes are closed.

{ Time | Continue reading }

image { Michael Mann, Manhunter, 1986 }

quote { Does the popular quote, “No artist tolerates reality,” belong to Nietzsche? }

‘Nothing is more rare in any man, than an act of his own.’ –R. W. Emerson

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Female 29 years of age, university student, from dysfunctional family. She began her suffering 11 years ago with personality dissociation, characterized by aversion to sacred objects and images, and psychomotor agitation with transient states of loss of consciousness with manifestations of spiritual possession that required psychiatric, and psychological treatment, and 5 exorcisms without improvement over a period of ten years. […]

With informed consent, a fMRI was accomplished before and in the beginning of a possession induced by exorcism performed by a Catholic priest. […] due to the involuntary motor activity and the patient’s loss of consciousness, it is not possible to perform the analysis completely in this case.

{ Trends in Medicine | Continue reading }

There were 16 people in total that participated in the project “Resting Stated-Tractography-fMRI in initial phase of spiritual possession.” 13 of them are health professionals: a surgeon, psychiatrist, psychologist, neurophysiologist, family medicine physician, neurosurgeon, 2 radiology technicians, a gynecologist, medical doctor, diagnostic radiology physician, exorcist and patient (Ex former medical student). The priest, mother and an aunt of the patient were not included. […]

8 out of 13 participants (61.53%) had accidents and sudden events that put their lives in danger […]

Eight days before the exorcism, the psychiatrist experienced malfunctioning of his computer […]

Seven days after the exorcism, the surgeon had a head trauma, chest trauma and multiple bruises in a forest accident with fall from a height of one meter; he also had a MVA (motor vehicle accident) 15 minutes before receiving the images of the patient’s tractografies […]

22 days after the exorcism the medical doctor presented sudden breakup of a ten years relationship with her boyfriend.

Eight days before and during the exorcism, the father of the patient (a family medicine physician) presented chest and back pain with a normal electrocardiogram; 37 days after the exorcism he is admitted to the Critical Care Unit “CCU” for massive acute myocardial infarction, with loss of myocardial function of 90%.

41 days after the exorcism, the gynecologist is involved in an offense she did not commit.

[…]

On the survey carried out, the 12 participants are much more afraid of organized crime in Mexico than of the devil.

{ Trends in Medicine | PDF }

There’s not enough popcorn in the world

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An astrophysicist of the University of Bologna and a neurosurgeon of the University of Verona compared the network of neuronal cells in the human brain with the cosmic network of galaxies, and surprising similarities emerged. […]

The human brain functions thanks to its wide neuronal network that is deemed to contain approximately 69 billion neurons. On the other hand, the observable universe can count upon a cosmic web of at least 100 billion galaxies. Within both systems, only 30% of their masses are composed of galaxies and neurons. Within both systems, galaxies and neurons arrange themselves in long filaments or nodes between the filaments. Finally, within both system, 70% of the distribution of mass or energy is composed of components playing an apparently passive role: water in the brain and dark energy in the observable Universe. […]

Probably, the connectivity within the two networks evolves following similar physical principles, despite the striking and obvious difference between the physical powers regulating galaxies and neurons”

{ Università di Bologna | Continue reading }

oil on canvas { Karel Appel, Portrait, 1966 }

‘Science does not think.’ —Heidegger

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Can lab-grown brains become conscious?

These tiny structures, known as brain organoids, are grown from human stem cells and have become a familiar fixture in many labs that study the properties of the brain. Muotri, a neuroscientist at the University of California, San Diego (UCSD), has found some unusual ways to deploy his. He has connected organoids to walking robots, modified their genomes with Neanderthal genes, launched them into orbit aboard the International Space Station, and used them as models to develop more human-like artificial-intelligence systems. Like many scientists, Muotri has temporarily pivoted to studying COVID-19, using brain organoids to test how drugs perform against the SARS-CoV-2 coronavirus.

But one experiment has drawn more scrutiny than the others. In August 2019, Muotri’s group published a paper in Cell Stem Cell reporting the creation of human brain organoids that produced coordinated waves of activity, resembling those seen in premature babies1. The waves continued for months before the team shut the experiment down. […]

The concerns over lab-grown brains have also highlighted a blind spot: neuroscientists have no agreed way to define and measure consciousness. Without a working definition, ethicists worry that it will be impossible to stop an experiment before it crosses a line.

{ Nature | Continue reading }

roboto a roboto

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Electrical activity from the brains of a pair of human subjects was transmitted to the brain of a third individual in the form of magnetic signals, which conveyed an instruction to perform a task in a particular manner. […]

In [another] report, a human using a noninvasive brain interface linked, via computer, to the BCI of an anesthetized rat was able to move the animal’s tail.

