What is the brain up to when the mind wanders?

The doorway effect is when people forget their task when entering a new space

The "why did I come in here?" feeling after walking into a room comes from the brain creating event boundaries to organize memories. Mentally revisiting a previous room can help recall tasks and reverse memory loss. (Some readers may experience a paywall.)

Sharp wave ripples in the brain tag experiences for long-term memory storage

These ripples were known to quickly replay neuronal sequences during sleep for consolidation. While awake, they help the brain prioritize memories to remember, and their disruption can impair memory formation.

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states

Mathematicians often solve problems using wordless mental processes

It's a common technique among expert mathematicians, where thinkers rely on intuition, blurry perceptions and subconscious work—no writing, no formulas. The state is distinct from daydreaming, and often relies on sudden illuminations stemming from extended periods of subconscious reflection.

Several brain regions are involved in lucid dreaming

Some scientists propose that lucid dreaming may require the emergence of a brain network, which is when multiple brain regions collaborate to perform certain functions. Research shows that lucid dreaming is associated with increased activity in the frontal lobes—associated with decision-making, voluntary movement, attention management, and more.

The human brain only uses 5% more energy during active tasks versus resting

Despite only being 2% of the weight of a human body, the average adult brain consumes 20% of its energy, with the majority of it spent on maintaining homeostasis—the stable equilibrium conditions of temperature, acidity, blood sugar, and other properties in the body. For infants, the consumption is closer to 50%.

Why 'spacing out' or dissociating may help reduce trauma awareness

Dissociation may have developed as a defense mechanism in the brain to help navigate intense emotional or physical situations by providing out-of-body experiences that put distance between the mind and the environment. However, in about 1.1% and 1.5% percent of the general population, a severe form of this separation can produce alternate identities, or alters.

Some animals may anchor their brain cells to specific landmarks to determine direction

In a study of bats exploring a new area, specific sets of "head direction cells" were seen becoming active based on bats' orientation when moving, and this activity became more coordinated over time. Researchers suspect, like humans, bats and other animals establish this sense of direction based on movement relative to known points of interest.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

The hippocampus plays a central role in dreaming

It's theorized that the hippocampus—a brain structure involved with memory formation and the simulation of imagined and novel scenarios using those memories—plays a major role in dreaming. Studies of people with damaged hippocampi show that they still dream, but their dreams lack the richness of detail described by others.

'Susan's Brain': what happens to the brain during addiction

This engaging animation from Harvard Online breaks down the neuroscience of addiction through the story of “Susan’s brain,” demonstrating how addictive substances hijack normal reward pathways. Through clear visual metaphors and approachable narration, it explains complex brain chemistry in understandable terms.

Various types of memory, each serving unique functions, create a complex brain system

These forms of memory, which can overlap in daily life, have been sorted into broad categories, such as short-term and long-term memory, and subtypes such as implicit memory, which uses saved information without conscious awareness that it’s being recalled.

How neurons give rise to thoughts

Neurons in the brain are singular nerve cells that flicker on and off or connect to each other based on incoming stimuli. The more neurons communicate by firing electrical impulses through tendrils known as synapses, the stronger their connection becomes. The electrical energy zipping along these interneural connections in an attempt to classify and respond to incoming stimuli may be what gives rise to thoughts.

How science explains déjà vu

Take a fun look at the science explaining the odd experience of déjà vu, which some theories suggest is actually a sign of a healthy brain.

Brain activity goes into overdrive around the point of death

Recent studies suggest increased electrical activity in the brain during and after clinical death could be responsible for near-death experiences. Both high-frequency gamma waves (linked to perception and attention) and low-frequency beta waves (related to focus and concentration) increased and became more synchronized across multiple brain regions, potentially resulting in a near-death state of heightened consciousness.

How do brain scans work?

There’s only one thing in our solar system sophisticated enough to study itself: the human brain. But this self-investigation is challenging because a living brain is shielded by skull, swaddled in tissue, and made up of billions of tiny cells. How do we study living brains without harming their owners? Two experts explain how the various techniques like EEGs, fMRIs, and PETs work in this TedEd talk.

