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Tero Toivanen

AK's Rambling Thoughts: Nerve Cells and Glial Cells: Redefining the Foundation of Intel... - 0 views

artksthoughts.blogspot.com/...nd-glial-cells-redefining.html

brain Glial Cells neuron action potential axon synapse network microglia macroglia astrocytes oligodendrocytes ependymal cells radial glia

shared by Tero Toivanen on 25 Jun 09 - Cached
  • Glia are generally divided into two broad classes, microglia and macroglia. Microglia are part of the immune system, specialized macrophages, and probably don't participate in information handling. Macroglia are present in both the peripheral and central nervous systems, in different types.
  • Traditionally, there were four types of glia in the CNS: astrocytes, oligodendrocytes, ependymal cells, and radial glia. Of these, the one type that's most important to the developing revolution in our ideas are those cells called astrocytes.2 It turns out that there are at least two types of cell (at least) subsumed under this name.24, 25, 31, 32 One, which retains the name of astrocyte, takes up neurotransmitters released by neurons (and glial cells), aids in osmoregulation,10 controls circulation in the brain,1, 31 and generally appears to provide support for the neurons and other types of glia.
  • Although both NG2-glia and astrocytes extend processes to nodes of Ranvier in white matter ([refs]) and synapses in grey matter, their geometric relationship to these neuronal elements is different. Thus, although astrocytes and NG2-glia bear a superficial resemblance, they are distinguished by their different process arborizations. This will reflect fundamental differences in the way these two glial cell populations interact with other elements in the neural network.
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  • Both types of glia are closely integrated with the nervous system, receiving information from action potentials via synapses22 (which, only a few years ago were thought to be limited to neurons), and returning control of neuron activity through release of neurotransmitters and other modulators. Both, then, demonstrate the potential for considerable intelligent activity, contributing to the overall intelligence of the brain.
  • Astrocytes probably (IMO) are limited, or mostly so, to maintaining the supplies of energy and necessary metabolites. They receive action potentials,3, 6 which allows them to closely and quickly monitor general activity and increase circulation in response, even before the neurons and NG2-glia have reduced their supply of ATP.21 They appear to be linked in a network among themselves,2, 5 allowing them to communicate their needs without interfering with the higher-level calculations of the brain.
  • NG2-glia appear to have several functions, but one of the most exciting things about them is that they seem to be able to fire action potentials.33 Their cell membranes, like those of the dendrites of neurons, have all the necessary channels and receptors to perform real-time electrical calculations in the same way as neural dendrites. They have also demonstrated the ability to learn through long term potentiation.
  • Dividing NG2-glia also retain the ability to fire action potentials, as well as receiving synaptic inputs from neurons.23 Presumably, they continue to perform their full function, including retaining any elements of long term potentiation or depression contained in their synapses.
  • Oligodendrocytes are responsible for the insulation of the axons, wrapping around approximately 1 mm of each of up to 50 axons within their reach, and forming the myelin sheath.
  • Although the precise type of neuron formed by maturing cells hasn't been determined, the very fact that cells of this type can change into neurons is very important. We actually don't know whether the cells that do this maturation are the same as those that perform neuron-like activities, there appear to be two separate types of NG2-glia, spiking and non-spiking.26 It may very well be that the "spiking" type have actually differentiated, while the "non-spiking" type may be doing the maturing. Of course, very few differentiated cell types remain capable of division, as even the "spiking" type do.
  • What's important about both dendrites and NG2-glia isn't so much their ability to propagate action potentials, as that their entire cell membranes are capable of "intelligent" manipulation of the voltage across it.
  • While there are many ion channels involved in controlling the voltage across the cell membrane, the only type we really need to worry about for action potentials is voltage-gated sodium channels. These are channels that sometimes allow sodium ions to pass through the cell membrane, which they will do because the concentration of sodium ions outside the cell is very much higher than inside. When and how much they open depends, among other things, on the voltage across the membrane.
  • A normal neuron will have a voltage of around -60 to -80mV (millivolts), in a direction that tends to push the sodium ions (which are positive) into the cell (the same direction as the concentration is pushing). When the voltage falls to around -55mV, the primary type of gate will open for a millisecond or so, after which it will close and rest for several milliseconds. It won't be able to open again until the voltage is somewhere between -55 and around -10mV. Meanwhile, the sodium current has caused the voltage to swing past zero to around +20mV.
  • When one part of the cell membrane is "depolarized" in this fashion, the voltage near it is also depressed. Thus, if the voltage is at zero at one point, it might be at -20mV 10 microns (μm) away, and -40mV 20μm away, and -60mV 30μm, and so on. Notice that somewhere between 20μm and 30μm, it has passed the threshold for the ion channels, which means that they are open, allowing a current that drives the voltage further down. This will produce a wave of voltage drop along the membrane, which is what the action potential is.
  • After the action potential has passed, and the gates have closed (see above), the voltage is recovered by diffusion of ions towards and away from the membrane, the opening of other gates (primarily potassium), and a set of pumps that push the ions back to their resting state. These pumps are mostly powered by the sodium gradient, except for the sodium/potassium pump that maintains it, which is powered by ATP.
  • the vast majority of calculation that goes into human intelligence takes place at the level of the network of dendrites and NG2-glia, with the whole system of axons, dendrites, and action potentials only carrying a tiny subset of the total information over long distances. This is especially important considering that the human brain has a much higher proportion of glial matter than our relatives.
  • This, in turn, suggests that our overall approach to understanding the brain has been far too axon centric, there needs to be a shift to a more membrane-centric approach to understanding how the brain creates intelligence.
  • Tero Toivanen on 25 Jun 09
     
