QUESTO POST RIPORTA UN ARTICOLO DI ALTRI, AL SOLO SCOPO DI RIASSUMERE, BREVEMENTE, LE ATTUALI POSIZIONI SCIENCE OF NEUROSCIENCE, not taking into account the transmission between the unconscious. All this for the next preparatory POST THIRD SECRET OF FATIMA.
THE SITE: http://www.positanonews.it/index.php?page=dettaglio&id=23143
Thoughts in the words of Luigi Di Bianco
25/04/2009
THE HUMAN BRAIN AND ITS RELATIONSHIP WITH 'SOUL.
In my piece last week, I denied that there may be personal immortality because the brain and soul are so closely related that the death of the body, and thus the brain, leads, inevitably, even the death of the soul. To verify the intimate blood-brain In this article we will see how it's done with the brain and how it functions as cognitive / intellectual.
The study of the brain is a real challenge given the enormous complexity and mystery that surrounds this body central to our existence. Even Spinoza, in the seventeenth century, wrote: "[...] the human brain than in all the ingenuity of the human development of expertise."
What's really surprising is that simple cells can lead to thought, action and consciousness. Although there has been remarkable progress in knowledge of brain processes, it must be said that the neurobiology is nevertheless very far from a complete theory of consciousness. A solid base of knowledge has been gained, however, about how the brain works.
neurons, the basic unit of the brain, are produced during fetal life. During this phase, the body produces about 250 000 neurons per minute. But about a month before the birth, production stops and the brain begins a second phase that will last a lifetime: the creation of connections between cells. In this process, cells that fail the connections are eliminated, so that at the time of birth are already halved. The memory of neurons becomes impressive 30-40 from the years when, without replacing the body, brain cells begin to die at a rate of 100 000 per day about 1 per second. But if you are over 30/40 years is that you do not worry too much: luckily there is a corresponding decline in mental ability to create new connections preserves, in fact, to a certain point, the mental faculties acquired.
The neuron, this tiny cell that is the brick of the brain may be likened to a miniature computer that collects, processes and transfers information, or rather, nerve impulses.
Figure I shows the diagram of a neuron. Each neuron consists of a cell body, or soma, which contains the cell nucleus, or to continue the similarity with the computer processing unit central (CPU). The information processing unit comes along a large number of fibers called dendrites. Each dendrite is a port of entry. How many input ports are there for each neuron? There is no fixed number. Each neuron can have a variable number of dendrites that can vary from several hundred to several tens of thousands. In the drawing I have indicated only three doors at three input lines.
If you consider that a neuron may have tens of thousands of input ports can you account for the complexity of this tiny computer. Now imagine that these miniature computer, the brain there are about 100 billion! Yes, you read that right ... one hundred billion.
Where do the signals input? From the sensory cells, such as the retina of the eye, or, more frequently, from other neurons.
signals arrive at the micro-computer through the input ports (dendrites) and are processed by the central (cell body). If and only if, the Central Unit under certain conditions, then the cell body 'shoot', or sends a signal along the only line of output or output port. The line of output is a single long fiber called an axon. The axon extends a long distance, usually about an inch (one hundred times the diameter of the cell body) and up to one meter in extreme cases.
Where does the output signal along the axon? You may go to activate muscle cells or, more frequently, is applied as input to other neurons. Towards the end even the axon is divided into many branches. It happens so that a single signal output is not only a recipient but may involve tens or hundreds of neurons or muscle cells linked.
Normally a neuron fires a signal all-or-nothing, or, to put it in computer terms, a digital signal of value 1 or 0. But what needs to check the CPU to decide whether to shoot or not the output signal? Each neuron has a threshold of activation, if the activation level reaches the threshold, the neuron fires, the output signal. The level of activation of the neuron at a given time is determined by signals applied to the hundreds or thousands of ports of entry.
But it's not that simple! Each port has a filter that can amplify or attenuate the incoming signal. The filter is called the synapse (in my drawing I have indicated with the letters w1, w2, and w3). If there are 100 billion neurons and each neuron may have tens of thousands of input ports ... there are many synapses in the brain? ... An impressive number in the thousands of trillions.
