Study Identifies First Brain Cells that Respond to Sound

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Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Sat Dec 23, 2017 3:42 pm





Study Identifies First Brain Cells that Respond to Sound
Dec 21, 2017 by News Staff / Source


A new study by University of Maryland’s Professor Patrick Kanold and co-authors is the first to identify a mechanism that could explain an early link between sound input and cognitive function, often called the ‘Mozart effect.’ The results are published in the Proceedings of the National Academy of Sciences.

Working with young ferrets, Professor Kanold and colleagues observed sound-induced nerve impulses in subplate neurons, which help guide the formation of neural circuits in the same way that a scaffolding helps a construction crew erect a new building.

This is the first time such impulses have been seen in these neurons.

“Our work is the first to suggest that very early in brain development, sound becomes an important sense,” said co-author Dr. Amal Isaiah, also from the University of Maryland.

“It appears that the neurons that respond to sound play a role in the early functional organization of the cortex. This is new, and it is really exciting.”

During development, subplate neurons are among the first neurons to form in the cerebral cortex — the outer part of the mammalian brain that controls perception, memory and, in humans, higher functions such as language and abstract reasoning.

The role of subplate neurons is thought to be temporary. Once the brain’s permanent neural circuits form, most subplate neurons disappear.

Scientists assumed that subplate neurons had no role in transmitting sensory information, given their transient nature.

They had thought that mammalian brains transmit their first sensory signals in response to sound after the thalamus, a large relay center, fully connects to the cerebral cortex.

Studies from some mammals demonstrate that the connection of the thalamus and the cortex also coincides with the opening of the ear canals, which allows sounds to activate the inner ear. This timing provided support for the traditional model of when sound processing begins in the brain.

However, researchers had struggled to reconcile this conventional model with observations of sound-induced brain activity much earlier in the developmental process.

Until Professor Kanold’s team directly measured the response of subplate neurons to sound.

“Previous research documented brain activity in response to sound during early developmental phases, but it was hard to determine where in the brain these signals were coming from,” Professor Kanold said.

“Our study is the first to measure these signals in an important cell type in the brain, providing important new insights into early sensory development in mammals.”

http://www.sci-news.com/othersciences/neuroscience/subplate-neurons-sound-05555.html

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Jared Magneson on Tue Dec 26, 2017 10:43 pm

Interesting stuff. Of course, physiology is a logical and necessary arena where the Charge Field will answer many questions, as we scale on up from the photon level in our research. I'm nowhere near being helpful on this topic yet, but it certainly interests me. Botany as well, but it occurs to me that if physics is full of so many holes, biology and physiology must be full of even more as an extension. Hopefully we can start filling in some of these holes now that we have a more solid foundational field to work with.

For example, I've always pondered the "electrical current" aspect of neurons as being highly suspicious. Sure, these impulses exist, but how? Considering that any and all major scientists in these fields didn't have the Charge Field or even know what electricity is, I think we can make headway in these areas, at least conceptually.

So the neuron itself is either generating the charge (recycling it in a certain direction) or redirecting charge from elsewhere. Are the dendrites "siphoning" local charge, feeding the neuron?

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by LongtimeAirman on Wed Dec 27, 2017 6:15 pm

.
I’ve always avoided the biological side of things, but I must say, the dendrites look like atoms, connected by main north/south axis charge channels, and secondary lesser carousal level charge flows between adjacent dendrites. Given recent discussion, it makes perfect sense that photon energy channeled between the dendrites may be detected as high velocity underwater sound.
.

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Jared Magneson on Thu Dec 28, 2017 12:43 am

I agree that charge is definitely in play here, but the illustration in the article is just that, an illustration. It's actually pretty hard to find good photos of neurons, which is strange since they're larger than sperm cells allegedly.

Here's on that I think might be real:


Here's another, from the Wiki. Golgi-stained neurons from a human brain:



And another from the Wiki, showing what they call pyramidal structure:



It's difficult to say if they're polarized, though. They aren't spinning, that I'm aware of. But the do seem to exhibit similar behavior to charge channels.

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Thu Dec 28, 2017 2:32 am

Always an interesting topic... chemistry and our "thinking" (charge field receiving/cycling/processing... AFAICT)

https://thequantifiedbody.net/oxaloacetate-anti-aging-alan-cash/

Interesting that the pathways for "fueling" the brain and body are connected directly with "health" generally.
AMPK and NADH/NAD+
http://quantifiedbody.podbean.com/mf/web/psz8rv/Quantified-Body-Podcast-Ep-30-oxaloacetate-anti-aging-with-Alan-Cash.mp3

A good paper:
BRAIN GLYCOGEN METABOLISM DURING HYPOGLYCEMIA: ROLE IN HYPOGLYCEMIA ASSOCIATED AUTONOMIC FAILURE, MEMORY, AND NEURONAL CELL DEATH
https://cardinalscholar.bsu.edu/bitstream/handle/123456789/194984/WeaverS_2011-3_BODY.pdf?sequence=1

https://en.wikiversity.org/wiki/Chemistry_and_consciousness/Is_consciousness_a_chemical_process%3F

Desperately seeking sugar: glial cells as hypoglycemia sensors.

http://europepmc.org/articles/PMC1297271/

Proposed glial-neuronal loop at work in central sensing of hypoglycemia via GLUT2, based on the study by Marty et al. in this issue (9). This scheme illustrates the pivotal role of GLUT2 in glial cells in first-hand detection of hypoglycemia. How these specific glial cells then connect to neurons within the brainstem (likely in the NTS and the dorsal motor nucleus of the vagus) to relay information is unknown but may involve the lactate shuttle as well as signaling via the Kir6.2 ATP-regulated K+ channel (not illustrated). The drop in glycemia may also be directly sensed by neurons and pancreatic α and β cells but not through GLUT2 (the transporter/detectors involved are so far unknown). Ultimately, autonomic nervous signals and the drop in intraislet insulin levels promote glucagon secretion.
http://europepmc.org/wicket/bookmarkable/uk.bl.ukpmc.web.utilities.redirect.RedirectPage?figure=F1/&articles=PMC1297271

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Fri Dec 29, 2017 12:14 am

Sorry that last post came across a bit random.  Was drinking a bit yesterday when I posted it.

