TED Talks - آموزش زبان

🔴Ode To The Only Black Kid In The Class I'm Clint Smith and this is "Ode to the Only Black Kid in the Class." You, it seems, are the manifestation of several lifetimes of toil. Brown v. Board in flesh. Most days the classroom feels like an antechamber. You are deemed expert on all things Morrison, King, Malcolm, Rosa. Hell, weren’t you sitting on that bus, too? You are every- body’s best friend until you are not. Hip-hop lyricologist. Presumed athlete. Free & Reduced sideshow. Exception and caricature. Too black and too white all at once. If you are successful it is because of affirmative action. If you fail it is because you were destined to. You are invisible until they turn on the Friday night lights. Here you are star before they render you asteroid. Before they watch you turn to dust. #TED_Ed #Animation #Poetry #Race #Inequality #Spoken_Word 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

🔴Ode To The Only Black Kid In The Class #TED_Ed #Animation #Poetry #Race #Inequality #Spoken_Word 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

🔴🔴برگزارى كلاس هاى انلاين ويژه مهارت اسپيكينگ، ارتقاء نمره 6.5 به 7 🔔مشاهده نمرات زبان آموزان از اینجا جهت اطلاع از شرايط ثبت نام با ID زير تماس بگيريد: @IELTSCANADAAUSTRALIA عضويت در كانال👇🏻👇🏻 Join ➣ @BestIELTS ☜ www.bestielts.ir

🔴What foods did your ancestors love? #History #Food #Indigenous_Peoples #Culture #Ancient_World #TEDx 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

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This distinction between "knowing that" and "knowing how" has underpinned all memory research since. H.M. died at the age of 82 after a mostly peaceful life in a nursing home. Over the years, he had been examined by more than 100 neuroscientists, making his the most studied mind in history. Upon his death, his brain was preserved and scanned before being cut into over 2000 individual slices and photographed to form a digital map down to the level of individual neurons, all in a live broadcast watched by 400,000 people. Though H.M. spent most of his life forgetting things, he and his contributions to our understanding of memory will be remembered for generations to come. #Consciousness #Brain #Memory #Medical_Research #Disease #Medicine #TED_Ed #Health_Care #Physiology #Human_Body #Healthcare #History #Science #Health #Animation #Surgery 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

🔴What happens when you remove the hippocampus On September 1st, 1953, William Scoville used a hand crank and a cheap drill saw to bore into a young man's skull, cutting away vital pieces of his brain and sucking them out through a metal tube. But this wasn't a scene from a horror film or a gruesome police report. Dr. Scoville was one of the most renowned neurosurgeons of his time, and the young man was Henry Molaison, the famous patient known as "H.M.", whose case provided amazing insights into how our brains work. As a boy, Henry had cracked his skull in an accident and soon began having seizures, blacking out and losing control of bodily functions. After enduring years of frequent episodes, and even dropping out of high school, the desperate young man had turned to Dr. Scoville, a daredevil known for risky surgeries. Partial lobotomies had been used for decades to treat mental patients based on the notion that mental functions were strictly localized to corresponding brain areas. Having successfully used them to reduce seizures in psychotics, Scoville decided to remove H.M.'s hippocampus, a part of the limbic system that was associated with emotion but whose function was unknown. At first glance, the operation had succeeded. H.M.'s seizures virtually disappeared, with no change in personality, and his IQ even improved. But there was one problem: His memory was shot. Besides losing most of his memories from the previous decade, H.M. was unable to form new ones, forgetting what day it was, repeating comments, and even eating multiple meals in a row. When Scoville informed another expert, Wilder Penfield, of the results, he sent a Ph.D student named Brenda Milner to study H.M. at his parents' home, where he now spent his days doing odd chores, and watching classic movies for the first time, over and over. What she discovered through a series of tests and interviews didn't just contribute greatly to the study of memory. It redefined what memory even meant. One of Milner's findings shed light on the obvious fact that although H.M. couldn't form new memories, he still retained information long enough from moment to moment to finish a sentence or find the bathroom. When Milner gave him a random number, he managed to remember it for fifteen minutes by repeating it to himself constantly. But only five minutes later, he forgot the test had even taken place. Neuroscientists had though of memory as monolithic, all of it essentially the same and stored throughout the brain. Milner's results were not only the first clue for the now familiar distinction between short-term and long-term memory, but show that each uses different brain regions. We now know that memory formation involves several steps. After immediate sensory data is temporarily transcribed by neurons in the cortex, it travels to the hippocampus, where special proteins work to strengthen the cortical synaptic connections. If the experience was strong enough, or we recall it periodically in the first few days, the hippocampus then transfers the memory back to the cortex for permanent storage. H.M.'s mind could form the initial impressions, but without a hippocampus to perform this memory consolidation, they eroded, like messages scrawled in sand. But this was not the only memory distinction Milner found. In a now famous experiment, she asked H.M. to trace a third star in the narrow space between the outlines of two concentric ones while he could only see his paper and pencil through a mirror. Like anyone else performing such an awkward task for the first time, he did horribly. But surprisingly, he improved over repeated trials, even though he had no memory of previous attempts. His unconscious motor centers remembered what the conscious mind had forgotten. What Milner had discovered was that the declarative memory of names, dates and facts is different from the procedural memory of riding a bicycle or signing your name. And we now know that procedural memory relies more on the basal ganglia and cerebellum, structures that were intact in H.M.'s brain.

