NEUROPLASTICITY

This is a very interesting topic, but very deep and difficult, as well. However, if you´re interested in this issue, here you can find information of your interest.

Definition of Neuroplasticity

Neuroplasticity: The brain's ability to reorganize itself by forming new neural connections throughout life. Neuroplasticity allows the neurons (nerve cells) in the brain to compensate for injury and disease and to adjust their activities in response to new situations or to changes in their environment.
Brain reorganization takes place by mechanisms such as "axonal sprouting" in which undamaged axons grow new nerve endings to reconnect neurons whose links were injured or severed. Undamaged axons can also sprout nerve endings and connect with other undamaged nerve cells, forming new neural pathways to accomplish a needed function.
For example, if one hemisphere of the brain is damaged, the intact hemisphere may take over some of its functions. The brain compensates for damage in effect by reorganizing and forming new connections between intact neurons. In order to reconnect, the neurons need to be stimulated through activity.
Neuroplasticity sometimes may also contribute to impairment. For example, people who are deaf may suffer from a continual ringing in their ears (tinnitus), the result of the rewiring of brain cells starved for sound. For neurons to form beneficial connections, they must be correctly stimulated.
Neuroplasticity is also called brain plasticity or brain malleability.

Brain Plasticity--An Overview What is brain plasticity? Does it mean that our brains are made of plastic? Of course not. Plasticity, or neuroplasticity, is the lifelong ability of the brain to reorganize neural pathways based on new experiences. As we learn, we acquire new knowledge and skills through instruction or experience. In order to learn or memorize a fact or skill, there must be persistent functional changes in the brain that represent the new knowledge. The ability of the brain to change with learning is what is known as neuroplasticity. To illustrate the concept of plasticity, imagine the film of a camera. Pretend that the film represents your brain. Now imagine using the camera to take a picture of a tree. When a picture is taken, the film is exposed to new information -- that of the image of a tree. In order for the image to be retained, the film must react to the light and ?change? to record the image of the tree. Similarly, in order for new knowledge to be retained in memory, changes in the brain representing the new knowledge must occur. To illustrate plasticity in another way, imagine making an impression of a coin in a lump of clay. In order for the impression of the coin to appear in the clay, changes must occur in the clay -- the shape of the clay changes as the coin is pressed into the clay. Similarly, the neural circuitry in the brain must reorganize in response to experience or sensory stimulation. Facts About Neuroplasticity FACT 1: Neuroplasticity includes several different processes that take place throughout a lifetime. Neuroplasticity does not consist of a single type of morphological change, but rather includes several different processes that occur throughout an individual?s lifetime. Many types of brain cells are involved in neuroplasticity, including neurons, glia, and vascular cells. FACT 2: Neuroplasticity has a clear age-dependent determinant. Although plasticity occurs over an individual?s lifetime, different types of plasticity dominate during certain periods of one?s life and are less prevalent during other periods. FACT 3: Neuroplasticity occurs in the brain under two primary conditions: 1. During normal brain development when the immature brain first begins to process sensory information through adulthood (developmental plasticity and plasticity of learning and memory). 2. As an adaptive mechanism to compensate for lost function and/or to maximize remaining functions in the event of brain injury. FACT 4: The environment plays a key role in influencing plasticity. In addition to genetic factors, the brain is shaped by the characteristics of a person's environment and by the actions of that same person. Developmental Plasticity: Synaptic Pruning Gopnick et al. (1999) describe neurons as growing telephone wires that communicate with one another. Following birth, the brain of a newborn is flooded with information from the baby?s sense organs. This sensory information must somehow make it back to the brain where it can be processed. To do so, nerve cells must make connections with one another, transmitting the impulses to the brain. Continuing with the telephone wire analogy, like the basic telephone trunk lines strung between cities, the newborn?s genes instruct the "pathway" to the correct area of the brain from a particular nerve cell. For example, nerve cells in the retina of the eye send impulses to the primary visual area in the occipital lobe of the brain and not to the area of language production (Wernicke?s area) in the left posterior temporal lobe. The basic trunk lines have been established, but the specific connections from one house to another require additional signals. Over the first few years of life, the brain grows rapidly. As each neuron matures, it sends out multiple branches (axons, which send information out, and dendrites, which take in information), increasing the number of synaptic contacts and laying the specific connections from house to house, or in the case of the brain, from neuron to neuron. At birth, each neuron in the cerebral cortex has approximately 2,500 synapses. By the time an infant is two or three years old, the number of synapses is approximately 15,000 synapses per neuron (Gopnick, et al., 1999). This amount is about twice that of the average adult brain. As we age, old connections are deleted through a process called synaptic pruning. Synaptic pruning eliminates weaker synaptic contacts while stronger connections are kept and strengthened. Experience determines which connections will be strengthened and which will be pruned; connections that have been activated most frequently are preserved. Neurons must have a purpose to survive. Without a purpose, neurons die through a process called apoptosis in which neurons that do not receive or transmit information become damaged and die. Ineffective or weak connections are "pruned" in much the same way a gardener would prune a tree or bush, giving the plant the desired shape. It is plasticity that enables the process of developing and pruning connections, allowing the brain to adapt itself to its environment. Plasticity of Learning and Memory It was once believed that as we aged, the brain?s networks became fixed. In the past two decades, however, an enormous amount of research has revealed that the brain never stops changing and adjusting. Learning, as defined by Tortora and Grabowski (1996), is ?the ability to acquire new knowledge or skills through instruction or experience. Memory is the process by which that knowledge is retained over time.? The capacity of the brain to change with learning is plasticity. So how does the brain change with learning? According to Durbach (2000), there appear to be at least two types of modifications that occur in the brain with learning: A change in the internal structure of the neurons, the most notable being in the area of synapses. An increase in the number of synapses between neurons. Initially, newly learned data are "stored" in short-term memory, which is a temporary ability to recall a few pieces of information. Some evidence supports the concept that short-term memory depends upon electrical and chemical events in the brain as opposed to structural changes such as the formation of new synapses. One theory of short-term memory states that memories may be caused by ?reverberating? neuronal circuits -- that is, an incoming nerve impulse stimulates the first neuron which stimulates the second, and so on, with branches from the second neuron synapsing with the first. After a period of time, information may be moved into a more permanent type of memory, long-term memory, which is the result of anatomical or biochemical changes that occur in the brain (Tortora and Grabowski, 1996). Injury-induced Plasticity: Plasticity and Brain Repair During brain repair following injury, plastic changes are geared towards maximizing function in spite of the damaged brain. In studies involving rats in which one area of the brain was damaged, brain cells surrounding the damaged area underwent changes in their function and shape that allowed them to take on the functions of the damaged cells. Although this phenomenon has not been widely studied in humans, data indicate that similar (though less effective) changes occur in human brains following injury.

