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Reference Terms
from Wikipedia, the free encyclopedia

Hallucination

A hallucination is a sensory perception experienced in the absence of an external stimulus, as distinct from an illusion, which is a misperception of an external stimulus. Hallucinations may occur in any sensory modality - visual, auditory, olfactory, gustatory, tactile, or proprioceptive (sense of balance and position in space). Psychological research has presented the idea that hallucinations may result from biases in what are known as metacognitive abilities. These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, memories, beliefs and thoughts). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences.

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Mind & Brain News

October 6, 2025

A University of New Mexico scientist is revealing what might be one of the most overlooked causes of dementia — damage in the brain’s tiny blood vessels. Dr. Elaine Bearer has created a new way to classify these changes, showing that many people ...
A new study shows glioblastoma isn’t confined to the brain—it erodes the skull and hijacks the immune system within skull marrow. The cancer opens channels that let inflammatory cells enter the brain, fueling its deadly progression. Even drugs ...
Stanford scientists found that aging disrupts the brain’s internal navigation system in mice, mirroring spatial memory decline in humans. Older mice struggled to recall familiar locations, while a few “super-agers” retained youthful brain ...
Researchers from Leeds found that overeating is driven more by what people believe about food than by its actual ingredients or level of processing. Foods perceived as fatty, sweet, or highly processed were more likely to trigger indulgence. ...
Scientists discovered that lifelong social support can slow biological aging. Using DNA-based “epigenetic clocks,” they found that people with richer, more sustained relationships showed younger biological profiles and lower inflammation. The ...
Researchers have uncovered how a protein called MRAP2 acts as a key regulator of hunger. It helps move the appetite receptor MC4R to the cell’s surface, allowing it to send stronger “stop eating” signals. The discovery offers new hope for ...
A massive new study combining observational and genetic data overturns the long-held belief that light drinking protects the brain. Researchers found that dementia risk rises in direct proportion to alcohol consumption, with no safe level ...
Researchers uncovered a key cellular regulator, PP2A-B55alpha, that controls both the cleanup of damaged mitochondria and the creation of new ones. In Parkinson’s disease models, reducing this regulator improved symptoms and mitochondrial health. ...
New research from Houston Methodist reveals how obesity may directly drive Alzheimer’s disease. Scientists discovered that tiny messengers released by fat tissue, called extracellular vesicles, can carry harmful signals that accelerate the buildup ...
A massive nationwide study has linked long-term exposure to the industrial chemical trichloroethylene (TCE) with a higher risk of Parkinson’s disease in older adults. Researchers examined over 1.1 million people, finding that those living in areas ...
New research shows that poor sleep could make the brain appear years older than it really is. Using MRI scans and machine learning, scientists found a clear link between unhealthy sleep patterns and accelerated brain ...
Penn researchers found that psilocybin can calm brain circuits tied to pain and mood, easing both physical suffering and emotional distress in animal studies. The compound works in the anterior cingulate cortex, bypassing injury sites and offering a ...

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