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🔴The journey through loss and grief #Beauty #Cancer #Death #Communication #Family #Happiness #Illness #Humanity #Love #Life #Personal_Growth #Parenting #Writing #Relationships 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

Now, back to that meal. What happens if in place of the healthy, balanced dish, you eat sugar-rich food instead? If you rarely eat sugar or don't eat much at a time, the effect is similar to that of the balanced meal. But if you eat too much, the dopamine response does not level out. In other words, eating lots of sugar will continue to feel rewarding. In this way, sugar behaves a little bit like a drug. It's one reason people seem to be hooked on sugary foods. So, think back to all those different kinds of sugar. Each one is unique, but every time any sugar is consumed, it kickstarts a domino effect in the brain that sparks a rewarding feeling. Too much, too often, and things can go into overdrive. So, yes, overconsumption of sugar can have addictive effects on the brain, but a wedge of cake once in a while won't hurt you. #TED_Ed #Health #Brain #Food #Health_Care #Animation #Public_Health #Addiction 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning

🔴How Sugar Affects The Brain Picture warm, gooey cookies, crunchy candies, velvety cakes, waffle cones piled high with ice cream. Is your mouth watering? Are you craving dessert? Why? What happens in the brain that makes sugary foods so hard to resist? Sugar is a general term used to describe a class of molecules called carbohydrates, and it's found in a wide variety of food and drink. Just check the labels on sweet products you buy. Glucose, fructose, sucrose, maltose, lactose, dextrose, and starch are all forms of sugar. So are high-fructose corn syrup, fruit juice, raw sugar, and honey. And sugar isn't just in candies and desserts, it's also added to tomato sauce, yogurt, dried fruit, flavored waters, or granola bars. Since sugar is everywhere, it's important to understand how it affects the brain. What happens when sugar hits your tongue? And does eating a little bit of sugar make you crave more? You take a bite of cereal. The sugars it contains activate the sweet-taste receptors, part of the taste buds on the tongue. These receptors send a signal up to the brain stem, and from there, it forks off into many areas of the forebrain, one of which is the cerebral cortex. Different sections of the cerebral cortex process different tastes: bitter, salty, umami, and, in our case, sweet. From here, the signal activates the brain's reward system. This reward system is a series of electrical and chemical pathways across several different regions of the brain. It's a complicated network, but it helps answer a single, subconscious question: should I do that again? That warm, fuzzy feeling you get when you taste Grandma's chocolate cake? That's your reward system saying, "Mmm, yes!" And it's not just activated by food. Socializing, sexual behavior, and drugs are just a few examples of things and experiences that also activate the reward system. But overactivating this reward system kickstarts a series of unfortunate events: loss of control, craving, and increased tolerance to sugar. Let's get back to our bite of cereal. It travels down into your stomach and eventually into your gut. And guess what? There are sugar receptors here, too. They are not taste buds, but they do send signals telling your brain that you're full or that your body should produce more insulin to deal with the extra sugar you're eating. The major currency of our reward system is dopamine, an important chemical or neurotransmitter. There are many dopamine receptors in the forebrain, but they're not evenly distributed. Certain areas contain dense clusters of receptors, and these dopamine hot spots are a part of our reward system. Drugs like alcohol, nicotine, or heroin send dopamine into overdrive, leading some people to constantly seek that high, in other words, to be addicted. Sugar also causes dopamine to be released, though not as violently as drugs. And sugar is rare among dopamine-inducing foods. Broccoli, for example, has no effect, which probably explains why it's so hard to get kids to eat their veggies. Speaking of healthy foods, let's say you're hungry and decide to eat a balanced meal. You do, and dopamine levels spike in the reward system hot spots. But if you eat that same dish many days in a row, dopamine levels will spike less and less, eventually leveling out. That's because when it comes to food, the brain evolved to pay special attention to new or different tastes. Why? Two reasons: first, to detect food that's gone bad. And second, because the more variety we have in our diet, the more likely we are to get all the nutrients we need. To keep that variety up, we need to be able to recognize a new food, and more importantly, we need to want to keep eating new foods. And that's why the dopamine levels off when a food becomes boring.

