These visions are known as Lilliputian hallucinations, named after the miniature inhabitants of "Gulliver's Travels," who stand just 6 inches tall. For decades, researchers suspected that cultural beliefs and folklore might explain why people in different regions described such similar experiences.

Now, a new study provides evidence that the phenomenon has a biological explanation.

Researchers at the University of Utah (U) used DNA sequencing to identify Lanmaoa asiatica as the mushroom responsible for these unusual hallucinations in Southwest China and the northern Philippines. Surprisingly, their investigation found no evidence of any known psychoactive mushroom compounds, including psilocybin.

The findings suggest that the mushroom may produce an entirely unfamiliar hallucinogenic substance. Identifying that chemical could help scientists better understand neurological disorders, unusual visual experiences, and the processes through which the brain creates our perception of reality.

The research was conducted by Colin Domnauer, a doctoral student at the U, and Bryn Dentinger, a mycologist affiliated with the university and the Natural History Museum of Utah. Their findings were published in the journal Mycologia.

In an interview with @theU, Domnauer explained how researchers traced the mushroom's identity, what makes its effects so unusual, and why the discovery could have implications far beyond the study of fungi.

A Century-Old Mystery of Tiny Human Hallucinations

The scientific mystery dates back to 1934, when Western researchers learned that people in Papua New Guinea sometimes experienced vivid visions of miniature humans after eating wild mushrooms. The bizarre effect became known as "mushroom madness."

During the 1950s and 1960s, anthropologists and mushroom specialists traveled to Papua New Guinea to investigate. Their work pointed toward several possible species belonging to the Boletaceae (bolete) family.

However, chemical testing failed to reveal any substances that could explain the hallucinations. Samples were even examined by Albert Hofmann, the scientist who first isolated psilocybin and discovered LSD. He, too, was unable to identify an active ingredient.

With no chemical explanation available, some researchers began questioning whether the mushrooms were responsible at all. They suggested that the visions might instead arise from cultural expectations or traditional beliefs. By the end of the 1960s, scientific investigation of the phenomenon had largely stopped.

The mystery resurfaced during the 1990s, when people in Yunnan, Southwest China, reported similar hallucinations after eating bolete mushrooms. Although the precise species remained uncertain, researchers suspected a recently described mushroom called Lanmaoa asiatica.

Scientists Identify the Mushroom Behind the Strange Visions

Another important clue appeared in 2024, when Domnauer learned of comparable experiences among an Indigenous community in the remote Northern Cordillera region of the Philippines.

Community members described a wild edible mushroom called "Sedesdem" that could sometimes cause people to see miniature human figures. Similar mushrooms were known locally as "Nonda" in Papua New Guinea and "Jian shou qing" in Yunnan.

These mushrooms have an important place in local food traditions, but consuming them without thoroughly cooking them can trigger the unusual hallucinations.

The Philippine accounts represented a third independent report of wild mushrooms causing remarkably similar visions of tiny people.

To investigate, Domnauer traveled to Yunnan and the Philippines, interviewed local residents, and collected specimens of L. asiatica along with other mushrooms belonging to the Lanmaoa genus.

The fieldwork included the first scientific survey of fungi in the northern Philippines. Researchers then analyzed DNA from the collected mushrooms to establish their identities and evolutionary relationships.

The results revealed that the mushrooms called Jian shou qing in China and Sedesdem in the Philippines were both L. asiatica.

This was an unexpected finding because scientists had previously believed the species occurred only in China.

Dentinger also visited Papua New Guinea in hopes of collecting specimens from the location where the mystery originally began. Unfortunately, unusually dry weather made it impossible to obtain samples for genetic comparison.

Although the Papua New Guinea mushroom remains unverified, the evidence from China and the Philippines provides a compelling connection. Three geographically separated cultures have described the same highly specific hallucinations, and DNA testing has linked two of those cases to a single mushroom species.

That consistency strongly suggests a shared chemical and neurological explanation rather than unrelated cultural influences.

Hallucinations of Tiny Humans That Seem Remarkably Real

What makes these hallucinations especially unusual is their striking similarity across different accounts.

People typically describe seeing dozens or even hundreds of miniature figures, generally measuring between 3 and 30 centimeters tall. The figures appear with extraordinary clarity, often seeming as solid and convincing as actual people.

According to Domnauer, approximately 90% of those experiencing the visions describe figures resembling elves, clowns, or other fairy-like characters, often wearing brightly colored clothing.

