An individual animal’s history of interaction with the environment—its “experience”—helps to shape neural circuitry and thus determines subsequent response.
In some cases, experience functions primarily as a switch to activate innate behaviours. More often, however, experience during a specific time in early life (referred to as a “critical period”) helps shape the adult behavioural repertoire.
Critical periods influence behaviours as diverse as maternal bonding and the acquisition of language.
Over the first few years of life, the brain grows rapidly. As each neurone 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 neurone to neurone. At birth, each neurone in the cerebral cortex has approximately 2,500synapses. By the time an infant is two or three years old, the number of synapses is approximately 15,000synapses per neurone (Gopnick, et al., 1999)[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.]. 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 pruningeliminates 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. Neurones must have a purpose to survive. Without a purpose, neurones die through a process called apoptosis in which neurones 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. Source: https://faculty.washington.edu/chudler/plast.html
Although it is possible to define the behavioural consequences of critical periods for these complex functions, their biological basis has been more difficult to understand. The most accessible and thoroughly studied example of a critical period is the one pertinent to the establishment of normal vision.
These studies show that experience is translated into patterns of neuronal activity that influence the function and connectivity of the relevant neurones. In the visual system, and other systems as well, competition between inputs with different patterns of activity is an important determinant of adult connectivity. Correlated patterns of activity in afferent axons tend to stabilise connections and conversely a lack of correlated activity can weaken or eliminate connections.
When normal patterns of activity are disturbed during a critical period in early life (experimentally in animals or by pathology in humans), the connectivity in the visual cortex is altered, as is the visual function. If not reversed before the end of the critical period, these structural and functional alterations of brain circuitry are difficult or impossible to change.
In normal development, the influence of activity on neural connectivity presumably enables the maturing brain to store the vast amounts of information that reflect the specific experience of the individual.
The capacity of the nervous system to change—generally referred to asneural plasticity—is obvious during the development of neural circuits.
The adult nervous system exhibits a plastic change in a variety of circumstances. Studies of behavioural plasticity in several invertebrates and of the neuromuscular junction suggest that modification of synaptic strength is responsible for much of the ongoing change in synaptic function in adults.
Synapses exhibit many forms of plasticity that occur over a broad temporal range. At the shortest times (seconds to minutes), facilitation, post-tetanic potentiation, and depression provide rapid but transient modifications based on alterations in Ca2+ signalling and synaptic vesicle pools at recently active synapses.
Some patterns of synaptic activity in the CNS produce a long-lasting increase in synaptic strength known as long-term potentiation(LTP), whereas other patterns of activity produce a long-lasting decrease in synaptic strength, known as long-term depression(LTD). LTP and LTDare broad terms that describe only the direction of change in synaptic efficacy; in fact, different cellular and molecular mechanisms can be involved in producing LTP or LTD at different synapses. In general, these different forms of synaptic plasticity are produced by different histories of activity and are mediated by different complements of intracellular signal transduction pathways in the nerve cells involved.
Functional changes in the somatic sensory cortex of an owl monkey following amputation of a digit.
(A) Diagram of the somatic sensory cortex in the owl monkey, showing the approximate location of the hand representation.
(B) The hand representation in the animal before amputation; the numbers correspond to different digits.
(C)The cortical map determined in the same animal two months after amputation of digit 3. The map has changed substantially; neurones in the area formerly responding to stimulation of digit 3 now respond to stimulation of digits 2 and 4. (After Merzenich et al., 1984.)
Longer-lasting forms of synaptic plasticity such as LTP and LTD are also based on Ca2+ and other intracellular second messengers. In these more enduring forms of plasticity, protein phosphorylation and changes in gene expression greatly outlast the period of synaptic activity and can yield persistent changes in synaptic strength (hours to days or longer). Different brain regions evidently use one or more of these strategies to learn new behaviours and acquire new memories.
Functional expansion of a cortical representation by a repetitive behavioural task. An owl monkey was trained in a task that required heavy usage of digits 2, 3, and occasionally 4. The map of the digits in the primary somatic sensory cortex prior to training is shown. After several months of “practice,” a larger region of the cortex contained neurones activated by the digits used in the task. Note that the specific arrangements of the digit representations are somewhat different from the monkey shown in Figure 24.14, indicating the variability of the cortical representation of particular animals. (After Jenkins et al., 1990.)
