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Contents contributed and discussions participated by Amira .

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Study shows map of brain connectivity changes during development | Physorg January 26, ... - 4 views

  • New research conducted at The Scripps Research Institute shows that this road atlas undergoes constant revisions as the brain of a young animal develops, with new routes forming and others dropping away in a matter of hours. "We have shown that the connectome is dynamic during development, but we expect it will also change according to an individual's experience and in response to disease,"
  • Cline's group has been studying how experience—the different sights and sounds and other environmental cues picked up by neurons—change connections and activities in the brain through a process known as plasticity. "Based on our prior research we expected that the connectome would be dynamic," says Cline. To start to document how the connectome changes and test current models of how the map is laid out, Cline and colleagues turned to the frog Xenopus laevis. They combined two new techniques to map in great detail all the connections that form during tadpole development in an area of the brain that receives and interprets signals from the eyes. In the nervous system, information is handed from one nerve cell to another through two arms, called dendrites and axons, stretching out from opposite sides of each cell. The axon carries information away from a nerve cell, or neuron, and passes it to the dendrite of another; dendrites receive the information, which travels through the cell to the axon. The region where information is transferred from one neuron to another (and where axons and dendrites connect) is called the synapse.
  • Cline's study shows instead the process is not as selective. Each growing dendrite samples not one but many possible partners before selecting one with which to maintain contact. As new branches grow from dendrites, they form many immature synapses on axons. Then, as each new dendrite branch matures, most immature synapses are eliminated; the ones not eliminated mature into stable synapses. "We did not know that dendrites make so many connections that are then removed," says Cline. "It is always fun in science when you see that what was expected is not what actually happens."
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    Connected highways of nerve cells carry information to and from different areas of the brain and the rest of the nervous system. Scientists are trying to draw a complete atlas of these connections -- sometimes referred to as the "connectome" -- to gain a better understanding of how the brain functions in health and disease.
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How Expectations Speed Up Perception | Science 2.0, Feb 5, 2011 - 1 views

  • The human brain works incredibly fast but visual impressions are so complex that their processing takes up to several hundred milliseconds before they enter our consciousness.  Researchers say they know why this delay may vary in length; if you already know what you are about to see, you recognize it faster.
  • In an experiment, participants perceived stimuli more efficiently and faster if they knew what to expect. To investigate this, the scientists showed the participants images with a background of randomly distributed dots on a monitor. During an image sequence, the distribution of the dots systematically changed such that a symbol gradually appeared. Following each image, the participants indicated if they could see the symbol by pressing a button. As soon as the symbol had appeared fully and was clearly recognizable, the scientists presented the same image sequence in reverse order, such that the symbol gradually faded again.
  • “Expectations based on previously acquired information apparently help to perceive the object consciously”
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  • Moreover, the measurements of EEG activity produced astonishing results. “We found that the timing of EEG activity for conscious perception changed depending on the person’s expectations”
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Seeking the Connectome, a Mental Map, Slice by Slice By ASHLEE VANCE | NYTimes.com - 0 views

  • is called connectomics, and the neuroscientists pursuing it compare their work to early efforts in genetics. What they are doing, these scientists say, is akin to trying to crack the human genome — only this time around, they want to find how memories, personality traits and skills are stored.
  • “You are born with your genes, and they don’t change afterward,” said H. Sebastian Seung, a professor of computational neuroscience at the Massachusetts Institute of Technology who is working on the computer side of connectomics. “The connectome is a product of your genes and your experiences. It’s where nature meets nurture.”
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Connectome - Wikipedia, the free encyclopedia - 1 views