    Our traditional idea of how the brain works is based on the neuron: it fires action potentials, which travel along the axon and, when the reach the synapses, the receiving neuron performs a calculation that results in the decision when (or whether) to fire its own action potential. Thus, the brain, from a thinking point of view, is viewed as a network of neurons each performing its own calculation. This view, which I'm going to call the axon-centric view, is simplistic in many ways, and two recent papers add to it, pointing up the ways in which the glial cells of the brain participate in ongoing calculation as well as performing their more traditional support functions.
Ruth Howard

You won't find consciousness in the brain - opinion - 07 January 2010 - New Scientist - 0 views

www.newscientist.com/...onsciousness-in-the-brain.html

consciousness brain neuroscience neurons

shared by Ruth Howard on 25 Mar 10 - Cached
  • MOST neuroscientists, philosophers of the mind and science journalists feel the time is near when we will be able to explain the mystery of human consciousness in terms of the activity of the brain. There is, however, a vocal minority of neurosceptics who contest this orthodoxy.
  • This may well happen, but my argument is not about technical, probably temporary, limitations.
  • It is about the deep philosophical confusion embedded in the assumption that if you can correlate neural activity with consciousness, then you have demonstrated they are one and the same thing, and that a physical science such as neurophysiology is able to show what consciousness truly is.
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  • While neural activity of a certain kind is a necessary condition for every manifestation of consciousness, from the lightest sensation to the most exquisitely constructed sense of self, it is neither a sufficient condition of it, nor, still less, is it identical with it.
  • Many features of ordinary consciousness also resist neurological explanation.
  • There is nothing in the convergence or coherence of neural pathways that gives us this "merging without mushing", this ability to see things as both whole and separate.
  • Then their "appearings" will depend on the viewpoint of the conscious observer.
  • Thus measurement takes us further from experience and the phenomena of subjective consciousness to a realm where things are described in abstract but quantitative terms. To do its work, physical science has to discard "secondary qualities", such as colour, warmth or cold, taste - in short, the basic contents of consciousness. For the physicist then, light is not in itself bright or colourful, it is a mixture of vibrations in an electromagnetic field of different frequencies. The material world, far from being the noisy, colourful, smelly place we live in, is colourless, silent, full of odourless molecules, atoms, particles, whose nature and behaviour is best described mathematically. In short, physical science is about the marginalisation, or even the disappearance, of phenomenal appearance/qualia, the redness of red wine or the smell of a smelly dog.
  • Consciousness, on the other hand, is all about phenomenal appearances/qualia.
  • There is nothing in physical science that can explain why a physical object such as a brain should ascribe appearances/qualia to material objects that do not intrinsically have them.
  • This concerns the disjunction between the objects of science and the contents of consciousness. Science begins when we escape our subjective, first-person experiences into objective measurement, and reach towards a vantage point the philosopher Thomas Nagel called "the view from nowhere".
  • Material objects require consciousness in order to "appear".
  • Our failure to explain consciousness in terms of neural activity inside the brain inside the skull is not due to technical limitations which can be overcome. It is due to the self-contradictory nature of the task, of which the failure to explain "aboutness", the unity and multiplicity of our awareness, the explicit presence of the past, the initiation of actions, the construction of self are just symptoms.
David McGavock

How Did Consciousness Evolve? - The Atlantic - 0 views

www.theatlantic.com/...485558

research Consciousness Evolution

shared by David McGavock on 12 Jun 16 - No Cached
  • consciousness, is rarely studied in the context of evolution.
  • What is the adaptive value of consciousness? When did it evolve and what animals have it?
  • Attention Schema Theory (AST),
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  • suggests that consciousness arises as a solution to one of the most fundamental problems facing any nervous system: Too much information constantly flows in to be fully processed. The brain evolved increasingly sophisticated mechanisms for deeply processing a few select signals at the expense of others,
  • The next evolutionary advance was a centralized controller for attention that could coordinate among all senses. In many animals, that central controller is a brain area called the tectum
  • It coordinates something called overt attention
  • The tectum is a beautiful piece of engineering. To control the head and the eyes efficiently, it constructs something called an internal model, a feature well known to engineers. An internal model is a simulation that keeps track of whatever is being controlled and allows for predictions and planning.
  • With the evolution of reptiles around 350 to 300 million years ago, a new brain structure began to emerge – the wulst
  • our version is usually called the cerebral cortex and has expanded enormously
  • The cortex is like an upgraded tectum
  • The most important difference between the cortex and the tectum may be the kind of attention they control
  • tectum is the master of overt attention—pointing the sensory apparatus toward anything important
  • cortex ups the ante with something called covert attention
  • Your cortex can shift covert attention from the text in front of you to a nearby person, to the sounds in your backyard, to a thought or a memory. Covert attention is the virtual movement of deep processing from one item to another.
  • the cortex must model something much more abstract.
  • it does so by constructing an attention schema
  • a constantly updated set of information that describes what covert attention is doing moment-by-moment and what its consequences are
  • The attention schema is therefore strategically vague. It depicts covert attention in a physically incoherent way, as a non-physical essence. And this, according to the theory, is the origin of consciousness. We say we have consciousness because deep in the brain, something quite primitive is computing that semi-magical self-description.
  • In the AST, the attention schema first evolved as a model of one’s own covert attention. But once the basic mechanism was in place, according to the theory, it was further adapted to model the attentional states of others, to allow for social prediction
  • theory of mind, the ability to understand the possible contents of someone else’s mind.
  • Language is perhaps the most recent big leap in the evolution of consciousness. Nobody knows when human language first evolved. Certainly we had it by 70 thousand years ago when people began to disperse around the world, since all dispersed groups have a sophisticated language.
  • Maybe partly because of language and culture, humans have a hair-trigger tendency to attribute consciousness to everything around us.
  • Justin Barrett called it the Hyperactive Agency Detection Device, or HADD
  • David McGavock on 12 Jun 16
     
