Mind Matters Natural and Artificial Intelligence News and Analysis

CategoryNeuroscience

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tunnel of light

Neuroscientists: Near-death perceptions not just hallucinations

Published in the Annals of the New York Academy of Sciences

One of the authors, Sam Parnia is a well-known researcher in this area: Due to advances in resuscitation and critical care, many people are surviving near-death experiences. Survivors’ recalled experiences are not consistent with hallucinations, but instead, follow a specific narrative arc involving perception. Scientific advances in the 20th and 21st centuries have led to a major evolution in the understanding of death. At the same time, for decades, people who have survived an encounter with death have recalled unexplained lucid episodes involving heightened consciousness and awareness. These have been reported using the popular—yet scientifically ill-defined—term “near-death experiences”. A multidisciplinary team of national and international leaders, led by Sam Parnia, MD, Ph.D., director of Critical Care and Resuscitation Research at Read More ›

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neuron cell with electrical pulses concept 3d illustration.

Our Neurons’ Electrical Synapses Are the Dark Matter of the Brain

These aren’t the familiar chemical synapses but a second set, the electrical synapses that enable currents to travel directly between neurons from pore to pore.

The universe has its dark matter, the 23% of matter that we know is out there but can’t see because it emits no light. The brain has its own “dark matter” too, in the form of electrical synapses. These are not the chemical synapses by which neurons transmit a stimulus from one cell to the next. They are a second layer of synapse that allows message-carrying currents to flow passively from one neuron to another through pores in the neurons’ cell walls. They are likely important because just about every type of animal except echinoderms (starfish and sand dollars, for example) has them — and yet we don’t know much about them: ”Electrical synapses are much rarer and are hard Read More ›

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Super macro shot tiny fruit flies on the top of a banana

The Brain Unfolds Like a Drama, With Neurons in Different Roles

Researchers studying fruit flies hope that spotting the stages at which human neurons go missing or wrong can help develop treatments to insert or replace them

We are not accustomed to thinking of fruit flies as even having brains. But they have 120 types of neurons in their visual system alone (which could be why they are so pesky): In the research published in Nature, the researchers studied the brains of the fruit fly Drosophila to uncover the complete set of tTFs needed to generate the roughly 120 neuron types of the medulla, a specific brain structure in the visual system of flies. They used state-of-the-art single-cell mRNA sequencing to obtain the transcriptome — all of the genes expressed in a given cell — of more than 50,000 individual cells that were then grouped into most of the cell types present in the developing medulla… The Read More ›

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Brain surgery

What Would Head or Partial Brain Transplants Do To Consciousness?

Researchers had some success swapping rodent heads (though there’s a catch) but no luck with monkeys. And then animal lovers weighed in…

Science writer Max G. Levy, profiling Brandy Schillace’s book, Mr. Humble and Dr. Butcher (2021), reminds us of the strange case of neurosurgeon Dr. Robert White (1926–2010) and his quest to develop human head transplants — or, as he liked to put it, body transplants. A new body for your old head… an offbeat form of immortality. White started with rhesus monkeys. At Case Western Reserve University, starting in 1970, he attempted many such transplants. Only one attempt succeeded (sort of). Without the usual spinal connections and thus without access to a body, the monkey head lived only nine days. Another such monkey head transplant was reported in 2016 — carried out by Xiaoping Ren at Harbin Medical University, China Read More ›

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dramatic lit image of a bloody crime scene with a knife on the floor

Firefly Episode 9: A Medical Heist — the Best So Far

Simon, with access to medical equipment, diagnoses his erratic sister’s neurological issues — after she has unaccountably stabbed Jayne

This is my favorite episode so far. It’s a classic heist with all the traditional beats! The crew is sitting around the table talking and eating while Jayne cleans his gun. He keeps spitting on the various parts for some reason, and Simon asks him to stop. He doesn’t. Jayne keeps spitting on the parts, glaring at Simon all the while River, Simon’s sister, gets up, grabs a butcher knife, and slashes Jayne across the chest. Jayne hits her, but she looks up, stares at the big man, and says, “He looks better in red.” With the stakes suddenly raised, the mystery of what happened to River surges to the forefront again. It’s time to get some answers. It so Read More ›