  • A connectome is a comprehensive map of neural connections in the brain. The production and study of connectomes, known as connectomics, may range in scale from a detailed map of the full set of neurons and synapses within part or all of the nervous system of an organism to a macro scale description of the functional and structural connectivity between all cortical areas and subcortical structures. The term "connectome" is used primarily in scientific efforts to capture, map, and understand the organization of neural interactions within the brain.
  • It is clear that, like the genome, which is much more than just a juxtaposition of genes, the set of all neuronal connections in the brain is much more than the sum of their individual components. The genome is an entity it-self, as it is from the subtle gene interaction that [life] emerges. In a similar manner, one could consider the brain connectome, set of all neuronal connections, as one single entity, thus emphasizing the fact that the huge brain neuronal communication capacity and computational power critically relies on this subtle and incredibly complex connectivity architecture.
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    A connectome is a comprehensive map of neural connections in the brain. The production and study of connectomes, known as connectomics, may range in scale from a detailed map of the full set of neurons and synapses within part or all of the nervous system of an organism to a macro scale description of the functional and structural connectivity between all cortical areas and subcortical structures. The term "connectome" is used primarily in scientific efforts to capture, map, and understand the organization of neural interactions within the brain. One such effort is the Human Connectome Project, sponsored by the National Institutes of Health, whose focus is to build a network map of the human brain in healthy, living adults. Another was the successful reconstruction of all neural and synaptic connections in C. elegans
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MoNETA: A Mind Made from Memristors | IEEE Spectrum - 1 views

  • It will perceive its surroundings, decide which information is useful, integrate that information into the emerging structure of its reality, and in some applications, formulate plans that will ensure its survival. In other words, MoNETA will be motivated by the same drives that motivate cockroaches, cats, and humans.
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    DARPA's new memristor-based approach to AI consists of a chip that mimics how neurons process information
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How the brain's architecture makes our view of the world unique | PhysOrg.com Dec 5, 2010 - 1 views

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    Wellcome Trust scientists have shown for the first time that exactly how we see our environment depends on the size of the visual part of our brain.
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New study shows humans are on auto pilot nearly half the time by Dr. David Rock | Psych... - 5 views

  • It turns out that just under half the time, 46.9% to be exact, people are doing what's called 'mind wandering'. They are not focused on the outside world or the task at hand, they are looking into their own thoughts. Unfortunately, the study of 2,250 people proposes, most of this activity doesn't make us feel happy.
  • people report being unhappy during mind wandering.Something that we do nearly half the time makes us unhappy! No wonder there are so many spiritual and religious traditions trying to implore people to 'live in the present'.
  • A 2007 study called "Mindfulness meditation reveals distinct neural modes of self-reference" by Norman Farb at the University of Toronto, along with six other scientists, broke new ground in our understanding of mindfulness from a neuroscience perspective.
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  • study how human beings experience their own moment-to-moment experience. They discovered that people have two distinct ways of interacting with the world, using two different sets of networks. One network for experiencing your experience involves what is called the "default network", which includes regions of the medial prefrontal cortex, along with memory regions such as the hippocampus. This network is called default because it becomes active when not much else is happening, and you think about yourself.
  • This is your default network in action. It's the network involved in planning, daydreaming and ruminating.This default network also become active when you think about yourself or other people, it holds together a "narrative". A narrative is a story line with characters interacting with each other over time. The brain holds vast stores of information about your own and other people's history. When the default network is active, you are thinking about your history and future and all the people you know, including yourself, and how this giant tapestry of information weaves together. In this way, in the Farb study they like to call the default network the ‘narrative' circuitry.
  • The default network is active for most of your waking moments and doesn't take much effort to operate. There's nothing wrong with this network, the point here is you don't want to limit yourself to only experiencing the world through this network. The Farb study shows there is a whole other way of experiencing experience. Scientists call this type of experience one of direct experience. When the direct experience network is active, several different brain regions become more active. This includes the insula, a region that relates to perceiving bodily sensations. The anterior cingulate cortex is also activated, which is a region central to switching your attention. When this direct experience network is activated, you are not thinking intently about the past or future, other people, or yourself, or considering much at all. Rather, you are experiencing information coming into your senses in real time. Sitting on the jetty, your attention is on the warmth of the sun on your skin, the cool breeze in your hair, and the cold beer in your hand.
  • A series of other studies has found that these two circuits, narrative and direct experience, are inversely correlated. In other words, if you think about an upcoming meeting while you wash dishes, you are more likely to overlook a broken glass and cut your hand, because the brain map involved in visual perception is less active when the narrative map is activated. You don't see as much (or hear as much, or feel as much, or sense anything as much) when you are lost in thought. Sadly, even a beer doesn't taste as good in this state.Fortunately, this scenario works both ways. When you focus your attention on incoming data, such as the feeling of the water on your hands while you wash up, it reduces activation of the narrative circuitry. This explains why, for example, if your narrative circuitry is going crazy worrying about an upcoming stressful event, it helps to take a deep breath and focus on the present moment. All your senses "come alive" at that moment.
  • Experiencing the world through the direct experience network allows you to get closer to the reality of any event. You perceive more information about events occurring around you, as well as more accurate information about these events. Noticing more real-time information makes you more flexible in how you respond to the world. You also become less imprisoned by the past, your habits, expectations or assumptions, and more able to respond to events as they unfold.
  • A study by Kirk Brown found that people high on a mindfulness scale were more aware of their unconscious processes. Additionally these people had more cognitive control, and a greater ability to shape what they do and what they say, than people lower on the mindfulness scale. If you're on the jetty in the breeze and you're someone with a good level or mindfulness, you are more likely to notice that you're missing a lovely day worrying about tonight's dinner, and focus your attention onto the warm sun instead. When you make this change in your attention, you change the functioning of your brain, and this can have a long-term impact on how your brain works too.
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    Humans are mentally checked out, unhappily, nearly half the time
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The Psychological Study of Smiling By Eric Jaffe | Association for Psychological Scienc... - 0 views