Different responses to injury in the peripheral (A) and central (B) nervous systems. Damage to a peripheral nerve leads to series of cellular responses, collectively called Wallerian degeneration (after Augustus Waller, the nineteenth century English physician who first described these phenomena). Distal to the site of injury, axons disconnected from their cell bodies degenerate, and invading macrophages remove the cellular debris. Schwann cells that formerly ensheathed the axons proliferate, align to form longitudinal arrays and increase their production of neurotrophic factors that can promote axon regeneration. Schwann cell surfaces and the extracellular matrix also provide a favourable substratum for the extension of regenerating axons. In the CNS, the removal of myelin debris is relatively slow, and the myelin membranes produce inhibitory molecules that can block axon growth. Astrocytes at the site of injury also interfere with regeneration. Proximal to the injury, neurone cell bodies react to peripheral nerve injury by inducing expression of growth-related genes, including those for major components of axonal growth cones. Following CNS injury, however, neurones typically fail to activate these growth-associated genes. As a result, axonal damage in the retina, spinal cord, or the rest of the brain leads to permanent blindness, paralysis, and other disabilities.
Neuronal damage can also induce plastic changes. Peripheral neurones can regenerate axons following the damage, though the capacity of CNS axons to regenerate is severely limited. In addition, neural stem cells are present in certain regions of the adult brain, allowing the production of some new neurones in a few brain regions. These various forms of adult plasticity can modify the function of the mature brain and provide some hope for improving the limited ability of the CNS to recover successfully from trauma and neurological disease.
Source: Neuroscience, 3rd edition
Editors: Dale Purves, George J Augustine, David Fitzpatrick, Lawrence C Katz, Anthony-Samuel LaMantia, James O McNamara, and S Mark Williams.
Sunderland (MA): Sinauer Associates; 2004.
“Impressionable minds get influenced by adult behaviour and media. Peer pressure affects not only children and teenagers, it is also prevalent in adults. it shows a lack of self esteem when people do not have the courage to say ‘no, thank you’ and stay away from negative influences?”
An eagle’s egg was placed in the nest of a prairie chicken. The eagle did what the prairie chickens did. It scratched in the dirt for seeds. It clucked and cackled. It never flew more than a few feet because that is what the prairie chickens did. One day he/she saw an eagle flying gracefully and majestically in the open sky. He/She asked the prairie chickens: “What is the beautiful bird?” The chickens replied, “That is an eagle. He/She is an outstanding bird, but you cannot fly like him because you are just a prairie chicken.” So the eagle never gave it a second thought, believing that to be the truth. He/She lived the life of and died a prairie chicken, depriving himself/Herself of his/her heritage because of his/her lack of vision. What a waste! He/She was born to win, but conditioned to loose.
The same thing is true for most of the people. The unfortunate part of life is as Oliver Wendall Holmessaid,
“Most people go to their graves, with music still in them.”
We don’t achieve excellence because of our own lack of vision.
If you want to soar like an eagle, you have to learn the ways of an eagle. If you associate with achievers, you will become one. If you associate with thinkers, you will become one. If you associate with givers you will become one. If you will associate with negative people, you will become one.
Whenever people succeed in life, people will take cracks at them and try to pull them down. When you refuse to fight petty people, you win. In martial arts, they teach that when someone takes a crack at you, instead of blocking you should step away. Why? Blocking requires energy. Why not use it more productively? Similarly, in order to fight petty people, you have to come down to their level. That is what they want, because now you are one of them.
Don’t let negative people drag you down.
Remember that a person’s character is not only judged by the company they keep but also the company they avoid.
At some institutions/establishments, such are the tactics that are employed by the administration, so that they can easily create a stranglehold over their students and employees. Residents are used to target fellow residents.
“Are we here for becoming good doctors”.
But shouldn’t a good doctor be also a good human being.
