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Anesthesia doesn't simply turn off the brain, it changes its rhythms -- ScienceDaily

"All the cortex has to be on the same page to produce consciousness," Miller said. "One theory about how this works is through thalamo-cortical loops that allow the cortex to synchronize. Propofol may be breaking the normal operation of those loops by hyper synchronizing them in prolonged down states. It disrupts the ability of the cortex to communicate." For instance, by making measurements in distinct layers of the cortex, the team found that higher frequency "gamma" rhythms, which are normally associated with new sensory information like sights and sounds, were especially reduced in superficial layers. Lower frequency "alpha" and "beta" waves, which Miller has shown tend to regulate the processing of the information carried by gamma rhythms, were especially reduced in deeper layers.

The Story of a New Name Quotes by Elena Ferrante

she was explaining to me that I had won nothing, that in the world there is nothing to win, that her life was full of varied and foolish adventures as much as mine, and that time simply slipped away without any meaning, and it was good just to see each other every so often to hear the mad sound of the brain of one echo in the mad sound of the brain of the other.

Brain tunes itself to criticality, maximizing information processing - ScienceBlog.com

Taking advantage of their ability to continuously track the activity of neurons for more than a week, the researchers first confirmed that network dynamics in the visual cortex are robustly tuned to criticality, even across light and dark cycles. Next, by blocking vision in one eye, the researchers revealed that criticality was severely disrupted, more than a day before the manipulation affected the firing rates of individual neurons. Twenty-four hours later, criticality re-emerged in the recordings — at which point individual neurons were suppressed by the visual deprivation.

Gamma wave - Wikipedia

A number of experiments conducted by Rodolfo Llinás supports a hypothesis that the basis for consciousness in awake states and dreaming is 40-Hz oscillations throughout the cortical mantle in the form of thalamocortical iterative recurrent activity. In two papers entitled "Coherent 40-Hz oscillation characterizes dream state in humans” (Rodolfo Llinás and Urs Ribary, Proc Natl Acad Sci USA 90:2078-2081, 1993) and "Of dreaming and wakefulness” (Llinas & Pare, 1991), Llinás proposes that the conjunction into a single cognitive event could come about by the concurrent summation of specific and nonspecific 40-Hz activity along the radial dendritic axis of given cortical elements, and that the resonance is modulated by the brainstem and is given content by sensory input in the awake state and intrinsic activity during dreaming. According to Llinás’ hypothesis, known as the thalamocortical dialogue hypothesis for consciousness, the 40-Hz oscillation seen in wakefulness and in dreaming is proposed to be a correlate of cognition, resultant from coherent 40-Hz resonance between thalamocortical-specific and nonspecific loops. In Llinás & Ribary (1993), the authors propose that the specific loops give the content of cognition, and that a nonspecific loop gives the temporal binding required for the unity of cognitive experience.

People with schizophrenia experience emotion differently from others, 'body maps' show -- ScienceDaily

The outcomes differed radically between groups, with the control group showing distinct maps of sensations for 13 different emotions, indicating specific patterns of increased arousal and decreased energy across the body for each emotion. However, in individuals with schizophrenia, there was an overall reduction of bodily sensation across all emotions. The study also found that individuals with schizophrenia don't differentiate on their body maps for varying emotions. That may pose a problem for them in identifying, recognizing and verbalizing their emotions or trying to understand the emotions of others. Torregrossa said the research will allow the team to move forward in developing ways to help people with schizophrenia process emotions, which, in turn, could improve interpersonal relationships. "The main outcome of this research is that we have a better understanding of why people with schizophrenia might have trouble interacting with others," she said. "What we can do now is help them learn to attend to physiological sensations arising from their bodies and use them to process emotions."

Could consciousness all come down to the way things vibrate?

