Neuroplasticity challenges the idea that brain functions are fixed in certain locations.

Neuroplasticity (variously referred to as brain plasticity or cortical plasticity) refers to the changes that occur in the organization of the brain as a result of experience. A surprising consequence of brain plasticity is that the location of a given function can move to another location in the brain as a consequence of training or brain damage. Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... Italic text // ahh addiing sum spiice iin hurr`` For other uses, see Brain (disambiguation). ...

The concept of neuroplasticity challenges the mechanistic idea that each brain function has a particular location that is hard-wired from birth, and the related idea that human nature is, to a large extent, fixed and unchangeable. According to the theory of neuroplasticity, thinking, learning, and acting actually change the brain's anatomy. Human heart and lungs, from an older edition of Grays Anatomy. ...

American psychiatrist Norman Doidge has called neuroplasticity "one of the most extraordinary discoveries of the twentieth century."^[1]

Brain plasticity and cortical maps

Cortical organization, especially for the sensory systems, is often described in terms of maps. For example, sensory information from the foot projects to one cortical site and the projections from the hand target in another site. As the result of this somatotopic organization of sensory inputs to the cortex, cortical representation of the body resembles a map (or homunculus).In the late 1970s and early 1980s, several groups began exploring the impacts of removing portions of the sensory inputs. Merzenich and Kaas used the cortical map as their dependent measure. They found, and this has been since corroborated by a wide range of labs, that if the cortical map is deprived of its input it will become activated at a later time in response to other, usually adjacent inputs. At least in the somatic sensory system, in which this phenomenon has been most thoroughly investigated, Wall and Xu have traced the mechanisms underlying this plasticity. Re-organization occurs at every level in the processing hierarchy to result in the map changes observed in the cerebral cortex. It is not cortically emergent. This article or section may be confusing for some readers, and should be edited to be clearer or more simplified. ... Cortical maps are collections (areas) of minicolumns in the brain cortex that have been identified as performing a specific information processing function (texture maps, color maps, contour maps, etc. ... Hartsoekers homunculus The concept of a homunculus (Latin for little man, sometimes spelled homonculus, plural homunculi) is often used to illustrate the functioning of a system. ... Michael M. Merzenich is a neuroscientist from UCSF. His contributions to the field are numerous. ... A termite cathedral mound produced by a termite colony: a classic example of emergence in nature. ...

Merzenich and Jenkins (1990) initiated studies relating sensory experience, without pathological perturbation, to cortically observed plasticity in the primate somatosensory system, with the finding that sensory sites activated in an attended operant behavior increase in their cortical representation. Shortly thereafter, Ebner and colleagues (1994) made similar efforts in the rodent whisker barrel (also somatic sensory system). These two groups largely diverged over the years. The rodent whisker barrel efforts became a focus for Ebner, Diamond, Armstrong-James, Sachdev, Fox, and Feldman, and great inroads were made in identifying the locus of change as being at cortical synapses expressing NMDA receptors, and in implicating cholinergic inputs as necessary for normal expression. However, the rodent studies were poorly focused on the behavioral end, and Frostig and Polley (1999,2004) identified behavioral manipulations as causing a substantial impact on the cortical plasticity in that system. Michael M. Merzenich is a neuroscientist from UCSF. His contributions to the field are numerous. ... Jenkins is a surname that originated in England, but came to be popular in southern Wales. ... Families 15, See classification A primate is any member of the biological order Primates, the group that contains all the species commonly related to the lemurs, monkeys, and apes, with the latter category including humans. ... Somatic sensation consists of the various sensory receptors that trigger the experiences labelled as touch or pressure, temperature (warm or cold), pain (including itch and tickle), and the sensations of muscle movement and joint position including posture, movement, and facial expression (collectively also called proprioception). ... There are multiple factors involved in any behavioral event. ... Ebner is a surname, and may refer to: Christina Ebner Margareta Ebner Marie von Ebner-Eschenbach Mark Ebner Michl Ebner This page or section lists people with the surname Ebner. ... Suborders Sciuromorpha Castorimorpha Myomorpha Anomaluromorpha Hystricomorpha Rodentia is an order of mammals also known as rodents. ... There are several kinds of whisker: Look up whisker in Wiktionary, the free dictionary. ... Illustration of the major elements in a prototypical synapse. ... Gene expression, or simply expression, is the process by which a genes DNA sequence is converted into the structures and functions of a cell. ... The NMDA receptor (NMDAR) is an ionotropic receptor for glutamate (NMDA (N-methyl d-aspartate) is a name of its selective specific agonist). ... A synapse is cholinergic if it uses acetylcholine as its neurotransmitter. ... Behavior (U.S.) or behaviour (U.K.) refers to the actions or reactions of an object or organism, usually in relation to the environment. ...

