electroencephalography

The electron beam of a microscope usually flies through emptiness, like a courier on an empty highway. Any air molecule is a bump that makes it bounce and lose direction. So before, to examine a sample, you had to freeze it, dry it, or coat it with metal—and still you could only look in a vacuum.

Every heartbeat sends a wave through the cerebral arteries that not only pushes blood but also briefly inflates the vessel. The arterial wall, like a tightly stretched rubber tube, passes that motion to the neighboring brain tissue, and the brain pulses ever so slightly in time with the heartbeat.

A doctor looks at a screen and sees two images of the same part of the body. One shows where blood is rich in oxygen, the other shows how fast it rushes through the finest vessels. Previously, these images were made by different devices, and combining them was difficult. Now engineers have built a device that takes both images simultaneously.

Catching light one particle at a time is like hearing a whisper in a roaring factory. An electron-multiplying camera (EMCCD) can do exactly that: it turns a single photon hitting a pixel into an avalanche of electrons that can be measured. These cameras are mounted on telescopes to spot a barely visible planet next to a dazzling star.

A medical record is like a long diary: doctor visits, diagnoses, prescriptions, lab results. A human doctor reads it cover to cover to understand what's going on with the patient. Now, a machine reads this diary, and does it in seconds. The developers created a model called Foresight-E. It was trained on de-identified records of about 61 million people: that's nearly the entire population of England.

A doctor places a stethoscope on the chest and listens: lub-dub, lub-dub. The rhythm is there, but how do you measure it when it's noisy around and the patient can't lie still? Conventional devices look for sharp peaks in the heartbeat recording, like catching hammer blows. But if the hammer hits a pillow instead of an anvil, the peaks blur and the device gets lost. CORAL, the new method, works differently.

A flashlight beam cuts through fog. The denser the fog, the more the light scatters and the later it reaches your eye. A similar principle works with fast radio bursts — mysterious, super-powerful pulses from distant galaxies. As their radio waves travel through space, they interact with free electrons — particles stripped from atoms.

Blood vessel cells were seeded onto a transparent film just 700 nanometers thick — a hundred times thinner than a human hair. Flat electrodes are hidden beneath the film. They send a weak alternating current and listen as the resistance changes.

A magnetoencephalograph, a helmet-like device with hundreds of sensors, picks up the weak magnetic fields generated by active neurons. When a person listens to speech, these signals contain imprints of the heard words. But extracting them is tricky: signals from thousands of sources merge into a tangled mess.

A stadium packed with fans hears the announcer’s voice for the first time, and instantly the whole place erupts. The message sounds again and again. Only a handful of people in nearby rows respond. That’s roughly how neural networks behave in brain organoids — tiny lab-grown replicas of the brain.

An eye prosthesis sends the brain not a photograph but a sparse pattern of bright dots — phosphenes. To make out a cup or keys in this flickering noise, a person has to move their head like a flashlight in the dark, piecing together the object's outline bit by bit. It's a slow process, like assembling a puzzle where most pieces have been thrown away.

Every time a child with cerebral palsy is about to move their leg, a distinctive electrical blip appears in the brain — a slow voltage shift. Scientists call it a movement-related potential. A brain-computer interface (a system that reads intentions from brain signals) can pick up this blip and turn it into a command for a training device.

A city at night: lights on in some windows, dark in others. If you connect with lines the windows that light up simultaneously, you get a web of connections. Researchers studied such a web in tiny brain organoids — living clusters of nerve cells grown in the lab.

To find an epileptic seizure in brain activity recordings, scientists used an approach akin to picking out sharp sounds in a noisy room: instead of deciphering the entire chorus of brainwaves (EEG), they isolated only the strongest spikes.

A neuron is like a complex musical instrument. To understand how it responds to a touch, you used to have to connect to each string directly — a delicate, slow procedure that only works for individual cells.

The heart sometimes loses its rhythm, like an orchestra where the violins suddenly start playing each on their own. Cardiologists in such cases look for the "out-of-tune" areas by reading the heart's electrical signals and precisely ablating them with a thin probe — a catheter.

A translator gets distracted by every rustle in the hall, and a one-hour meeting stretches into two. That's how the standard method of locating an epileptic focus works: it waits for loud phrases — the moments when a seizure flares up in the brain.

A patchwork quilt where each patch is a recording of activity from a small brain region. One patch was stitched on Monday in London, another on Tuesday in New York, and a third a month ago in Tokyo. This mosaic covers the brain only partially, and there is no common seam to join them.

A quantum computer is like an orchestra where each ion is a musician and laser pulses are the conductor's baton. But if someone in the audience rustles, the delicate melody of quantum states goes off key.

The open archives OpenNeuro and NEMAR hold 791 recordings of the brain's electrical activity from nearly forty thousand people. In total, that's 86,051 hours of signals — roughly ten years of continuous listening. Previously, to take even one such recording off the shelf, you had to write thousands of lines of code: download, unzip, fix format errors, and slice it into chunks of the desired length.

When the conductor leaves the orchestra, the musicians keep playing from memory for a while. But without a unified rhythm, each one starts to speed up or slow down on their own, and the harmonious symphony turns into disjointed noise. According to new research, the brain and heart behave much the same way in the last hours of a person's life.