Even more surprising is the way these imaginary figures seem to behave.

Rather than floating through walls or ignoring their surroundings, they appear to follow familiar physical rules. They walk around obstacles, move across ordinary objects, and sometimes tumble from the edges of tables.

Domnauer recalled one particularly unusual account involving someone eating soup. The person reported seeing tiny humans leap from a spoon into the bowl, where they began swimming. When the person took another spoonful, the miniature figures reportedly remained visible inside their mouth.

Such detailed interactions distinguish these visions from many other forms of drug-induced hallucination.

A Mysterious Psychedelic Compound Unlike Any Known Drug

Scientists also investigated whether L. asiatica contains any of the chemicals already known to cause psychedelic experiences.

Using both chemical testing and genetic analysis, the researchers searched for established psychoactive compounds found in other mushroom species.

They found no trace of them.

The absence of familiar hallucinogens was particularly intriguing because the mushroom's effects differ so dramatically from those associated with known psychedelic drugs.

Researchers now suspect that L. asiatica produces an unidentified psychoactive substance responsible for the tiny human hallucinations.

The compound has not yet been isolated or chemically identified, so its exact nature and mechanism remain unknown.

Discovering it could open an entirely new avenue of research into how certain chemicals alter visual perception.

What the Mushroom Could Reveal About the Human Brain

Although L. asiatica provides an unusually consistent trigger for Lilliputian hallucinations, the phenomenon is not limited to mushroom consumption.

Stories involving miniature humanlike beings appear throughout folklore around the world. Similar hallucinations have also been documented in people experiencing alcohol withdrawal, dementia, macular degeneration, and other neurological conditions.

These connections suggest that the visions may arise from a fundamental feature of the way the human brain processes visual information.

However, scientists still do not fully understand the neurological mechanisms responsible for these experiences or how best to treat them when they occur in medical settings.

This is where the mysterious mushroom could become especially valuable.

Unlike the neurological and medical conditions in which Lilliputian hallucinations occur relatively rarely, L. asiatica can produce the phenomenon in a more consistent and recognizable way.

If researchers can isolate the chemical responsible, they may gain a useful tool for investigating the brain circuits and processes that create these unusually detailed visual experiences.

Such research could eventually improve scientific understanding of hallucinations associated with neurological diseases.

The research team's next major objective is to isolate and identify the suspected psychedelic compound.

DNA Sequencing Reveals Four Previously Unknown Mushroom Species

The investigation also produced important discoveries about fungal biodiversity.

Rather than studying L. asiatica alone, Domnauer and Dentinger conducted the first comprehensive genomic analysis of the Lanmaoa genus.

They examined 53 mushroom specimens collected from natural habitats and preserved in fungarium collections around the world.

Genetic sequencing revealed 17 species within the group, including four species previously unknown to science.

Remarkably, two of those newly identified species had already been preserved in existing collections in the United States. Their distinct identities had gone unrecognized until researchers examined their DNA.

The analysis also indicated that L. asiatica is the only species in the genus currently known to produce psychoactive effects.

Scientists are now working to reconstruct the group's evolutionary history. They hope to determine how the unusual chemical trait developed and whether closely related mushrooms might produce comparable substances.

The findings also demonstrate the scientific value of museum collections. Specimens preserved for years can contain biological discoveries that become apparent only when newer analytical techniques are applied.

For Domnauer, the hidden diversity found in these collections is a reminder that many species and potentially important biological characteristics remain undiscovered, even among organisms that scientists have already collected.

Exploring Fungi Could Lead to New Medicines and Discoveries

The broader implications extend well beyond unusual hallucinations.

Fungi remain one of the least thoroughly explored groups of organisms, and researchers believe their chemical diversity could provide valuable clues about biology, medicine, and the nervous system.

One of the most famous examples is penicillin, the antibiotic originally obtained from a fungus that transformed the treatment of bacterial infections and became one of the most consequential medical discoveries of the last century.

Scientists hope continued exploration of fungal biodiversity could reveal other medically useful compounds and previously unknown biological processes.

The mysterious effects of L. asiatica illustrate just how much remains to be learned about the fungal kingdom. A mushroom long consumed by communities in Asia may contain a substance capable of revealing new information about the human brain and how it creates conscious experience.

The research received funding from the National Science Foundation (award #DEB-2114785).