Posts Tagged ‘brain

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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Stanford scientists create circuit board modeled on the human brain

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Stanford scientists have developed faster, more energy-efficient microchips based on the human brain – 9,000 times faster and using significantly less power than a typical PC. This offers greater possibilities for advances in robotics and a new way of understanding the brain. For instance, a chip as fast and efficient as the human brain could drive prosthetic limbs with the speed and complexity of our own actions.

Written by physicsgg

April 28, 2014 at 3:00 pm


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Analog And Digital Codes In The Brain

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Physicists have developed a technique that can tell which parts of the brain rely on analog signals and which rely on digital signals.
brainOne of the great debates in neuroscience is how neurons encode information that is sent to and from the brain. At issue is whether the information is sent in digital or analog form or indeed whether the brain can process both at the same time. That’s important because it can change the way we think about how the brain works.

But solving this question isn’t easy. The digital signals used by conventional computers are entirely different from the analog signals used in devices such as old-fashioned TVs and radios. That makes them easy to distinguish,

But the same can’t be said of neural signals, where digital and analog signals are hard to tell apart. So a useful step forward would be a way to distinguish between neural signals that are analog and those that are digital.

Today, Yasuhiro Mochizuki and Shigeru Shinomoto at Kyoto University in Japan say they’ve come up with just such a technique. And these guys have used it to distinguish between analog and digital signals in the brain for the first time.

Neuroscientists have long known that neurons carry signals in the form of electrical pulses that they call action potentials or spikes. A series of these is known as a spike train.

Exactly how information is encoded in a spike train isn’t known but researchers have discovered at least two different encoding protocols. In the 1990s, neuroscientists found that the way a muscle becomes tense is determined by the number of spikes in a given time interval, the rate which they arrive. This kind of signal is either on or off and so is clearly digital.

But other neuroscientists say that information can be encoded in another way–in the precise timings between single spikes as they arrive. This is analog encoding.

The difficulty is in telling these two apart since they both depend on the pattern of spikes that travel along a neuron. And that causes much dispute in the neuroscience community because nobody agrees on when a signal is analog or digital.

Now Mochizuki and Shinomoto have come up with a way to automatically distinguish between these types encoding. Their approach is based on the idea that some statistical models are better at representing digital codes than analog ones and vice versa.

For example, an approach known as empirical Bayes modelling is specifically designed to simulate analog signals. By contrast, hidden Markov modelling is particularly good at capturing the properties of digital codes.

Mochizuki and Shinomoto’s idea is to exploit the strengths of each method to determine whether a neuronal signal is digital or analog.

Their method is straightforward. They analyse a neuronal signal and then try to reproduce it using the empirical Bayes model and then using the hidden Markov model. They then decide whether it is digital or analog depending on the model that best simulates the characteristics of the original signal.

So if the empirical Bayes model best simulates the signal, it must be analog. And if the hidden Markov model triumphs then the signal must be digital.

These guys have tested their approach by analysing the signals produced in different parts of the brains of long-tailed macaques. And they say their approach indicates that different parts of the brain rely on different forms of encoding. “Fractions of neurons exhibiting analog and digital coding patterns differ between the three brain regions,” they say.

That’s an interesting discovery. If their method proves sound, it could finally help to settle the question of how the brain encodes information to do different tasks. And it could also help engineers build chips that can recreate these kinds of signals to make better interfaces between humans and machines and even to replace nerve function once it has been irreparably damaged.

There’s certainly more to come on this topic. But in the meantime, interesting stuff!

Ref: Analog And Digital Codes In The Brain


Written by physicsgg

November 27, 2013 at 5:11 pm


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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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Written by physicsgg

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 »

Written by physicsgg

September 27, 2011 at 4:39 pm

Posted in BIOLOGY, Neuroscience

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Mapping the most complex object in the known universe

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It’s paint-by-numbers for neuroscientists. At the Max-Planck Institute for Medical Research in Heidelberg, Germany, researchers have devised a faster way of computing the neural connections that make up the brain. Mapping out this intricate web previously depended on the human eye as no computer was powerful enough to handle the brain’s complex network of 70 billion neurons and thousands of kilometres of circuits. For this gargantuan task, even the smallest sliver of neural tissue was painstaking, demanding an experienced team to make modest progress.
Now with the help of two computer programs, Moritz Helmstaedter, Kevin Briggman and Winfried Denk have developed a faster and more accurate way of completing this neural cartography.
The first program, KNOSSOS – named after an ancient palace labyrinth in Crete – lets untrained users visualise and annotate 3D image data while the second, RESCOP summarises their work. In a test of this method, a team of 70 students created a detailed rendering of the connections between more than 100 retinal neurons in a mouse. Pictured above, the reconstruction outlines the dense bundles their projections form to receive input from photoreceptors.
The new programs could make the difficult but vital task of plotting out the brain’s neural circuitry possible.

Written by physicsgg

July 29, 2011 at 9:08 pm

Posted in Neuroscience

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Research finds how words are formed in the brain

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Scientists have discovered a way to watch words form in the human brain in a breakthrough that could one day allow those with severe disabilities to ‘speak’.
The researchers have found a way to peer into the deepest recesses of the brain in order to watch words forming.

Mind-reader: Researchers have found the signals the brain gives off as speech is formed - and it is hope that this could lead to scientists being able to translate thoughts into words

Using electrodes they found the area of the brain that is involved in creating the 40 or so sounds that form the English language.
They then discovered that each of these sounds has its own signal which they believe could eventually allow a computer programme to read what people want to say by the power of their thoughts.
The mind-reading research was undertaken by a team from the Centre for Innovation in Neuroscience and Technology at the University of Washington.
Led by its director, Eric Leuthardt, they studied four people who suffered from severe epilepsy who each had 64 electrodes implanted into their heads.
The original reason for this was an attempt to try to find the cause of their epilepsy but Leuthardt also monitored the areas of the brain where speech is formed.
The subjects were asked to make four repeated sounds – ‘oo’, ‘ah’, ‘eh’, and ‘ee’.
The team then monitored the Wenicke’s and Broca’s areas of the brain for signals related to speech formation.
The scientists were then able to pick out the corresponding electrical signals, and while these four signals will not be enough to form sentences, further research could lead to this becoming possible.
Leuthardt told the Sunday Times: ‘What it shows is that the brain is not the black box that we have philosophically assumed it to be for generations past.
‘I’m not going to say that I can fully read someone’s mind. I can’t. But I have evidence now that it is possible.’
During his study, Leuthardt also found that the brain generates a signal when people just think about the sounds – but it was very different to when they speak it.
This has led to the implication that doctors could one day read people’s private thoughts as well as what they want to say.
And it is hoped the research will one day give people with locked-in syndrome the chance to speak – as currently electrode treatment on the brain can be carried out those that are severely ill.
It could, in principal, also lead to technology that could read the mind without surgery – and even lead forms of communication which work only by thought.
The research was published in the Journal of Neural Engineering.

Written by physicsgg

May 30, 2011 at 1:21 pm

Posted in Neuroscience

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