    The Attention Schema Theory (AST), developed over the past five years, may be able to answer those questions. The theory suggests that consciousness arises as a solution to one of the most fundamental problems facing any nervous system: Too much information constantly flows in to be fully processed. The brain evolved increasingly sophisticated mechanisms for deeply processing a few select signals at the expense of others, and in the AST, consciousness is the ultimate result of that evolutionary sequence. If the theory is right-and that has yet to be determined-then consciousness evolved gradually over the past half billion years and is present in a range of vertebrate species.
Tero Toivanen

The five ages of the brain: Adolescence - life - 04 April 2009 - New Scientist - 0 views

www.newscientist.com/...-of-the-brain-adolescence.html

Adolescence brain scanning grey-matter neural connections prefrontal cortex white matter

shared by Tero Toivanen on 21 Jun 09 - Cached
  • Jay Giedd at the National Institute of Mental Health in Bethesda, Maryland, and his colleagues have followed the progress of nearly 400 children, scanning many of them every two years as they grew up. They found that adolescence brings waves of grey-matter pruning, with teens losing about 1 per cent of their grey matter every year until their early 20s (Nature Neuroscience, vol 2, p 861).
  • This cerebral pruning trims unused neural connections that were overproduced in the childhood growth spurt, starting with the more basic sensory and motor areas.
  • Among the last to mature is the dorsolateral prefrontal cortex at the very front of the frontal lobe. This area is involved in control of impulses, judgement and decision-making, which might explain some of the less-than-stellar decisions made by your average teen. This area also acts to control and process emotional information sent from the amygdala - the fight or flight centre of gut reactions - which may account for the mercurial tempers of adolescents.
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  • As grey matter is lost, though, the brain gains white matter
  • These changes have both benefits and pitfalls. At this stage of life the brain is still childishly flexible, so we are still sponges for learning. On the other hand, the lack of impulse control may lead to risky behaviours such as drug and alcohol abuse, smoking and unprotected sex.
  • Substance abuse is particularly concerning, as brain imaging studies suggest that the motivation and reward circuitry in teen brains makes them almost hard-wired for addiction.
  • since drug abuse and stressful events - even a broken heart - have been linked to mood disorders later in life, this is the time when both are best avoided.
  • Making the most of this time is a matter of throwing all that teen energy into learning and new experiences - whether that means hitting the books, learning to express themselves through music or art, or exploring life by travelling the world.
  • Tero Toivanen on 21 Jun 09
     
    Jay Giedd at the National Institute of Mental Health in Bethesda, Maryland, and his colleagues have followed the progress of nearly 400 children, scanning many of them every two years as they grew up. They found that adolescence brings waves of grey-matter pruning, with teens losing about 1 per cent of their grey matter every year until their early 20s (Nature Neuroscience, vol 2, p 861).
David McGavock

Scientific Understanding of Consciousness - 0 views

willcov.com/bio-consciousness

understanding consciousness experts writers summary

shared by David McGavock on 02 Mar 14 - No Cached
  • During the past 20 years or so, biological sciences have advanced to the point that scientists have begun researching biological mechanisms of brain function and suggesting some reasonably well-founded hypotheses for consciousness. Leading the way in these pioneering efforts, in my judgment, have been:   Gerald Edelman with his hypothesis of the Dynamic Core, Antonio Damasio with his concepts of  Protoself, Core Self, Autobiographical Self, Core Consciousness and Extended Consciousness, Joseph LeDoux and his emphasis on the intricacies of synapses and the emotional brain,
  • Rudolfo Llinás and his researches into ~40 Hz oscillations and synchronization, György Buzsáki with his discussion and exploration of neural mechanisms related to oscillation and synchronization in the neocortex and hippocampus for perception and memory, Joaquín Fuster, the world’s preeminent expert on the frontal lobes, and his concept of the "perception-action cycle," Susan Greenfield's notion of "neuronal gestalts" as a way of conceptualizing a highly variable aggregation of neurons that is temporarily recruited around a triggering epicenter. I use the neuronal gestalts idea in my way of visualizing the functionality of the dynamic core of the thalamocortical system, Eric Kandel who has explored short-term and long-term memory,
  • The late Francis Crick with his collaborator Christof Koch who have pursued the neural correlate of consciousness (NCC), Michael Gazzaniga with the concept of the left hemisphere ‘interpreter’ unifying consciousness experience, Edmund Rolls and Gustavo Deco with their mathematical models of brain function using information theory approaches for biologically plausible neurodynamical modeling of cognitive phenomena corroborated by brain imaging studies, David LaBerge with his discussion of the thalamocortical circuit and attention, Alan Baddeley who continues to refine his model for working memory, Philosopher John Searle who endorses the idea that consciousness is an emergent property of neural networks.
  • David McGavock on 02 Mar 14
     
    "My objective in this website has been to bring together salient features of these assorted interpretations by science experts into a synthesis of my own understanding of consciousness. I consider these statements and interpretations to be a framework on which to build a fuller understanding as further data, concepts and insights develop from ongoing research."
Tero Toivanen