🔴How Sugar Affects The Brain #TED_Ed #Health #Brain #Food #Health_Care #Animation #Public_Health #Addiction 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

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🔴Why Is Colonialism (Still) Romanticized #Global_Issues #History #Philosophy #TEDx #Society #Storytelling 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

♦️یه پست خیلی خوب در خصوص لیسنینگ👇👇 https://www.instagram.com/p/CKg5KVKFxou/?igshid=1e8d6mxaw2gkp

🔴The Surprising Effects Of Pregnancy Muscles and joints shift and jostle. The heart’s pounding rhythm speeds up. Blood roars through arteries and veins. Over the course of a pregnancy, every organ in the body changes. Ignited by a range of hormones, these changes begin as soon as pregnancy begins. Just days after fertilization, the embryo implants in the lining of the uterus. Because its DNA doesn’t exactly match the mother’s, the immune system should theoretically recognize it as an invader, attack, and destroy it, like it would bacteria or other harmful microbes. That’s the challenge: the mother’s immune system needs to protect both her and the fetus, but can’t act as it usually does. What happens is not as simple as decreasing the immune response. Instead, it’s a complex interaction we’re just beginning to understand, involving many different types of immune cells— some of which seem to protect the fetus from attack by other immune cells. The body also creates an antibacterial plug made of mucus on the cervix, which keeps germs away and stays sealed until labor. As a pregnancy progresses, the uterus expands upward and outward with the growing fetus. To make room, hormones called progesterone and relaxin signal muscles to loosen. The muscles that propel food and waste through the digestive tract also loosen, which makes them sluggish, causing constipation as passage through the tract slows down. Loosened muscles at the top of the stomach might allow acid to escape into the esophagus and throat, causing heartburn and reflux. These changes can worsen morning sickness, which is caused in part by hormone HCG— and can also happen at other times of day. As the uterus grows, it pushes on the diaphragm, the muscle that expands and contracts the chest with each breath. This limits the diaphragm’s range. To compensate, the hormone progesterone acts as a respiratory stimulant, making the pregnant woman breathe faster so both she and the baby can both get enough oxygen with less lung capacity. This all may leave the pregnant woman feeling short of breath. Meanwhile, the kidneys make more erythropoietin, a hormone that increases red blood cell production. The kidneys also keep extra water and salt rather than filtering it out into urine to build up the volume of the blood. A pregnant woman’s blood volume increases by 50% or more. But it’s also a bit diluted, because it only has 25% more red blood cells. Usually, the body makes blood cells using iron from our food. But during pregnancy, the fetus is also building its own blood supply from nutrients in the mother’s food— leaving less iron and other nutrients for the mother. The heart has to work extra hard to pump all this blood through the body and placenta. A pregnant woman’s heart rate increases, but we don’t fully understand how blood pressure changes in a healthy pregnancy— an important area of research, because some of the most serious complications are related to the heart and blood pressure. The expanding uterus may press on veins— causing fluid buildup in the legs and feet. If it presses on a large vein called the inferior vena cava, it might interfere with blood returning to the heart, causing a dizzying drop in blood pressure after standing for too long. Some of these changes start to reverse even before birth. Shortly before delivery, the fetus drops down, decreasing the pressure on the diaphragm and allowing the pregnant woman to take deeper breaths. During labor and birth, much of the extra fluid in the body is lost when the water breaks. The uterus shrinks back down in the weeks after birth. Like the rest of the body, pregnancy affects the brain— but its effects here are some of the least understood. Recent studies show differences in brain scans after pregnancy and early parenting, and suggest that these changes are adaptive. #TED_Ed #Animation #Pregnancy #Education #Women #Science #Human_Body #Medical_Research #Biology #Brain 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

