Building Sentences - Spiraling Cortex - Losing Olfaction - Brain Rot

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Jun 20, 2026, 11:27:18 AM (9 days ago) Jun 20

https://www.nature.com/articles/d41586-026-01922-w

How the brain builds sentences, neuron by neuron

Max Kozlov

In the fraction of a second before a person speaks, their brain weaves together complex grammar, precise vocabulary and the underlying meaning of the language. Now, researchers have tracked the electrical crackle of individual brain cells in real time during unscripted conversations, capturing how sentences are built before a single word is spoken.

By observing these neurons in a region of the human brain called the frontotemporal cortex, scientists have discovered that individual brain cells act as specialized linguistic building blocks. “We used to think language was this diffuse, whole-network phenomenon,” says Ziv Williams, a neurosurgeon at Massachusetts General Hospital (MGH) in Boston and co-author of the study. “But it turns out you have specific neurons that only care if a word is a noun, or only care if a phrase is ending.”

The work was published today in Nature1.

To capture this activity, Williams and his colleagues used electrodes that were temporarily implanted in people with epilepsy to monitor their seizures. Because these participants were awake and speaking freely, the team could observe how the brain operated as they spoke. Neuroscientist Jing Cai, also at MGH, says that this set-up provided a rare opportunity to eavesdrop on the cellular processes that underlie speech, capturing details that standard brain-imaging devices cannot obtain.

Access to such data provides a “rare” glimpse into the biological machinery that governs speech, says Angela Friederici, a neuropsychologist at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany.

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https://www.science.org/content/article/speedy-spiraling-electrical-waves-may-be-key-brain-s-information-flow

Speedy, spiraling electrical waves may be key to brain’s information flow

By Jennie Erin Smith

Like a stadium full of sports fans doing the wave, neurons coordinate their electrical signals in rhythmic patterns that sweep across the cortex, the brain’s outermost layer. Recent studies in humans and animals have shown these patterns, called traveling waves, can take on complex shapes, among them a rotating spiral that has been observed during deep sleep, memory retrieval, and other brain processes. A new study has now captured the fast-spinning waves spanning whole brains, offering clues to how they’re organized and what they might do.

The study, published today in Science, examined the brains of mice using multiple recording and imaging methods to reveal brainwide patterns that unite disparate regions from the cortex to the deep brain. The research suggests rotating waves have a key role in coordinating the flow of information across the brain to support perception and behavior. It also offers an explanation for the waves’ spiral pattern by showing that they move along a circular path laid by axons—the long projections of neurons.

“This is very exciting work,” says neuroscientist Earl Miller of the Massachusetts Institute of Technology, whose team recently reported that rotating waves in the prefrontal cortex appeared to help monkeys regain their focus after a distraction. The new paper shows the waves are “highly organized across the [mouse] cortex and amazingly, across the hemispheres. When you see this kind of organization, it means something fundamental to function.”

It’s been hard to see brainwide patterns of rotating waves because most previous studies have captured them with grids of electrodes that sit on the cortex and gauge signals from nearby neurons. Neuroscientists Nick Steinmetz and Zhiwen Ye of the University of Washington got a broader and more precise sense of the waves’ timing and structure by combining two approaches: rapid widefield calcium imaging, which can record the activity of large populations of neurons in the cortex, and Neuropixels probes, ultrathin microelectrodes that can penetrate brain layers, to record deeper regions such as the thalamus and striatum.

https://knowablemagazine.org/content/article/health-disease/2026/what-happens-brain-lose-sense-of-smell

When the ability to smell goes away

By Victoria Clayton

About 14 years ago, Chrissi Kelly lost her sense of smell. She had traveled to the Czech Republic to visit family and caught some virus. Months later, when she still couldn’t smell, she made the rounds to doctors, including her general practitioner and an ear, nose and throat specialist, trying to find answers.

She was diagnosed with anosmia (smell loss), and like many patients with her condition, was told she’d have to learn to live with it. But for her, the loss was catastrophic. “After about six months of complete loss, I was just climbing the walls, and I did not feel like myself anymore,” she says.