The existence of these synapses was discovered by Charles Scott Sherrington, the great neurophysiologist, Nobel Prize 1932 for la medicina e la fisiologia. Le sinapsi non sono connessioni fisiche perché tra due neuroni s’interpone sempre una microscopica fessura. Per superare questo varco, i segnali si trasformano: da elettrici, diventano chimici. La terminazione dell’assone rilascia sostanze, dette neurotrasmettitori, che, saltata la fessura della sinapsi, sono raccolte dagli appositi recettori presenti sulla membrana della cellula-obiettivo. Catturato il neurotrasmettitore, il messaggio chimico viene riconvertito in impulso elettrico.
Per i nostri scopi, possiamo tralasciare la complicata reazione elettrochimica e vedere le sinapsi come un semplici filtri che amplificano o attenuano i segnali elettrici che vengono frapposti fra l’assone della cellula mittente and the dendrite of the receiving cell.
Back to my figure than before. To know the level of activation reached a certain point in the neuron in the figure to be calculated the formula: A = i1 * w1 + w2 + i2 * i3 * w3 where the value of 'w' is positive in the case of excitatory synapses and negative the inhibitory synapses. Well, think about it, even if it's thousands of synapses, the activation level of the neuron will be determined once and for all, from the result of a precise calculation. No way! The factor of amplification / attenuation of w1, w2, and w3 is not fixed. The synaptic connections exhibit, in fact, a certain plasticity, which may change the factor of amplification / attenuation of w1, w2, w3, and in response to certain patterns of stimulation. In other words, the brain is capable of shaping itself through the continuous remodeling of existing synapses and the creation of new synapses.
Your brain, my brain is not the same as it was only 1 second ago, it reshapes the time, every time we use it changes. Every single thought that passes through our minds change something in our brain's neural circuits.
We have already seen that two neurons to communicate, exchange chemicals that cause them to generate specific electrical impulses. Imagine repeating this process, millions, billions of times and you'll have an idea, albeit simplified, of the transfer of information (visual, acoustic ...) within the neural circuitry of the human brain.
hours Put together the individual pieces and try to imagine the 100 billion neurons, and the thousands of trillions of synapses connected together in a complex architecture of interconnections traveled continuously by electrochemical signals. At this point you can grasp the complexity of the architecture of the brain insane, this lump of matter amorphous, shapeless, slightly repulsive and too often underestimated (see Descartes).
But what this complex architecture? That report with the processes of learning, with the saving? The secret is stored in neuronal plasticity, cioè nella capacità delle sinapsi di modificare il fattore di amplificazione o di attenuazione di un segnale.
Vediamo un caso semplice. Immagina, per esempio, di cogliere un fiore mai visto prima e che qualcuno ti dica che il fiore in questione si chiama ‘fresia’ (in costiera amalfitana, dove crescono spontaneamente, le fresie dovrebbero essere già fiorite in questo periodo). Ti accorgi che questo fiore è caratterizzato da un profumo piacevolissimo e lo annusi varie volte. Questo tipo di informazione viaggerà dalla tua mucosa olfattiva (la parte interna del naso che "sente" gli odori), lungo il nervo olfattivo, fino alla parte della corteccia cerebrale organizzata per analizzare e comprendere i profumi. Nel fare ciò, information will observe a huge number of synapses, creating the equivalent of a "path" of neurons. From repeated experience, every time riannusi the flower, the information will travel back along the same path and also strengthened even more, just as the passage of many people on the snow creates a deeper groove in relation to the number of people they pass.
This process, called "facilitation" is the physical basis of the processes of learning and memory: when the information is passed many times through the same "path", ie the same sequence of synapses, the synapses themselves are so "Easier", for example, when you hear, after a certain time, the same pleasant fragrance, it will automatically combine the image of a flower called freesia. That's created a memory. I felt the scent of freesias as a child and still be able to recognize him with his eyes closed.
The same thing happened when, at school, trying to memorize a poem. Mentally repeating, again and again, a sequence of words is going to reinforce a certain neural pathway that also was easy to recall when it was questioned in the classroom. This mechanism also explains another little mystery: why, when we learned a poem, reciting it is so difficult starting from the second verse, and not from the beginning? Just because the whole store is part of a process "easy" end only the beginning you can go back without difficulty. This
learning theory was proposed for the first time by the Canadian psychologist Donald Olding Hebb who introduced what is still known as the "Hebb rule", or learning Hebb. According to this rule: "When a neuron is close enough (minimum synaptic cleft, note) to neuron B repeatedly to contribute in a lasting manner to his excitement, then takes place in both neurons a growth process or metabolic change that and the effectiveness of A B is increased in exciting. "
Obviously the process of learning is much more complex. The information to learn and memorize are characterized by different parameters (color, taste, sound, emotion, dimension, joy, sorrow ...) which, taken one by one, affecting different brain areas. The brain is in fact divided into hundreds of regions, each of which governs a specific function.