Just wanted to add this article from the linked paper. "Thinking" and memory is connected with the neurons and the glutamine/glutamate/glycogen cycles.  Apparently this cycle is pretty autonomous unless hypoglycemia occurs -- then memory and thinking rather quickly "fail" to occur. The charge field/chemical reactions must get glucose/glycogen/glutamine/glutamate to pulse the cycle again for thinking and recall to occur again.
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(Weaver paper page 16)
Glutamate synthesis and metabolism in the neuron and astrocyte In the neuron and astrocyte, glucose is metabolized through glycolysis to pyruvate. In the astrocyte, glycogen can also be metabolized to pyruvate. Pyruvate can then be metabolized anaerobically to generate lactate or aerobically to generate acetyl CoA using pyruvate dehydrogenase. Acetyl CoA then enters the TCA cycle condensing with oxaloacetate to make citrate. Citrate then goes through a variety of intermediates to generate ATP and regenerate oxaloacetate to ensure another turn of the TCA cycle. In the astrocyte, however, pyruvate can also be metabolized aerobically to generate a new molecule of oxaloacetate using pyruvate carboxylase. If pyruvate enters the TCA cycle as a new molecule of oxaloacetate, it can condense with acetyl CoA to make a new molecule of citrate. The new molecule of citrate can then generate α-ketoglutarate which can leave the TCA cycle to undergo transamination to form glutamate. Glutamate is then converted to glutamine using glutamine synthetase. The glutamine synthesized in the astrocyte is shuttled across the extracellular space to the neuron where it is converted to glutamate using phosphate activated glutaminase. Glutamate can then be released from the neuron as an excitatory neurotransmitter, metabolized to GABA, an inhibitory neurotransmitter, or undergo a transamination reaction to generate α-ketoglutarate which can be metabolized for energy in the TCA cycle. If glutamate is released from the neuron, it is taken back up by the astrocyte and converted to glutamine by glutamine synthetase or can undergo a transamination reaction to form α-ketoglutarate which can then be metabolized for energy in the TCA cycle. If the glutamate is turned into glutamine, the glutamine can once again be shuttled to the neuron. The shuttling of glutamate and glutamine is known as the glutamate/glutamine cycle.

Glycogen is proposed to be the major precursor to glutamate synthesis and, hence, is expected to be important for learning and memory consolidation. The importance of glycogen was shown using bead discrimination tests in day-old chicks treated with various inhibitors of glycogenolysis and glutamate uptake. Brain glycogen turnover increases during neuronal activation. However, when the breakdown of glycogen is inhibited, memory consolidation was dramatically reduced in the chick (18). When glycogen phosphorylase was inhibited, memory formation decreased in a dose dependent manner. When glutamate uptake was inhibited, memory loss was immediate (15). These findings suggest that glycogen may be the preferred precursor to glutamate in regards to learning and memory consolidation.

------------

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Fri Dec 29, 2017 12:38 am

Related... sorry if this rambles:
--------

Francis Crick -- The Astonishing Hypothesis

The death of Francis Crick at the end of last month drew many eulogies, most of which naturally highlighted the discovery of the double helix structure of DNA. In the latter part of his life, however, Crick turned his attention to the problem of consciousness rather than genetics or microbiology. He seems to have been temperamentally inclined to working in collaboration with a partner - having cracked the mystery of DNA with Watson, he now developed a fruitful partnership with Christof Koch. His view of consciousness, however, was summed up in his own book 'The Astonishing Hypothesis'.

The hypothesis in question is '...that "You", your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behaviour of a vast assembly of nerve cells and their associated molecules.'

It has been suggested by some that this is not such an astonishing hypothesis after all. Certainly the idea that our mental life arises from the activity of the brain has been a mainstream one for a considerable time, but the key words in Crick's hypothesis are perhaps 'no more than'. On the face of it, this is indeed a fairly extreme claim; a reductionism which stops just short of denying the actual existence of consciousness. The quotation marks around the word 'You' suggest that Crick was also tempted by scepticism about the self.

It's difficult to be absolutely clear about Crick's philosophical position, however. Searle criticised 'The Astonishing Hypothesis' for not being clear about exactly what kind of reductionism it was putting forward, and with some justice: at times Crick talks in terms of emergence, and he seems to want to disavow naive or eliminativist reductionism, but his bottom line does seem to be that consciousness is nothing more than the activity of neurons.

One reason for this lack of clarity is perhaps that Crick, as he very fairly points out, is not even trying to set out a finished theory, only a hypothesis and a suggested line of attack. But the fundamental reason is that Crick is really interested in telling a scientific story, not a philosophical one. Most of the book is taken up with doing this. Crick's strategy is to approach consciousness via a consideration of the faculty of vision. He gives a very clear and interesting account of research in this area, with a well-judged balance of speculation and caution. Personally, however, I think the focus on vision dooms the enterprise from the start, at least as far as consciousness is concerned. The best one can hope to get by investigating vision alone is some insight into attention and sensory awareness; the central issues of consciousness are likely to remain untouched. Blind people are fully conscious, after all!

It's also true that Crick's close focus on neurons at the expense of philosophy seems to lead him into some dubious positions. He and Koch are particularly known for the view that consciousness arises when sets of neurons fire in a co-ordinated way, at frequencies around 40 Hertz. Crick suggests that synchronised firing of this kind might, in particular, be the neural correlate of visual awareness. To be really consistent with Crick's general attitude, the firing really needs to be visual awareness, not just correlated with it, but that is perhaps a nit-picking point: the more fundamental difficulty is that no explanation is ever offered as to why co-ordinated firing should give rise to conscious experience. Crick suggests that this kind of co-ordination might be the answer to the notorious binding problem, because it explains how neurons in different visual areas which respond to different qualities of the seen object (form colour, motion, etc) 'temporarily become active as a unit', but it seems that at best that might be part of the answer. A particularly difficult aspect of the problem is that different pieces of sensory data which relate to the same object don't arrive in one place in the brain at the same time, yet our conscious experience never seems to suffer from, as it were, faulty lip sync. It's hard to see how simultaneous patterns of firing could deal with the chronological problem.

At the end of the book, Crick offers a short and tentative postscript setting out an idea about free will. This is really an explanation for why people think they have free will - Crick is presumably a determinist. His idea is that there is an unconscious part of the brain which makes the plans for what we are going to do: these plans then pop into the conscious mind as if from nowhere, giving an impression of free will. The conscious mind may be able to guess the factors behind the plans, or it may get them wrong: either way, it feels there is some mystery about the process. Crick, drawing on some research by Damasio, goes so far as to suggest that this unconscious planning facility (the 'seat of the will') is probably located in or near the anterior cingulate sulcus.

Of course it is perfectly true that the processes which give rise to conscious thought are not themselves conscious (otherwise we should be caught in a vicious regress), but that does not imply that consciousness is not in the driving seat. Often when we make a complex decision or draw up an explicit plan, we weigh the factors and consider possible events consciously in our minds, and it seems very hard to believe that this kind of process, which surely bears a remarkable resemblance to decision-making, is not ultimately responsible for the plan or decision which is eventually arrived at. Indeed, I think most people believe that making decisions and plans, and allowing human beings to rise above the influence of their immediate current environment, is exactly what consciousness is for.

(more at link)
http://www.consciousentities.com/crick.htm

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Fri Dec 29, 2017 1:13 am

Christof Koch who worked with Crick:
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One of the institute’s projects involves taking bits of cortical tissue extracted during brain surgeries at Seattle hospitals, and running them through experiments while the brain cells are still fresh.

“This is not a mouse brain. This is a piece of living human brain,” Koch said. “Twenty minutes ago, it was part of somebody’s brain, with somebody’s memories of their first kids. But now it’s here, it’s in the lab, we can look at the morphology, we can study it in great detail.”

Koch said a database of human brain-cell reconstructions, including 3-D imagery, would be made freely available via the institute’s website later this month. As the database grows, researchers can use the reconstructions to model how electrical fields might affect brain function — or precisely what happens in the brains of patients with Alzheimer’s disease.