Sign language study shows multiple brain regions wired for language - 1 views

www.eurekalert.org/...uor-sls042910.php

sign language study language brain University of Rochester language capabilities

shared by Tero Toivanen on 30 Apr 10 - Cached
  • A new study from the University of Rochester finds that there is no single advanced area of the human brain that gives it language capabilities above and beyond those of any other animal species.
  • Instead, humans rely on several regions of the brain, each designed to accomplish different primitive tasks, in order to make sense of a sentence.
  • "We're using and adapting the machinery we already have in our brains," said study coauthor Aaron Newman. "Obviously we're doing something different [from other animals], because we're able to learn language unlike any other species. But it's not because some little black box evolved specially in our brain that does only language, and nothing else."
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  • The team of brain and cognitive scientists
  • published their findings in the latest edition of the journal Proceedings of the National Academies of Sciences.
  • The study found that there are, in fact, distinct regions of the brain that are used to process the two types of sentences: those in which word order determined the relationships between the sentence elements, and those in which inflection was providing the information.
  • In fact, Newman said, in trying to understand different types of grammar, humans draw on regions of the brain that are designed to accomplish primitive tasks that relate to the type of sentence they are trying to interpret. For instance, a word order sentence draws on parts of the frontal cortex that give humans the ability to put information into sequences, while an inflectional sentence draws on parts of the temporal lobe that specialize in dividing information into its constituent parts, the study demonstrated.
  • Tero Toivanen on 30 Apr 10
     
    A new study from the University of Rochester finds that there is no single advanced area of the human brain that gives it language capabilities above and beyond those of any other animal species.
Tero Toivanen

Wired 14.02: Buddha on the Brain - 0 views

www.wired.com/...dalai.html

brain meditation Dalai Lama Buddha buddhism Tibet neuroscience

shared by Tero Toivanen on 28 Jun 09 - Cached
  • Davidson's research created a stir among brain scientists when his results suggested that, in the course of meditating for tens of thousands of hours, the monks had actually altered the structure and function of their brains.
  • Lutz asked Ricard to meditate on "unconditional loving-kindness and compassion." He immediately noticed powerful gamma activity - brain waves oscillating at roughly 40 cycles per second -�indicating intensely focused thought. Gamma waves are usually weak and difficult to see. Those emanating from Ricard were easily visible, even in the raw EEG output. Moreover, oscillations from various parts of the cortex were synchronized - a phenomenon that sometimes occurs in patients under anesthesia.
  • In the traditional view, the brain becomes frozen with the onset of adulthood, after which few new connections form. In the past 20 years, though, scientists have discovered that intensive training can make a difference. For instance, the portion of the brain that corresponds to a string musician's fingering hand grows larger than the part that governs the bow hand - even in musicians who start playing as adults. Davidson's work suggested this potential might extend to emotional centers
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  • The researchers had never seen anything like it. Worried that something might be wrong with their equipment or methods, they brought in more monks, as well as a control group of college students inexperienced in meditation. The monks produced gamma waves that were 30 times as strong as the students'. In addition, larger areas of the meditators' brains were active, particularly in the left prefrontal cortex, the part of the brain responsible for positive emotions.
  • But Davidson saw something more. The monks had responded to the request to meditate on compassion by generating remarkable brain waves. Perhaps these signals indicated that the meditators had attained an intensely compassionate state of mind. If so, then maybe compassion could be exercised like a muscle; with the right training, people could bulk up their empathy. And if meditation could enhance the brain's ability to produce "attention and affective processes" - emotions, in the technical language of Davidson's study - it might also be used to modify maladaptive emotional responses like depression.
  • Davidson and his team published their findings in the Proceedings of the National Academy of Sciences in November 2004. The research made The Wall Street Journal, and Davidson instantly became a celebrity scientist.
  • Tero Toivanen on 28 Jun 09
     
    Davidson's research created a stir among brain scientists when his results suggested that, in the course of meditating for tens of thousands of hours, the monks had actually altered the structure and function of their brains
Tero Toivanen

New Light On Nature Of Broca's Area: Rare Procedure Documents How Human Brain Computes ... - 0 views

www.sciencedaily.com/...091015141500.htm

brain Broca's area Wernicke's area language cerebral cortex Sahin

shared by Tero Toivanen on 17 Oct 09 - Cached
  • The study – which provides a picture of language processing in the brain with unprecedented clarity – will be published in the October 16 issue of the journal Science.
  • "Two central mysteries of human brain function are addressed in this study: one, the way in which higher cognitive processes such as language are implemented in the brain and, two, the nature of what is perhaps the best-known region of the cerebral cortex, called Broca's area," said first author Ned T. Sahin, PhD, post-doctoral fellow in the UCSD Department of Radiology and Harvard University Department of Psychology.
  • The study demonstrates that a small piece of the brain can compute three different things at different times – within a quarter of a second – and shows that Broca's area doesn't just do one thing when processing language.
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  • The procedure, called Intra-Cranial Electrophysiology (ICE), allowed the researchers to resolve brain activity related to language with spatial accuracy down to the millimeter and temporal accuracy down to the millisecond.
  • "We showed that distinct linguistic processes are computed within small regions of Broca's area, separated in time and partially overlapping in space," said Sahin. Specifically, the researchers found patterns of neuronal activity indicating lexical, grammatical and articulatory computations at roughly 200, 320 and 450 milliseconds after the target word was presented. These patterns were identical across nouns and verbs and consistent across patients.
  • Tero Toivanen on 17 Oct 09
     
    "Two central mysteries of human brain function are addressed in this study: one, the way in which higher cognitive processes such as language are implemented in the brain and, two, the nature of what is perhaps the best-known region of the cerebral cortex, called Broca's area," said first author Ned T. Sahin, PhD, post-doctoral fellow in the UCSD Department of Radiology and Harvard University Department of Psychology.
Tero Toivanen