The central thesis of our approach is this: the particular linkages that allow for large-scale consciousness – like those humans and other mammals enjoy – result from a shared resonance among many smaller constituents. The speed of the resonant waves that are present is the limiting factor that determines the size of each conscious entity in each moment. As a particular shared resonance expands to more and more constituents, the new conscious entity that results from this resonance and combination grows larger and more complex. So the shared resonance in a human brain that achieves gamma synchrony, for example, includes a far larger number of neurons and neuronal connections than is the case for beta or theta rhythms alone. What about larger inter-organism resonance like the cloud of fireflies with their little lights flashing in sync? Researchers think their bioluminescent resonance arises due to internal biological oscillators that automatically result in each firefly syncing up with its neighbors.

Could consciousness all come down to the way things vibrate?

Gamma waves are associated with large-scale coordinated activities like perception, meditation or focused consciousness; beta with maximum brain activity or arousal; and theta with relaxation or daydreaming. These three wave types work together to produce, or at least facilitate, various types of human consciousness, according to Fries. But the exact relationship between electrical brain waves and consciousness is still very much up for debate. Fries calls his concept “communication through coherence.” For him, it’s all about neuronal synchronization. Synchronization, in terms of shared electrical oscillation rates, allows for smooth communication between neurons and groups of neurons. Without this kind of synchronized coherence, inputs arrive at random phases of the neuron excitability cycle and are ineffective, or at least much less effective, in communication.

Giant Neurons in the Brain May Play Similarly Giant Role in Awareness and Cognition - Neuroscience News

To Tabansky’s surprise, the NGC neurons were found to express the gene for an enzyme, endothelial nitric oxide synthase (eNOS), which produces nitric oxide, which in turn relaxes blood vessels, increasing the flow of oxygenated blood to tissue. (No other neurons in the brain are known to produce eNOS.) They also discovered that the eNOS-expressing NGC neurons are located close to blood vessels. In Pfaff’s view, the neurons are so critical for the normal functions of the central nervous system that they have evolved the ability to control their own blood supply directly. ‘”We’re pretty sure that if these neurons need more oxygen and glucose, they will release nitric oxide into these nearby blood vessels in order to get it,” he says.

Slow, steady waves keep brain humming: Such rhythmic waves linked to state of consciousness -- ScienceDaily

As the waves passed through each area of the brain, they enhanced the electrical activity there. Neurons fired more enthusiastically when a wave was in the vicinity. Moreover, the ultra-slow waves persisted when the mice were put under general anesthesia, but with the direction of the waves reversed. "There is a very slow process that moves through the brain to create temporary windows of opportunity for long-distance signaling," Mitra said. "The way these ultra-slow waves move through the cortex is correlated with enormous changes in behavior, such as the difference between conscious and unconscious states." The fact that the waves' trajectory changed so dramatically with state of consciousness suggests that ultra-slow waves could be fundamental to how the brain functions. If brain areas are thought of as boats bobbing about on a slow-wave sea, the choppiness and direction of the sea surely influences how easily a message can be passed from one boat to another, and how hard it is for two boats to coordinate their activity.

Prevailing theories of consciousness are challenged by novel cross-modal associations acquired between subliminal stimuli. - PubMed - NCBI

The results demonstrate the acquisition of novel cross-modal associations between stimuli which are not consciously perceived and thus challenge the global access hypothesis and those theories embracing it.

Panpsychism: The idea that everything from spoons to stones are conscious is gaining academic credibility — Quartz

Consciousness is a fundamental feature of physical matter; every single particle in existence has an “unimaginably simple” form of consciousness, says Goff. These particles then come together to form more complex forms of consciousness, such as humans’ subjective experiences. This isn’t meant to imply that particles have a coherent worldview or actively think, merely that there’s some inherent subjective experience of consciousness in even the tiniest particle.