“This is going to be a long road ahead,” Koch acknowledged. But eventually, neuroscientists could gain enough of an understanding of the nervous system’s circuitry to restore lost functionality.

Researchers have already found ways to rewire paralyzed limbs so that they can respond to brain commands, and even provide sensory feedback, although the apparatus that’s been developed so far is typically too bulky for practical use.

Koch thinks it’s only a matter of time before brain-machine interfaces become small enough and capable enough to restore full function to a patient’s nervous system — and go even further.

“We are all interested in also enhancing all of our performance,” he said, “because I think this is one way we can continue to compete against our own creation. So this is the challenge for this century, really. The last century has been called the century of physics. This century is really the century of biology, and particularly brain science: trying to understand our brain, to cure diseases, but also to enhance our brain for our long-term survival.”

Koch isn’t alone in his view: Elon Musk, the billionaire CEO of SpaceX and Tesla, is also backing a venture called Neuralink that is focusing on developing powerful brain implants.

After his talk, Koch told GeekWire that he was on board with Musk’s vision for future brain chips.

“In general, that’s the right way to go,” Koch said. “The question is, how long is it going to take? Particularly, the regulatory hurdles are big. Anytime you drill a hole in somebody’s brain, you better have a very good reason for doing it, typically because the health is in danger.”

It can take a decade or two for surgical technology to make its way from the lab to the operating room, Koch pointed out. “If we want to attempt to make a difference in our lives, and not just in the lives of our children’s children, we have to do this faster,” he said.

Koch speculated that Musk just might be among the first people to get a brain chip purely for the purpose of mental enhancement rather than to restore lost neural function.

“All it takes is well-known people, maybe like Elon Musk, saying, ‘Yes, I’m going to put that chip into my brain. I’m going to get some surgeons, no matter when — and see? I can now do things that nobody else can do,'” Koch said. “Then, suddenly, you’ll see thousands of people everywhere who’ll want to do it.”

Love space and science? Sign up for our GeekWire Space & Science email newsletter for top headlines from Alan Boyle, GeekWire’s aerospace and science editor.

https://www.geekwire.com/2017/brain-scientist-christof-koch-merge-machine/

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Fri Dec 29, 2017 1:20 am

Consciousness and Neuroscience
by
Francis Crick and Christof Koch
Cerebral Cortex     1998
Volume 8:97-107
----------------------------------------------------------------------------
http://virtual.sai.msu.su/~bond/crick-koch-cc-97.html



My comments on “Consciousness and Neuroscience”

Crick has done neurobiology a service by taking on the challenge of trying to find specific types of neuronal activity that are correlated with consciousness. This project has dramatic philosophical implications because so many philosophers have thought that issues like understanding consciousness are beyond the power of materialistic reductionistic science. “Consciousness and Neuroscience” is not much different after 8 years from “Towards a Neurobiological Theory of Consciousness” (1). This in itself could be taken as good evidence that most neurobiologists are correct when they think that it is premature for them to study consciousness. This sense of prematurity is amplified by the fact that there are only a few rare sources of data that Crick and Koch have so far found useful for analysis of the “neuronal correlate of consciousness”: 1) cases of human brain damage that alter consciousness, or results form lesioning studies in animals, 2) Non-invasive brain scanning methods like functional MRI and electrophysiological recordings from animals which are used in attempts to identify specific types of neurons with activity patterns that match the perceptual states of the animals. Some times these methods can be combined with method #1, and 3) electrical stimulation of specific brain regions that seem to be able to shift an animal’s conscious perception of a stimulus.
In the first part of this article, Crick and Koch summarize some recent results from these kinds of experiments.

When Crick took up the challenge of trying to identify a neuronal basis for consciousness, he must have thought that there was a real possibility that something relatively simple like 40 Hz feedback loops among thalamic and cortical brain regions would solve the problem. This was not a silly idea, as some philosophers have suggested, only overly optimistic. The most interesting parts of “Consciousness and Neuroscience” are the indications that Crick is now admitting that he will have to widen his search strategy and accept the fact that consciousness is a tougher problem to solve than the structure of DNA.

A main reason for the broadening of Crick’s analysis of consciousness is that simple tricks like the 40 Hz feedback signals have not solved the problem. Crick now accepts the idea that additional brain regions (such as prefrontal cortex) beyond the early visual sensory processing regions are important for even the most basic forms of visual sensory awareness, while the 40 Hz signals seem largely restricted to “lower” sensorymotor brain regions.

In a section called “Future Experiments” Crick and Koch issue a call for additional experimental techniques that could aid in the search for neural correlates of consciousness. It has recently become possible to reversibly inactivate specific populations of neurons using genetic engineering tricks. It should be possible to extend these methods to the primates used for consciousness research. Crick and Koch also point out that recent understanding about the molecular controls of the patterns of connectivity between neuron populations should lead to methods for specifically eliminating types of brain connections. This is a good idea, but it is interesting that “virtual elimination” of connection pathways is easy in computer models of the brain, and is one of the powerful tools available to people who work with computer models of the brain. Crick has never shown much interest in computer models of the brain, probably because he has hoped that solving problems like consciousness will be simple enough that we will not need to use computers as tools for aiding our understanding of how brains work. I suspect that he is overly optimistic about how easy it will be to understand things like consciousness in neurobiological terms.

Crick and Koch have provided a few short sections where they mention philosophy of mind. A section called, “Why are we conscious” deals with the idea of “zombies”. In a section called “Philosophical matters” they deal with qualia and “The problem of meaning”. Their general attitude towards philosophy of mind is reflected in the statement, “In recent years the amount of discussion about consciousness [by philosophers] has reached absurd proportions compared to the amount of relevant experimentation.” However, it is interesting that they thank Chalmers and Searle for helpful comments concerning this article. As a biologist, I am fairly comfortable with what Crick and Koch have to say about zombies and qualia, but I doubt that it is very satisfying for many philosophers.

In the section called, “The on-line system” Crick and Koch say, “It is obviously important to discover the difference between the on-line system [of vision, as can be shown to operate in people with blind-sight], which is unconscious, from the seeing system, which is conscious.” Contrast this with what they say near the end in discussing what will happen once neurobiologists have found a neuronal explanation for consciousness, “It is likely that scientists will then stop using the term consciousness except in a very loose way.” They compare this to the disinterest of biologists in debating the question of whether viruses are alive or dead. This is a very weak analogy by which the fact that viruses are in the fuzzy gray region between alive and dead is taken to imply that the word “alive” is not really of much use to biologists and that the word “consciousness” is similar in this regard. This is very misleading and misses to point entirely. The word “alive” is not usually found within the literature of biology because most of the time the distinction between what is alive and what is not alive is clear to everyone. We would no more expect to see an economist pausing frequently to point out to his audience what elements of an economic system are money, he and his readers all know this. What elements of ecosystems are alive, what elements of economies are money, and which aspects of brain activity are the neural correlates of consciousness are all issues of fundamental importance.