  • emotional data funnels to the brain, exciting the left anterior temporal region in particular, then smolders to the surface of the face, where two muscles, standing at attention, are roused into action: The zygomatic major, which resides in the cheek, tugs the lips upward, and the orbicularis oculi, which encircles the eye socket, squeezes the outside corners into the shape of a crow’s foot. The entire event is short — typically lasting from two-thirds of a second to four seconds — and those who witness it often respond by mirroring the action, and smiling back.
  • For decades, many psychologists agreed that smiles reflected a vast array of emotions rather than a universal expression of happi­ness. This belief persisted until the 1970s, when Paul Ekman and Wallace Friesen, psychologists at the University of California at San Francisco, captured the precise muscular coordinates behind 3,000 facial expressions in their Facial Action Coding System, known as FACS. Ekman and Friesen used their system to resurrect Duchenne’s distinction, by that time forgotten, between genuine smiles of enjoyment and other types of smiles.
  • Some researchers now believe that genuine smiles are not transient sparks of emotion but rather clear windows into a person’s core disposition.
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  • “People photograph each other with casual ease and remarkable frequency, usually unaware that each snapshot may capture as much about the future as it does the passing emotions of the moment,” Harker and Keltner wrote in a 2001 issue of the Journal of Personality and Social Psychology. A related study, published in a 2009 issue of Motivation and Emotion, confirmed a correlation between low-intensity smiles in youth and divorce later in life.
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Positive mood allows human brain to think more creatively | ScienceDaily (Dec. 15, 2010) - 1 views

  • "Generally, positive mood has been found to enhance creative problem solving and flexible yet careful thinking," says Ruby Nadler, a graduate student at the University of Western Ontario.
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    People who watch funny videos on the internet at work aren't necessarily wasting time. They may be taking advantage of the latest psychological science -- putting themselves in a good mood so they can think more creatively
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Brain's grey matter helps you introspect by Miriam Frankel | New Scientist Sep 20, 2010 - 0 views