Visualizing 11 cognitive biases that influence how you think

Humans are hardwired to make mental mistakes called cognitive biases, affecting the way we view our world. Among the most common are confirmation bias (seeking only evidence that affirms your views), authority bias (overweighting things said by authority figures), groupthink (assimilating ideas to avoid conflict), and more. This quick chart gives an overview of some of the most notable ways we mislead ourselves.

How to build curiosity

Change and uncertainty induce stress, but reframing the unknown into an opportunity for discovery has tangible benefits. Approaching change with curiosity enhances activity in the hippocampus and promotes neuroplasticity, promoting learning and serving as a barrier against anxiety. A neuroscientist explains how embracing the unknown, trying small experiments, and other techniques build curiosity.

Brain hemispheres control opposite sides of the body without either dominating

Although distinctions exist between the two halves—language processing is left-oriented, and emotions are right-oriented—signals are sent along neural pathways between the hemispheres and across different regions to collectively process information about external stimuli.

The myth of multitasking's prestige

In this article, renowned neurologist Richard Cytowic seeks to expose multitasking as a fool’s errand. Cytowic explains how the brain, like a computer, switches between tasks rather than handling multiple tasks at once. He shares that attempting to focus on multiple activities at the same time consequentially decreases the brain's ability to ignore distractions, maintain focus, and organize information. Instead, he suggests, try to focus on completing one thing at a time.

Humans experience the world subjectively. What does that mean for scientific research?

When you close your eyes, do you see static or colorful patterns or an "intrinsic grey" known as Eigengrau in German? This variation of our internal experiences is just the tip of the iceberg, one that scientists are increasingly studying and...

Prolonged stress impairs the prefrontal cortex

Burnout isn't just a feeling—it physically affects the brain. Prolonged stress impairs regions of the brain responsible for decision-making, emotional control, memory, and more. It can also lead to chemical imbalances, like reduced dopamine and norepinephrine levels, that worsen these effects.

How Alzheimer's caregivers get pulled into their loved one's reality

Caregivers, most often children and spouses, do not just witness a family member's cognitive decline—they also often become drawn into it, navigating a world in which the typical rules of time, order, or logical continuity may not apply.

What happens to the brain during migraine?

Migraine is a neurological condition that can cause debilitating symptoms across various bodily functions. So, what exactly is happening in the brain during these attacks? This five-minute video briefly overviews the internal machinations behind the painful episodes. An incapacitating headache is a common symptom of migraine, though migraine can occur without any headache.

The origins of our fascination with time travel

Humans have been captivated by the prospect of leaping forward and backward in time for thousands of years. Georgia Institute of Technology Science Fiction Studies Professor Lisa Yaszek recounts how the concept has been utilized by storytellers from 400 BCE to modern-day to explore our relationship with the supernatural, technology, and the past. In a way, this historical recounting is a journey through time.

How reading and writing can lower dementia risk by almost 40%

Research published in 2026 that tracked almost 2,000 older adults for an average of nearly eight years suggests that lifelong exposure to intellectual stimulation, such as learning a language, reading, and writing, can lower dementia risk by as much as 40%.

To get that song out of your head, try distracting yourself or playing a new song

Around 90% of people experience getting a snippet of a song stuck in their head, also known as an earworm. Researchers think they are linked to memory, repetition, and inner rehearsal. Before written language, music was used alongside rhyming in many cultures to help people preserve oral histories.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

Netflix profits when you're not watching, and its movies are designed that way—read a detail-rich critical essay exposing lesser-known Netflix takes

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

Explore our favorite visualization of the immense scale of space, from an astronaut to the size of the observable universe

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

Use this calculator to find the dollar value of your mental load, from meal planning to coordinating after-school care for your children.

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

A vending machine run with Anthropic's AI went out of business after it was convinced to give away items for free and sell a video game console.

The Mona Lisa's celebrity status and repeated restorations have obscured what made the painting so revolutionary for its time

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

In 2009, the nation was gripped by the story of a missing young boy who was believed to be floating over Colorado in a homemade balloon, until it was revealed that he was at home the whole time.

In 1945, Surrealist artist Salvador Dalí and legendary animator Walt Disney began collaborating on a short film that was not completed until 2003, years after both men had died.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

NBA superstar Victor Wembanyama spent the 2025 summer training with monks in central China to enhance his body and mind.