What I find most interesting in this paper is that Crick and Koch show signs of moving in the direction that Gerald Edelman proposed for consciousness research 10 years ago. One key aspect of Edelman’s theory of consciousness was that he proposed that consciousness is a global brain function, meaning that many widely distributed parts of the brain are important for consciousness. As mentioned above, 10 years ago Crick and Koch were pursuing the idea that a mechanism for a simple form of consciousness, visual awareness, might be found with just a few brain regions, the closely linked thalamic and visual cortex regions. Thus, it is remarkable to find Figure 1 in this article showing whole series of sensory and motor regions and even the environment. This is the kind of diagram which is found throughout Gerald Edelman’s work. The point that Crick makes with Figure 1 is that there are many possible control systems in a brain for taking sensory input and producing adaptive behavioral responses based on the sensory input. These systems seem to exist in a hierarchy from very quick and unconscious to conscious systems that, while slower, can be more refined. What is the basis of this “refinement” in behavior that is made possible by consciousness? Crick and Koch are reluctant to say the words, but the key is learning and memory. The brain contains several memory systems which allow animals to combine current sensory inputs with past experience to produce adaptive behavior that makes sense for the animal in terms of the environment that the animal exists in.

Why are Crick and Koch so reluctant to admit that the problems of learning and memory are fundamentally involved in consciousness? Basically, because learning and memory are the real “hard problem” of mind. Crick has hoped that there is some simple trick that brains use to produce consciousness that can be found without us first having to understand learning and memory. However, I think Crick is wrong. I favor Gerald Edelman’s approach to consciousness which places memory squarely at the center of the problem of consciousness.

This fundamental issue (the relevance of memory mechanisms and learning in our attempt to understand consciousness) is most directly (and it is not very direct at all) confronted in the section called “The problem of meaning.” I agree with the idea that the problem of meaning has two aspects: 1) how is meaning expressed in neural terms?, and 2) how does the expression of meaning arise? These are the two issues at the heart of Gerald Edelman’s theory of consciousness. The answers to these questions are simply 1) memory and 2) learning. Importantly, Edelman’s approach is to tackle the two together, since memories are the result of learning. I think Crick is admitting (very quietly) that the unconscious-consciousness hierarchy (see Figure 1 of "Consciousness and Neuroscience") is defined by the memory mechanisms that are involved in each level of the hierarchy. Crick is admitting that understanding the neuronal correlate of consciousness would be a sterile result in itself because what is really important to consciousness is meaning. A person can be conscious of sensory inputs, but if those experienced inputs have no meaning for a person, then no sensible behavior will result, you would have a zombie that has low-level awareness, but nothing more. It is hard to see the distinction between such a meaningless conscious existence and unconsciousness. The distinction between consciousness and unconsciousness depends on the meaningfulness of conscious experiences and memory is the source of meaning. Edelman saw this all clearly, and I think, in the end, Crick will have to admit openly that Edelman was correct. This is hard for Crick to do because 10 years ago he issued a scathing attack on Edelman’s theory of mind and Crick went off in a different direction. It is at least promising to see Crick finally starting to open the door towards his acceptance of the importance of memory and learning in our attempt to understand consciousness. I see the same glimmer of hope in Rey’s CRTT, in which he admits that there must be a mechanism for getting meaning (semantic content) into his LOT. Memory and learning are tough problems for neurobiologists, but progress is being made. It is not too much to hope that the neurobiology of learning and memory will soon begin to allow us to start to understand consciousness. Edelman was the first to show how this can work in theory, only the details of the explanation remain to be filled in.   Back to first Crick page.

1. Francis Crick and Christof Kock "Towards a Neurobiological Theory of Consciousness" (1990) Seminars in the Neurosciences, 2: 263-275.


https://web.archive.org/web/19991012163508/www.geocities.com/ResearchTriangle/System/8870/books/crick2.html

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Fri Dec 29, 2017 2:32 am

What dopamine does in the brain
http://www.pnas.org/content/108/47/18869.full

(a pretty good article on neurotransmitters... note the dependency on "ion channels" for proper "thinking".)


The biosynthesis of acetylcholine, serotonin, norepinephrine, and GABA had been elucidated, and their degradative pathways had been established. Their release by exocytosis was generally accepted. Synaptic inactivation by an enzyme in the case of acetylcholine and for amines and amino acids, by reuptake into the nerve endings that had released them seemed on solid ground. However, molecular characterization of the most important element of synaptic transmission, transmitter receptors, was still unattained, at least in the brain.

It was generally assumed that neurotransmitters bound to receptor proteins on postsynaptic membranes. Several investigators had identified the receptor protein for the actions of acetylcholine in the electric organ of the electric eel through the binding of radiolabeled α-bungarotoxin (3). However, the receptor in these electric organs comprises 20% of membrane protein, about 1 million times as dense as what would be expected in the brain. Thus, few investigators anticipated ever understanding neurotransmitter receptors in the brain at a biochemical level, and the identification by ligand binding of neurotransmitter and drug receptors in the mid-1970s came as a surprise (4).

For neurotransmitters that act by opening ion channels, such as acetylcholine at the neuromuscular junction, transmitter recognition was presumed to be transformed into an opening or closing of ion channels. For the biogenic amines, such as norepinephrine and serotonin, the picture was murkier. Hence, the work of Kebabian and Greengard (5) and Kebabian et al. (6) (Fig. 1) implying that dopamine in the superior cervical ganglion and the brain's caudate nucleus acts through a receptor coupled to a cAMP-forming enzyme—adenylate cyclase—was a giant step forward.

----

Abstract

The effect of the putative amino acid transmitter, L-glutamate, on adenylate cyclase in crude membrane preparations of the rat tapeworm Hymenolepis diminuta was investigated to determine if glutamate effects the generation of the second messenger cAMP. Addition of glutamate at 10−3 and 5.5 × 10−9 M resulted in significant elevations in basal activity of adenylate cyclase, while concentrations in the 10−5–10−7 M range caused significant depressions below basal activity. Assays with glutamate agonists and other acidic compounds showed glutamate to be the only amino acid, dicarboxylic acid, or acidic compound capable of this pattern of stimulation and inhibition. While the response of adenylate cyclase to glutamate agonists suggested that an N-methyl-D-aspartic acid (NMDA) type receptor may be present, glutamate agents acting as NMDA antagonists in vertebrate systems were agonists. Metabolic end products of glycolysis stimulated adenylate cyclase, suggesting that these, along with metabolic glutamate may regulate glycolytic enzymes. Only 10−3 M L-glutamate significantly stimulated adenylate cyclase activity in tissue slices, and this response was restricted to those slices rich in nervous tissues. L-Glutamate eliminated the 5-hydroxytryptamine (5-HT) stimulated adenylate cyclase response suggesting that glutamate can modulate the 5-HT stimulated elevations in adenylate cyclase activity. The data support the hypothesis that L-glutamate is a neurotransmitter–modulator in the cestode.

http://www.nrcresearchpress.com/doi/abs/10.1139/y91-005?journalCode=cjpp

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Mon Jan 29, 2018 12:33 am

Miles touches on this as well but indirectly in a few of his papers.  Just remember this paragraph from earlier:

Glycogen is proposed to be the major precursor to glutamate synthesis and, hence, is expected to be important for learning and memory consolidation. The importance of glycogen was shown using bead discrimination tests in day-old chicks treated with various inhibitors of glycogenolysis and glutamate uptake. Brain glycogen turnover increases during neuronal activation. However, when the breakdown of glycogen is inhibited, memory consolidation was dramatically reduced in the chick (18). When glycogen phosphorylase was inhibited, memory formation decreased in a dose dependent manner. When glutamate uptake was inhibited, memory loss was immediate (15). These findings suggest that glycogen may be the preferred precursor to glutamate in regards to learning and memory consolidation.
(basically glutamate is essential for "conciousness" -Cr6)


----
Idealism and the Mind-Body Problem

David J. Chalmers

When I was in graduate school, I recall hearing “One starts as a materialist, then one becomes a dualist, then a panpsychist, and one ends up as an idealist”.1

...