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Orchestra rehearsal

Memory Leans More on the Brain’s Electric Field Than on Neurons

MIT researchers compare the electric field to an orchestra conducting the neurons as players

The Picower Institute for Learning and Memory at MIT offers an interesting new model of how memories are processed in the brain. Using two macaques playing a game while their brain activities were recorded, the researchers suggest the orchestra as a model. The neurons are the players and the electric field is the conductor: As the brain strives to hold information in mind, such as the list of groceries we need to buy on the way home, a new study suggests that the most consistent and reliable representation of that information is not the electrical activity of the individual neurons involved but an overall electric field they collectively produce. Indeed, whenever neuroscientists have looked at how brains represent information in Read More ›

Depth electrode on brain MRI imaging.

Imaging Studies Fail Badly at Linking Brain and Behavior

Aha! news stories about what brain imaging reveals about human behavior are probably based on studies whose findings would not be confirmed by further research.

Brain imaging has shed much light on medical conditions in recent decades. So it was hardly good news for neuroscientist Scott Marek at the University of Washington when the results of a study linking brain function with intelligence in 2000 children produced very counterintuitive results. He and his colleagues had divided the sample into two groups of 1000 and run the same analysis on each — and they did not match. At first, he told Nature, “I stared out of my apartment window in depression, taking in what it meant for the field.” Then the team decided to study the problem on a larger scale, using the three key studies in this type of research, the Adolescent Brain Cognitive Development Read More ›

Brain under water 3D render, subconscious mental life and brainstorm idea.

Consciousness Experiments Confirm Each Research Group’s Theories

Human consciousness is by far the biggest mystery in the universe. We can be pretty sure that a researcher bold enough to claim to have found simple answer is mistaken. A recent study out of Tel Aviv University dramatically illustrates the problems we face. The researchers, focusing on the methods of study (methodological choices) that consciousness researchers from various schools of thought chose, found that a computer program could predict their results with 80% accuracy. That wasn’t supposed to happen: “The big question is how consciousness is born out of activity in the brain, or what distinguishes between conscious processing and unconscious processing,” Prof Mudrik explains. “For example, if I see a red rose, my visual system processes the information Read More ›

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Concept of modern technical equipment to scanning damaged brain

Confirmed: “Secret” Tunnels Connect Our Skulls and Brains

The newly confirmed skull tunnels produce immune system cells and funnel them to the brain in case of inflammation or damage

Neuroscientists usesd to think that immune system cells were carried in the bloodstream from, say, big leg bones in order to address brain inflammation following a stroke, injury, or disorder. It turns out that the brain gets neutrophils from much closer to home, right under the scalp. That’s what one group discovered when looking for the cells in the tibia (the larger of the shinbones in the leg) in mice: They found that the skull contributed significantly more neutrophils to the brain in the event of stroke and meningitis than the tibia. But that raised a new question – how were the neutrophils being delivered? “We started examining the skull very carefully, looking at it from all angles, trying to Read More ›

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Frog hiding in the mud

Science Writer: Explain-Away-the-Mind Book Doesn’t Succeed

In a departure from an all-too familiar approach to science writing, Philip Ball offers constructive criticism of the “nothing but”approach to the mind

At eminent science journal Nature, science writer Philip Ball reviews a book offering to explain how the mind arose from the mud. And he departs from the script. The book is Journey of the Mind: How Thinking Emerged from Chaos by neuroscientists Ogi Ogas and Sai Gaddam. One would expect a conventional science writer to announce that this new book is an important contribution to the quest to naturalize the human mind — to show that the mind is a mere adaptation that enabled the tailless ape to survive the savannah. Such a belief needn’t be true (and isn’t); it’s intended as a placeholder for a better-founded purely naturalist belief. Yet Ball looks at the claims made in Journey of Read More ›

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Texture of multi-colored sweet marshmallows. Marshmallows candy for background.

Can Waiting for a Marshmallow Predict a Child’s Future?

