Auditory hallucinations involve hearing sounds without an external source. Voices are a common form in schizophrenia, although people may also hear music, footsteps or other noises. A voice may seem to come from outside the…Continue Reading
Visual hallucinations involve seeing something without a matching external stimulus. They can be simple, such as flashes or shapes, or complex, such as people, animals or complete scenes. They differ from illusions, in which a…Continue Reading
Hallucinations can involve touch, smell, taste or bodily sensations as well as hearing and vision. Tactile hallucinations may feel like crawling, touching or pressure on the skin. Olfactory hallucinations involve smells without an external source…Continue Reading
Scientists investigate hallucinations as changes in the processes that construct perception. The brain combines sensory input with expectations, memories and attention. One hypothesis proposes that expectations receive too much weight when external information is uncertain.…Continue Reading
The impact of hallucinations depends on their content, frequency, meaning and the person’s sense of control. A quiet but threatening voice may be more distressing than a loud neutral one. Fear, exhaustion and isolation can…Continue Reading