I don’t know where this comes from, but I think the idea was something like this. First, one is impressed by the successes of science, endorsing materialism about everything and so about the mind. Second, one is moved by problem of consciousness to see a gap between physics and consciousness, thereby endorsing dualism, where both matter and consciousness are fundamental. Third, one is moved by the inscrutability of matter to realize that science reveals at most the structure of matter and not its underlying nature, and to speculate that this nature may involve consciousness, thereby endorsing panpsychism. Fourth, one comes to think that there is little reason to believe in anything beyond consciousness and that the physical world is wholly constituted by consciousness, thereby endorsing idealism.

I will understand idealism broadly, as the thesis that the universe is fundamentally mental, or perhaps that all concrete facts are grounded in mental facts. As such it is meant as a global metaphysical thesis analogous to physicalism, the thesis that the universe is fundamentally physical, or perhaps that all concrete truths are grounded in physical truths. The only difference is that “physical” is replaced by “mental”.

We can understand mental facts as facts wholly about the instantiation of mental properties.3 Later we will examine possible versions of idealism that loosen this constraint. My focus is largely on conscious experience as opposed to non-conscious mental states, so the mental states and properties I will focus on are largely experiential states and properties, but in principle the definition includes views on which other sorts of mental states play a role. As for concreteness: this excludes truths about abstract domains, such as mathematics. In practice most physicalists and idealists are not committed to the strong claim that mathematical truths are grounded in physical or mental truths, and the restriction to concrete domains helps to avoid the issue.

Although it is common to define idealism as a global metaphysical thesis analogous to materialism, in practice idealism is often understood more narrowly as a version of Berkeley’s “esse est percipi” thesis, holding that appearance constitutes reality. This sort of idealism is typically seen as a paradigm of anti-realism, in that it holds that there is no concrete reality external to how things appear: all concrete non-mental truths p are grounded in or constituted by appearances that p, or in closely related truths involving appearances. If we understand appearances as experiences (most naturally as perceptual experiences, though thoughts about the external world are also sometimes understood as appearances in a broad sense), it follows that the physical world is fully grounded in the experiences as of a physical world had by observers.

http://consc.net/papers/idealism.pdf

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Sun Mar 18, 2018 10:58 pm

Just wanted to add this article from MIT Technology Review.  Sheds some light on details around creating "thought"...

Ref: arxiv.org/abs/1708.08887: Are There Optical Communication Channels in the Brain?
....

(more at link...)


Are There Optical Communication Channels in Our Brains?

Neuroscientists have long observed biophotons produced in brain tissue. Nobody knows what these photons are for, but researchers are beginning to explore the possibilities.

   by Emerging Technology from the arXiv September 6, 2017

Many organisms produce light to communicate, to attract mates, and so on. Twenty years ago, biologists discovered that rat brains also produce photons in certain circumstances. The light is weak and hard to detect, but neuroscientists were surprised to find it at all.



Since then, the evidence has grown. So-called biophotons seem to be produced naturally in the brain and elsewhere by the decay of certain electronically excited molecular species. Mammalian brains produce biophotons with wavelength of between 200 and 1,300 nanometers—in other words, from near infrared to ultraviolet.

If cells in the brain naturally produce biophotons, it’s natural to ask whether nature may have taken advantage of this process to transmit information. For that to happen, the photons must be transmitted from one place to another, and that requires some kind of waveguide, like an optical fiber. So what biological structure could perform that function?

Today we get an answer of sort thanks to the work of Parisa Zarkeshian at the University of Calgary in Canada and a few pals. They've studied the optical characteristics of axons, the long thread-like parts of nerve cells, and conclude that photon transmission over centimeter distances seems entirely feasible inside the brain.

The work is a review of previous experiments and studies of axons. The team first reviewed a study that calculated the optical properties of myelinated axons by solving Maxwell’s famous electromagnetic equations in three-dimensions to determine the cell’s optical properties.

This study suggests that an axon’s outer coating—its myelin sheath—can act as a waveguide to channel biophotons. But it also suggests that a wide range of factors can influence this phenomenon by scattering light or absorbing it.

These factors include how light transmission is affected by bends in the axon, by changes in the radius of the sheath, by non-circular cross sections, and so on.

Zarkeshian and co conclude that axons with lengths of around 2 millimeters—about the length of axons in the brain—could transmit between 46 percent and 96 percent of the biophotons that enter them. “It is worth noting that photons can propagate in either directions: from the axon terminal up to the axon hillock or in the opposite direction along the axon,” they say.

The team goes on to calculate the data communication rates that this allows. Biologists have measured biophotons produced by rat brains at the rate of one photon per neuron per minute. Although that does not sound like many, there are 1011 neurons in a human brain, which suggests it could produce more than a billion photons per second.

“This mechanism appears to be sufficient to facilitate transmission of a large number of bits of information, or even allow the creation of a large amount of quantum entanglement,” say Zarkeshian and co.

Of course, there are numerous uncertainties in these calculations. Nobody knows the precise optical properties of myelin sheaths, for example, because they have never been measured.

The best way to find out more is to test the optical transmission properties of brain tissue. Zarkeshian and co suggest a number of straightforward experiments that would move this field forward. “One way is to light up one end of a thin brain slice and look for the bright spots related to the open ends of the myelinated axons at the other end,” they say. There are various other approaches too. That’s something a neuroscientist with time on his or her hands could take on.

All this points to a bigger conundrum. If our brains have optical communications channels, what are they for? This is a question that is ripe for blue skies speculation.

One line of thought is based on the fact that photons are good carriers of quantum information. Many people have theorized that quantum processes may be behind some of the brain’s more mysterious  processes, not least of which is consciousness itself. Zarkeshian and co are clearly enamored with this idea.

But this is no more than wild speculation. Quantum communication requires significantly more than optical communication channels. There must also be mechanisms that can encode, receive, and process quantum information. It is possible that light-sensitive molecules exist in the brain but there is little evidence for this and still less that they serve as quantum processors.

Still, this kind of thinking is exciting and worth pursuing at a basic level. If nature produces biophotons, evolution may well have found a way to exploit them. The question is how.

If cells in the brain naturally produce biophotons, it’s natural to ask whether nature may have taken advantage of this process to transmit information. For that to happen, the photons must be transmitted from one place to another, and that requires some kind of waveguide, like an optical fiber. So what biological structure could perform that function?