🔴The Surprising Effects Of Pregnancy #TED_Ed #Animation #Pregnancy #Education #Women #Science #Human_Body #Medical_Research #Biology #Brain 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

🔴You Are Not Alone In Your Loneliness #Creativity #Compassion #Personal_Growth #Writing #Empathy #Visualizations #Art #Humanity #Community #Relationships 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜

🔴Does Stress Affect Your Memory? You spend weeks studying for an important test. On the big day, you wait nervously as your teacher hands it out. You’re working your way through, when you’re asked to define ‘ataraxia.’ You know you’ve seen it before, but your mind goes blank. What just happened? The answer lies in the complex relationship between stress and memory. There are many types and degrees of stress and different kinds of memory, but we’re going to focus on how short-term stress impacts your memory for facts. To start, it helps to understand how this kind of memory works. Facts you read, hear, or study become memories through a process with three main steps. First comes acquisition: the moment you encounter a new piece of information. Each sensory experience activates a unique set of brain areas. In order to become lasting memories, these sensory experiences have to be consolidated by the hippocampus, influenced by the amygdala, which emphasizes experiences associated with strong emotions. The hippocampus then encodes memories, probably by strengthening the synaptic connections stimulated during the original sensory experience. Once a memory has been encoded, it can be remembered, or retrieved, later. Memories are stored all over the brain, and it’s likely the prefrontal cortex that signals for their retrieval. So how does stress affect each of these stages? In the first two stages, moderate stress can actually help experiences enter your memory. Your brain responds to stressful stimuli by releasing hormones known as corticosteroids, which activate a process of threat-detection and threat-response in the amygdala. The amygdala prompts your hippocampus to consolidate the stress-inducing experience into a memory. Meanwhile, the flood of corticosteroids from stress stimulates your hippocampus, also prompting memory consolidation. But even though some stress can be helpful, extreme and chronic stress can have the opposite effect. Researchers have tested this by injecting rats directly with stress hormones. As they gradually increased the dose of corticosteroids, the rats’ performance on memory tests increased at first, but dropped off at higher doses. In humans, we see a similar positive effect with moderate stress. But that only appears when the stress is related to the memory task— so while time pressure might help you memorize a list, having a friend scare you will not. And the weeks, months, or even years of sustained corticosteroids that result from chronic stress can damage the hippocampus and decrease your ability to form new memories. It would be nice if some stress also helped us remember facts, but unfortunately, the opposite is true. The act of remembering relies on the prefrontal cortex, which governs thought, attention, and reasoning. When corticosteroids stimulate the amygdala, the amygdala inhibits, or lessens the activity of, the prefrontal cortex. The reason for this inhibition is so the fight/flight/freeze response can overrule slower, more reasoned thought in a dangerous situation. But that can also have the unfortunate effect of making your mind go blank during a test. And then the act of trying to remember can itself be a stressor, leading to a vicious cycle of more corticosteroid release and an even smaller chance of remembering. So what can you do to turn stress to your advantage and stay calm and collected when it matters the most? First, if you know a stressful situation like a test is coming, try preparing in conditions similar to the stressful environment. Novelty can be a stressor. Completing practice questions under time pressure, or seated at a desk rather than on a couch, can make your stress response to these circumstances less sensitive during the test itself. Exercise is another useful tool. #TED_Ed #Health #Memory 🎙Join ➣ @TEDTalksLearning ☜ 🎙Join ➣ @TEDTalksLearning ☜