This is the reason why there is an increased spate of suicides at some premier medical institutions in India: but the blame is put on increased work pressure all in the name of maintaining ‘QUALITY‘.
I quote “The whole educational and professional training system is a very elaborate filter, which just weeds out people who are too independent, and who think for themselves, and who don’t know how to be submissive, and so on — because they’re dysfunctional to the institutions.”
― Noam Chomsky
“The smart way to keep people passive and obedient is to strictly limit the spectrum of acceptable opinion, but allow very lively debate within that spectrum….”
― Noam Chomsky, The Common Good
“All over the place, from the popular culture to the propaganda system, there is constant pressure to make people feel that they are helpless, that the only role they can have is to ratify decisions and to consume.”
― Noam Chomsky
[within the context of above mentioned institutions and establishments.]
I was shocked to recognise that for these acts they even employ doctors from Indian armed forces that get admitted in these institutions, purely on sponsored seats. Aren’t we a sovereign, socialist, secular, democratic republic, or military dictatorship is deliberately allowed to linger in nooks and corners of these institutions of national importance to achieve some desired but blatantly illegal objectives.
Even intelligence agencies are employed to closely monitor every aspect of residents’ lives, they are entrusted with security of the consultants/faculty of these institutions. They want to control every aspect of the lives of their residents and future consultants.
I thought we were freed from colonial rule way back in 1947! or is it ?
But we should only abide by the ‘TheConstitution of India’ which is the supreme law of India the basic tenets of which includes
JUSTICE, social, economic and political; LIBERTY of thought, expression, belief, faith and worship;
EQUALITY of status and of opportunity;
and to promote among them all
FRATERNITY assuring the dignity of the individual and the unity and integrity of the Nation
“It is the responsibility of intellectuals to speak the truth and expose lies.”
― Noam Chomsky
“I was never aware of any other option but to question everything.”
― Noam Chomsky
Recently, I came across the news of opening up of 17 new A.I.I.M.S or ‘All India Institute of Medical Sciences’ by Health minister of India. Do we really need that many super speciality centres in a developing country like India, with almost 1/3rd of the population living at the bare minimum of <$1.25per day; the answer is ‘YES’. With a population already having crossed one billion mark at the turn of the century; it is a necessity that one has to learn to live with.
But with current system of affairs where honesty, sincerity, credibility and integrity has no value (here we tend to put a price tag on everything) where unscrupulous and crooked individuals rule the roost;
Can India truly become a global powerhouse in the field of medical education?
A question which the concerned authorities be made to answer.
Indiais a Republic because it ruled by a bunch of representatives, backed by a body of law. This is in contrast to a monarchy, where one person can dictate terms without heeding to the existing laws. When the Constitution of India was officially brought to force on Jan 26, 1950, India formally became a republic and the day is celebrated as the Republic Day. Because then the representatives had a rule of law to guide them.
Since India is a democratic republic, even if the majority of the population, through the Parliament, want a certain law, it can still be struck down by the Supreme Court of India. Because, it is the constitution that is supreme, which acts as a guide to formulate various policies and laws, sometimes, even accommodating whims of the public at large.
That said, in the modern parlance, most democracies are republics too. However, a few centuries ago these terms means were quite opposite of each other. In a traditional democracy, it is all about people and their vote. People gathered in a town hall and then voted which direction something should move. It doesn’t really matter if that decision is consistent with past decision, or problems that might be faced by a country in future, as they do not have the required expertise.
As you can see, this can be quite chaotic and deadly. The people who vote are the same people who “like” and dislike various stuff on Facebook [https://en.wikipedia.org/wiki/Facebook].