They said it!

"The principal activities of brains are making changes in themselves." --Marvin L. Minsky (from Society of the Mind, 1986)

For references and more information on neuroplasticity, see: Drubach, D. (2000). The Brain Explained, Upper Saddle River, NJ: Prentice-Hall, Inc. Gopnic, A., Meltzoff, A., Kuhl, P. (1999). The Scientist in the Crib: What Early Learning Tells Us About the Mind, New York, NY: HarperCollins Publishers. John F. Kennedy Center for Research on Human Development, Vanderbilt University Staff. Brain Plasticity, Retrieved July 28, 2002 from http://kc.vanderbilt.edu/kennedy/research/topics/plasticity.html Kandel, E.R., Schwartz, J.H., and Jessell, T.M. (2001). Principles of Neural Science. (4th ed.), New York: McGraw-Hill. Kolb, B. (Winter 2000). Experience and the developing brain. Education Canada, 39(4), 24-26. Neville, H.J. and Bavelier, D. (2000). Specificity and plasticity in neurocognitive development in humans. In Gazzaniga, M.S. (Ed). The New Cognitive Neurosciences. (2nd ed.), Cambridge, MA: The MIT Press, pp. 83-99. Society for Neuroscience. (July 2000). Brain Plasticity, Language Processing and Reading, Retrieved August 3, 2002 from http://web.sfn.org/content/Publications/BrainBriefings/brain_lang_reading.htm Sousa, D.A. (2001). How the Brain Learns (2nd ed.), Thousand Oaks, CA: Corwin Press, Inc. Tortora, G. and Grabowski, S. (1996). Principles of Anatomy and Physiology. (8th ed.), New York: HarperCollins College Publishers. Tulving, E. and Craik, F.I.M. (Eds.) (2000). The Oxford Handbook of Memory, London and New York: Oxford University Press. General Memory Sites: Memory Exhibit - from the Exploratorium Brain Top to Bottom

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Neuroplasticity: Your Brain’s Amazing Ability to Form New Habits

One of the most popular areas of research in psychology these days is neuroplasticity.  Neuroplasticity refers to the brain’s ability to restructure itself after training or practice.  In many ways, neuroplasticity is what makes personal growth and development possible at its most basic level.  With the understanding that change is indeed possible, you’re able to focus on the ways in which you’d like to grow instead of whether or not it’s achievable for you.  It’s possible, it’s proven, and now it’s up to you!