Merzenich and Blake (2002,2005,2006) went on to use cortical implants to study the evolution of plasticity in both the somatosensory and auditory systems. Both systems show similar changes with respect to behavior. When a stimulus is cognitively associated with reinforcement, its cortical representation is strengthened and enlarged. In some cases, cortical representations can increase two to three fold in 1-2 days at the time at which a new sensory motor behavior is first acquired, and changes are largely finished with at most a few weeks. Control studies show that these changes are not caused by sensory experience alone: they require learning about the sensory experience, and are strongest for the stimuli that are associated with reward, and occur with equal ease in operant and classical conditioning behaviors. Michael M. Merzenich is a neuroscientist from UCSF. His contributions to the field are numerous. ... The somatosensory system is the sensory system of somatic sensation. ... This article is about compression waves. ... For the Pet Shop Boys album of the same name see Behaviour Behavior or behaviour (see spelling differences) refers to the actions or reactions of an object or organism, usually in relation to the environment. ... In operant conditioning, reinforcement is the behavioral operationalization of the effects of reinforcers. ...

An interesting phenomenon involving cortical maps is the incidence of phantom limbs. This is most commonly described in people that have undergone amputations in hands, arms, and legs, but it is not limited to extremities. The phantom limb feeling, which is thought to result from disorganization in the homunculus and the inability to receive input from the targeted area, may be annoying or painful. Incidentally, it is more common after unexpected losses than planned amputations. There is a high correlation with the extent of physical remapping and the extent of phantom pain. As it fades, it is a fascinating functional example of new neural connections in the human adult brain. This article is about the syndrome. ... Partial hand amputation For the song Amputations by Death Cab for Cutie, see You Can Play These Songs with Chords Amputation is the removal of a body extremity by trauma (also referred to as avulsion) or surgery. ... “Hurting” redirects here. ... Positive linear correlations between 1000 pairs of numbers. ...

The concept of plasticity can be applied to molecular as well as to environmental events. The phenomenon itself is complex and can involve many levels of organization. To some extent the term itself has lost its explanatory value because almost any changes in brain activity can be attributed to some sort of "plasticity". For example, the term is used prevalently in studies of axon guidance during development, short-term visual adaptation to motion or contours, maturation of cortical maps, recovery after amputation or stroke, and changes that occur in normal learning in the adult. Some authors separate forms into adaptations that have positive or negative consequences for the animal. For example, if an organism, after a stroke, can recover to normal levels of performance, that adaptiveness could be considered an example of "positive plasticity". An excessive level of neuronal growth leading to spasticity or tonic paralysis, or an excessive release of neurotransmitters in response to injury which could kill nerve cells, would have to be considered perhaps as a "negative or maladaptive" plasticity. Spasticity is a disorder of the bodys motor system in which certain muscles are continuously contracted. ... This article or section does not cite its references or sources. ... Chemical structure of D-aspartic acid, a common amino acid neurotransmitter. ...

