Aphantasia involves a lack of mental images—but doesn't affect behavior

Some people really cannot imagine. Literally.

There are many people who are astonished to discover that their complete lack of ability to picture visual imagery is different from the norm.

Anhedonia, which means 'without pleasure' in Greek, is typical in major depressive disorder

This common symptom—a flat affect—results in previously enjoyable hobbies no longer bringing pleasure. People with anhedonia may also avoid social situations because they anticipate they'll bring no joy, not because of anxiety or fear.

Always forget a face? The science of face-blindness

Faces and names don't always go together in some people's minds. While everyone forgets other peoples's names occasion, people diagnosed with prosopagnosia can't recognize faces, much less names. Even friends can family members can appear to be strangers. This article covers the diagnosis and issues attendant to prosopagnosia and its sufferers.

Anosmia is the total loss of the sense of smell

This type of loss—due to disease or trauma—has ripple effects, including an altered or limited sense of taste. This video details the anatomy and physiology of our sense of smell and taste and how these senses are interrelated.

Apeirophobia is an overwhelming fear of living forever, perhaps stemming from the brain's inability to conceptualize an infinite life.

Photographic memory isn’t real, but other rare memory types do exist

While 2% of children can recall sensory experiences with extreme detail (eidetic memory) and some adults can remember life events or dates with high accuracy (hyperthymesia), there is no scientific evidence for the flawless recall popularized in fiction. Most memory feats instead rely on training and memorization techniques.

The neuroscience of REM atonia disorders, where patients act out dreams

What prevents the typical person from acting out their dreams? Temporary paralysis of skeletal muscles, usually leading up to, and during, REM sleep. This academic article and related graphics explore what happens when this process doesn't go as planned, leading to REM sleep behavior disorder.

Apeirophobia is the fear of everlasting life

The fear may stem from the human brain's inability to conceptualize the concept of anything happening beyond what it can project out, such as the concept of an infinite life.

Individuals with synesthesia experience involuntarily overlapping sensations

Tasting words or seeing colors in music results from the brain retaining extrasensory connections from infancy. While most lose these neural pathways during development, about 4% of people are synesthetes, maintaining them without realizing it's unusual.

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.

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

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.

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

This type of extreme reaction to harmless holes, dots, cracks, and seed collections can be debilitating for those who have it, but it is not an officially recognized disorder in the DSM-5.

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...

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

She can't feel pain, hunger, or danger

Olivia Farnsworth, born with a rare chromosome 6p deletion, may be the only person known to lack pain, hunger, and fear responses. This overview explores her unique condition, the incredible incidents that revealed it, and how scientists hope her case could unlock new insights into human survival and sensory systems.

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

Bill Nye did not have children for fear of passing on ataxia

In his 2017 documentary, Nye revealed the congenital, neurological condition on his father's side of the family, which is characterized by a lack of balance and problems with fine motor movement. He has since learned he likely does not have the disease, though both his siblings have shown symptoms.

How dreams affect your memory

In 1999, scientists conducted a study in which participants were asked to recall images flashed before them for milliseconds. They found that participants who slept before recalling the information performed better than those who had been asked to recall the same information that same day. This was some of the earliest convincing evidence of how crucial sleep is for learning and memory, findings that current research continues to strengthen.

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

SAD uniquely affects people with attention-deficit hyperactivity disorder

Those with ADHD—chronic issues with attention and executive function—are primed for SAD. Many are disproportionately evening chronotypes (more awake in the evening), have a delayed sleep phase, and have low sensitivity to light in the morning. This podcast explores the overlap between these two groups.

AI hallucinations are inaccuracies or falsehoods in generated content

AI hallucinations are a by-product of the sequential creation of content based on patterns in text, which may not reflect the context or meaning behind a prompt. Back-end issues like biased datasets and overfitting of model data contribute to hallucinations.

Axions, a hypothetical subatomic particle, are a leading dark matter candidate

Among the possibilities for what makes up dark matter, some physicists champion axions, which could clump into galaxy-scale quantum states. These states would act as massive, unified superparticles that could explain the observational evidence for the universe's missing matter.

Alzheimer's can cause brain shrinkage of between 10% and 30%

While the exact cause of Alzheimer's is debated, the buildup of amyloid plaques and tau protein tangles is instantly recognizable in post-mortem examinations. The atrophy of brain cells caused by this molecular pileup leads to noticeable physical changes, including significant shrinkage in affected brain regions.

Are you hypnotizable?

What causes some people to genuinely fall under the spell of hypnosis and others not? The technique only appears to work easily on about 10% of people, and a variety of both genetic and psychological factors determines one's susceptibility. Researchers suggest effective hypnosis has more to do with a person's self-control than with external influence—and the technique can have tangible benefits.

The macula is a small area in the center of the retina

This part of the eye—roughly the bullseye of the back of the eye—is responsible for processing the central vision of the eye. Degradation of the macula, formally called macular degeneration, leads to symptoms including blurred vision, the need for brighter lighting, and difficulty recognizing faces. The condition doesn't affect peripheral vision, but if you lose central vision, you can still be considered blind.

The color blue is almost never mentioned in ancient Greek literature

Linguists have noted blue is regularly the last color to enter the language of most cultures. Researchers guess that the color's rarity in living organisms is partly the cause of its linguistic absence.

How art helps us process our feelings

The internet is chock full of hacks and apps that supposedly help you optimize yourself into a more productive person. But Aparna Chivukula argues that spending so much mental energy on "wellness" misses a larger philosophical issue, one that can only be explored through art.

The anechoic chamber at Bell Labs absorbs 99.999% of created sound

The space nearly eliminates sound wave reflection, allowing visitors to become aware of noises created by their own bodies, including their heartbeat and skeletal conduction. Experiments inside have contributed to the development of digital audio and phone touch tones.

Americans think being informed is a priority for voting, but don't prioritize reading the news

Many Americans report feeling "news fatigue," finding much of the news they encounter irrelevant. Still, being informed is recognized as a major civic duty. Many Americans have stopped seeking out the news or are far more selective about where they receive it, and an increasing sense that its up to individuals to confirm the facts they're being told.

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

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

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.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

Georgia O'Keeffe's flower paintings are often assumed to be sexual, though the artist claimed she was simply interested in highlighting the beauty of flowers that most people neglect

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

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.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

American dance legend Martha Graham, sometimes called 'the Picasso of dance,' refused to perform at the 1936 Olympics in Berlin and conceived the piece 'Chronicle' in response to the experience.

Many legends about George Washington, including his supposed wooden teeth and the story of cutting down the cherry tree, lack evidence.

A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," resulting in countless memes, the creation of a music festival, and eventually the arrests of those who did try to approach the area.

The tragic Pulitzer Prize-winning image 'The Vulture and the Little Girl' (1993) generated controversy, raised concerns about ethics in photography, and eventually led to the photographer's death.

See the 25 of the best photos of auroras from around the world.

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

The first robot in literature may have been a 'mechanical man' in 1907's 'Ozma of Oz,' a book in L Frank Baum's 'Wizard of Oz' series.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

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