Today we get an answer of sort thanks to the work of Parisa Zarkeshian at the University of Calgary in Canada and a few pals. They've studied the optical characteristics of axons, the long thread-like parts of nerve cells, and conclude that photon transmission over centimeter distances seems entirely feasible inside the brain.

The work is a review of previous experiments and studies of axons. The team first reviewed a study that calculated the optical properties of myelinated axons by solving Maxwell’s famous electromagnetic equations in three-dimensions to determine the cell’s optical properties.

This study suggests that an axon’s outer coating—its myelin sheath—can act as a waveguide to channel biophotons. But it also suggests that a wide range of factors can influence this phenomenon by scattering light or absorbing it.

These factors include how light transmission is affected by bends in the axon, by changes in the radius of the sheath, by non-circular cross sections, and so on.

Zarkeshian and co conclude that axons with lengths of around 2 millimeters—about the length of axons in the brain—could transmit between 46 percent and 96 percent of the biophotons that enter them. “It is worth noting that photons can propagate in either directions: from the axon terminal up to the axon hillock or in the opposite direction along the axon,” they say.

The team goes on to calculate the data communication rates that this allows. Biologists have measured biophotons produced by rat brains at the rate of one photon per neuron per minute. Although that does not sound like many, there are 1011 neurons in a human brain, which suggests it could produce more than a billion photons per second.

“This mechanism appears to be sufficient to facilitate transmission of a large number of bits of information, or even allow the creation of a large amount of quantum entanglement,” say Zarkeshian and co.

Of course, there are numerous uncertainties in these calculations. Nobody knows the precise optical properties of myelin sheaths, for example, because they have never been measured.

The best way to find out more is to test the optical transmission properties of brain tissue. Zarkeshian and co suggest a number of straightforward experiments that would move this field forward. “One way is to light up one end of a thin brain slice and look for the bright spots related to the open ends of the myelinated axons at the other end,” they say. There are various other approaches too. That’s something a neuroscientist with time on his or her hands could take on.

All this points to a bigger conundrum. If our brains have optical communications channels, what are they for? This is a question that is ripe for blue skies speculation.

One line of thought is based on the fact that photons are good carriers of quantum information. Many people have theorized that quantum processes may be behind some of the brain’s more mysterious  processes, not least of which is consciousness itself. Zarkeshian and co are clearly enamored with this idea.

But this is no more than wild speculation. Quantum communication requires significantly more than optical communication channels. There must also be mechanisms that can encode, receive, and process quantum information. It is possible that light-sensitive molecules exist in the brain but there is little evidence for this and still less that they serve as quantum processors.

https://www.technologyreview.com/s/608797/are-there-optical-communication-channels-in-our-brains/

.......


The Puzzling Role Of Biophotons In The Brain
Various work suggests that neurons emit and even conduct photons. Could it be that biophotons help to synchronise the brain?

December 17, 2010

In recent years, a growing body of evidence shows that photons play an important role in the basic functioning of cells. Most of this evidence comes from turning the lights off and counting the number of photons that cells produce. It turns out, much to many people’s surprise, that many cells, perhaps even most, emit light as they work.

In fact, it looks very much as if many cells use light to communicate. There’s certainly evidence that bacteria, plants and even kidney cells communicate in this way. Various groups have even shown that rats brains are literally alight thanks to the photons produced by neurons as they work.

And that raises an interesting question: what role does light play in the work of neurons? The fact that neurons emit light does not mean that they can receive it or process it.

But interesting evidence is beginning to emerge that light may well play an important role in neuronal function. For example, earlier this year, one group showed that spinal neurons in rats can actually conduct light.

Today, Majid Rahnama at Shahid Bahonar University of Kerman in Iran and a group of pals, suggest how this might work. And they even go on to make a startling prediction about the role that photons might play in the way the brain works.

To begin with, Rahnama and co point out that neurons contain many light sensitive molecules, such as porphyrin rings, flavinic, pyridinic rings, lipid chromophores and aromatic amino acids. In particular, mitochondria, the machines inside cells which produce energy, contain several prominent chromophores.

The presence of light sensitive molecules makes it hard to imagine how they might not be not influenced by biophotons.

But photons would also be absorbed by other stuff in the cell, liquids, membranes etc, and this ought to make cells opaque. So Rhanama and co hypothesise that microtubules can act as wave guides, channeling light from one part of a cell to another.

Microtubules are the internal scaffolding inside cells, providing structural support but also creating highways along which molecular machines transport freight around the cell. They’re extraordinary things. Could it be that they also work like optical fibres?

Maybe. They go on to suggest that the light channelled by microtubules can help to co-ordinate activities in different parts of the brain. It’s certainly true that electrical activity in the brain is synchronised over distances that cannot be easily explained. Electrical signals travel too slowly to do this job, so something else must be at work.

And of course Rhanama and co are not the first to suggest that microtubules play a central role in the functioning of the brain. 15 years ago, Roger Penrose suggested that consciousness is essentially a phenomenon of quantum mechanics and that microtubules were the medium in which quantum mechanics takes place.

It’s a big jump to assume that photons do this job. But science is built on leaps of imagination like this. What Rhanama and co need now is somebody to test this idea for them, which is not going to be easy. There’s no harm in speculation but evidence is king.

What’s for sure is that biophotonics is one of the fastest moving and exciting fields in science today. And in this kind of rapidly moving environment, thinking like this can sometimes trigger a revolution.

Ref: arxiv.org/abs/1012.3371 : Emission of Biophotons and Neural Activity of the Brain

https://www.technologyreview.com/s/422069/the-puzzling-role-of-biophotons-in-the-brain/

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Mon Mar 19, 2018 12:41 am

Nicotinamide mononucleotide protects against β-amyloid oligomer-induced cognitive impairment and neuronal death.
Wang X1, Hu X2, Yang Y2, Takata T3, Sakurai T4.
Author information

Abstract


Amyloid-β (Aβ) oligomers are recognized as the primary neurotoxic agents in Alzheimer's disease (AD). Impaired brain energy metabolism and oxidative stress are implicated in cognitive decline in AD. Nicotinamide adenine dinucleotide (NAD(+)), a coenzyme involved in redox activities in the mitochondrial electron transport chain, has been identified as a key regulator of the lifespan-extending effects, and the activation of NAD(+) expression has been linked with a decrease in Aβ toxicity in AD. One of the key precursors of NAD(+) is nicotinamide mononucleotide (NMN), a product of the nicotinamide phosphoribosyltransferase reaction. To determine whether improving brain energy metabolism will forestall disease progress in AD, the impact of the NAD(+) precursor NMN on Aβ oligomer-induced neuronal death and cognitive impairment were studied in organotypic hippocampal slice cultures (OHCs) and in a rat model of AD. Treatment of intracerebroventricular Aβ oligomer infusion AD model rats with NMN (500mg/kg, intraperitoneally) sustained improvement in cognitive function as assessed by the Morris water maze. In OHCs, Aβ oligomer-treated culture media with NMN attenuated neuronal cell death. NMN treatment also significantly prevented the Aβ oligomer-induced inhibition of LTP. Furthermore, NMN restored levels of NAD(+) and ATP, eliminated accumulation of reactive oxygen species (ROS) in the Aβ oligomer-treated hippocampal slices. All these protective effects were reversed by 3-acetylpyridine, which generates inactive NAD(+). The present study indicates that NMN could restore cognition in AD model rats. The beneficial effect of NMN is produced by ameliorating neuron survival, improving energy metabolism and reducing ROS accumulation. These results suggest that NMN may become a promising therapeutic drug for AD.