Every time we think, remember, speak, sing, run, smell or suffer, these areas are activated in a transversal way, through a process not yet elucidated the integration of individual aspects of reality. The greater mystery is how do the pieces scattered in various areas of the brain to recompose if necessary, in a few milliseconds, making the memory full resume. Easier, however, is to understand why some memories are lost (or be made to disappear voluntarily): Just the way that "facilitated" between synapses can not be obliterated or severely weakened, and the memory becomes inaccessible.
course, it is legitimate to think that learning is something more than the restructuring of a number of synapses ... but it is absolutely certain, there is substantial evidence that the neuronal plasticity without we would not be able to learn and remember.
So far I have tried to give an idea as simple as possible, the structure and functioning of the brain. Now provo a passare ad un argomento molto più controverso e ancora avvolto nel mistero. Ora “si tratta di capire come si passa dal cervello alla mente. Come si passa cioè dal corpo allo spirito”. (Edoardo Boncinelli)
Ecco qui, penserai, … ricompare lo spirito e la speranza di immortalità. Ma se pensi di poterti ancora aggrappare allo spirito a cui si riferisce Boncinelli per continuare ad illuderti di essere immortale … sorry … sei cascato male.
Il neuro-scienziato Antonio Damasio, portoghese operante negli USA, rappresenta una delle figure di maggior spicco a livello mondiale nel campo delle neuroscienze. Secondo Damasio, lo studio delle funzioni cognitive, e in particolare della coscienza, è stato long been neglected because of the philosophical tradition which, as you saw in my previous article on the soul, can be traced back to Descartes. Damasio, in 1994 he published the book "Descartes' Error" which explains how Descartes did not understand that nature has built the apparatus of rationality, self-awareness, not only above that to which the biological but also from it and within itself. For the record I note that Damasio, in 2003, has also published "Looking for Spinoza. Emotions, feelings, and brain. "
He reports the case of patients with damage in the prefrontal region that seem to have lost consciousness and the capacity to experience some of the most common emotions. These patients behave like zombies, are, that is, able to move and do things, but seem to have lost self-consciousness. In other words, these patients seem to have lost its soul.
While the structure and functioning of the brain we have made great strides, same can not be said for the study of cognitive functions, and in particular of consciousness. We must admit that it is still far from a theory of consciousness.
report here, however, the theory of consciousness proposed by Antonio Damasio.
consciousness, in the model Damasio, emerges from specific phenomena that occur in the neurons of the brain. Damasio uses terminology very special to present his theory. He introduces the word "movie-in-the-brain" or "film-in-head" to describe the brain's ability to create images of the world and one's body based on neural maps of the brain. The image of his body and his feelings is something called "proto-self" or "proto-self." Finally, he uses the term core-consciouness to define self-awareness or "autobiographical self."
I introduced above, the term 'neural map'. What is this strange thing? A neural map can be thought of as a set of addresses to specific memory locations in the brain. Wanting to make a similarity with the web pages of the web we can say that the map corresponds to the set of neuronal hyperlinks on the home page Positanonews. Clicking on the link or hyperlink jumps to another page with access to information of interest.
consciousness, according to Damasio, is to construct mental images, a movie in my head (movie-in-the-brain) generated by specific neural maps. Let's see how it works. In the film there are two main characters interacting.
The first figure, the body image (proto-self) and their feelings of the moment. Extrasensory abilities of this character are very limited: the only proof that sensations are those of the moment generated by the relationship interazione con il secondo personaggio del film. Il proto-sé ha scarsissima memoria: l'unico passato che possiede è quello, vago, relativo a ciò che è appena accaduto. Non sa fare previsioni per il futuro.
Il secondo personaggio del film è l’immagine di un qualsiasi oggetto del mondo esterno. ‘Oggetto’ qui deve intendersi in modo molto esteso. Può essere un’altra persona, una faccia, un auto, una melodia, un mal di denti, il ricordo di un fatto, ecc. Nel film-nella-testa i due personaggi interagiscono fra di loro in serie di reciproche azioni e reazioni.