Treatment of brain damage

Neuroplasticity is a fundamental issue that supports the scientific basis for treatment of acquired brain injury with goal-directed experiential therapeutic programs in the context of rehabilitation approaches to the functional consequences of the injury. A neurological condition, Acquired Brain Injury (or simply ABI) is damage to the brain after birth. ... Rehabilitation of sensory and cognitive function typically involves methods for retraining neural pathways or training new neural pathways to regain or improve neurocognitive functioning that has been diminished by disease or traumatic injury. ...

The adult brain is not "hard-wired" with fixed and immutable neuronal circuits. Many people have been taught to believe that once a brain injury occurs, there is little to do to repair the damage. This is simply not the case and there is no fixed period of time after which "plasticity" is blocked or lost. We simply do not know all of the conditions that can enhance neuronal plasticity in the intact and damaged brain, but new discoveries are being made all of the time. There are many instances of cortical and subcortical rewiring of neuronal circuits in response to training as well as in response to injury. There is solid evidence that neurogenesis, the formation of new nerve cells, occurs in the adult, mammalian brain--and such changes can persist well into old age. The evidence for neurogenesis is restricted to the hippocampus and olfactory bulb. In the rest of the brain, neurons can die, but they cannot be created. However, there is now ample evidence for the active, experience-dependent re-organization of the synaptic networks of the brain involving multiple inter-related structures including the cerebral cortex. The specific details of how this process occurs at the molecular and ultrastructural levels are topics of active neuroscience research. The manner in which experience can influence the synaptic organization of the brain is also the basis for a number of theories of brain function including the general theory of mind and epistemology referred to as Neural Darwinism and developed by immunologist Nobel laureate Gerald Edelman. The concept of neuroplasticity is also central to theories of memory and learning that are associated with experience-driven alteration of synaptic structure and function in studies of classical conditioning in invertebrate animal models such as Aplysia. This latter program of neuroscience research has emanated from the ground-breaking work of another Nobel laureate, Eric Kandel, and his colleagues at Columbia University College of Physicians and Surgeons. Hard Wired is an album by Front Line Assembly, released in 1995. ... From Texture of the Nervous System of Man and the Vertebrates by Santiago Ramón y Cajal. ... The references in this article would be clearer with a different and/or consistent style of citation, footnoting or external linking. ... The hippocampus is structurally located inside the medial temporal lobe of the brain. ... The olfactory bulb is a structure of the vertebrate forebrain involved in olfaction, the perception of odors. ... The term Neural Darwinism is used in two different ways. ... Gerald Maurice Edelman (born July 1, 1929) is a biologist who won the Nobel Prize in Physiology or Medicine in 1972 for his work on the immune system. ... Classical conditioning (also Pavlovian conditioning, respondent conditioning or alpha-conditioning) is a type of associative learning. ... Species See text. ... Eric Richard Kandel (born November 7, 1929) is a neuroscientist who won a Nobel Prize in the year 2000 for his research on the physiological basis of memory storage in neurons. ... Seal of the Columbia University College of Physicians and Surgeons The Columbia University College of Physicians and Surgeons, abbreviated P&S, is a graduate school of Columbia University located on the health sciences campus in the Washington Heights neighborhood of Manhattan. ...