https://www.ncbi.nlm.nih.gov/pubmed/27130898

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Re: Study Identifies First Brain Cells that Respond to Sound

Post by Cr6 on Sat Mar 24, 2018 1:46 am

Interesting show....tDCS used for cancer pain therapy:

www.jpsmjournal.com/article/S0885-3924(07)00491-5/pdf

https://gumc.georgetown.edu/news/Electrical-Brain-Stimulation-Enhances-Creativity-Researchers-Say
https://www.sciencedaily.com/releases/2015/05/150505152140.htm

DIY Brain Stimulation Raises Concerns
Nancy A. Melville
July 10, 2013
https://www.medscape.com/viewarticle/807593

Ethical Dilemma

Despite several recent published editorials and papers on the issue, the exact extent of use of home tDCS devices is unknown, and with the additional lack of evidence on benefits and potential risks, Peter Reiner, PhD, who coauthored one of the papers, published in the Journal of Medical Ethics, said that he and his colleagues had strong reservations about even publishing their paper.

"This device is moving very rapidly from concept to implementation and while we don't know how widely it's being used as a do-it-yourself at-home device, we have a responsibility not make that problem worse by reporting upon it," said Dr. Reiner, from the National Core for Neuroethics at the University of British Columbia in Vancouver, Canada.

"So we thought very long and hard before publishing this with concern about whether we were really going to draw so much attention to it that people would wind up taking it up," he told Medscape Medical News.

"But we have seen more Web sites selling this and more commercial outfits either preparing to launch or launching this, so we thought the time was right."

The most intriguing aspect of tDCS is also what makes it particularly worrisome — the potential for long-term manipulation of neuroplasticity.

In a recent small study, researchers trained participants for 6 days with numeric symbols while concurrent tDCS was applied to the parietal lobes. They found sustained improvements in numeric proficiency as much as 6 months after the training (Curr Biol. 2010;20:2016-2020).

"The specificity and longevity of tDCS on numerical abilities establishes tDCS as a realistic tool for intervention in cases of atypical numerical development or loss of numerical abilities because of stroke or degenerative illnesses," those authors wrote.

Acknowledging such potentially long-term effects of tDCS, Dr. Reiner and his colleagues compared the potential benefits to that of functional MRI.

"Much as functional MRI has fuelled a revolution in measuring brain activity, tDCS seems poised to radically change our ability to manipulate brain activity in living humans," the authors write.

"Neither technique has the resolution that the synaptically oriented neurocognoscenti might wish for, but what they lack in specificity they make up for in versatility."

"Together, these are the Swiss Army knives of human neuroscience," they add.


Episode 21 – Michael Weisend
Does tDCS Accelerate Learning? Is it Safe?


https://thequantifiedbody.net/tdcs-accelerate-learning-dr-michael-weisend/
http://quantifiedbody.podbean.com/mf/web/bmaxzr/Quantified-Body-Podcast-Ep-21-tdcs-accelerate-learning-with-Dr-Michael-Weisend.mp3

Recently, transcranial direct current stimulation (tDCS) or the non-invasive targeting of weak direct current (DC) to specific brain regions has received media attention. Among the scientific research community, tDCS has been a subject of great interest owing to its usage ease, relative inexpensiveness, and encouraging research results on a range of functions. Studies have seen tDCS accelerate learning, reduce symptoms of dementia, and improve attention in those with Attention Deficit Disorder (ADD). Understandably, a coinciding rise in the DIY community has also prompted an increase in consumer devices available for home use in hopes of mimicking tDCS’s potential neuroenhancement abilities.

This episode’s tracking will look at how to use different types of brain scans to understand the impact tDCS is having on the brain. In circumstances such as these, where the long term consequences are not known or understood, the tracking becomes even more important.

“What tDCS appears to do is to essentially turn the amplifier up, or the volume up, just a little bit on the brain areas that are receiving stimulation from the outside world. [Thus] you get a slightly larger reaction in the brain to stimuli that are coming in through endogenous pathways as a result of this exogenous tDCS stimulation.”

– Dr. Michael Weisend

Dr. Michael Weisend is a neuroscience pioneer in the research and broad range application of tDCS. He is an expert in the neurophysiological mechanisms of learning, cognition, and memory and has developed and advanced non-invasive brain stimulation strategies under neuroimaging guidance to enhance memory and other aspects of human performance. He has worked with the U.S. Air Force, Defense Advanced Research Projects Agency (DARPA), and the National Institute for Health (NIH).

The show notes, biomarkers, and links to the apps, devices and labs and everything else mentioned are below. Enjoy the show and let me know what you think in the comments!

itunes quantified body
Show Notes

In order to stimulate the brain to enhance performance, areas of the brain being stimulated should be matched to the places in the brain that are active (4:11).
Through image subtraction, the essential difference between two brain states (tired vs. rested, inattentive vs. attentive, novice vs. expert) can be identified. Once identified, the goal is to target stimulation in order to aid in the transition from an undesirable brain state to a desirable state (5:54).
Dr. Michael Weisend’s lab has mainly focused on learning. It will shortly start work with subjects with lingering symptoms from traumatic brain injuries (6:28).
In the near future, tDCS will have an impact in depression (7:10).
tDCS is inexpensive and could be a wearable for many (8:40).
Because of advances in neuroimaging, current is able to be placed into critical brain structures for specific tasks (9:50).
tDCS employs direct current (DC), which turns on and stays on at a steady rate; while machines found in physical therapy use alternating current (AC), which alternates current up and down (13:42).
DC current, instead of directly causing an activity, is thought to “turn the amplifier up, or the volume up” on the areas in the brain that receive stimulation from the outside world (15:32).
Using DC in tDCS allows for less variables to be involved (18:35).
There are various theories on what different brain wave frequencies mean, and different frequencies are thought to do different things. For instance, sleep and waking have different wave activities at various cyclic points across a spectrum (19:55).
Research has looked at a subject’s ability to find a target. Similar to the game Where’s Waldo, a subject looking for a specific individual would have to go through hours of imagery in order to complete the search, while simultaneously balancing essential components critical to the search. By studying multiple variables in conjunction with tDCS, Dr. Michael Weisend is able to see if, for a variable amount of time, subjects would make fewer errors (22:00).
In the case of traumatic brain injury, the damage is subtle and hard to find via conventional scanning. A more specialized test, the diffusion tensor imaging MRI, can often reveal damage to the network (24:15).
There are three places where to target stimulation: (1)where you sense (2)where you process and (3)where you act (27:45).
When the brain is stimulated, it is more reactive to natural environmental stimuli. In theory, when the brain is in a more reactive state, there will be a greater number of active cells. This allows for additional opportunities for neuroplasticity to take place. In other words, because more cells are firing and more cells are wiring, a more rapid acquisition of information, able to be measured by changes in behavior, take place (29:30).
MEG measures the magnetic energy produced by the brain, while EEG measures the electrical energy (33:00).
Carefully using tDCS, Dr. Michael Weisend has doubled the rate of learning in a Where’s Waldo type task (39:00).
Dr. Michael Weisend is biased for two reasons against the consumer devices: (1) devices currently out there do not take care of the electrode-skin interface; and (2) devices for home use have not been tested for safety or effectiveness (43:10).
There is an active debate in the neuroscience community as to whether electrical brain stimulation is more like caffeine or more like a cigarette. There currently are no imaging studies looking at the effects of long term stimulation with tDCS (45:07).
Could tDCS enhance performance? It could reduce the perceived effort. With the current level of understanding, however one might decrease performance instead (46:20).
In the future, Dr. Michael Weisend sees combined therapies, or closed loop therapies, leading the field (52:39).
White matter changes have been seen with tDCS; however, no grey matter changes have been observed (54:20).
Dr. Michael Weisend uses the original Polar Loop to track steps on a routine basis to monitor and improve his health, longevity and performance. He also looks at the actigraphy for information about sleep, and downloads the information to analyze if he is reaching his goals.
Dr. Michael Weisend’s biggest recommendation on using body data to improve your health, longevity and performance is to meditate a few minutes every morning. He recommends to think through your body, and mindfully self-check.

