hallucinations
hallucinations — noun
- hallucinationssingular
- hallucinationsesplural
1. a state in which a person perceives things through sight, hearing, smell, or tou
a state in which a person perceives things through sight, hearing, smell, or touch that are not actually present — typically linked to illness, mental health conditions, or drugs, and the person experiencing it cannot separate what is real from what is imagined.
The patient started having visual hallucinations of colors that did not exist in the room.
collocation: have + hallucinations
Nadia heard a voice whispering her name every night, though her apartment was completely empty.
auditory hallucination: hearing a voice with no real source
After the surgery, the woman experienced vivid hallucinations that lasted for two full days.
The nurse explained that fever-induced hallucinations usually stop once the body temperature returns to normal.
During a migraine, people may see hallucinations of flashing lights or strange patterns.
- reality
things that actually exist and can be verified by others
文法句型
hallucination + of + noun phrase
have + hallucinations
suffer from + hallucinations
用法筆記
Often paired with adjectives specifying the sensory type: visual, auditory, olfactory, tactile. In medical writing, hallucinations are distinguished from illusions (misperceptions of real stimuli) and delusions (false beliefs).
常見錯誤
2. a specific imagined object, voice, or sensation that a person perceives during a
a specific imagined object, voice, or sensation that a person perceives during a hallucination — for example, hearing a particular voice calling their name or seeing a specific animal cross the floor, where the content of the unreal perception is the focus rather than the experience itself.
One of his hallucinations was a voice saying that people were watching his every move.
hallucination of + specific content (a voice)
The elderly man described hallucinations of small animals crawling across the kitchen floor.
Many patients report hallucinations of familiar places, like their childhood bedroom or neighborhood.
Dr. Park asked Mei-Ling to draw the hallucinations she described so the team could examine the patterns.
- percept
technical term in psychology for the object of perception
文法句型
hallucination of + noun phrase
describe + hallucinations
用法筆記
This sense treats hallucinations as countable individual items — each hallucination is a distinct perceptual event with specific content. Distinguish from sense 1 (the general phenomenon).
常見錯誤
3. a piece of incorrect or invented content that an artificial intelligence system
a piece of incorrect or invented content that an artificial intelligence system produces and presents as if it were a fact — the AI makes up details, names, or events that sound believable but are not true.
The chatbot produced hallucinations about historical events, inventing dates and people that never existed.
collocation: produce + hallucinations (AI context)
Yuki asked a chatbot about cold medicine dosage, and the AI hallucinated a drug that does not exist.
specific object of AI hallucination: a non-existent drug
The programmer found several hallucinations in the language model's output before the software update.
Researchers found that users trusted the AI's hallucinations because the false statements sounded confident.
- fabrication
emphasises that the AI made something up from scratch
- confabulation
used in AI research to describe plausible-sounding false statements
- fact
a true piece of information verified against reality
文法句型
AI + produce + hallucinations
hallucinations + in + [system/model]
用法筆記
Common in computing and AI research contexts. Unlike medical hallucinations (sense 1), AI hallucinations are not a sensory experience — they refer to incorrect text or data that an algorithm generates. Often used in the plural when discussing multiple instances of incorrect output.
常見錯誤
4. the broad systemic problem of artificial intelligence systems generating false i
the broad systemic problem of artificial intelligence systems generating false information that appears factual — discussed as an ongoing technical challenge rather than referring to any single false output.
Diego's hospital paused plans to use an AI chatbot for reviewing patient records because of the risk of hallucinations.
uncountable: hallucinations as a systemic obstacle
The paper proposed a new method for detecting and reducing hallucinations in language models.
Industry leaders agree that tackling hallucinations is essential before AI can serve customers safely.
Hallucinations happen because AI systems learn to sound natural, not to be correct.
Many engineers view hallucinations as a design flaw that needs fundamentally new solutions.
- fabrication tendency
less common, describes the same systemic issue more literally
文法句型
hallucinations + is + [problem/challenge]
the problem of + hallucinations
用法筆記
In this sense, 'hallucinations' is treated as an uncountable mass noun referring to the phenomenon as a whole, not to individual false outputs. Compare sense 3, which refers to specific countable instances of false information.
常見錯誤
5. a firmly held belief or opinion that has no basis in reality and persists despit
a firmly held belief or opinion that has no basis in reality and persists despite clear evidence against it — used figuratively for a misconception that feels real but is not, similar to a collective fantasy or a stubborn wrong idea.
The journalist called the conspiracy theory a collective hallucination shared by distrustful readers.
figurative use: collective hallucination
His belief that the company would recover without changes turned out to be a hallucination.
Professor Adegoke warned that the team's optimism about the project was a hallucination, not a realistic forecast.
Elena called her opponent's entire theory a hallucination, and the moderator asked her to tone down the language.
文法句型
be + a + hallucination
dismiss + something + as + a + hallucination
用法筆記
This is the figurative, non-medical sense. It overlaps with 'delusion' but carries a stronger implication of something imagined or fabricated by the mind rather than a fixed false belief. Avoid in clinical settings where precise diagnostic terms are needed.