Archive for the ‘Neuroscience’ Category

The Four-Dimensional Brain?

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Towards a fourth spatial dimension of brain activity.
Tozzi A, Peters JF.

Current advances in neurosciences deal with the functional architecture of the central nervous system, paving the way for general theories that improve our understanding of brain activity. From topology, a strong concept comes into play in understanding brain functions, namely, the 4D space of a “hypersphere’s torus”, undetectable by observers living in a 3D world. The torus may be compared with a video game with biplanes in aerial combat: when a biplane flies off one edge of gaming display, it does not crash but rather it comes back from the opposite edge of the screen. Our thoughts exhibit similar behaviour, i.e. the unique ability to connect past, present and future events in a single, coherent picture as if we were allowed to watch the three screens of past-present-future “glued” together in a mental kaleidoscope. Here we hypothesize that brain functions are embedded in a imperceptible fourth spatial dimension and propose a method to empirically assess its presence. Neuroimaging fMRI series can be evaluated, looking for the topological hallmark of the presence of a fourth dimension. Indeed, there is a typical feature which reveal the existence of a functional hypersphere: the simultaneous activation of areas opposite each other on the 3D cortical surface. Our suggestion-substantiated by recent findings-that brain activity takes place on a closed, donut-like trajectory helps to solve long-standing mysteries concerning our psychological activities, such as mind-wandering, memory retrieval, consciousness and dreaming state.


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Written by physicsgg

June 11, 2016 at 2:09 pm

Posted in Neuroscience, Psychological Sciences

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Computer Can Read Letters Directly from the Brain

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By analysing MRI images of the brain with an elegant mathematical model, it is possible to reconstruct thoughts more accurately than ever before. In this way, researchers from Radboud University Nijmegen have succeeded in determining which letter a test subject was looking at. (Credit: Image courtesy of Radboud University Nijmegen)

By analysing MRI images of the brain with an elegant mathematical model, it is possible to reconstruct thoughts more accurately than ever before. In this way, researchers from Radboud University Nijmegen have succeeded in determining which letter a test subject was looking at. The journal Neuroimage has accepted the article, which will be published soon.
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August 20, 2013 at 1:03 pm

Posted in Neuroscience, TECHNOLOGY

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Near-death experiences are ‘electrical surge in dying brain’

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Near-death survivors have reported seeing bright white lights and having out-of-body experiences

A surge of electrical activity in the brain could be responsible for the vivid experiences described by near-death survivors, scientists report.

A study carried out on dying rats found high levels of brainwaves at the point of the animals’ demise.

US researchers said that in humans this could give rise to a heightened state of consciousness.

The research is published in the Proceedings of the National Academy of Sciences.

The lead author of the study, Dr Jimo Borjigin, of the University of Michigan, said: “A lot of people thought that the brain after clinical death was inactive or hypoactive, with less activity than the waking state, and we show that is definitely not the case.

“If anything, it is much more active during the dying process than even the waking state.”


From bright white lights to out-of-body sensations and feelings of life flashing before their eyes, the experiences reported by people who have come close to death but survived are common the world over.

However, studying this in humans is a challenge, and these visions are little understood.

To find out more, scientists at the University of Michigan monitored nine rats as they were dying.

In the 30-second period after the animal’s hearts stopped beating, they measured a sharp increase in high-frequency brainwaves called gamma oscillations.

These pulses are one of the neuronal features that are thought to underpin consciousness in humans, especially when they help to “link” information from different parts of the brain.

In the rats, these electrical pulses were found at even higher levels just after the cardiac arrest than when animals were awake and well…..


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August 13, 2013 at 10:18 am

Posted in BIOLOGY, Neuroscience

Psychiatry needs its Higgs boson moment

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(Image: Andrzej Krauze)

(Image: Andrzej Krauze)

Fighting the scourge of mental illness means giving psychiatry the kind of boost that physics got from the Higgs hunt

by Nick Craddock
Recently, some colleagues and I launched a report, Strengthening Academic Psychiatry in the UK, and found ourselves justifying how psychiatry had acquired – and was still struggling to shrug off – the label of a “vulnerable academic discipline”. There were particular concerns about a fall in academic recruitment and unfilled academic posts.