Le immagini del proto-sé e dell’oggetto vengono generate da una mappa neuronale di primo livello che permette l’accesso a limited knowledge base of the brain. In the film we
then the two characters, proto-self and object, which interact with one another in terms of frame, but we do not have a mechanism to record the story of: a neural map of the first level is low. To record the history need to switch to a second level neural map managed by a third character, the "silent narrator."
He watches the film, notes and currency, in silence, the mutual actions and reactions of the two characters. It 'important to consider that the silent narrator has a neuronal map of the second level and is therefore able to access a wide base of knowledge brain, with all the memories, experiences, and especially the somatic markers.
I will not dwell here on the concept of somatic markers otherwise the article does not come to an end. Suffice it to say that the somatic markers recall the outcome, positive or negative, of similar encounters between proto-self and object.
The narrator contemplates the scene of the silent film but it is not a passive spectator, he, in addition to "think about thinking", the proto-self, may adopt measures, in accordance with its broader base of knowledge, to update the map neuronal first level and then adjust your attitude and feel of the proto-self in relation to the object. The narrator
silent non è quindi uno semplice spettatore del movie-in-the-brain. Egli stesso sta dentro un film generato dal cervello, o meglio è il protagonista principale del film dal titolo “il narratore che guarda il film dell'incontro fra proto-sé e oggetto”. Ma c'è di più, oltre a contemplare il film, il narratore silenzioso può modificare la storia del film che sta guardando.
La capacità del “narratore solitario” di contemplare le interazioni fra il proto-sé e il mondo e, nello stesso tempo, la sua facoltà di influenzare la storia del rapporto, costituisce, per Damasio, l’essenza della core-consciouness o coscienza di sé.
Rileggendo quest’ultima parte dell’articolo I realized that maybe the whole story of the movie-in-the-brain you will be very tight if not obscure. I think that phrases like "think about Thinking" and "the narrator watches the film of the encounter between self and proto-object" are not very happy, but I can not find anything better. Try making an extra effort of imagination. Just think, for example, a shoe box inside a shoe box bigger. The outer box is the "silent narrator," in the inner box are the proto-self el 'object. The two boxes together are the film-in-head generated by neuronal maps.
This is my personal interpretation of the Damasio's theory of consciousness. We have to do two assessments: the first is whether I've actually fully understood the theory of Damasio and the second is whether Damasio has hit the mark in developing his theory.
One thing is certain: to Damasio should certainly be credited with helping to bring the body into the scientific discussion on consciousness. The idea that the body is involved in conscious experience breaks sharply with a tradition that the mind quite distinct from the body and returns to consciousness itself the biological requirements necessary to make an object of scientific study.
In the next installment will try to attack the second illusion man considered one of the center ed il fine ultimo di tutto l’Universo.
A sabato prossimo!
Luigi Di Bianco
comments are welcomed ... ldibianco@alice.it
Il contenuto di questo articolo ed i relativi diritti sono di proprietà dell´autore.
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Riporto un articolo apparso sul Corriere della Sera il 25 giugno 2009
LA RICERCA
Cervello: «fotografato» un ricordo
Grazie a un'etichetta fluorescente confermati i meccanismi molecolari della memoria
L'incremento della fluorescenza (verde) fra le frecce gialle rappresenta il momento della formazione del ricordo (Science)
ROMA - Scattata la foto della formazione of a memory at the molecular level: a light switch at the level of synapses (the bridges of communication of neurons), American and Canadian scientists have observed in all stages of direct molecular 's engraving of a memory trace in the brain. Announced last week in the journal Science, the result is due to Wayne Sossin of the Montreal Neurological Institute and Hospital (The Neuro), McGill University, with experts from the University of California, Los Angeles.
FLUORESCENT LABEL - When a memory is formed at the level of the synapses that connect neurons and put in communication, there is a consolidation of the structure of the 'synaptic bridge' through the production of new proteins. A year ago, thanks to Gary Lynch of the University of California Irvine, in a paper published in the Journal of Neuroscience, the formation of a memory was immortalized for the first time by microscopic techniques in the brains of mice with a "close" on the reorganization of synapses . Now the group Sossin reiterated the company with a different method. With a fluorescent label that binds to the new proteins formed, Sossin showed that the level of synapses, immediately after the seizure of information by the brain, increases the fluorescence. This means, to further confirm what we already knew, that while we train and set a reminder, new proteins are produced in the synapses and thanks to such that the synapse is strengthened and the memory remains fixed in the brain long term.
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