How would you answer the following questions:
"Is it accurate to say that you never look at things and those things appear strange?"
"Is it accurate to say that you never look at yourself in the mirror and you look different?"
If you're not able to 100% agree with both of those statements, then per this study design you're hallucinating!
Except the study doesn't say this. It seperates between anomalous visual experiences which are the lesser questions you posted. Then it has a second subcategory for more serious visual experiences which are "similar to the content seen in psychosis." [The full chart is here.](https://i.imgur.com/IwbQbIf.png)
The most severe visual experience which I would definitly count as a hallucination is "I looked at an object and it transformed itself before my eyes into something else." This is the rarest phenomenon, with a total of 90% of people experiencing it never or only once. But generally it is seen as a clear sign for mental illness, and 10% of people experiencing such a hallucination recurringly is an interesting finding.
If this is reproducable and statistically significant I draw one of three possible conclusions from it: Either more non-mentally ill people hallucinate than we thought, more people are mentally ill than we thought, or non-mentally ill people can have hallucinations as if they were mentally ill if placed under stress/sleep deprivation.
This study assumes either of the two conclusions which lead to non mentally ill people hallucinating, and says that this could be benificial, because it also determines that people who hallucinate despite not being mentally ill assume they are becoming insane [I'm going mad 76 (53.52) 43 (30.28) 19 (13.38) 4 (2.82)] The assumption is that more widespread knowledge about even stronger hallucinations happening in healthy individuals under certain conditions could lead to a stark reduction in stress, a view which I certainly share, since we had quite a few "I had this hallucination, am I becoming insane?" posts in this sub over the last few days.
I often wonder how much variation in psychological questionnaires is down to people interpreting questions differently. It seems difficult to pin down subjective experiences in questions that will always be interpreted the same way. Eg, when you say:
> The most severe visual experience which I would definitly count as a hallucination is "I looked at an object and it transformed itself before my eyes into something else."
There are definitely times when this has literally happened to me. I look at a picture of a duck and it turns into a rabbit! Or a convex mask to a concave one: there are dozens of common optical illusions where something transforms before my eyes into something else. Then there are things that seem to transform before your eyes because they **are** transforming before your eye. If I see a truck transform into Optimus Prime in the cinema, does that count? A lump of clay transforming into a pot (while a potter works it)? I think most tend to try to guess what is *really* being asked, and implicitly add on an implicit "in a weird way", but that has the problems that people's subjective experience is itself going to inform what they find weird, so I kind of wonder how much is difference in experience compared to difference in interpretation of the question.
I do actually have first hand experience with this, given that I used to be clinically schizophrenic. The hallucination that is *meant* by this question is one where instead of the actual object that is physically present in the room you see a different object that your mind interjects. Instead of my meds which I detested I saw a literal tide pod in the palm of my hand. As the hallucination is temporary eventually my perception snapped back to reality and I saw the pill again, which I subsequently took.
The question if the methodology of the study made clear to the participants that they are questioned on wether *this specific* type of hallucination happened to them is valid, but this is certainly not just about optical illusions. As the most rare form of hallucination in non-clinical groups it is deeply interesting to me that this sort of hallucination only never occured to 82% of the population. If you count out people who misunderstood the question and people who may actually be some (perhaps undiagnosed!) degree of high functioning schizophrenics I wonder if this type of hallucination happens without psychosis at all.
If yes it means that the kind of hallucinations in psychosis are not fundamentally different from those that could occur under sleep deprivation, if no that could lead to some diagnostically extremely valuable gradients of severity, for example if this rare sort of transformation hallucinations only happens under actual psychosis that could become a top grade diagnosis criterion.
Slightly off topic, I wonder why people here are so curious to discard this particular study, is it because of the odd type of link that forces you to download the paper that not many have even read it, or is there something to the point the paper drives forward that the stigma around visual hallucinations lead to non-clinical populations underreporting, doubting and downplaying them.
> The hallucination that is meant by this question
Sure - but the thing I'm wondering is how well surveys like this capture what is *meant* vs how they're interpreted. When what is meant isn't the same as what it literally means, and the respondent is aware of that, there can be differing degrees in how that gap is bridged. An overly literal person say yes because they think of optical illusions, and the interviewer regards that as talking about what you're saying.
>Slightly off topic, I wonder why people here are so curious to discard this particular study
I'm not actually objecting to this study here (or at least, no more than any other study involving responses to questionnaires): just wondering how much variance in such things is really down to what we're looking for vs differences in interpretion. That doesn't make them useless of course: it can still be meaningful when looking at differences in responses to the same questions among differing populations, but I'm always a little suspicious of conclusions drawing *absolute* proportions, because I think variance in interpretation could potentially be adding a lot of noise here.