Albert Einstein recognized individual and unique God given glory inside each creation. Each gifting flourishes in a given predetermined environment if you allow it to be. The absence of a particular gift limiting performance in a particular environment does not connote stupidity. He uses the analogy of a ‘fish climbing a tree’ to underscore the fact that fish do not have the physical and genetic make up for climbing but excellent in water as we all know. You may not be an excellent accountant but an excellent historian. You may not be a good chef or a good cook but an excellent eater. You enjoy everything edible thrown at you. In other words everyone is a genius. You need to identify your area of exceptional performance to let your glory shine. If you cannot be a fish, be a panda. If you can’t be an elephant, be an insect or if you can’t be a rock star, be a ferocious boxer. William Odoch
It is not about smartness or stupidity, every citizen has a different level and area of expertise, I believe everyone is different, has a different talent, interests, weaknesses and strengths. In order for one to thrive and excel, one needs to be put into the right environment where they get to exercise their strengths and passion, not their weaknesses. For example, a creative, visual person would struggle in a data-driven environment. A superb accountant would probably do a poor job at coming up with a logo design. A designer would also do poorly at crunching numbers. [Mo Seetubtim]
I am a doctor but I am extremely stupid at singing because that is not my area of talent or expertise.
Hence, not every citizen has the ability to understand, tricks and nuisances of politics, nor the ability or talent to judge, formulate and interpret various policies, and laws, that can decide the future of an entire nation, or for that matter the whole planet.
This fear was known for centuries and had disturbed the U.S.A founding fathers quite a bit.
The Declaration of Independence: A Transcription
IN CONGRESS, July 4, 1776.
The unanimous Declaration of the thirteen united States of America,
U.S.A- the United States of America (USA), commonly referred to as the United States (U.S.) or America, is a federal republic composed of 50 states, a federal district, five major territories and various possessions. https://en.wikipedia.org/wiki/United_States
Thus, the ‘Democracy’was tempered with the ‘Republic’where the people don’t directly decide policies but elect representatives for a few years, who will vote on the policies and run the nation in accordance with the body of law. Indiaand other democracies got inspired from the U.S.A model and these days the term ‘democracy’ has become the term to mean the U.S.A style of ‘democratic republic’. However, there are still various types of democratic ideas without the republic idea [say referendums] and such things must always be tempered/controlled [one reason why Indian constitution doesn’t allow referendums to decide sovereignty]
Peer pressure is when the social media platform is being used for detrimental purposes like — bullying someone; when someone pretends to like EDM (Electronic dance music) music just because it is popular with others in their social circle.
Peer influence on Facebook has also been found a contributing factor for teenage alcohol and drug consumption; adoption of fashion and undertaking unnatural cosmetic treatments to get a particular ‘look’; mass bunking in colleges.
Even, joining Facebook or any other social media site is often an action taken under peer pressure. This behaviour is born out of the fear of missing out and the fear that one will be left out of their peer group which eventually leads to stress and depression.
On the other hand, Facebook/social media enables peer power. It empowers today’s youth with collective strength, it helps them contribute to change with far reaching consequences and the technology has been a catalyst in today’s youth being conscious and confident; it would include the recent ‘selfie‘ culture.
Peer power is highlighted when the country’s youth participated in larger number to contribute to matters of national importance like the Anna Hazare movement, the AAP movement, large voting turnouts; the revolution at Tahrir Square where social media helped people mobilise themselves and topple a dictator.
Power is when students can connect with and befriend professors leading to more meaningful knowledge sharing.
It has lead to the success of independent music and films, which have benefitted from crowd sourcing and crowd funding; it has lead to the creation of flash mobs; the success of fundraising for cancer research under the Terry Fox runs; it has lead to important projects like Wikipedia; it enables customers to benefit from peer reviews and opinions and has made companies more sensitive towards customers.
With all these boons, we have only started with harnessing the power of peer influence on the social media. In the years to come, we will see more revolutions in this space. Also, the generation currently contributing to this phenomenon is young and it is when they reach the age when they can meaningfully contribute to a society that its real effects will be seen. In the good and bad of peer influence through social media, I would like to side with the good, as I believe that the power surpasses the pressure.
I feel that youth sharing their feelings, fights, breakups, and troubles on the social media should be encouraged, as there will be someone who will pick this up and initiate a conversation. There have been numerous instances when such an act has lead to an aversion of suicidal tendencies.
Yes there are grave issues with this trend, but that is true for all things from a pen to a gun; they have the power to save and to kill. It is when we focus on the positives and deal with the negatives that we harness the real power of trends and technologies.