Whenever I hear about stuff like this, I wonder: Is there anything the failure modes of the human brain allow us to deduce about the software architecture?
Maybe memories are stored in some partitioned database, and one of the partitions is always stuff relating to "my identity", and somehow this partition can get unlinked and temporarily re-linked to a blank one, which is discarded after a few hours.
Hmm, maybe this is actually a feature, not a bug. In ancient times people often had to deal with being abused, enslaved, etc. Maybe being able to blank out really unpleasant experiences helped young slaves tolerate their abuse without becoming totally insane or going the route of suicide or rebellion (assuming the latter's success rate was negligible, rebellion would basically be the same as suicide from the standpoint of evolutionary pressures). Which ultimately helped them survive and reproduce.
Then once the mechanism exists, it can still get triggered naturally in modern humans if they're abused, or artificially by drugs.
Failure modes are almost the best ways to figure it out. H.M. (https://en.wikipedia.org/wiki/Henry_Molaison) is a famous case of what can go wrong with seemingly small areas of architecture.
One thing to keep in mind is that the brain is not an OS, it is more of a FPGA (https://en.wikipedia.org/wiki/Field-programmable_gate_array) that is programmed by experience and life. Memory is very much dissociated all over the brain and in non-intuitive ways. For example the motor cortex deals with voluntary (non-reflexive) movement and is in the cortex near the top of your brain. However, given enough time and practice, these movements become controlled by the cerebellum, that little wrinkly thing hanging onto the back and bottom of your brainstem (https://en.wikipedia.org/wiki/Cerebellum#Learning).
Abuse has a much longer history than just the social ones the we humans experience. Though your description of the mechanisms that may underlie this and the reasoning behind it is cloudy, I would assume that the evolutionary pressure to disassociate mentally is a preserved one throughout evolution. We can see this most memorably with dogs that learn to roll over or become head-shy, this may be a form of the behavior that has been with mammals and manifests itself similarly though not in the same way for each species. Also, our view of slavery is distorted and brutal, Roman slave laws were permissive in the later years of the empire (https://en.wikipedia.org/wiki/Slavery_in_ancient_Rome#Treatm...) and even allowed legal redress of the slave to the master. If we evolved in this system, then most humans had to be slaves from the point of view of genes. This is possible, though not probable.
Hacker News: where a very human story of empathy and healing immediately turns into a discussion of what this can tell us about the brain's computational architecture.
It most definitely is a feature, not a bug. We all dissociate, but to a much lesser degree. When it happens repeatedly and to extreme degrees of trauma it allows the victim to continue functioning (surviving) without being overwhelmed by the past trauma. It's (somewhat) similar to how ships have compartments that prevent the entire ship from sinking in case of a collision.
Can you give more specific examples of "We all dissociate, but to a much lesser degree". Looks interesting to do more googling on that, but I have no keywords.
This is why a lot of cognitive psychologists study abnormal psychology. It's when things break that you can find out what's going on.
I do think being able to blank things out (including times of immense pain) is a feature that increases survival rather than a bug. If you are excessively afraid, your ability to pass on your genes goes down.
>> It's when things break that you can find out what's going on.
Please correct me if I'm wrong, early part of Medical academics is all about studying how a healthy body body works. So that when they start studying the diseases they can learn to distinguish between a disease and a expected behaviour.
So to know if something is an abnormal psychology, you need to first know what is normal.
This is the most fascinating part of mental illness. And it's a bittersweet thought that as horrible as mental illness is, it might be what allows us to really understand the human mind.
However, making evolutionary arguments for psychological traits is tricky business and while I'm not a professional evolutionary psychologist myself, I think the explanation you gave violates a fundamental principle of evolutionary arguments.
Imagine gene A confers a fitness advantage because it allows a person to better cope with a selection pressure X, and gene B confers an additional fitness advantage against X, but onlyifgeneAispresent, and does nothing otherwise. In this (common) case, gene B will not be selected for unless gene A is already universal in the population. Following the same rules, imagine we then get gene C which is dependent on B, then a variant of gene A called A* which is dependent on B and C, and so on. Eventually, if even one gene is removed (either by sexual reproduction with someone who doesn't have it or by mutation), the whole tower falls down and the entire piece of complex biological machinery is broken.
Basically, there's no way for selection pressure X on a significantchunk but not all of the population to produce a piece of complex machinery (read: involving 2+ interdependent genes) in the first place, and it would be broken beyond all repair in all offspring who didn't have both parents with the full genetic instructions. So the idea that "many humans were abused, enslaved, etc." only works if the selection pressure was on everyone and the adaptation is universal in the human population, unless it's attributed to a single mutation.
The rarity of this condition isn't consistent with it being a feature. Seems like a bug to me.