Circadian meta rhythm needed for consciouness?

of Surrey and the University of Salzburg, Austria, examined circadian body temperature variations of 18 patients suffering from severe brain injuries and the potential link to consciousness. Circadian rhythms are an approximate 24-hour cycle governed by the body's internal clock and they determine a number of physiological processes in the body including core body temperature, which fluctuates throughout the day. To assess the body temperature of patients, researchers used four external skin sensors to monitor the circadian rhythm, which was found to range between 23.5 hours and 26.3 hours. The level of consciousness of each patient was evaluated through the Coma Recovery Scale-Revised, which among others measures responsiveness to sound or a patient's ability to spontaneously open eyes without or only with stimulation by the examiner. Researchers discovered that patients who scored better on the Coma Recovery Scale-Revised, especially, those patients with a stronger arousal had body temperature patterns that were more closely aligned with a healthy 24-hour rhythm. This finding demonstrates a newly discovered relationship between circadian body temperature variation and the level of consciousness of a patient with severe brain damage. This finding suggests that patient's consciousness levels should be assessed during time windows when their circadian rhythm predicts them to be more responsive. The effects of bright light stimulation on patients with severe brain injuries was also investigated during this study. To measure its effectiveness, eight patients received bright light stimulation, three times per day for one hour over the course of one week. After one week, improvements were found in the level of consciousness of two patients, whose condition improved from vegetative state/unresponsive wakefulness to a minimally conscious state. Interestingly, in these two patients, a shift in their circadian body temperature, closer to a healthy 24-hour rhythm was also recorded. Co-investigator of the paper Dr Nayantara Santhi from the Surrey Sleep Research Centre, University of Surrey, said: "Prior to our study little was known about the circadian rhythms of patients with brain injuries. What we have learnt is that the circadian body temperature holds vital clues to the state of consciousness of patients which could potentially enable doctors to tailor medical treatment more effectively. "Circadian rhythms hold the secret to the workings of the body and we will be looking further into this in future research."

What Is This Thing Called Consciousness?

Yet the cerebellum has everything you expect of neurons. It has gorgeous neurons. In fact, some of the most beautiful neurons in the brain, so-called Purkinje cells, are found in the cerebellum. Why does the cerebellum not contribute to consciousness? It has a very repetitive and monotonous circuitry. It has 69 billion neurons, but they have simple feed-forward loops. So I believe the way the cerebellum is wired up does not give rise to consciousness. Yet another part of the brain, the cerebral cortex, seems to be wired up in a much more complicated way. We know it’s really the cortex that gives rise to conscious experience.

Born without a cerebellum

We also know that consciousness does not require your entire brain. You can lose 80 percent of your neurons. You can lose the little brain at the back of your brain called the cerebellum. There was recently a 24-year-old Chinese woman who discovered, when she had to get a brain scan, that she has absolutely no cerebellum. She’s one of the extremely rare cases of people born without a cerebellum, including deep cerebellar nuclei. She never had one. She talks in a somewhat funny way and she’s a bit ataxic. It took her several years to learn how to walk and speak, but you can communicate with her. She’s married and has a child. She can talk to you about her conscious experiences. So clearly you don’t need the cerebellum.

To bee or not to bee

Their brains contain roughly a million neurons. By comparison, our brains contain about 100 billion, so a hundred thousand times more. Yet the complexity of the bee’s brain is staggering, even though it’s smaller than a piece of quinoa. It’s roughly 10 times higher in terms of density than our cortex. They have all the complicated components that we have in our brains, but in a smaller package. So yes, I do believe it feels like something to be a honey bee. It probably feels very good to be dancing in the sunlight and to drink nectar and carry it back to their hive. I try not to kill bees or wasps or other insects anymore.

The hard problem of consciousness is a distraction from the real one | Aeon Essays

Predictive processing can also help us understand unusual forms of visual experience, such as the hallucinations that can accompany psychosis or psychedelic trips. The basic idea is that hallucinations occur when the brain pays too little attention to incoming sensory signals, so that perception becomes unusually dominated by the brain’s prior expectations. Different sorts of hallucination – from simple geometric experiences of lines, patterns and textures to rich hallucinatory narratives full of objects and people – can be explained by the brain’s over-eagerness to confirm its predictions at different levels in the cortical hierarchy.