We are what we repeatedly do.  Excellence, then, is not an act, but a habit. – Aristotle
An example of how neuroplasticity works: when you view the brains of people who frequently practice playing the violin under fMRI (functional MRI) they appear to have developed a larger area of their brain devoted to mapping their fingers.  This change is directly related to the quantity and the quality of the practice they’re performing – their brains are adapting in very real and tangible ways unbeknownst to them.
One of the fun sayings around neuroplasticity: “neurons that fire together wire together… and neurons that fire apart wire apart.”.  Effectively this means that when neurons activate at the same time as a response to an event, the neurons become associated with one another and the connections become stronger.  This is why people talk about “neural pathways being set” with respect to increased practice – the more practice you accumulate, the more ingrained or grooved the pathways become.  Of course the inverse happens as well: if those pathways aren’t utilized, the space will be used by other pathways needing room to grow. Use it or lose it!
You can picture this yourself by imagining the flow of water through sand (I’m writing this from a beach in Kauai so excuse the metaphor – but I always find a mental motion picture is worth a thousand words!)  When seawater first runs over the sand, there isn’t a path for it to follow so it starts to form one for itself.  As the water continues to flow over the sand, the pathway forms a real groove in the sand and gets deeper and more defined.  It may start to branch off and take up more room in the sand if necessary, even reforming pathways on top of pathways that are no longer in use if it needs to.  Once the pathways are formed, it becomes more difficult to change the water flow – and if the water ever stops flowing, the pathway will remain for some time in the hopes that it’ll be used again at some point.  (This is why picking something back up after some time of inactivity is easier than starting a new activity cold).
The research around neuroplasticity is burgeoning these days – many people in psychology are talking about the hows and whys around it, and over the last decade a fair amount of research has already been done on the brain and its ability to reshape itself.  It’s no longer considered a theory in brain science, it’s fact.  Up until the 1980s or early 1990s, most scientists believed that your brain developed in your early years (throughout childhood) and then became “hardened” like dried concrete.  One has to assume this is where the moniker, “you can’t teach an old dog new tricks” came from.  But it turns out this just isn’t true.  You can fundamentally change your brain so long as oxygen and blood is flowing through you.  Which means you have no excuse when it comes to forming new habits.
In Tibetan Buddhism, the concept of neuralplasticity has been around for far longer than Western science has recognized it – the term for it is le-su-rung-wa which means “pliability”; your brain can change based on repeated experience. It’s no surprise then that studies have been performed on plasticity during meditation and have shown that the brain can change based purely on mental training.  This of course has huge ramifications for mental practice and its impact on overall well-being.  If you can think yourself into being more compassionate, or more positive and more resourceful, or calmer and more content, it seems a little too good to be true.  But with some effort, it’s possible.
There are a few interesting things to note about neuroplasticity.  Change takes place rather suddenly in the brain.  A recent study has shown that habits can be formed in as little as 7 days of repeated activity, but can dissipate just as easily.  In other words, change comes naturally and quickly and can disappear just as quickly as it arrived.  It also appears that “learning a variety of new things, rather than simply practicing old skills, may be most effective in terms of brain structure alterations”.  And while neuroplasticity is possible in adults, it appears that in children it’s rampant – which makes logical sense as it aligns with our overall perspective on learning.
In short: this is relevant research to all of us.  It implies that people of any age have the ability to learn new things and form new habits.  Therefore contentment (my preferred term for ‘happiness’) isn’t a state you’re born into, it’s a state you can discover.  And the sky’s the limit for the ability to learn and perfect new things throughout your life.
So what are you waiting for?

For decades, scientists thought that the adult human brain was static and unchanging. But in the last few decades, we have learned that the adult brain is more dynamic than we ever imagined!
This short film was created for the Society for Neuroscience 2011 Brain Awareness Video Contest.

Written, directed, and edited by Neil Losin and Liz Losin. Featuring music by Dan Warren (www.danwarren.net).

This is a very interesting topic, but very deep and difficult, as well. However, if you´re interested in this issue, here you can find information of your interest.

On the other hand, there is a group of scientists? who do not share these opinions  about neuroplasticity. If you are not in a hurry, you can have a quick glance at this web page

To finish, here you have another webpage in which you can find the most frequently asked questions about this controversial issue.