Visual training to retain driving competence - and your independence! | On the Brain by... - 1 views

merzenich.positscience.com/?p=250

brain visual training automobile drivers DriveSharp merzenich

shared by Tero Toivanen on 19 Jul 09 - Cached
  • Today, Posit Science announced the release of a new computer-based visual training tool, DriveSharp, specifically designed to improve the performance abilities of adult automobile drivers to a degree that can be expected to very substantially impact their driving safety.
  • Again, with a few hours of intensive training, a youthful MOT performance level can be achieved for most individuals. The result: A still FURTHER increase of driving safety.
  • In our fast-moving world, losing control of one’s peripheral vision is a main cause of driving accidents.
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  • Ball and Roenker demonstrated that these losses are substantially reversible, through appropriate, intensive training, in almost all older drivers. UFOVs can be re-expanded to relatively youthful ability levels through only a few hours of exercise. The result: About 50% fewer driving accidents in the over-65 population.
  • Moreover, once your UFOV is opened up again, you use it!
  • You can use DriveSharp repeatedly, over the rest of your days, to keep yourself in fine driving fettle!
  • The second training program that is included in DriveSharp is designed to improve your ability to keep track of more than one thing happening at the same time. This fundamental visual skill — called “multiple object tracking” (MOT) — also dramatically declines as you get older.
  • As you get older, you progressively lose the ability to accurately detect and respond to visual events in your far visual periphery.
  • If you’ve reached your 50th birthday, DriveSharp training is especially important for upgrading and sustaining your driving competence. It’s all about maintaining your performance abilities in driving as in all other ways at the highest possible level, throughout the second half of life.
  • few other benefits demonstrated by published studies originating with the Ball/Roenker team (including University of South Florida scientist Sherri Willis and a University of Iowa scientist, Fred Wolinsky).
  • 1) You’re healthier after DriveSharp training! Five years after training, Physical indices of Quality of Life are more than 30% higher — maybe because you get out more.
  • Trainees are much more likely to have retained your driver’s license — and to have sustained their personal independence.
  • After DriveSharp, you are a more confident driver, as expressed by gains in the number of times you drive each week, by an increase in average driving distances, and by your driving more often at night, or in the rain or snow.
  • Try DriveSharp now: If you are a member of one of the participating AAA clubs, please visit your AAA club’s website for more information and a special offer on DriveSharp. If not, please visit www.DriveSharp.com or call (866)599-6463 to learn more.
  • Tero Toivanen on 19 Jul 09
     
    Today, Posit Science announced the release of a new computer-based visual training tool, DriveSharp, specifically designed to improve the performance abilities of adult automobile drivers to a degree that can be expected to very substantially impact their driving safety.
Tero Toivanen

Map of Synapse May Help Understand Basis of Many Diseases - NYTimes.com - 3 views

www.nytimes.com/...21brain.html

synapse map brain research neuroscience neurons science

shared by Tero Toivanen on 22 Dec 10 - No Cached
  • The research team, led by Seth Grant of the Sanger Institute near Cambridge, England, compiled the first exact inventory of all the protein components of the synaptic information-processing machinery. No fewer than 1,461 proteins are involved in this biological machinery, they report in the current issue of Nature Neuroscience.
  • Each neuron in the human brain makes an average 1,000 or so connections with other neurons. There are 100 billion neurons, so the brain probably contains 100 trillion synapses, its most critical working part.
  • The 1,461 genes that specify these synaptic proteins constitute more than 7 percent of the human genome’s 20,000 protein-coding genes, an indication of the synapse’s complexity and importance.
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  • Dr. Grant believes that the proteins are probably linked together to form several biological machines that process the information and change the physical properties of the neuron as a way of laying down a memory.
  • The new catalog of synaptic proteins “should open a major new window in mental disease,” said Jeffrey Noebels, an expert on the genetics of epilepsy at the Baylor College of Medicine. “We can go in there and systematically look for disease pathways and therefore druggable targets.”
  • Tero Toivanen on 22 Dec 10
     
    The research team, led by Seth Grant of the Sanger Institute near Cambridge, England, compiled the first exact inventory of all the protein components of the synaptic information-processing machinery. No fewer than 1,461 proteins are involved in this biological machinery
  • Ruth Howard on 26 Dec 10
     
    Seeing mental health as a druggable target is psychotic...
Tero Toivanen

NIMH · Our brains are made of the same stuff, despite DNA differences - 0 views

www.nimh.nih.gov/...-despite-dna-differences.shtml

nimh brains dna differences gene prefrontal cortex schizophrenia autism research study genetic variation neuroscience neurons

shared by Tero Toivanen on 30 Oct 11 - No Cached
  • “Having at our fingertips detailed information about when and where specific gene products are expressed in the brain brings new hope for understanding how this process can go awry in schizophrenia, autism and other brain disorders,” said NIMH Director Thomas R. Insel, M.D.
  • Among key findings in the prefrontal cortex:Individual genetic variations are profoundly linked to expression patterns. The most similarity across individuals is detected early in development and again as we approach the end of life.Different types of related genes are expressed during prenatal development, infancy, and childhood, so that each of these stages shows a relatively distinct transcriptional identity. Three-fourths of genes reverse their direction of expression after birth, with most switching from on to off.Expression of genes involved in cell division declines prenatally and in infancy, while expression of genes important for making synapses, or connections between brain cells, increases. In contrast, genes required for neuronal projections decline after birth – likely as unused connections are pruned.By the time we reach our 50s, overall gene expression begins to increase, mirroring the sharp reversal of fetal expression changes that occur in infancy.Genetic variation in the genome as a whole showed no effect on variation in the transcriptome as a whole, despite how genetically distant individuals might be. Hence, human cortexes have a consistent molecular architecture, despite our diversity.
  • Among key findings:Over 90 percent of the genes expressed in the brain are differentially regulated across brain regions and/or over developmental time periods. There are also widespread differences across region and time periods in the combination of a gene’s exons that are expressed.Timing and location are far more influential in regulating gene expression than gender, ethnicity or individual variation.Among 29 modules of co-expressed genes identified, each had distinct expression patterns and represented different biological processes. Genetic variation in some of the most well-connected genes in these modules, called hub genes, has previously been linked to mental disorders, including schizophrenia and depression.Telltale similarities in expression profiles with genes previously implicated in schizophrenia and autism are providing leads to discovery of other genes potentially involved in those disorders.Sex differences in the risk for certain mental disorders may be traceable to transcriptional mechanisms. More than three-fourths of 159 genes expressed differentially between the sexes were male-biased, most prenatally. Some genes found to have such sex-biased expression had previously been associated with disorders that affect males more than females, such as schizophrenia, Williams syndrome, and autism.
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  • Our brains are all made of the same stuff. Despite individual and ethnic genetic diversity, our prefrontal cortex shows a consistent molecular architecture.
  • Males show more sex-biased gene expression. More genes differentially expressed (DEX) between the sexes were found in males than females, especially prenatally. Some genes found to have such sex-biased expression had previously been associated with disorders that affect males more than females, such as schizophrenia, Williams syndrome, and autism.
  • Tero Toivanen on 30 Oct 11
     