  • What happens in our brain when the mind is considering itself? Until now, it has been unclear what happens during a navel-gazing session. Now a team of neuroscientists has shed light on the process by identifying an area of the brain that is larger in more introspective individuals. Introspection is the act of assessing or thinking about one's own thoughts, decisions and feelings. Stephen Fleming from University College London and his colleagues were interested in how the act of introspection - thought to be a crucial component of consciousness - links to the physiology of the brain.
  • Individuals with a high level of introspective ability should be more confident after making a correct choice and less confident after a poor decision than people who are less good at self-reflection. After the perceptual test, the team scanned the participants' brains using functional magnetic resonance imaging to look for links between the individual's introspective ability and their brain structure. They found that people with a high introspective ability had a larger amount of grey matter in the right anterior prefrontal cortex, an area of the brain located just behind the eyes, involved in decision-making. It is thought that there are different levels of consciousness. Sometimes we are aware of mental processes, like playing the piano, while others may proceed in the absence of consciousness, like driving a car, says Fleming. Thinking about our own thoughts occurs when we are more highly aware of our own consciousness.
  • "I am cautious about saying that what we are measuring here is consciousness," he says. "But we might be measuring something that is required for a particular type of conscious awareness." "The study addresses an intriguing problem," says neuroscientist Alan Cowey from the University of Oxford in the UK. "The results reveal a fascinating correlation between a level of self-awareness and activity in the prefrontal cortex. They do not yet reveal the neural mechanisms that underlie introspection but that will surely follow".
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Exposing a Galaxy within the Brain by Emily Singer | MIT Technology Review Sep 18, 2010 - 1 views

  • The cortex of the human brain holds more than 100 trillion neural connections, or synapses, packed into a layer of tissue just 2 to 4 millimeters thick. Visualizing these densely packed units individually has proved extremely challenging. Synapses in the brain are crowded in so close together that they cannot be reliably resolved by even the best of traditional light microscopes, explains Stanford neuroscientist Stephen Smith in a press release from the university.
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    A new imaging method developed at Stanford reveals the complex array of synapses in the cortex.
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Mind - Past Adversity May Aid Emotional Recovery By Benedict Carey | NYTimes.com Jan 3,... - 0 views

  • It is clear that with time, most people can and do psychologically recover from even devastating losses, like the death of a spouse; but reactions to the same blow vary widely, and no one can reliably predict who will move on quickly and who will lapse into longer-term despair.
  • The role of genes is likewise uncertain. In a paper published online Monday in The Archives of General Psychiatry, researchers at the University of Michigan who analyzed more than 50 studies concluded that variations in a single gene determine people’s susceptibility to depression following stressful events. But an earlier analysis, of fewer but similar studies, concluded that the evidence was not convincing. New research suggests that resilience may have at least as much to do with how often people have faced adversity in past as it does with who they are — their personality, their genes, for example — or what they’re facing now. That is, the number of life blows a person has taken may affect his or her mental toughness more than any other factor.
  • “Frequency makes a difference: that is the message,” said Roxane Cohen Silver, a psychologist at the University of California, Irvine. “Each negative event a person faces leads to an attempt to cope, which forces people to learn about their own capabilities, about their support networks — to learn who their real friends are. That kind of learning, we think, is extremely valuable for subsequent coping,”
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    It is clear that with time, most people can and do psychologically recover from even devastating losses, like the death of a spouse; but reactions to the same blow vary widely, and no one can reliably predict who will move on quickly and who will lapse into longer-term despair.
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The Creative Advantage: How Vivid Memories of the Past Help Predictions for the Future ... - 0 views