Consciousness is tied to 'entropy', say researchers - physicsworld.com

Key to this has been the study of synchronization – how the electrical activity of one set of neurons can oscillate in phase with that of another set. Synchronization in turn implies that those sets of neurons are physically tied to one another, just as oscillating physical systems, such as pendulums, become synchronized when they are connected together. The latest work stems from the observation that consciousness, or at least the proper functioning of brains, is associated not with high or even low degrees of synchronicity between neurons but by middling amounts. Jose Luis Perez Velazquez, a biochemist at the University of Toronto, and colleagues hypothesized that what is maximized during consciousness is not connectivity itself but the number of different ways that a certain degree of connectivity can be achieved.

Dopamine signaling as a neural correlate of consciousness

The neural correlates of consciousness are largely unknown but many neural circuits are likely to be involved. Our experiments with mice that cannot synthesize dopamine suggest that dopamine signaling is a critical component necessary for the expression of consciousness. Although dopamine-deficient mice are awake and respond to many stimuli, they are unmotivated and have profound deficits in all but the simplest learning tasks. Dopamine-deficient mice are unable to attend to salient sensory information, integrate it with prior experience, store it in long-term memory, or choose appropriate actions. While clearly conscious from a general anesthetic point of view, dopamine-deficient mice have marginal arousal and appear to be virtually unconscious from a behavioral point of view. Restoration of dopamine signaling within the striatum by viral gene therapy strategies restores most behaviors.

Mind plus mind = new mind

Objective reality is just conscious agents, just points of view. Interestingly, I can take two conscious agents and have them interact, and the mathematical structure of that interaction also satisfies the definition of a conscious agent. This mathematics is telling me something. I can take two minds, and they can generate a new, unified single mind. Here’s a concrete example. We have two hemispheres in our brain. But when you do a split-brain operation, a complete transection of the corpus callosum, you get clear evidence of two separate consciousnesses. Before that slicing happened, it seemed there was a single unified consciousness. So it’s not implausible that there is a single conscious agent. And yet it’s also the case that there are two conscious agents there, and you can see that when they’re split. I didn’t expect that, the mathematics forced me to recognize this. It suggests that I can take separate observers, put them together and create new observers, and keep doing this ad infinitum. It’s conscious agents all the way down.

How the brain produces consciousness in 'time slices' of .4 seconds

The new model proposes a two-stage processing of information. First comes the unconscious stage: The brain processes specific features of objects, e.g. color or shape, and analyzes them quasi-continuously and unconsciously with a very high time-resolution. However, the model suggests that there is no perception of time during this unconscious processing. Even time features, such as duration or color change, are not perceived during this period. Instead, the brain represents its duration as a kind of "number", just as it does for color and shape. Then comes the conscious stage: Unconscious processing is completed, and the brain simultaneously renders all the features conscious. This produces the final "picture", which the brain finally presents to our consciousness, making us aware of the stimulus. The whole process, from stimulus to conscious perception, can last up to 400 milliseconds, which is a considerable delay from a physiological point of view. "The reason is that the brain wants to give you the best, clearest information it can, and this demands a substantial amount of time," explains Michael Herzog. "There is no advantage in making you aware of its unconscious processing, because that would be immensely confusing." This model focuses on visual perception, but the time delay might be different for other sensory information, e.g. auditory or olfactory.

This device can tell how conscious you are

Being conscious is about more than simply being awake -- it's also made up of "noticing and experiencing", Chennu says. "When someone is conscious, there are patterns of synchronised neural activity racing across the brain, that can be detected using EEG and quantified using our software."

Animal awareness of others' needs

As long ago as 1959, Russell Church of Brown University set up a test which allowed laboratory rats in half of a cage to get food by pressing a lever. The lever also delivered an electric shock to rats in the other half of the cage. When the first group realised that, they stopped pressing the lever, depriving themselves of food. In a similar test on rhesus monkeys reported in the American Journal of Psychiatry in 1964, one monkey stopped giving the signal for food for 12 days after witnessing another receive a shock. There are other examples of animals preferring some sort of feeling over food.

Animals plan for the future

Santino is a chimpanzee in Furuvik zoo in Sweden. In the 2000s zookeepers noticed that he was gathering little stockpiles of stones and hiding them around his cage, even constructing covers for them, so that at a later time he would have something to throw at zoo visitors who annoyed him. Mathias Osvath of Lund University argues that this behaviour showed various types of mental sophistication: Santino could remember a specific event in the past (being annoyed by visitors), prepare for an event in the future (throwing stones at them) and mentally construct a new situation (chasing the visitors away).