    Our brains are all made of the same stuff. Despite individual and ethnic genetic diversity, our prefrontal cortex shows a consistent molecular architecture. 
Tero Toivanen

Autism Blog - Autism: Is it all about bigger brains? « Left Brain/Right Brain - 0 views

leftbrainrightbrain.co.uk/?p=3552&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+LeftBrain%2FrightBrain+%28Left+Brain%2FRight+Brain%29&utm_content=Google+Reader

autism brain research cell division Glial Cells minicolumns

shared by Tero Toivanen on 26 Dec 09 - Cached
  • in light of the increased cranial volumn and minicolumnar density in autism, more recent studies have begun targeting certain proteins and steroids called Growth Factors, which are in part intimately involved in neocortical expansion.
  • Basic Fibroblast Growth Factor (bFGF or FGF2) has particularly important implications in autism given its involvement in prolonging the period of cell division of the number of undifferentiated radial glial cells (cortical stem cells) which determine the total number of eventual minicolumns: the longer these radial glial divide, the greater the number of minicolumns, like that seen in autism.
  • It’s fascinating to think that while autism can undoubtedly provide for its share of handicap, these foundational elements may be “abnormal” only in the sense that they’re extremes of those things which make us most human.
  • Tero Toivanen on 26 Dec 09
     
    Basic Fibroblast Growth Factor (bFGF or FGF2) has particularly important implications in autism given its involvement in prolonging the period of cell division of the number of undifferentiated radial glial cells (cortical stem cells) which determine the total number of eventual minicolumns: the longer these radial glial divide, the greater the number of minicolumns, like that seen in autism.
Tero Toivanen

Use It or Lose It: The Principles of Brain Plasticity - 3 views

articles.mercola.com/...brain-plasticity.aspx

brain plasticity research learning neurons memory Use It or Lose It Brain Gym nutrition

shared by Tero Toivanen on 09 Dec 12 - No Cached
  • You probably haven't realizd it, but as you acquire an ability – for example, the ability to read – you have actually created a system in the brain that does not exist, that's not in place, in the non-reader. It [the ability; the brain system that controls the ability] actually evolves in you as it has been acquired through experience or learning.
  • "There are some very useful exercises at www.BrainHQ.com that are free, and using them can give a person a better understanding of how exercising your brain can drive it in a rejuvenating direction. Using exercises at BrainHQ, most people, of any age, can drive sharp improvements in brain speed and accuracy, and thereby rewire the brain so that it again represents information in detail," he says.
  • Children operating in the 10th to 20th percentile of academic performance are commonly able to improve their scores to the middle or average level with 20-30 hours of intensive computer-based training. "That's a big difference for the child," he says. "It carries most children who are near the bottom of the class, on the average, to be somewhere in the middle or above average in the class. And that gives struggling children a chance to really succeed and in many cases excel in school."
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  • Careful controlled studies in seniors have also been reported in scientific journals. After 40 hours of computer-based training, the average improvement in cognitive performance across the board was 14 years. On average, if you were 70 years old when you underwent the training after 40 hours of brain training, your cognitive abilities operated like that of a 56-year old. Equally strong or even greater effects were seen in 40 to 50 year olds using the program. Individuals who worked on the BrainHQ exercises at home did just as well as those who completed training in a clinic or research center.
  • Ideally, it would be wise to invest at least 20 minutes a day. But no more than five to seven minutes is to be spent on a specific task. When you spend longer amounts of time on a task, the benefits weaken. According to Dr. Merzenich, the primary benefits occur in the first five or six minutes of the task.
  • Find ways to engage yourself in new learning
  • "When it matters to you, you are going to drive changes in your brain," he explains. "That's something always to keep in mind. If what you're doing seems senseless, meaningless, if it does not matter to you, then you're gaining less from it."
  • Get 15-30 minutes of physical exercise each day,
  • Spend about five minutes every day working on the refinement of a specific, small domain of your physical body.
  • You can typically improve yourself to the highest practical or possible level in anywhere between five to a dozen brief sessions of seven or eight minutes each. Again, having a sense of purpose is crucial.
  • Stay socially engaged.
  • Practice "mindfulness,"
  • Foods have an immense impact on your brain, and eating whole foods as described in my nutrition plan will best support your mental and physical health.
  • The medical literature is also showing that coconut oil can be of particular benefit for brain health, and anecdotal evidence suggests it could be very beneficial in the treatment of Alzheimer's disease.
  • Optimize your vitamin D levels
  • Take a high-quality animal-based omega-3 fat.
  • Avoid processed foods and sugars, especially fructose
  • Avoid grains
  • Avoid artificial sweeteners
  • Avoid soy
  • Men who ate tofu at least twice weekly had more cognitive impairment, compared with those who rarely or never ate the soybean curd, and their cognitive test results were about equivalent to what they would have been if they were five years older than their current age.
  • Tero Toivanen on 09 Dec 12
     