{ Scientific American | Continue reading }

art { Barbara Stauffacher Solomon, San Francisco Museum of Art, Calendar, 1969 }

That the mind is united to the body we have shown from the fact, that the body is the object of the mind

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The mind-body problem enjoyed a major rebranding over the last two decades and is generally known now as the “hard problem” of consciousness […] Fast forward to the present era and we can ask ourselves now: Did the hippies actually solve this problem? My colleague Jonathan Schooler of the University of California, Santa Barbara, and I think they effectively did, with the radical intuition that it’s all about vibrations … man. Over the past decade, we have developed a “resonance theory of consciousness” that suggests that resonance—another word for synchronized vibrations—is at the heart of not only human consciousness but of physical reality more generally. […]

Stephen Strogatz provides various examples from physics, biology, chemistry and neuroscience to illustrate what he calls “sync” (synchrony) […] Fireflies of certain species start flashing their little fires in sync in large gatherings of fireflies, in ways that can be difficult to explain under traditional approaches. […] The moon’s rotation is exactly synced with its orbit around the Earth such that we always see the same face. […]

The panpsychist argues that consciousness (subjectivity) did not emerge; rather, it’s always associated with matter, and vice versa (they are two sides of the same coin), but mind as associated with most of the matter in our universe is generally very simple. An electron or an atom, for example, enjoy just a tiny amount of consciousness. But as matter “complexifies,” so mind complexifies, and vice versa.

{ Scientific American | Continue reading | Thanks Tim }

On ne sait pas ce que peut le corps

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The new “eyes wide shut” illusion uses a standard enlarging (shaving or makeup) mirror. Close one eye and look at the closed eye in the mirror; the eye should take up most of the mirror. Switch eyes to see the other closed eye. Switch back-and-forth a few times, then open both eyes. You see an open eye. Which eye is it? To find out, close one eye. Whichever you close, that’s the eye you see. How can this be possible? The brain is fusing two images of the two eyes.

{ Perception | Continue reading | Thanks Brad! }

However, no one has hitherto laid down the limits to the powers of the body, that is, no one has as yet been taught by experience what the body can accomplish solely by the laws of nature, in so far as she is regarded as extension. No one hitherto has gained such an accurate knowledge of the bodily mechanism, that he can explain all its functions; nor need I call attention to the fact that many actions are observed in the lower animals, which far transcend human sagacity, and that somnambulists do many things in their sleep, which they would not venture to do when awake: these instances are enough to show, that the body can by the sole laws of its nature do many things which the mind wonders at.

Again, no one knows how or by what means the mind moves the body, nor how many various degrees of motion it can impart to the body, nor how quickly it can move it.

{ Spinoza, Ethics, III, Proposition II, Scholium | Continue reading }

unrelated { eye colour may not be a priority when choosing a partner }

My leaves have drifted from me

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In a study published in Nature Neuroscience on Jan. 21, neuroscientists and systems biologists from Harvard Medical School reveal just how inexorably interwoven nature and nurture are.

Using novel technologies developed at HMS, the team looked at how a single sensory experience affects gene expression in the brain by analyzing more than 114,000 individual cells in the mouse visual cortex before and after exposure to light.

Their findings revealed a dramatic and diverse landscape of gene expression changes across all cell types, involving 611 different genes, many linked to neural connectivity and the brain’s ability to rewire itself to learn and adapt.

The results offer insights into how bursts of neuronal activity that last only milliseconds trigger lasting changes in the brain, and open new fields of exploration for efforts to understand how the brain works.

{ Harvard Medical School | Continue reading }

art { Josef Albers, Hotel Staircase, Geneva, 1929/1932 }

‘The second half of a man’s life is made up of nothing but the habits he has acquired during the first half.’ –Dostoyevsky

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When you’re doing two things at once – like listening to the radio while driving – your brain organizes itself into two, functionally independent networks, almost as if you temporarily have two brains. That’s according to a fascinating new study from University of Wisconsin-Madison neuroscientists Shuntaro Sasai and colleagues.

{ Neuroskeptic | Continue reading }

art { Harri Peccinotti }

‘We are all broken, that’s how the light gets in.’ –Ernest Hemingway

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When one draws a correlation between body mass and brain mass for living primates and extinct species of Homo, it is not humans—whose brains are three times larger than those of chimpanzees, their closest primate relative—that are an outlier. Instead, it is the great apes—gorillas and the orangutan—with brains far smaller than would be expected in relation to their body mass. We are the new normal in evolution while the great apes are the evolutionary oddity that requires explanation.

But we remain special in another way. Our 86 billion neurons need so much energy that if we shared a way of life with other primates we couldn’t possibly survive: there would be insufficient hours in the day to feed our hungry brain. It needs 500 calories a day to function, which is 25 percent of what our entire body requires.

{ New York Review of Books | Continue reading }

art { Christopher Wool, Untitled, 2006 }

Is Wagner a human being at all? Is he not rather a disease?

Neil Harbisson, an artist with colorblindness, has a chip implanted in his head and antenna attached to his skull that allows him to hear a different frequency of sound for each color.

Meanwhile, his artistic partner Moon Ribas has an implanted magnet that allows her to feel the tremors of earthquakes around the world.

{ Quartz | Continue reading }

When you speak, you learn nothing

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Normal aging is known to be accompanied by loss of brain substance.

Machine learning was used to estimate brain ages in meditators and controls.

At age 50, brains of meditators were estimated to be 7.5 years younger than that of controls.

These findings suggest that meditation may be beneficial for brain preservation.

{ NeuroImage | Continue reading }

image { Jonathan Puckey }