Pooled consciousness? No...

‘Take a sentence of a dozen words, and take twelve men and tell to each one word. Then stand the men in a row or jam them in a bunch, and let each think of his word as intently as he will; nowhere will there be a consciousness of the whole sentence’. This is how William James illustrated the combination problem of panpsychism [110]. Or take John Searle: ‘Consciousness cannot spread over the universe like a thin veneer of jam; there has to be a point where my consciousness ends and yours begins’ [117]. Indeed, if consciousness is everywhere, why should it not animate the United States of America? IIT deals squarely with this problem by stating that only maxima of integrated information exist. Consider two people talking: within each brain, there will be a major complex—a set of neurons that form a maximally irreducible cause–effect structure with definite borders and a high value of Φmax. Now let the two speak together. They will now form a system that is also irreducible (Φ > zero) due to their interactions. However, it is not maximally irreducible, since its value of integrated information will be much less than that of each of the two major complexes it contains. According to IIT, there should indeed be two separate experiences, but no superordinate conscious entity that is the union of the two. In other words, there is nothing-it-is-like-to-be two people, let alone the 300 plus million citizens making up the USA.13

Consciousness: here, there and everywhere? | Philosophical Transactions of the Royal Society B: Biological Sciences

A corollary of IIT that violates common intuitions is that even circuits as simple as a ‘photodiode’ made up of a sensor and a memory element can have a modicum of experience [80] (see also figure 5a, right panel). It is nearly impossible to imagine what it would ‘feel like’ to be such a circuit, for which the only phenomenal distinction would be between ‘this rather than not this’ (unlike a photodiode, when we are conscious of ‘light’ or of ‘dark,’ our experience is what it is because it includes scores of negative concepts, such as no colours, no shapes, no thoughts and so on, that are all available to us). But consider that normal matter at −272.15°C, one degree above absolute zero, still contains some heat. However, in practice its temperature is as cold as it gets. Similarly, there may well be a practical threshold for Φmax below which people do not report feeling much of anything, but this does not mean that consciousness has reached its absolute minimum, zero. Indeed, when we fall into a deep, dreamless sleep and don't report any experience upon being awoken, some small complex of neurons within our sleeping brain will likely have a Φmax value greater than zero, yet that may not amount to much compared to that of our rich, everyday experience.

Neurons as adventurous voyagers

Each neuron is imprisoned in your brain. I now think of these as cells within cells, as cells within prison cells. Realize that every neuron in your brain, every human cell in your body (leaving aside all the symbionts), is a direct descendent of eukaryotic cells that lived and fended for themselves for about a billion years as free-swimming, free-living little agents. They fended for themselves, and they survived.              They had to develop an awful lot of know-how, a lot of talent, a lot of self-protective talent to do that. When they joined forces into multi-cellular creatures, they gave up a lot of that. They became, in effect, domesticated. They became part of larger, more monolithic organizations. My hunch is that that's true in general. We don't have to worry about our muscle cells rebelling against us, or anything like that. When they do, we call it cancer, but in the brain I think that (and this is my wild idea) maybe only in one species, us, and maybe only in the obviously more volatile parts of the brain, the cortical areas, some little switch has been thrown in the genetics that, in effect, makes our neurons a little bit feral, a little bit like what happens when you let sheep or pigs go feral, and they recover their wild talents very fast. Maybe a lot of the neurons in our brains are not just capable but, if you like, motivated to be more adventurous, more exploratory or risky in the way they comport themselves, in the way they live their lives. They're struggling amongst themselves with each other for influence, just for staying alive, and there's competition going on between individual neurons. As soon as that happens, you have room for cooperation to create alliances, and I suspect that a more free-wheeling, anarchic organization is the secret of our greater capacities of creativity, imagination, thinking outside the box and all that, and the price we pay for it is our susceptibility to obsessions, mental illnesses, delusions and smaller problems.