<Tr> <Th> MeSH </Th> <Td> D006212 </Td> </Tr> <Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> A hallucination is a perception in the absence of external stimulus that has qualities of real perception . Hallucinations are vivid, substantial, and are perceived to be located in external objective space . They are distinguishable from several related phenomena, such as dreaming, which does not involve wakefulness; pseudohallucination, which does not mimic real perception, and is accurately perceived as unreal; illusion, which involves distorted or misinterpreted real perception; and imagery, which does not mimic real perception and is under voluntary control . Hallucinations also differ from "delusional perceptions", in which a correctly sensed and interpreted stimulus (i.e., a real perception) is given some additional (and typically absurd) significance . </P> <P> Hallucinations can occur in any sensory modality--visual, auditory, olfactory, gustatory, tactile, proprioceptive, equilibrioceptive, nociceptive, thermoceptive and chronoceptive . </P>

Are sensory experiences that occur in the absence of real stimuli