Measurings of brain activity during sleep walking on a monitor

Sleepwalking: What Happens in the Brain?

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<p>Eyes glazed and hands outstretched, some sleepwalkers look like they came straight out of a zombie movie. Other sleepwalkers can paint, eat, or even drive—often without any memory of these actions after they wake up. How is it possible for people to do these impressive feats when they should be out cold?</p>
<p>“Sleepwalking is a glitch in the system. Our identity is not in control,” said Dr. Emmanuel During from the Icahn School of Medicine at Mount Sinai in an interview for the NOVA documentary “<a href="https://www.pbs.org/wgbh/nova/video/your-brain-whos-in-control/">Your Brain: Who's in Control?</a>”</p>
<p>Sleepwalking—also called somnambulism—is a common type of sleeping disorder that affects up to four percent of adults. Though scientists do not fully understand the exact neuroscience behind sleepwalking, they do know this: Sleepwalking occurs when different parts of your brain are stuck between deep sleep and wakefulness, causing confusion between your brain and body.</p>
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<p>Normally, your brain is whirring with activity during the day, but after you doze off, it begins to quiet down. The first few stages of sleep occur as your brain prepares itself for rest, decreasing your ability to react to external stimuli and your muscle activity. Soon, your brainwaves also drop down into slow, monotonous motion. This signals that you’ve entered deep sleep.</p>
<p>During sleepwalking, some parts of the brain are suddenly yanked out of their slumber. These include the motor cortex, which is in charge of movement; the visual cortex, which processes visual information; and additional parts of the brain that coordinate behaviors like balance and speech.</p>
<p>Other areas, however, remain dark. One key region that remains asleep is the prefrontal cortex, the brain’s decision maker. When you’re awake, it’s in charge of self-awareness and deliberate choices. Yet during sleepwalking, the awoken areas can work mostly independently of the prefrontal cortex—which is stuck in such deep sleep that it’s hard to wake up. That results in an inability for rational thought, which means it’s also easier for sleepwalkers to do abnormal or nonsensical things that they otherwise wouldn’t.</p>
<p>In other words, everything that takes place during sleepwalking is happening without the person’s conscious awareness. They look awake, but they are unresponsive. It’s this breakdown in brain function that allows sleepwalkers to perform complex actions, all without knowing what’s going on.</p>
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<p data-block-key="7cjqo">Why sleepwalkers can paint, eat, or even drive when part of their brain is asleep.</p>

Removing CO2 from the Atmosphere: Where Does It Go?

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<p>About half of all the CO2 humans have ever emitted still hangs over our heads, literally. Since the Industrial Revolution began, that totals nearly 1,000 metric gigatons stuck in the atmosphere.</p><p>Now, scientists are working around the clock to create all sorts of new, innovative technologies to suck that CO2 back down. The holy grail would be reversing it all: finding a way to remove as much CO2 from the atmosphere as we’ve put in.</p><p>Direct air capture is one such sci-fi-esque method to literally pull CO2 right out of the air. Featured in the NOVA documentary “Can We Cool the Planet?”, Climeworks is a Swiss start-up specializing in this type of negative emissions technology. Their direct air capture technology uses filters with highly reactive chemicals called amines to catch even the smallest concentrations of CO2 from the air. After the filters are heated, the bonds are broken. Then, pure concentrated CO2 can be extracted, about three-quarters of the CO2 originally sucked in. But what do you do with it afterwards?</p>
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<p>One answer is to put the CO2 where it originally came from: right back into the ground. Basalt is one type of porous rock that readily bonds with CO2 over a time scale of centuries. But the Icelandic company CarbFix has found a way to shrink this timeline to less than two years. The key is to dissolve the gaseous CO2 into water. Then, the fizzy water is injected into basalt. Once inside the rock, the dissolved CO2 reacts with metals in basalt to form new solid minerals like calcium carbonate. Most importantly, the carbon can then stay inside the rock forever.</p><p>But if the promise of negative emissions technologies sounds too good to be true, that’s because it partially is. As of now, it’s nearly impossible to scale them up to a meaningful amount. They’re too expensive and require too much energy for a favorable tradeoff. Unfortunately, there’s no giant vacuum that can hoover up all the fossil fuel emissions of the world just yet.</p>
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<p data-block-key="o9xou">To combat climate change, scientists are working to remove carbon dioxide from the atmosphere.</p>

How Do Wind Turbines Work?

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<p>For millennia, humans have harnessed the power of wind. Wind fueled the boats of the Egyptians, the irrigation of the Babylonians, and the grain-grinding windmills of the Persians. Today, modern wind turbines have amped up wind’s potential even more. Now, wind power can be directly converted into clean, usable electricity for our cities and homes.</p><p>Where does wind come from? As the sun beams solar radiation toward the Earth, different areas warm up at different rates. In the areas that absorb more heat, hot air begins to rise. This creates a gap of lower pressure, which cooler air quickly rushes in to fill. That’s wind!</p><p>Once gusts reach about seven to eleven mph, the rotor of a wind turbine can capture the wind’s kinetic energy. A rotor usually has three massive blades, each on average about as long as the width of a U.S. football field. Rather than being pushed like sails, wind turbine blades act more like airplane wings. They’re shaped so that wind flows at different speeds above and below them. As a result, there’s a pressure difference on each side, which “lifts” the blades toward the low-pressure area and makes the rotor begin spinning.</p>
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<p>Kinetic energy has been transformed into mechanical energy. But one more conversion is needed. How do you change the mechanical energy into electric energy, a.k.a. electricity?</p><p>The key is a generator, which uses the properties of electromagnetic induction. In wind turbines, the rotor is connected to a shaft, which in turn enters an electrical generator made out of an assembly of magnets and a coil of wire.</p><p>When the rotor spins the shaft, the shaft then spins the assembly of magnets. This generates a voltage in the coil of wire. Voltage, a difference in electrical charge, drives a current. As a result, electrical current comes out from the generator. Then, the electricity can be funneled through power lines for distribution.</p><p>With turbines both on land and in the sea, wind energy is now the largest source of renewable energy in the United States. It’s only poised to grow more: as long as the sun shines, wind will blow, and we can continue to power the grid.</p>
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<p data-block-key="a4zeu">How wind turbines convert wind power into clean, usable electricity.</p>

Illustration of a brain of a person struggling with addiction.