Compare this with a field like physics. At just one frontier, it has a standard model that describes particles, Higgs field theory, the search for the Higgs boson and the Large Hadron Collider. These constitute a clear narrative: there is a global collaborative search for a “missing” particle based on fundamental theory, using a large and expensive piece of equipment that allows experimental testing of this and other predictions. This heady mix understandably makes physics a popular career choice.

Psychiatry, on the other hand, started the new millennium a few hundred years behind physics. But the decade that followed saw radical change, and set the stage for an intense period of catch-up. It is not fanciful to describe what will happen as the equivalent of some 200 to 300 years of progress being compressed into 20 to 30 years. This corresponds to the period of greatest productivity in a scientist or clinician’s career, so someone starting research now stands to make great headway (….)
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April 29, 2013 at 10:13 am

Posted in Neuroscience, Psychological Sciences

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The Emerging Revolution in Game Theory

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The discovery of a winning strategy for Prisoner’s Dilemma is forcing game theorists to rethink their discipline. Their conclusion? Winning isn’t everything.

The world of game theory is currently on fire. In May, Freeman Dyson at Princeton University and William Press at the University of Texas announced that they had discovered a previously unknown strategy for the game of prisoner’s dilemma which guarantees one player a better outcome than the other.

That’s a monumental surprise. Theorists have studied Prisoner’s Dilemma for decades, using it as a model for the emergence of co-operation in nature. This work has had a profound impact on disciplines such as economics, evolutionary biology and, of course, game theory itself. 

The game is this: imagine Alice and Bob have committed a crime and are arrested. The police offer each one a deal–snitch and you go free while your friend does 6 months in jail. If both Alice and Bob snitch, they both get 3 months in jail. If they both remain silent, they both get one month in jail for a lesser offence.  

What should Alice and Bob do? 

If they co-operate, they both spend only one month in jail. Nevertheless, in a single game, the best strategy is to snitch because it guarantees that you don’t get the maximum jail term. 

However, the game gets more interesting when played in repeated rounds because players who have been betrayed in one round have the chance to get their own back in the next iteration.

Until now, everyone thought the best strategy in iterative prisoner’s dilemma was to copy your opponents behaviour in the previous round. This tit-for-tat approach guarantees that you both spend the same time in jail.  

That conclusion was based on decades of computer simulations and a certain blind faith in the symmetry of the solution.  

So the news that there are other strategies that allow one player to not only beat the other but to determine their time in jail is nothing short of revolutionary. 

The new approach is called the zero determinant strategy (because it involves the process of setting a mathematical object called a determinant to zero). 

It turns out that the tit-for-tat approach is a special case of the zero determinant strategy: the player using this strategy determines that the other player’s time in jail is equal to theirs. But there are a whole set of other strategies that make the other player spend far more time in jail (or far less if you’re feeling generous).

The one caveat is that the other player must be unaware that they are being manipulated. If they discover the ruse, they can play a strategy that results in the maximum jail time for both players: ie both suffer.

Game theorists call this the Ultimatum Game. It’s equivalent to giving Alice £100 and asking her to divide it between her and Bob. Bob can accept the division or refuse it if he thinks the division is unfair, in which case both players get nothing. The refusal is Bob’s way of punishing Alice for her greed. 

The interesting thing here is that when both players are aware of the zero determinant ruse, the prisoner’s dilemma turns into a different game.

Press and Dyson’s discovery has sent game theorists scurrying to work out the implications. They’ve been using prisoner’s dilemma to gain insight into everything from Cold War politics and climate change negotiations to psychology and, of course, the evolutionary origin of co-operation itself. 

Today, we see one of the first paper’s to study these implications in detail. Christoph Adami and Arend Hintze from Michigan State University in East Lansing investigate whether the zero determinant strategies are evolutionary stable. 