Researchers estimate that up to 22 percent of the population lives with smell impairments, like hyposmia (partial smell loss) or anosmia (complete smell loss). And many others live with smell disorders like phantosmia, in which a person picks up phantom smells, or parosmia, where typically pleasant scents like coffee or shampoo begin to register as highly unpleasant (think feces or vomit). Yet the conditions have been poorly understood, underdiagnosed and often minimized by clinicians.
Photos of shampoo, coffee, trees and logs.

A world without scents or with warped ones can feel deeply unfamiliar. When our sense of smell goes awry, normally pleasant scents such as shampoo or coffee may be perceived as disgusting, or strong, unmistakable odors such as pine trees in a forest or fresh-cut lumber may fail to be registered at all.

The pandemic changed that. Covid brought unprecedented attention — and research interest — to the sense of smell. There have been 780 million reported cases of Covid-19 since December 2019 (and many more unreported), according to the World Health Organization, and smell loss is a well-known symptom. In one 2023 survey published in the journal Laryngoscope, 60 percent of individuals with Covid experienced smell loss, most temporarily, but some over the longer term.
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https://www.sciencenews.org/article/brain-rot-digital-online-mental-health

The truth about brain rot, according to science

By Kathryn Hulick

Emma Lembke joined Instagram at age 12. Soon, she found herself “scrolling mindlessly for hours, addicted to gaining a certain number of likes, a certain number of comments.” She often wanted to stop — but couldn’t.

She’s not alone. Most of us these days know the feeling of mindlessly scrolling through low-quality content. We call this sensation “brain rot.” The term can also refer to the content being consumed. Tung Tung Tung Sahur, a personified wooden drum (illustrated above), is one in a slew of silly AI-generated characters deemed “Italian brain rot” because many of them have Italian-sounding names. Trendy among middle schoolers, these absurdist characters show up in memes, videos, Roblox games and more.

Brain rot is kind of a joke, but it also really isn’t. A growing number of young people and their parents claim that spending too much time on social media, the spawning ground for brain rot, can mess with mental health. Thousands of cases accusing social media companies of harming young users with addictive features are now making their way through U.S. courts.

In May, the U.S. government released a Surgeon General’s warning about the harms of screen use for young people, calling out social media as well as gaming, chatbots and more. “Policy makers and tech companies need to acknowledge the potential for harm and create frameworks to protect children to allow for healthy and joyful use,” states the warning, which includes a disclaimer that the document was edited using the AI tool ChatGPT.

But the term “brain rot” evokes something more pernicious. Could browsing through stupid content actually make us stupid? This fear isn’t new. Back in 2009, the former CEO of Google, Eric Schmidt, voiced concerns about how digital media was impacting young people’s intelligence: “I worry that the level of interrupt, the sort of overwhelming rapidity of information … is in fact affecting cognition,” he said in an interview with talk show host Charlie Rose.

https://www.thetransmitter.org/cognitive-neuroscience/cortical-area-remixes-macaques-knowledge-blocks-to-solve-new-problems/

Cortical area remixes macaques’ knowledge blocks to solve new problems

By Lauren Schenkman

Many animals can solve novel problems, often in a single go. For humans, that could be writing the first line of a poem, tackling a complex equation or improvising a jazz solo. For a macaque monkey, it might mean climbing a new tree to snag a delectable fruit.

A new study, published in May in Nature, adds support to the long-standing idea that the brain accomplishes these feats by piecing together bits of existing knowledge (words, mathematical functions, riffs or tree-climbing moves, for example)—a process called compositional generalization.

Single-neuron recordings in macaques locate the knowledge blocks, according to the study. The brain activity patterns that occur in the ventral premotor cortex when monkeys learn to draw simple symbols recur in concert when the animals are later prompted to draw complex shapes made up of those symbols.

“We have quite a lot of behavioral evidence for compositional generalization across a wide array of different tasks,” says Charlie Wilson, a tenured researcher at the Institut National de la Santé et de la Recherche Médicale (INSERM) and the Stem Cell and Brain Research Institute in Lyon, who was not involved in the new research. “The interesting element here is the step towards showing a neural basis for that.”

The new work is part of a growing effort in the field to “bring modern techniques and modern understanding back to bear on this kind of question,” says Tim Buschman, professor of neuroscience and psychology at Princeton University. Buschman was not involved in the study but co-authored a 2025 Nature paper showing how macaques use compositional generalization to respond with specific eye movements to different types of images. “I think it’s really wonderful seeing evidence for these types of components.”