A flashlight shines through skin and bone to gently switch on neurons at the right spot in the brain. That is how transcranial magnetic stimulation works — a coil on the head creates brief magnetic pulses that trigger electrical signals in cells. But if you tilt the flashlight or move it away, the light goes astray.

Enceladus is a tiny moon of Saturn, covered in a thick crust of ice. Beneath it sloshes a salty ocean, and deep down, a hot, porous core may be at work, like a sponge soaked with water and heat. But how do you see through tens of kilometers of ice? No need to drill: you can use an electromagnetic "echo." A person with a metal detector walks along a beach.

Ultrasound penetrates bone like sunlight through frosted glass, but the image comes out blurry. The skull is uneven and dense, scattering sound waves, so hitting a precise spot in the brain is tricky. Conventional devices try to fix this with electronics, but the result is still far from perfect.

A person hears a ringing that isn't there. The doctor asks them to describe it — loudness, pitch, persistence. But it's subjective: one might say "like a mosquito," another "like steam from a kettle." We need a way to see tinnitus directly, in the brain itself.

Each vowel sound is a distinct shape of the mouth, tongue, and throat. When you say 'ah,' 'ee,' or 'oo,' not only does the air inside your head change, but so does the way radio waves pass through it. Researchers peered into this process using MRI scans taken right during speech and built a precise computer model of the head — from bones to soft tissues.

A flashlight shines into the eye, and the retina responds with electrical impulses, like an echo, but not of sound, of light. This echo can be recorded, and it reveals not only how the eye is working but also how the brain is. After all, the retina is a piece of the brain that has been pushed out to the periphery.

Your finger is a living sensor: beneath the skin, arteries pulse in time with your heart. Traditional blood pressure cuffs squeeze your arm and give a single number, but this ring uses eight electrodes to pass a weak current through the tissue and map blood flow.

At night in a dark room, the human body emits a barely perceptible glow. This light is so faint that only highly sensitive detectors can catch it. Some researchers thought this glow from the head could tell us about brain activity — no scanners or wires needed. But when put to the test, the story changed.

You sleep, but your heart keeps telling stories. The rhythm of beats, the pauses between them, the respiratory waves — all shift from one sleep stage to the next. In a sleep lab, this is read from a host of sensors on the head, face, legs, and chest. It's cumbersome, expensive, and not something you can do at home.

Potassium in the blood is like salt in a soup: just a bit too much, and the heart starts to falter. Doctors usually monitor this mineral with blood draws from a vein, but for people with kidney disease or a weak heart, frequent lab visits become a ordeal.

Radio waves that oscillate less than once per second pass through the earth and water with almost no loss. Such signals are used to communicate with submarines and to search for minerals. But a conventional antenna for them would need to be hundreds of meters long, and its sensitivity leaves much to be desired.

A patient with schizophrenia comes in for a procedure that feels like a mild tingling in the ear. The doctor switches on a small electrical stimulator attached to the earlobe, and after a few weeks, some people find their apathy and withdrawal receding, while others see no change at all. Until now, predicting this was impossible.

The heart doesn't contract all at once but as a wave: an electrical signal travels through the muscle, and behind it, like ripples spreading on water, a contraction rolls through. In arrhythmia, this wave goes awry: it stalls in one spot, loops in another, and the pump starts working in a disorganized way.

Depression is sometimes sought in the brain's electrical waves. The logic is simple: if a disease has stages (acute, maintenance, recovery) then the signals should change gradually, like volume when you turn a knob. Researchers took EEG recordings from 74 people: 24 in the acute phase, 23 in the maintenance phase, and 27 healthy.

An electrocardiogram is like a recording of an engine's hum: an experienced mechanic can hear when something's off. A heart ultrasound shows the engine itself from the inside, but the machine is pricey and specialists are scarce.

An electrocardiogram is like a long strip of paper on which the heart leaves its signature. A doctor studies it to catch rhythm disturbances, but when the recording lasts for days, the strip stretches for miles. The eye tires, attention wanders, and rare but dangerous irregularities can slip by. AI-HEART works like a tireless assistant that scans the entire strip without a break.

The heart beats, and on a paper ECG strip, each beat looks like a sharp spike with two humps: a quick rise, then a smaller wave, then a descent. A doctor looks at such a strip and sees the rhythm, but the shape of each spike, how exactly the muscle contracted, is hard to discern, especially if the recording lasts a full day. This new method turns that strip into a colorful carpet.

A rat runs down a track — not because a motor forces it, but because it feels like it. On its skull sits a grid of 32 tiny sensors, like a swim cap with wires. The sensors pick up the faint electrical waves emitted by the brain. Previously, to find out how fast an animal was running, you had to implant electrodes directly into the brain.

An ECG is not just a wavy line on paper. Like a diary, it records the state of the entire heart: rhythm, wall thickness, and hints of future problems. But currently, programs that learn to read this diary are trained on very narrow tasks — mostly detecting arrhythmias. That's like teaching someone to understand a book by showing them only a list of typos.