    "It was once thought that any brain function lost was irretrievable. Today, research into what's referred to as "brain plasticity" has proven that this is not the case. On the contrary, your brain continues to make new neurons throughout life in response to mental activity."
Tero Toivanen

Tests find benefit of sleeping on job - Science, News - The Independent - 0 views

www.independent.co.uk/...f-sleeping-on-job-1700191.html

brain sleep REM problem solving

shared by Tero Toivanen on 09 Jun 09 - Cached
  • A type of dreamy sleep that occurs more frequently in the early morning is important for solving problems that cannot be easily answered during the day, a study has found.
  • The discovery could explain many anecdotal accounts of famous intellectuals who had wrestled with a problem only to find that they have solved it by the morning after a good night's sleep.
  • Scientists believe that a form of dreaming slumber called rapid-eye movement (REM) sleep, when the brain becomes relatively active and the eyes flicker from side to side under closed eyelids, plays a crucial role in subconscious problem solving.
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  • In a series of tests on nearly 80 people, the researchers found that REM sleep increases the chances of someone being able to successfully solve a new problem involving creative associations – finding an underlying pattern behind complex information.
  • Those people who had enjoyed REM sleep improved significantly, by about 40 per cent, while the other volunteers who had not had REM sleep showed little if any improvement, according to the study published in the journal Proceedings of the National Academy of Sciences.
  • The researchers suggest that it is not merely sleep itself, or the simple passage of time, that is important for the solving of a new problem, but the act of being able to fall into a state of REM sleep where the brain slips into a different kind of neural activity that encourages the formation of new nerve connections.
  • Tero Toivanen on 09 Jun 09
     
    A type of dreamy sleep that occurs more frequently in the early morning is important for solving problems that cannot be easily answered during the day, a study has found.
Tero Toivanen

Creativity and the Aging Brain | Psychology Today Blogs - 0 views

blogs.psychologytoday.com/...creativity-and-the-aging-brain

creativity aging brain

shared by Tero Toivanen on 23 May 09 - Cached
  • So instead of promoting retirement at age 65, perhaps we as a society should be promoting transition at age 65: transition into a creative field where our growing resource of individuals with aging brains can preserve their wisdom in culturally-valued works of art, music, or writing.
  • Numerous studies suggest that highly creative individuals also employ a broadened rather than focused state of attention. This state of widened attention allows the individual to have disparate bits of information in mind at the same time. Combining remote bits of information is the hallmark of the creative idea.
  • Other studies show that certain areas of the prefrontal cortex involved in self-conscious awareness and emotions are thinner in the aging brain. This may correlate with the diminished need to please and impress others, which is a notable characteristic of both aging individuals and creative luminaries.
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  • Finally, intelligence studies indicate that older individuals have access to an increasing store of knowledge gained over a lifetime of learning and experience. Combining bits of knowledge into novel and original ideas is what the creative brain is all about.
  • Tero Toivanen on 23 May 09
     
    The aging brain resembles the creative brain in several ways. For instance, the aging brain is more distractible and somewhat more disinhibited than the younger brain (so is the creative brain). Aging brains score better on tests of crystallized IQ (and creative brains use crystallized knowledge to make novel and original associations).
Tero Toivanen

Scientists capture the first image of memories being made - 0 views

www.eurekalert.org/...mu-sct061809.php

brain memory protein translation long-term memory proteins synapse synaptic connection learning synaptic plasticity post-synaptic cell neurons

shared by Tero Toivanen on 21 Jun 09 - Cached
  • A new study by researchers at the Montreal Neurological Institute and Hospital (The Neuro), McGill University and University of California, Los Angeles has captured an image for the first time of a mechanism, specifically protein translation, which underlies long-term memory formation. The finding provides the first visual evidence that when a new memory is formed new proteins are made locally at the synapse - the connection between nerve cells - increasing the strength of the synaptic connection and reinforcing the memory. The study published in Science, is important for understanding how memory traces are created and the ability to monitor it in real time will allow a detailed understanding of how memories are formed.
  • research has focused on synapses which are the main site of exchange and storage in the brain.
  • They form a vast but also constantly fluctuating network of connections whose ability to change and adapt, called synaptic plasticity, may be the fundamental basis of learning and memory.
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  • Using a translational reporter, a fluorescent protein that can be easily detected and tracked, we directly visualized the increased local translation, or protein synthesis, during memory formation.
  • Importantly, this translation was synapse-specific and it required activation of the post-synaptic cell, showing that this step required cooperation between the pre and post-synaptic compartments, the parts of the two neurons that meet at the synapse.
  • This study provides evidence that a mechanism that mediates this gene expression during neuronal plasticity involves regulated translation of localized mRNA at stimulated synapses.
  • Tero Toivanen on 21 Jun 09
     
    A new study by researchers at the Montreal Neurological Institute and Hospital (The Neuro), McGill University and University of California, Los Angeles has captured an image for the first time of a mechanism, specifically protein translation, which underlies long-term memory formation.
Tero Toivanen