  • "It's a poor sort of memory that only works backwards..." - Lewis Carroll, Through the Looking Glass
  • Episodic memory is an autobiographical that encodes specific times, places, sensory details and context, in contrast to semantic or non-personal memory that encodes facts (like 3 + 2 = 5 or the definition of a shoe) that can deal with more abstract or representational information that now may only be distantly linked to prior experiences.
  • When researchers looked at the brain regions involved in looking at the past, they found many of the same regions activated in response to prompts to imagine events in the future.
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  • It was Suddendorf and Corballis who raised the idea that mental time travel into the past was closely linked to time travel into the future.
  • Any other significance to the brain areas found to be activated into future visualization experiments? Maybe - these are the same areas important for theory of mind or thinking about the perspectives of others, and spatial navigation tasks.
  • It's not hard to find examples of highly creative forward-thinking adults who seem to have had this prodigious memory pattern (Nikola Tesla, Isaac Asimov, Leonardo Da Vinci etc.) but amazingly we think we see some of these budding versions in our clinic because of our interest in highly gifted and twice exceptional (gifted with LD) learners. Vivid personal memory doesn't always translated into academic success in the early years of education - because it's usually impersonal or rote memory that's emphasized in school. Vivid visualizers can be easily distracted, lost in their daydreams, or more concerned with personal trivia (what Toby brought to school, the games on Sarah's DS, etc.) or personal experimentation (homemade catapults) than the steps for rounding decimals or regurgitating dates and names for a history test.
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    "It's a poor sort of memory that only works backwards..." - Lewis Carroll, Through the Looking Glass
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Memories are made of this. Kandel outlines how brains manage data, and are changed by i... - 0 views

  • “The brain is a creativity machine,” Columbia University neuroscientist Eric Kandel told his Harvard audience on Feb. 8. “We get incomplete information from the outside world, and we make a whole lot of things up. This is why the brain can be deceived so easily — because it’s guessing all the time.”
  • “If you remember anything about this lecture, it’s because genes in your brain will be altered,” said the Columbia University professor, who shared the 2000 Nobel Prize in physiology or medicine for his studies on memory. “If you remember this tomorrow, or the next day, a week later, you will have a different brain than when you walked into this lecture.”
  • “Memory, as you know, makes us who we are,” Kandel said. “It’s the glue that binds our mental life together. Without the unifying force of memory, we would be broken into as many fragments as there are moments in the day.”
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  • “Long-term memory differs from short-term memory in requiring the synthesis of new proteins,” Kandel said, adding that there’s a high threshold for information to be entered into long-term memory. “Something really has to be important to be remembered,” he said. Long-term memory stimulates protein syntheses, Kandel said, by altering gene expression. While the genes themselves remain unchanged, their activity levels are tweaked by the molecules involved in the creation of long-term memory.
  • “Many of us are accustomed, naively, to thinking that genes are the determinants of our behavior,” he said. “We are not accustomed to thinking that genes are also the servants of the mind.” The genes affected, he said, lead the brain’s 100 billion neurons to grow new synapses, or connections with other neurons. A typical neuron, he said, connects to about 1,200 others. But neurons that are subject to repeated stimuli have been found to have much denser networks, with up to 2,800 synapses.
  • The brain is especially susceptible to forming such new connections early in life, he said, when its structure is highly malleable, or plastic. “This is why almost all great musicians, all great basketball players, all great anything, all get started very early in life,” Kandel said.
  • “There are a lot of cells up there,” he said. “Each one of them connects to 1,000 other cells, so you’ve got more synapses than there are stars in the universe. When you finish counting those stars in the universe, I will be ready for the connectome.”
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Human brain uses grid to represent space | UCL Institute of Cognitive Neuroscience - 0 views

  • ‘Grid cells’ that act like a spatial map in the brain have been identified for the first time in humans, according to new research by UCL scientists which may help to explain how we create internal maps of new environments. The study is by a team from the UCL Institute of Cognitive Neuroscience and was funded by the Medical Research Council and the European Union. Published today in Nature, it uses brain imaging and virtual reality techniques to try to identify grid cells in the human brain. These specialised neurons are thought to be involved in spatial memory and have previously been identified in rodent brains, but evidence of them in humans has not been documented until now.
  • Grid cells represent where an animal is located within its environment, which the researchers liken to having a satnav in the brain. They fire in patterns that show up as geometrically regular, triangular grids when plotted on a map of a navigated surface. They were discovered by a Norwegian lab in 2005 whose research suggested that rats create virtual grids to help them orient themselves in their surroundings, and remember new locations in unfamiliar territory. Study co-author Dr Caswell Barry said: “It is as if grid cells provide a cognitive map of space. In fact, these cells are very much like the longitude and latitude lines we’re all familiar with on normal maps, but instead of using square grid lines it seems the brain uses triangles.”
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    "'Grid cells' that act like a spatial map in the brain have been identified for the first time in humans, according to new research by UCL scientists which may help to explain how we create internal maps of new environments. The study is by a team from the UCL Institute of Cognitive Neuroscience and was funded by the Medical Research Council and the European Union. Published today in Nature, it uses brain imaging and virtual reality techniques to try to identify grid cells in the human brain. These specialised neurons are thought to be involved in spatial memory and have previously been identified in rodent brains, but evidence of them in humans has not been documented until now."
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Mapping the brain. MIT neuroscientists are making computers smart enough to see the con... - 0 views