Believing so was all the rage in recent decades but later research didn’t back up the idea

You’ve maybe heard of Stanford University’s “marshmallow experiment,” right? A child’s future can be predicted, we were told by psychologist Walter Mischel (1930–2018), by whether the child can delay gratification: Walter Mischel’s pioneering research at Bing in the late 1960s and early 1970s famously explored what enabled preschool-aged children to forgo immediate gratification in exchange for a larger but delayed reward… This research identified some of the key cognitive skills, strategies, plans and mindsets that enable self-control. If the children focused on the “hot” qualities of the temptations (e.g., “The marshmallows are sweet, chewy, yummy”), they soon rang the bell to bring the researcher back. If they focused on their abstract “cool” features (“The marshmallows are puffy and round like Read More ›

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Astronaut on rock surface with space background. Elements of this image furnished by NASA

After Months in Space, Astronauts’ Brains Are “Rewired”

The “very new and very unexpected” changes in fluid flow and shape can last for months after a return to Earth

The effects of long-term space travel on humans are only beginning to be understood: In a new study, a collaborative effort between the European Space Agency and Russia’s space agency Roscosmos, researchers have explored how cosmonauts’ brains change after traveling to space and back. And they showed how the brain adapts to spaceflight, finding that the brain is almost “rewired,” and both fluid shifts and shape changes occur. These changes can last for months after a person returns to Earth, the researchers found. The strange brain changes that the team observed were “very new and very unexpected,” study lead Floris Wuyts, a researcher at the University of Antwerp in Belgium, told Space.com. Chelsea Gohd, “Cosmonaut brains are ‘rewired’ by space Read More ›

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Federleicht

Our Sense of Touch: So Sharp It Spans a Single Fingerprint Ridge

Each of tens of thousands of sensory neurons is tuned in to a tiny surface area of the skin

If you’ve ever wondered why your sense of touch, even on the dead surface of the skin, seems so acute, researchers looked into that and shared their findings last year: Sensory neurons in the finger can detect touch on the scale of a single fingerprint ridge, according to new research published in Journal of Neuroscience. The hand contains tens of thousands of sensory neurons. Each neuron tunes in to a small surface area on the skin — a receptive field — and detects touch, vibration, pressure, and other tactile stimuli. The human hand possesses a refined sense of touch, but the exact sensitivity of a single sensory neuron has not been studied before. Society for Neuroscience, “Fingerprints Enhance Our Sense Read More ›

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Audio waveform abstract technology background

Researchers: Ultrasound Can Control Neurons, Bypassing Implants

A Salk team is researching it, not just to control mice but to control cells now controlled by pacemakers, insulin pumps, electrodes, and other therapies

Light has been used to turn cells on and off for over a decade. The process, called optogenetics, can be therapeutic but because light can’t get through tissues, the light source must be embedded in the skin or beneath the skull. A new method, sonogenetics, which means using sound instead of light to control cells, may show promise in regulating pacemakers and insulin pumps, among other things: In a new study published today (February 9) in Nature Communications, researchers report they’ve found a way to use ultrasound to noninvasively activate mouse neurons, both in culture and in the brains of living animals. The technique, which the authors call sonogenetics, elicits electrical activity in a subset of brain cells that have Read More ›

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Super macro shot tiny fruit flies on the top of a banana skin

Single Neurons Perform Complex Math — Even in Fruit Flies

The fly wants something simple — to avoid getting swatted or eaten, for example — but that requires some algebra

We may not think of our neurons as performing complex calculations but they must do so in order to determine where sound is coming from or where a moving object is headed. For a long while, how they do it has been a mystery. Recently, researchers at the Max Planck Institute reported that they have “discovered the biophysical basis by which a specific type of neuron in fruit flies can multiply two incoming signals,” the “algebra of neurons”: We easily recognize objects and the direction in which they move. The brain calculates this information based on local changes in light intensity detected by our retina. The calculations occur at the level of individual neurons. But what does it mean when Read More ›

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Nerve Cell. 3D. Neurons

When a Tiny Brain Is Actually an Advantage

Small size — which includes having a small brain — hones the gnat ogre’s remarkable neurological abilities