First Evidence That Musical Training Affects Brain Development In Young Children - 0 views

www.sciencedaily.com/...060920093024.htm

music brain development young children brain development memory IQ Suzuki method MEG

shared by Tero Toivanen on 21 Jun 09 - Cached
  • The findings, published today (20 September 2006) in the online edition of the journal Brain [1], show that not only do the brains of musically-trained children respond to music in a different way to those of the untrained children, but also that the training improves their memory as well. After one year the musically trained children performed better in a memory test that is correlated with general intelligence skills such as literacy, verbal memory, visiospatial processing, mathematics and IQ.
  • Researchers have found the first evidence that young children who take music lessons show different brain development and improved memory over the course of a year compared to children who do not receive musical training.
  • While previous studies have shown that older children given music lessons had greater improvements in IQ scores than children given drama lessons, this is the first study to identify these effects in brain-based measurements in young children.
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  • The researchers chose children being trained by the Suzuki method for several reasons: it ensured the children were all trained in the same way, were not selected for training according to their initial musical talent and had similar support from their families. In addition, because there was no early training in reading music, the Suzuki method provided the researchers with a good model of how training in auditory, sensory and motor activities induces changes in the cortex of the brain.
  • Analysis of the MEG responses showed that across all children, larger responses were seen to the violin tones than to the white noise, indicating that more cortical resources were put to processing meaningful sounds. In addition, the time that it took for the brain to respond to the sounds (the latency of certain MEG components) decreased over the year. This means that as children matured, the electrical conduction between neurons in their brains worked faster.
  • Of most interest, the Suzuki children showed a greater change over the year in response to violin tones in an MEG component (N250m) related to attention and sound discrimination than did the children not taking music lessons.
  • Analysis of the music tasks showed greater improvement over the year in melody, harmony and rhythm processing in the children studying music compared to those not studying music. General memory capacity also improved more in the children studying music than in those not studying music.
  • The finding of very rapid maturation of the N250m component to violin sounds in children taking music lessons fits with their large improvement on the memory test. It suggests that musical training is having an effect on how the brain gets wired for general cognitive functioning related to memory and attention.
  • It is clear that music is good for children's cognitive development and that music should be part of the pre-school and primary school curriculum.
  • Tero Toivanen on 21 Jun 09
     
    Researchers have found the first evidence that young children who take music lessons show different brain development and improved memory over the course of a year compared to children who do not receive musical training.
Tero Toivanen

Neurophilosophy : Experience induces global reorganization of brain circuitry - 0 views

scienceblogs.com/...ization_of_brain_circuitry.php

neurophilosophy brain LTP learning memory

shared by Tero Toivanen on 23 May 09 - Cached
  • Now referred to as long-term potentiation (LTP), this mechanism has since become the most intensively studied in modern neuroscience,and is widely believed to be the cellular basis of learning and memory, although this is yet to be proven unequivocally.
  • In the new study, Santiago Canals of the Max Planck Institute for Biological Cybernetics in Tübingen and his colleagues used the same protocol to induce LTP. But while the vast majority of researchers have investigated LTP in slices of hippocampal tissue, this study involved observing LTP in live animals.
  • This new research provides the first evidence that the local modifications in synaptic connections induced by LTP lead to long-lasting changes in the activity of a diffuse network of brain regions, and even to facilitated communication between the two hemispheres. The fMRI data showed that hippocampal LTP recruits higher order association areas, as well as regions involved in emotions and others subserving different sensory modalities, all of which are known to be involved in memory formation.
  • Tero Toivanen on 23 May 09
     
    Experience induces global reorganization of brain circuitry. This new research provides the first evidence that the local modifications in synaptic connections induced by LTP lead to long-lasting changes in the activity of a diffuse network of brain regions, and even to facilitated communication between the two hemispheres.
Tero Toivanen

» Brain Plasticity: How learning changes your brain   « Brain Fitness Revolut... - 0 views

www.sharpbrains.com/...ow-learning-changes-your-brain

brain neuroplasticity learning

shared by Tero Toivanen on 23 May 09 - Cached
  • A surprising consequence of neuroplasticity is that the brain activity associated with a given function can move to a different location as a consequence of normal experience, brain damage or recovery.
  • The brain compensates for damage by reorganizing and forming new connections between intact neurons. In order to reconnect, the neurons need to be stimulated through activity.
  • Research has shown that in fact the brain never stops changing through learning. Plasticity IS the capacity of the brain to change with learning. Changes associated with learning occur mostly at the level of the connections between neurons. New connections can form and the internal structure of the existing synapses can change.
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  • It looks like learning a second language is possible through functional changes in the brain: the left inferior parietal cortex is larger in bilingual brains than in monolingual brains.
  • For instance, London taxi drivers have a larger hippocampus (in the posterior region) than London bus drivers (Maguire, Woollett, & Spiers, 2006)…. Why is that? It is because this region of the hippocampus is specialized in acquiring and using complex spatial information in order to navigate efficiently. Taxi drivers have to navigate around London whereas bus drivers follow a limited set of routes.
  • Did you know that when you become an expert in a specific domain, the areas in your brain that deal with this type of skill will grow?
  • Plastic changes also occur in musicians brains compared to non-musicians.
  • They found that gray matter (cortex) volume was highest in professional musicians, intermediate in amateur musicians, and lowest in non-musicians in several brain areas involved in playing music: motor regions, anterior superior parietal areas and inferior temporal areas.
  • Medical students’ brains showed learning-induced changes in regions of the parietal cortex as well as in the posterior hippocampus. These regions of the brains are known to be involved in memory retrieval and learning.
  • Tero Toivanen on 23 May 09
     
    A surprising consequence of neuroplasticity is that the brain activity associated with a given function can move to a different location as a consequence of normal experience, brain damage or recovery.
Tero Toivanen

PLoS ONE: Scale-Free Music of the Brain - 0 views

www.plosone.org/...10.1371%2Fjournal.pone.0005915

brain brain waves music EEG

shared by Tero Toivanen on 19 Jun 09 - Cached
  • Tero Toivanen on 19 Jun 09
     
    In this study, audibly recognizable scale-free music was deduced from individual Electroencephalogram (EEG) waveforms. The translation rules include the direct mapping from the period of an EEG waveform to the duration of a note, the logarithmic mapping of the change of average power of EEG to music intensity according to the Fechner's law, and a scale-free based mapping from the amplitude of EEG to music pitch according to the power law.
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