Final answer:
A flashback is the reexperiencing of perceptual changes from psychedelic intoxication in a nondrug state. Hallucinogens can cause these perceptual changes and sometimes lead to flashbacks. The correct answer to the question is 'flashback'.
Step-by-step explanation:
In a nondrug state, the reexperiencing of one or more of the perceptual alterations that occurred during psychedelic intoxication is known as a flashback. A hallucinogen is a type of psychoactive drug that can lead to hallucinations, significant alterations in sensory and perceptual experiences, and sometimes flashbacks. When a person experiences a flashback, they temporarily feel the same or similar effects from their drug experience without taking the drug again. This phenomena is not to be confused with synesthesia, confabulation, or hyperkinesia, which are entirely different concepts related to sensory integration, memory inaccuracies, and increased movement, respectively.