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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

February 5, 2026

A massive Swedish study tracking nearly 28,000 people for 25 years found an unexpected link between full-fat dairy and brain health. Among adults without a genetic risk for Alzheimer’s, eating more full-fat cheese was associated with a noticeably ...
Scientists still don’t know how the brain turns physical activity into thoughts, feelings, and awareness—but a powerful new tool may help crack the mystery. Researchers at MIT are exploring transcranial focused ultrasound, a noninvasive ...
Chronic stress can damage the gut’s protective lining, triggering inflammation that may worsen depression. New research shows that stress lowers levels of a protein called Reelin, which plays a key role in both gut repair and brain health. ...
When the brain rests, it usually replays recent experiences to strengthen memory. Scientists found that in Alzheimer’s-like mice, this replay still occurs — but the signals are jumbled and poorly coordinated. As a result, memory-supporting brain ...
Middle age is becoming a tougher chapter for many Americans, especially those born in the 1960s and early 1970s. Compared with earlier generations, they report more loneliness and depression, along with weaker physical strength and declining memory. ...
Scientists warn that rapid advances in AI and neurotechnology are outpacing our understanding of consciousness, creating serious ethical risks. New research argues that developing scientific tests ...
Scientists in Sweden and Norway have uncovered a promising way to spot Parkinson’s disease years—possibly decades—before its most damaging symptoms appear. By detecting subtle biological signals in the blood tied to how cells handle stress and ...
A massive international study of more than 3,100 long COVID patients uncovered a striking divide in how brain-related symptoms are reported around the world. In the U.S., the vast majority of non-hospitalized patients described brain fog, ...
Where your body stores fat may matter just as much as how much you carry—especially for your brain. Using advanced MRI scans and data from nearly 26,000 people, researchers identified two surprising fat patterns tied to faster brain aging, ...
AI may learn better when it’s allowed to talk to itself. Researchers showed that internal “mumbling,” combined with short-term memory, helps AI adapt to new tasks, switch goals, and handle complex challenges more easily. This approach boosts ...
A common parasite long thought to lie dormant is actually much more active and complex. Researchers found that Toxoplasma gondii cysts contain multiple parasite subtypes, not just one sleeping form. Some are primed to reactivate and cause disease, ...
Findings could create new opportunities to treat and study neurodegenerative diseasesScientists discovered that sugar metabolism plays a surprising role in whether injured neurons collapse or cling to life. By activating internal protective ...

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