That’s an interesting question. It asks the following: if an entire population of individuals all play zero determinant strategies, could another strategy spread through the population and take over? If not, zero determinant strategies are evolutionary stable.

Adami and Hintze show that zero determinant strategies are not evolutionary stable. The reason is that they do not perform well against each other and that leaves the door open for other strategies to sneak in and take over. 

Zero determinant strategies are not stable in another way. Adami and Hintze show that if the player’s strategies evolve, the changes that occur between one generation and the next ensure that the new strategy is generally not zero determinant. So the strategy cannot survive. 

However, there is one scenario in which Adami and Hintze say the new strategy should be stable. That’s when the zero determinant players can work out whether other players are using the same strategy or not. In that case, they can avoid the loses that occur when playing against their own while exploiting ignorant players. 

So to be stable, zero determinant strategies require additional information about their opponents.This information gives them a clear advantage but probably only a temporary one. “Such an advantage is bound to be short-lived as opposing strategies evolve to counteract the recognition,” they say. 

In other words, the other players ought to develop a kind of camouflage that prevents them being spotted and exploited.

That may explain why nobody’s found examples of zero determinant strategies in nature: in most cases they won’t be stable and even if they are, the situation is likely to be short lived. As Adami and Hintze put it in the title of their paper: winning isn’t everything.

That’s not to say there aren’t examples out there ready to be found. On the contrary. “This type of evolutionary arms race has been, and will be, observed throughout the biosphere,”  say Adami and Hintze. 

Of course, this is just the beginning of an entirely new approach to game theory that has profound implications. Suggestions for where it might have the most impact in the comments section please.

Read more: – isn’t everything: Evolutionary stability of Zero Determinant strategies

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August 16, 2012 at 5:24 pm

Posted in MATHEMATICS, Neuroscience

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Theory of Brain Function, Quantum Mechanics and Superstrings

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D. Nanopoulos

Psychological or Personality profile as a function of time, parametrized by different values of the MT-network synchordic collapse frequency γ (≡ 1/τc“Brain”), as indicated in (a) through (d)

Recent developments/efforts to understand aspects of the brain function at the subneural level are discussed.
MicroTubules (MTs), protein polymers constructing the cytoskeleton, participate in a wide variety of dynamical processes in the cell.
Of special interest to us is the MTs participation in bioinformation processes such as learning and memory, by possessing a well-known binary error-correcting code [K1(13, 26, 5)] with 64 words.
In fact, MTs and DNA/RNA are unique cell structures that possess a code system.
It seems that the MTs’ code system is strongly related to a kind of “Mental Code” in the following sense.
The MTs’ periodic paracrystalline structure make them able to support a superposition of coherent quantum states, as it has been recently conjectured by Hameroff and Penrose, representing an external or mental order, for sufficient time needed for efficient quantum computing.
Then the quantum superposition collapses spontaneously/dynamically through a new, stringderived mechanism for collapse proposed recently by Ellis, Mavromatos, and myself.
At the moment of collapse, organized quantum exocytosis occurs, i.e., the simultaneous emission of neurotransmitter molecules by the synaptic vesicles, embedded in the “firing zone” of the presynaptic vesicular grids.
Since in the superposition of the quantum states only those participate that are related to the “initial signal”, when collapse occurs, it only enhances the probability for “firing” of the relevant neurotransmitter molecules.
That is how a “mental order” may be translated into a “physiological action”.
Our equation for quantum collapse, tailored to the MT system, predicts that it takes 10,000 neurons O(1 sec) to dynamically collapse, in other words to process and imprint information.
Different observations/experiments and various schools of thought are in agreement with the above numbers concerning “conscious events”.
If indeed MTs, with their fine structure, vulnerable to our quantum collapse mechanism may be considered as the microsites of consciousness, then several, unexplained (at least to my knowledge) by traditional neuroscience, properties of consciousness/awareness, get easily explained, including “backward masking”, “referal backwards in time”, etc.
Furthermore, it is amusing to notice that the famous puzzle of why the left (right) part of the brain coordinates the right (left) part of the body, i.e., the signals travel maximal distance, is easily explained in our picture.
In order to have timely quantum collapse we need to excite as much relevant material as possible, thus signals have to travel the maximal possible distance.
The non-locality in the cerebral cortex of neurons related to particular missions, and the
related unitary sense of self as well as non-deterministic free will are consequences of
the basic principles of quantum mechanics, in sharp contrast to the “sticks and balls”
classical approach of conventional neural networks.
The proposed approach clearly belongs to the reductionist school since quantum physics is an integrated part of our physical world.
It is highly amazing that string black-hole dynamics that have led us to contemplate some modifications of standard quantum mechanics, such that the quantum collapse becomes a detailed dynamical mechanism instead of being an “external” ad-hoc process, may find some application to some quantum aspects of brain function.
It looks like a big universality principle is at work here, because both in the black hole and the brain we are struggling with the way information is processed, imprinted, and retrieved.