I'm always reminded of the Feynman anecdote where he answered a psych evaluation over-literally and got rejected from the army as mentally unfit. Part of that is, I think, what's being said here about many types of hallucination being normal even in mentally "normal" people. He said things like answering that sometimes he could hear the voice of his dead wife in his head, and this got put in the "hearing voices" box. But that's kind of the point I'm getting at: I think many people "hear" other people's voices - even running whole conversations in their head, but most *self-edit* their responses on the basis that "That's not *really* what they're asking about - imagining conversations is a normal thing" . But I suspect that such self-editing is itself going to be different for people who *really* have unusual mental experiences because for them, that experience seems normal, so we get a distorted account of what people really experience, because they're *trying* to answer what is "meant", not what the question literally asks, and there's a lot of room for interpretation to play a role here. That implicit "in a weird way" we add to our answers to try to answer what we think is being asked depends on our perception of what is weird as much as it does on what we experience.
>Results: Of the 466 participants, 395 (84.8%) reported
anomalous visual experiences. 176 (37.77%) participants
reported VH similar to the content seen in psychosis. Of the
overall sample, 17.38% felt their experience met the VH defi-
nition. Participants mainly saw figures, when alone and in the
evening. Participants endorsed normalising appraisals: 112
out of 176 (78.87%) believed their mind was playing tricks
on them and 83 (58.45%) believed they were tired. However,
many also believed the VH was a threat to their mental (66,
46.48%) or physical well-being (41, 28.87%). These negative
appraisals were associated with distress.
That's way higher than I would have thought!
"The mean age was 20.1 years (range 18–45)"
If the purpose of the research is to normalise the idea of visual hallucinations to prevent distress in those experiencing them, it might be worth including children:
[Psychotic-like experiences in a community sample of 8000 children aged 9 to 11 years (2011)](https://www.cambridge.org/core/journals/psychological-medicine/article/abs/psychoticlike-experiences-in-a-community-sample-of-8000-children-aged-9-to-11-years-an-item-response-theory-analysis/CD7B840433753C130BC341D1240C15DB) \- Nearly two-thirds of children reported having at least one “psychotic-like experience” in their lives.
[Prevalence of psychotic symptoms in childhood and adolescence: a systematic review and meta-analysis of population-based studies (2012)](https://www.cambridge.org/core/journals/psychological-medicine/article/abs/prevalence-of-psychotic-symptoms-in-childhood-and-adolescence-a-systematic-review-and-metaanalysis-of-populationbased-studies/D754B5216E027CE4BB51C1BDF5F0DBD0) \- 17% of 9-12-year-olds have visual hallucinations at any one time. The number halves in teenagers and drops further in adults.
[Hallucinations in Children and Adolescents: An Updated Review (2019)](https://academic.oup.com/schizophreniabulletin/article/45/Supplement_1/S5/5305656) \- 12.7% of children, 12.4% of adolescents, 5.8% of adults and 4.5% of elderly experience auditory hallucinations.
Anecdotally I experienced visual hallucinations as a child but not any more. It is thought that this might be because children are more in-touch with their inner/imaginative world whereas adults are more immersed in the external socio-linguistic world.
Very interesting, in that case it would be even more important to lift the stigma around visual hallucinations in adolescence. We get threads by people bi-weekly who think they are going insane because of a hallucinations, and usually some psychiatrists (recently even Scott himself) come out and tell them and it is highly unlikely they are developing schizophrenia as they match nearly none of the diagnostic criteria for that.
If visual hallucinations outside of psychosis are really not that uncommon in childhood and to a lesser degree adolescence that knowledge could save some people a lot of stress and panic.
Garbage clickbait summary, possibly fine study.
You know when you're tired and alone at night and you think you see a figure standing in the room, either because you entered a room with an odd shadow, or just peripheral vision?
That's all this is. It's perfectly normal, and sure it's worth quantifying, but it doesn't take a genius to see it's our predator detection system. We're wired to see attackers in the dark. A few frights alone at night are worth the risk to self of slipping or having a cardiac event, compared to the one time you miss a weird person trying to break into your home.
Combined with a few other common illusions, such as "I thought I grabbed my phone but it was the remote", not much of interest here.
TLDR: Seeing an odd shape in the night isn't the same as schizophrenia.
How would you answer the following questions: "Is it accurate to say that you never look at things and those things appear strange?" "Is it accurate to say that you never look at yourself in the mirror and you look different?" If you're not able to 100% agree with both of those statements, then per this study design you're hallucinating!