The University of Minnesota, pointing to a just-published research paper, asks us to contemplate a remarkable piece of flight engineering on the part of a rather frightening fly: For those of us who occasionally trip over a curb or bump into a door frame, it’s hard to imagine an organism with a brain smaller than the period at the end of this sentence deftly maneuvering around obstacles while chasing fast-moving prey on the wing… The research, carried out by Paloma Gonzalez-Bellido, Mary Sumner, and Trevor Wardill of the University of Minnesota’s College of Biological Sciences, and Sam Fabian of the Imperial College London Department of Bioengineering, focuses on the aerial feats of a miniature robber fly known as a gnat Read More ›

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unique stone stand out from the crowd concept -

How Does Dualism Understand Personal Identity?

Both neurosurgeon Michael Egnor and theology professor Joshua Harris acknowledge weaknesses in their philosophies’ understanding of personal identity

In “The Body and the Soul” podcast, neurosurgeon Michael Egnor interviews theology professor Joshua Farris on how a sense of personal identity is preserved (or not) in Aristotelian vs. Cartesian philosophy (both are dualist philosophies; they do not think that the mind is merely a product of the brain). Along the way, Michael Egnor talks about the remarkable way that neuroscience affirms a dualist view. https://mindmatters.ai/wp-content/uploads/sites/2/2022/02/Mind-Matters-News-Joshua-Farris-Episode-2-rev1.mp3 A partial transcript and notes follow: Michael Egnor: Had it not been for neuroscience, which led me to a Thomist view, I would probably be a Cartesian because I do agree that there’s a great deal to say for it. Although my sense of Cartesianism is that the closer we get to Berkeley and Read More ›

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model of the human brain, the concept of medical health, intellectual capabilities, the study of the activity of the cerebral cortex, psyche and consciousness

Researchers Locate 440 Genes That Develop Each Brain Differently

Large-scale MRI and genetic datasets are helping us understand the common variants of the genes that help build the human cerebral cortex

To map regions of the brain to specific genes, researchers at the University of California – San Diego did genome-wide association studies (GWAS) of the regional cortical surface area and thickness of 39,898 adults and 9,136 children. That is, they scanned complete sets of DNA (genomes), looking for genetic variations. They were especially interested in variations that might be associated with a problem like autism, epilepsy, or dementia. By and large, construction of the human brain is determined by heredity, though factors like environmental exposures also play a role, particularly during sensitive periods of neurodevelopment during childhood. Large-scale MRI and genetic datasets have increasingly illuminated the common genetic variants that help build the human cerebral cortex — the outer, layered Read More ›

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x-ray image of spine

Man With Severed Spinal Cord Walks Again, Thanks to AI Implant

Most of us would have said that Michael Rocatti, whose spinal cord was severed in a motorcycle accident in 2017, would never walk again. But he did.

Rocatti had lost all feeling and motion in his legs after the motorbike crash. But thanks to electrodes implanted in their spines in experimental surgery in Lausanne, Switzerland, he and two other young men (29–41) were able to “to stand, walk, ride a bike and even kick their legs in a swimming pool” again. (Guardian) He is slow and unsteady but he is walking. The implant provides a bridge between the brain and the nerves that are severed from it: When prompted, the device sends activity-specific pulses of electricity to various nerves that were cut off from the central nervous system, allowing the Rocatti and other paralyzed people to send the appropriate stimulation and instructions to their legs. Rocatti and Read More ›

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Cute little baby looking into the camera

The Mystery of How Newborns Know Things Gets Deeper

But learning more about it may help us understand autism spectrum disorders better

Neuroscientist Giorgio Vallortigara ponders the mystery of how exactly babies quickly recognize things when they are born — like human faces — that they simply cannot have learned. We might call it “imprinting” or “instinct” but that’s just a classification, not an explanation. The author of Born Knowing (MIT Press, 2021) decided to start with chicks. That’s a bit simpler. Psychology students know, of course, that newly hatched chicks seem to know that they should follow their mother and do what she does. But what specific cues enable them to identify their mother? It turns out, according to his and colleagues’ research, that they are looking for specific geometrical patterns: Chicks need to actively explore and learn about their environment Read More ›