Brain plasticity during operation of brain-machine interfaces

Brain-machine interface (BMI) is a rapidly developing field of Neuroscience. According to the results obtained by Mikhail Lebedev, Miguel Nicolelis and their colleagues (Lebedev et al. 2005), operation of BMIs results in incorporation of artificial actuators into brain representations. The scientists showed that modifications in neuronal representation of the monkey's hand and the actuator that was controlled by the monkey brain occurred in multiple cortical areas while the monkey operated a BMI. In these single day experiments, monkeys initially moved the actuator by pushing a joystick. After mapping out the motor neuron ensembles, control of the actuator was switched to the model of the ensembles so that the brain activity, and not the hand, directly controlled the actuator. The activity of individual neurons and neuronal populations became less representative of the animal's hand movements while representing the movements of the actuator. Presumably as a result of this adaptation, the animals could eventually stop moving their hands yet continue to operate the actuator. Thus, during BMI control, cortical ensembles plastically adapt, within tens of minutes, to represent behaviorally significant motor parameters, even if these are not associated with movements of the animal's own limb. A brain-computer interface (BCI) or direct neural interface is literally a direct technological interface between a brain and a computer not requiring any motor output from the user. ... A brain-computer interface (BCI) or direct neural interface is literally a direct technological interface between a brain and a computer not requiring any motor output from the user. ... Drawing of the cells in the chicken cerebellum by S. Ramón y Cajal Neuroscience is a field that is devoted to the scientific study of the nervous system. ... Mikhail A. Lebedev (Михаил Альбертович Лебедев) is a Russian-born (1963) Neuroscientist known for his neurophysiological studies of cerebral cortex. ... Miguel Nicolelis, MD, PhD, is a Brazilian scientist best known for his pioneering work in reading monkey thought. He implanted electrode arrays into the monkey brain that were able to detect monkeys motor intent and thus able to control reaching and grasping movements performed by a robotic arm. ...

Active laboratory groups include those of John Donoghue at Brown, Richard Andersen at Caltech, Krishna Shenoy at Stanford, Nicholas Hatsopoulos of University of Chicago, Andy Schwartz at Pitt, Sandro Mussa-Ivaldi at Northwestern and Miguel Nicolelis at Duke. Donoghue and Nicolelis' groups have independently shown that animals can control external interfaces in tasks requiring feedback, with models based on activity of cortical neurons, and that animals can adaptively change their minds to make the models work better. Donoghue's group took the implants from Richard Normann's lab at Utah (the "Utah" array), and improved it by changing the insulation from polyimide to parylene-c, and commercialized it through the company Cyberkinetics. These efforts are the leading candidate for the first human trials on a broad scale for motor cortical implants to help quadriplegic or trapped patients communicate with the outside world. Cyberkinetics was cofounded by John Donoghue, Nicho Hatsopoulos, Mijail Serruya, and Gerhard Friehs of Brown University. ...

Thought and neuroplasticity

The Dalai Lama suggested the theory that the simple act of thinking could change the mind. Most scientists believed this idea to be false, but they agreed to test the theory. One such experiment involved a group of eight Buddist monk adepts and ten volunteers who had been trained in meditation for one week. All the people tested were told to meditate on compassion and love. Two of the controls, and all of the monks, experienced an increase in the number of gamma waves in their brain during meditation. As soon as they stopped meditating, the volunteers' gamma wave production returned to normal, while the monks, who had meditated on compassion for more than 10,000 hours in order to attain the rank of adept, did not experience a decrease to normal in the gamma wave production after they stopped meditating. The synchronized gamma wave area of the monks' brains during meditation on love and compassion was found to be larger than that corresponding activation of the volunteers' brains.^[2][3]

See also

• Tetris effect

The Tetris effect refers to the ability of any activity to which people devote sufficient time and attention to begin to dominate their thoughts, images, and dreams. ...

Notes

Further reading

• Donoghue JP, "Connecting cortex to machines: recent advances in brain interfaces." Nat Neurosci., 2002 Nov;5 Suppl:1085-8.
• Flor, H. (2002). "Phantom limb pain: Characteristics, causes, and treatments." Lancet Neurology, 1: 182-189.
• Lebedev, M.A., Carmena, J.M., O’Doherty, J.E., Zacksenhouse, M., Henriquez, C.S., Principe, J.C., Nicolelis, M.A.L. (2005), Cortical ensemble adaptation to represent actuators controlled by a brain-machine interface. J. Neurosci. 25: 4681-4693 [1]
• Ramachandran & Hirstein (1998). "The perception of phantom limbs", Brain, 121: 1603-1630.
• Monkeys Treat Robot Arm as Their Own
• Monkeys treat robot arm as bonus appendage
• Monkey See, Robotics Do
• Meditation Alters Brain Structure