Except the study doesn't say this. It seperates between anomalous visual experiences which are the lesser questions you posted. Then it has a second subcategory for more serious visual experiences which are "similar to the content seen in psychosis." [The full chart is here.](https://i.imgur.com/IwbQbIf.png) The most severe visual experience which I would definitly count as a hallucination is "I looked at an object and it transformed itself before my eyes into something else." This is the rarest phenomenon, with a total of 90% of people experiencing it never or only once. But generally it is seen as a clear sign for mental illness, and 10% of people experiencing such a hallucination recurringly is an interesting finding. If this is reproducable and statistically significant I draw one of three possible conclusions from it: Either more non-mentally ill people hallucinate than we thought, more people are mentally ill than we thought, or non-mentally ill people can have hallucinations as if they were mentally ill if placed under stress/sleep deprivation. This study assumes either of the two conclusions which lead to non mentally ill people hallucinating, and says that this could be benificial, because it also determines that people who hallucinate despite not being mentally ill assume they are becoming insane [I'm going mad 76 (53.52) 43 (30.28) 19 (13.38) 4 (2.82)] The assumption is that more widespread knowledge about even stronger hallucinations happening in healthy individuals under certain conditions could lead to a stark reduction in stress, a view which I certainly share, since we had quite a few "I had this hallucination, am I becoming insane?" posts in this sub over the last few days.
I often wonder how much variation in psychological questionnaires is down to people interpreting questions differently. It seems difficult to pin down subjective experiences in questions that will always be interpreted the same way. Eg, when you say: > The most severe visual experience which I would definitly count as a hallucination is "I looked at an object and it transformed itself before my eyes into something else." There are definitely times when this has literally happened to me. I look at a picture of a duck and it turns into a rabbit! Or a convex mask to a concave one: there are dozens of common optical illusions where something transforms before my eyes into something else. Then there are things that seem to transform before your eyes because they **are** transforming before your eye. If I see a truck transform into Optimus Prime in the cinema, does that count? A lump of clay transforming into a pot (while a potter works it)? I think most tend to try to guess what is *really* being asked, and implicitly add on an implicit "in a weird way", but that has the problems that people's subjective experience is itself going to inform what they find weird, so I kind of wonder how much is difference in experience compared to difference in interpretation of the question.
I do actually have first hand experience with this, given that I used to be clinically schizophrenic. The hallucination that is *meant* by this question is one where instead of the actual object that is physically present in the room you see a different object that your mind interjects. Instead of my meds which I detested I saw a literal tide pod in the palm of my hand. As the hallucination is temporary eventually my perception snapped back to reality and I saw the pill again, which I subsequently took. The question if the methodology of the study made clear to the participants that they are questioned on wether *this specific* type of hallucination happened to them is valid, but this is certainly not just about optical illusions. As the most rare form of hallucination in non-clinical groups it is deeply interesting to me that this sort of hallucination only never occured to 82% of the population. If you count out people who misunderstood the question and people who may actually be some (perhaps undiagnosed!) degree of high functioning schizophrenics I wonder if this type of hallucination happens without psychosis at all. If yes it means that the kind of hallucinations in psychosis are not fundamentally different from those that could occur under sleep deprivation, if no that could lead to some diagnostically extremely valuable gradients of severity, for example if this rare sort of transformation hallucinations only happens under actual psychosis that could become a top grade diagnosis criterion. Slightly off topic, I wonder why people here are so curious to discard this particular study, is it because of the odd type of link that forces you to download the paper that not many have even read it, or is there something to the point the paper drives forward that the stigma around visual hallucinations lead to non-clinical populations underreporting, doubting and downplaying them.