  • The scientists, including several at MIT, are working on technologies needed to accelerate the slow and laborious process that the C. elegans researchers originally applied to worms. With these technologies, they intend to map the connectomes of our animal cousins, and eventually perhaps even those of humans. Their results could fundamentally alter our understanding of the brain. Mapping the millions of miles of neuronal “wires” in the brain could help researchers understand how those neurons give rise to intelligence, personality and memory, says Sebastian Seung, professor of computational neuroscience at MIT. For the past three years, Seung and his students have been building tools that they hope will allow researchers to unravel some of those connections. To find connectomes, researchers will need to employ vast computing power to process images of the brain. But first, they need to teach the computers what to look for.
  • “Instead of specifying the details of how the computer does something, you give it an example of what you want it to do and an algorithm that tries to figure out how to do what you want,” says Jain. After the computer is trained on the human tracings, it is applied to electron micrographs that have not been traced by humans. This new technique represents the first time that computers have been effectively taught to segment any kind of images, not just neurons.
  • “Doing such a microscopic level of resolution seemed to be infeasible at the time,” he says. “But now I’m coming around to the idea that something like that may well be possible.” The machine learning technology that Seung and his students are developing could be “a big leap forward” in making that kind of diagram a reality, Sporns adds.
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  • Some neuroscientists believe that mapping connectomes could have just as much impact as sequencing the human genome. Much as genetic researchers can now compare individuals’ genes to look for variability that might account for diseases, brain researchers could discover which differences in the wiring diagrams are important in diseases like Alzheimer’s and schizophrenia, says Turaga
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    The scientists, including several at MIT, are working on technologies needed to accelerate the slow and laborious process that the C. elegans researchers originally applied to worms. With these technologies, they intend to map the connectomes of our animal cousins, and eventually perhaps even those of humans. Their results could fundamentally alter our understanding of the brain. Mapping the millions of miles of neuronal "wires" in the brain could help researchers understand how those neurons give rise to intelligence, personality and memory, says Sebastian Seung, professor of computational neuroscience at MIT. For the past three years, Seung and his students have been building tools that they hope will allow researchers to unravel some of those connections. To find connectomes, researchers will need to employ vast computing power to process images of the brain. But first, they need to teach the computers what to look for.
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Our brains are confused about time by Lin Edwards | Physorg.com January 8, 2010 - 0 views

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    A recent study published in the journal Psychological Science has found our concept of time is distorted, and we consistently underestimate how much time has passed since events in the past, condensing the time.
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Malcolm Gladwell - If what I.Q. tests measure is immutable and innate, what explains th... - 0 views

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    "One Saturday in November of 1984, James Flynn, a social scientist at the University of Otago, in New Zealand, received a large package in the mail. It was from a colleague in Utrecht, and it contained the results of I.Q. tests given to two generations of Dutch eighteen-year-olds. When Flynn looked through the data, he found something puzzling. The Dutch eighteen-year-olds from the nineteen-eighties scored better than those who took the same tests in the nineteen-fifties-and not just slightly better, much better."
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You won't find consciousness in the brain by Ray Tallis | New Scientist 07 January 2010 - 2 views

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    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. Among them are those who focus on claims neuroscience makes about the preciseness of correlations between indirectly observed neural activity and different mental functions, states or experiences.
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