“…the Astonishing Hypothesis – that each of us is the behavior of a
vast, interacting set of neurons.” Francis Crick in The Astonishing Hypothesis

“…what will they think? – What I tell them to think.” Orson Welles in Citizen Kane

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November 20, 2011 at 12:20 pm

A brief history of the brain

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IT IS 30,000 years ago. A man enters a narrow cave in what is now the south of France. By the flickering light of a tallow lamp, he eases his way through to the furthest chamber. On one of the stone overhangs, he sketches in charcoal a picture of the head of a bison looming above a woman’s naked body.

In 1933, Pablo Picasso creates a strikingly similar image, calledMinotaur Assaulting Girl….. Read the rest of this entry »

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September 27, 2011 at 4:39 pm

Posted in BIOLOGY, Neuroscience

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Neuroscientists Find Famous Optical Illusion Surprisingly Potent

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The yellow jacket (Rocky, the mascot of the University of Rochester) appears to be expanding. But he is not. He is staying still. We simply think he is growing because our brains have adapted to the inward motion of the background and that has become our new status quo.

Similar situations arise constantly in our day-to-day lives — jump off a moving treadmill and everything around you seems to be in motion for a moment.

This age-old illusion, first documented by Aristotle, is called the Motion Aftereffect by today’s scientists. Why does it happen, though? Is it because we are consciously aware that the background is moving in one direction, causing our brains to shift their frame of reference so that we can ignore this motion? Or is it an automatic, subconscious response?

Davis Glasser, a doctoral student in the University of Rochester’s Department of Brain and Cognitive Sciences thinks he has found the answer. The results of a study done by Glasser, along with his advisor, Professor Duje Tadin, and colleagues James Tsui and Christopher Pack of the Montreal Neurological Institute, is published in the journal Proceedings of the National Academy of Sciences (PNAS).

In their paper, the scientists show that humans experience the Motion Aftereffect even if the motion that they see in the background is so brief that they can’t even tell whether it is heading to the right or the left.

Even when shown a video of a pattern that is moving for only 1/40 of a second (25 milliseconds) — so short that the direction it is moving cannot be consciously distinguished — a subject’s brain automatically adjusts. If the subject is then shown a stationary object, it will appear to him as though it is moving in the opposite direction of the background motion. In recordings from a motion center in the brain called cortical area MT, the researchers found neurons that, following a brief exposure to motion, respond to stationary objects as if they are actually moving. It is these neurons that the researchers think are responsible for the illusory motion of stationary objects that people see during the Motion Aftereffect.

This discovery reveals that the Motion Aftereffect illusion is not just a compelling visual oddity: It is caused by neural processes that happen essentially every time we see moving objects. The next phase of the group’s study will attempt to find out whether this rapid motion adaptation serves a beneficial purpose — in other words, does this rapid adaptation actually improve your ability to estimate the speed and direction of relevant moving objects, such as a baseball flying toward you.

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September 12, 2011 at 9:20 am

Posted in Neuroscience

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