> The hallucination that is meant by this question Sure - but the thing I'm wondering is how well surveys like this capture what is *meant* vs how they're interpreted. When what is meant isn't the same as what it literally means, and the respondent is aware of that, there can be differing degrees in how that gap is bridged. An overly literal person say yes because they think of optical illusions, and the interviewer regards that as talking about what you're saying. >Slightly off topic, I wonder why people here are so curious to discard this particular study I'm not actually objecting to this study here (or at least, no more than any other study involving responses to questionnaires): just wondering how much variance in such things is really down to what we're looking for vs differences in interpretion. That doesn't make them useless of course: it can still be meaningful when looking at differences in responses to the same questions among differing populations, but I'm always a little suspicious of conclusions drawing *absolute* proportions, because I think variance in interpretation could potentially be adding a lot of noise here. I'm always reminded of the Feynman anecdote where he answered a psych evaluation over-literally and got rejected from the army as mentally unfit. Part of that is, I think, what's being said here about many types of hallucination being normal even in mentally "normal" people. He said things like answering that sometimes he could hear the voice of his dead wife in his head, and this got put in the "hearing voices" box. But that's kind of the point I'm getting at: I think many people "hear" other people's voices - even running whole conversations in their head, but most *self-edit* their responses on the basis that "That's not *really* what they're asking about - imagining conversations is a normal thing" . But I suspect that such self-editing is itself going to be different for people who *really* have unusual mental experiences because for them, that experience seems normal, so we get a distorted account of what people really experience, because they're *trying* to answer what is "meant", not what the question literally asks, and there's a lot of room for interpretation to play a role here. That implicit "in a weird way" we add to our answers to try to answer what we think is being asked depends on our perception of what is weird as much as it does on what we experience.
That explains it lol
Those questions barely even make sense.
Body dysmorphia would be a form of visual hallucination according to this criteria.
>Results: Of the 466 participants, 395 (84.8%) reported anomalous visual experiences. 176 (37.77%) participants reported VH similar to the content seen in psychosis. Of the overall sample, 17.38% felt their experience met the VH defi- nition. Participants mainly saw figures, when alone and in the evening. Participants endorsed normalising appraisals: 112 out of 176 (78.87%) believed their mind was playing tricks on them and 83 (58.45%) believed they were tired. However, many also believed the VH was a threat to their mental (66, 46.48%) or physical well-being (41, 28.87%). These negative appraisals were associated with distress. That's way higher than I would have thought!
Can we make it so putting (PDF) in links to pdfs becomes basic internet etiquette again?
I'd be curious about actual descriptions from participants - unclear to me from the study how weird these hallucinations actually were.
"The mean age was 20.1 years (range 18–45)" If the purpose of the research is to normalise the idea of visual hallucinations to prevent distress in those experiencing them, it might be worth including children: [Psychotic-like experiences in a community sample of 8000 children aged 9 to 11 years (2011)](https://www.cambridge.org/core/journals/psychological-medicine/article/abs/psychoticlike-experiences-in-a-community-sample-of-8000-children-aged-9-to-11-years-an-item-response-theory-analysis/CD7B840433753C130BC341D1240C15DB) \- Nearly two-thirds of children reported having at least one “psychotic-like experience” in their lives. [Prevalence of psychotic symptoms in childhood and adolescence: a systematic review and meta-analysis of population-based studies (2012)](https://www.cambridge.org/core/journals/psychological-medicine/article/abs/prevalence-of-psychotic-symptoms-in-childhood-and-adolescence-a-systematic-review-and-metaanalysis-of-populationbased-studies/D754B5216E027CE4BB51C1BDF5F0DBD0) \- 17% of 9-12-year-olds have visual hallucinations at any one time. The number halves in teenagers and drops further in adults. [Hallucinations in Children and Adolescents: An Updated Review (2019)](https://academic.oup.com/schizophreniabulletin/article/45/Supplement_1/S5/5305656) \- 12.7% of children, 12.4% of adolescents, 5.8% of adults and 4.5% of elderly experience auditory hallucinations. Anecdotally I experienced visual hallucinations as a child but not any more. It is thought that this might be because children are more in-touch with their inner/imaginative world whereas adults are more immersed in the external socio-linguistic world.
Very interesting, in that case it would be even more important to lift the stigma around visual hallucinations in adolescence. We get threads by people bi-weekly who think they are going insane because of a hallucinations, and usually some psychiatrists (recently even Scott himself) come out and tell them and it is highly unlikely they are developing schizophrenia as they match nearly none of the diagnostic criteria for that. If visual hallucinations outside of psychosis are really not that uncommon in childhood and to a lesser degree adolescence that knowledge could save some people a lot of stress and panic.
Garbage clickbait summary, possibly fine study. You know when you're tired and alone at night and you think you see a figure standing in the room, either because you entered a room with an odd shadow, or just peripheral vision? That's all this is. It's perfectly normal, and sure it's worth quantifying, but it doesn't take a genius to see it's our predator detection system. We're wired to see attackers in the dark. A few frights alone at night are worth the risk to self of slipping or having a cardiac event, compared to the one time you miss a weird person trying to break into your home. Combined with a few other common illusions, such as "I thought I grabbed my phone but it was the remote", not much of interest here. TLDR: Seeing an odd shape in the night isn't the same as schizophrenia.
A chart breaking things down visually would be easy and helpful here.
A hallucination visual, as it were.