Dr. Michael Weisend

Dr. Michael Weisend’s Bio Link
Dr. Michael Weisend’s PubMed Link
TEDx presentation: Dr. Michael Weisend’s TEDx presentation looking at viable applications of brain stimulation.

The Tracking
Biomarkers

Magnetic Fields: are assessed by magnetoencephalography (MEG). Neural activity in the brain results in measurable currents and magnetic fields. Magnetic fields produced by the brain are measured in the unit Telsa (T).
Electrical Activity: is assessed by electroencephalogram (EEG). When enough concurrent electrical activity is generated by neurons firing, simple periodic waveforms are distinguishable. Rhythms generated by electrical activity are measured by their frequency and amplitude. Frequency is expressed in the unit Hertz (Hz) while amplitude is recorded in microvolts (μV).

Brain Imaging Devices

Diffusion Tensor Imaging: a magnetic resonance imaging technique that captures how water travels along neurons in the brain. This test reveals damage to the neuronal network in traumatic brain injuries, which other scans may miss.
Electroencephalography (EEG): a method to record the electrical activity of the brain resulting from current flows within the neurons of the brain.
Functional MRI (fMRI): is a functional neuroimaging technique using magnetic resonance imaging (MRI) to measure spatial localization of brain activity through detection in associated changes in blood flow. Dr. Michael Weisend only sometimes uses fMRI, because it is an indirect measurement of brain activity.
Magnetoencephalography (MEG): is a functional neuroimaging technique to map brain activity using magnetic signals. Dr. Michael Weisend prefers to use MEG compared to other techniques because magnetic fields are less distorted by tissue or bone and the MEG allows measurement of neurons turning on and off hundreds of times a second, thus allows ongoing measurement of activity.
Functional MRI (fMRI): is a functional neuroimaging technique using magnetic resonance imaging (MRI) to measure spatial localization of brain activity through detection in associated changes in blood flow. Dr. Michael Weisend only sometimes uses fMRI, because it is an indirect measurement of brain activity.
Structural MRI (MRI): provides a picture of the brain. The MRI signal generated is dependent on characteristics of different tissue types within the brain. For instance, gray matter has certain cellular properties different from white matter and these differences are visualized by contrasts expressed in a MRI image.

Consumer Devices

Muse Headband: a consumer EEG device, used by Damien, to track different frequencies of brain waves.
Thync: Dr. Michael Weisend looks forward to this company’s consumer electrical brain stimulation device. He hopes their “safety record is as stellar as they hope it will be”.

Terms

Alpha Wave: the alpha rhythm is the most prominent EEG wave pattern of a brain that is awake but relaxed. When moving from lighter to deeper stages of sleep (prior to REM sleep) the pattern of alpha waves diminishes.
Alternating Current (AC): current that alternates with time in voltage.
Beta Wave: occurs at the highest frequency (Hz). These patterns are found when the brain is alert. Paradoxically, these rhythms also occur during REM (Rapid Eye Movement) sleep.
Closed-loop system: a system capable of diagnosing electrophysiological abnormalities and treating them promptly.
Delta Wave: are low-frequency (only 1-4 Hz) that increase during sleep. When moving from lighter to deeper stages of sleep (prior to REM sleep) the pattern of delta waves increases.
Direct Current (DC): flow of electric charge (current) in a constant direction.
Gamma Wave: a wave pattern with activities in sensory processing.
Grey Matter: areas of the brain containing unmyelinated neurons and other cells.
Neuroplasticity: the ability of the brain’s neuron network and synapses to change.
Sine wave: associated with an AC current. Dr. Michael Weisend describes it as “just a fancy word for something that goes up and down equally around zero amps, or zero volts”.
White Matter: areas of the brain containing myelin coated axons.

The Tools & Tactics

Transcranial Direct Current Stimulation (tDCS): is a non-invasive targeting of weak direct current (DC) to specific brain regions. This low-intensity electrical current is passed at a constant rate from electrodes applied to the head. This type of brain stimulation induces currents able to regulate neuronal activity. The effects of tDCS can be modified by the size and polarity of electrodes used, intensity of current, and the period of stimulation.
Transcranial Alternating Current Stimulation (tACS): is non-invasive targeting of alternating current (AC). Dr. Weisend explains, this is different from DC, because waves or rhythms are entrained into the brain. For example, if stimulated with 10 Hz, the stimulation will have a frequency of going up and down 10 times per second. Once to the brain, this frequency will produce a sympathetic rhythm at 10 hertz, but may also enhanced in amplitude. Thus, with tACS, determining the appropriate frequency of AC for the task is an additional variable.

Other People, Books & Resources
People

Luigi Galvani: is credited for the discovery of bioelectricity.
Roi Cohen Kadosh Ph.D.: has studied tDCS to enhance mathematical ability and found data indicating that brain stimulation may enhance one type of math, while decreasing an individual’s ability to perform another type of math.
Andrew McKinley Ph.D.: is a colleague of Dr. Michael Weisend, who has demonstrated that giving sleep-deprived individuals brain stimulation can have the same benefit as a cup of coffee.

Books

The Organization of Behavior: originally published in 1949, Donald Hebb first wrote the old (but still true) adage “cells that fire together, wire together” in this book.

Resources

DIYtDCS website: a blog, described by Dr. Michael Weinstein, that stays up-to-date on literature and has conducted interviews with the top scientists in the tDCS field.

Other

ElectRX Program: a DARPA program aimed at identifying and studying biomarkers to monitor body and organ function. It will also look at what equipment is needed to monitor, and then interact with the system electrically to change its function.
Nootropics: are a wide variety of both pharmaceutical and non-pharmaceutical enhancers to improve one’s cognitive abilities. There is little known about their long term effects.
Pavlov’s dogs: initially, a bell and food were presented together. After a few times, the bell alone would cause salivation. Thus, Pavlov’s dogs learned to salivate to the sound of a bell in anticipation of food.

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