There is no RationalWiki without you. We are a small non-profit with no staff—we are hundreds of volunteers who document pseudoscience and crankery around the world every day. We will never allow ads because we must remain independent. We cannot rely on big donors with corresponding big agendas. We are not the largest website around, but we believe we play an important role in defending truth and objectivity. |
Fighting pseudoscience isn't free. We are 100% user-supported! Help and donate $5, $10, $20 or whatever you can today with ![]() ![]() |
Hallucination
Tell me about your mother Psychology |
![]() |
For our next session... |
Popping into your mind |
A hallucination is a "perception without a stimulus" — in other words, seeing something that isn't there. It is distinct from delusion, or demonstrably false belief of pathological origin; however, the two are often caused by the same mental illnesses.
Hallucinations are often a symptom of certain mental illnesses, such as schizophrenia, certain forms of dementia, Parkinson's disease,[1] and epilepsy.[2] They can also be experienced due to the ingestion of psychoactive substances, most notably LSD.
There are two common forms of hallucination unrelated to mental illness called hypnagogic and hypnopompic hallucinations, the former occurring before sleep and the latter during the process of waking up. Blurred vision and switching between alert and sleeping states can cause anyone to see strange things. These hallucinations can create false memories. Similarly, sleep paralysis can cause memorably frightening hallucinations. There are many other conditions of high mental or bodily stress during which a person may possibly experience hallucinations.
See also[edit]
- Mass hysteria
- Religion — a common side-effect of hallucinations