What Causes Addiction?

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<p><i>“I had no idea how dangerous pain medication would be. I never woke up any day and said, ‘Man, I want to be an addict today.’ And I asked myself, ‘How did you end up here?"</i></p><p><i>-Mark Edwards for the NOVA documentary “Addiction”</i></p>
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<p>Addiction destroys lives. In far too many cases, addiction also ends them. Overdose is a leading cause of cause of death for people under 50 in America.</p><p>Far from a moral failing, as the stigma has long painted it to be, addiction is a complex biological disorder that develops when drugs hijack, rewire, and even reshape the brain. The process is largely tied to the brain’s pleasure hormone, dopamine. Dopamine is naturally released when endorphins, the body’s natural pain relievers, bind to receptor proteins. Dopamine tells the brain, “This experience was good. Repeat it.”</p>
<p>Opioid drugs mimic endorphins. However, they release a tsunami of dopamine up to ten times higher than normal. The brain’s reward pathway is thus flooded with a high unlike anything it’s probably ever experienced.</p><p>“Individuals struggling with addiction are actually battling millions of years of evolution because our brains are exquisitely evolved to seek rewards, to seek reinforcement wherever and whenever we can.” says Stanford University’s Dr. Robert Malenka for “Addiction."</p>
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<p>At the turning point, drugs are no longer about reducing original pain or seeking pleasure. Instead, they’re necessary for the agony of withdrawal. The brain and body physically demand more not to relish the high, but to escape the low.</p><p>Withdrawal is crippling. When opioids are abruptly paused, stress hormones surge at catastrophic levels. This imbalance leads to the opposite symptoms of opioid use, including shaking, anxiety, pain, and intense dysphoria. The pain is all-consuming — some people describe it as feeling like their bones are being ripped out of their bodies.</p>
<p>As the brain screams for more, the compulsion to get more drugs clouds over logic and rational judgment. There’s physical evidence for this shift. Brain scans show chronic drug use is associated with reduced gray matter in the prefrontal cortex, the brain’s executive control center that governs decision-making. The lower the amount of gray matter, the less someone is able to control their behavior.</p><p>Addiction has now taken over. And so the cycle continues.</p>
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<p data-block-key="t7r01">How addiction works in the brain, and why opioids are so dangerously addictive.</p>

How Do Hurricanes Form?

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<p>Few things beat a hurricane when it comes to showcasing nature’s fury. A hurricane’s gales alone can churn out about half as much energy as the global electrical generating capacity — not to mention the torrential flooding it leaves in its wake. But before a hurricane can grow to such a beastly size, its birth first requires a specific set of conditions.</p><p>Hurricanes, which scientists call “tropical cyclones,” vary in name by region: they're hurricanes in the Atlantic and eastern Pacific, but cyclones and typhoons elsewhere.</p><p>A tropical wave often kickstarts the whole process. These formations are not ocean waves, but instead an area of low atmospheric pressure that rolls off the African coast and moves westward through the tropics. They normally develop when hot air from the Sahara clashes with cooler, more humid air from the forested central Africa. Sometimes, thunderstorms follow.</p><p>The next ingredient is warm ocean water. As the tropical wave travels over waters above 26.5°C (about 80°F), warm, moist air starts rising upwards. This movement means there’s less air left near the surface — in other words, lower air pressure. Air molecules move from high to low pressure as they look for the path of least resistance, and as they do, the air from nearby areas with higher air pressure rushes in. Then, the new air becomes warm and moist and rises too.</p>
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<p>Up in the sky, the water in the moist air cools off and condenses into clouds. The process releases heat, further powering the growing tempest. This happens over and over again until giant cumulonimbus clouds emerge. As long as winds near the top of the system are not too strong — which could scatter the structure of the blooming clouds — an epic storm will begin to brew. Once the storm’s winds exceed 74 mph, it’s officially a tropical cyclone.</p><p>But why do hurricanes rotate? That’s due to something called the Coriolis effect. As Earth spins on its axis, an object on the equator must move much faster than an object by the poles. Rather than traveling in a straight line, winds coming to and from the poles are diverted. When different winds collide, they begin swirling. As a result, hurricanes spin clockwise in the Southern Hemisphere and counterclockwise in the Northern. In the center is the eye, an open area around which the rest of the storm rotates.</p><p>As long as hurricanes have warm ocean water to feed on, they will continue to amass speed and strength. Once they hit land, they can dump many inches of rain, down trees, and trigger dangerous storm surges, until eventually, a lack of fuel on land causes the hurricane to finally splutter out.</p>
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<p data-block-key="bg6ct">Warm ocean waters fuel some of the most violent storms on Earth.</p>

Celina Zhao

Articles

Sleepwalking: What Happens in the Brain?

Removing CO2 from the Atmosphere: Where Does It Go?

How Do Wind Turbines Work?

What Causes Addiction?

How Do Hurricanes Form?

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