I think (I'm no neuro-*) that one of the things that make the brain so hard to understand is that a lot of the things that a brain is capable of doing could very well be just a side effect or emergent behavior, instead of something that's actually "architectured" (if that even means something..) or designed to do that.
Maybe that applies here and so only the emergent behavior was disrupted instead of actually a "piece" of the system?
I just happened to be reading Consciousness and the Social Brain [1] which gives a theory of consciousness as the brain's representation of attention.
One of their points was that if consciousness is just a representation it should be possible for your brain to alternate between representations, much like as happens in multi-stable perception [2], which would explain DID.
Oliver Sacks' books looks at a wide range of failure modes, and what those failure modes mean about the structure of the brain (e.g. The man who mistook his wife for a hat). Brilliant writer, scientist, and seems like an all round good guy.
> Whenever I hear about stuff like this, I wonder: Is there anything the failure modes of the human brain allow us to deduce about the software architecture?
There is a long history of this in Neuropsychology. It's referred to as Double Dissociation [1]. Arguably, this is more about the hardware, but the hardware affects the software ("Brain is the seat of the Mind").
> Whenever I hear about stuff like this, I wonder: Is there anything the failure modes of the human brain allow us to deduce about the software architecture?
Like a fault attack to reveal the inners of human. Brilliant :)
And I want to say yes! I've read about it somewhere: a region of the brain was damaged on some persons, and they would function normally most of the time, except they couldn't understand metaphors. I can't remember where I read this though...
You ... get used to it. Familiarity, is, as mentioned, the key - narrating the location and why it should be familiar and when they moved there and ways they can prove it's theirs (e.g. keys fitting the front door) tend to help quite a bit. A dissociated mind still wants to believe it should be where it is and that that makes complete sense, it just doesn't have the data available.
Eventually, with luck, you can get them to remember who you are reasonably quickly, and things get a lot less complicated - having the intelligence to call her ex as a substitute was a brilliant move on the author's part.
Me: "It's going to be okay. This happens when you get bad headaches. I can give you some medicine. Once your headache gets better you will remember everything"
At that point she will usually trust me and the situation becomes much more manageable. In her case, she suffered abuse as a child, and her absentee incidents are always associated with bad migraines. Once we break the migraine, she improves quickly.
Wouldn't something like polaroids be a good strategy, you know, like in Memento? When she forgets everything, have her grab photos from her bag, one together with every person she trusts, one of her in front of her building, one of her in front of a street sign for her neighbourhood. Also, a pocket mirror if she really forgets who or even what she is.
Disassociating doesn't always work like played out in films or TV, sadly. It's terrifying, and often find it hard to trust what's in front of you. Familiarity is needed, as it acts to ground you, and a key part of this is to feel safe on a number of different levels. Simply having photos alone may not be enough, unless those photos are something you regularly examine and experience.
Grounding is a common method of dealing with anxiety and other mental health issues. The idea of finding your place, finding familiarity, centring yourself. Something you are very used to doing normally and when safe is important, as is having that also associated very strongly with being safe.
For some people, photos will work well for this - they might capture moments with strong association with safety and happiness. Some people may be able to instead use an object, a talisman of sorts.
For others, or for when the disassociation is worse, a single grounding method may not be enough. It's about building the complete story - getting home and watching something familiar. The grounding only happens from weight of evidence.
Finally, there's something you don't hear talked about much. Coming back around from disassociating can be utterly terrifying in it's own right. Both as one tries to return, and after coming back. Having multiple entirely different means to ground helps with this.
Imagine if today, someone walked up to you and started telling you who you really were. They even have pictures to prove what they are saying is true. You have no memory of any of it. Are you going to believe them?
My wife has these episodes. Evidence-based and logic-based approaches are very ineffective. If I can convince her to go for a ride in the car, and we drive around the city she has lived in her entire life, and drive by the house she grew up in, schools she went to, and get some food from a drive through she's been to hundreds of times, it will reduce her time-to-return by 24-48 hours usually. We can look through several thick photo albums, and at the end she just shrugs and says, "I don't know who any of these people are".
>> having the intelligence to call her ex as a substitute was a brilliant move on the author's part.
I still don't understand why he didn't have her look for HIM in her phone. Like dude, you know me, look in your phone I'm so-and-so. Look at texts between us. There should be a picture of him too. And why TF was there a picture of her ex in her appartment, but not this guy? This aspect of the story made it seem fake to me, but OK maybe it was very stressful to him and he honestly figured the ex would be more familiar than himself. IDK.
She would have seen that he was in the phone, but she wouldn't have known what to do with that information. In any case, he had her call George because he knew what to do in that situation. I think her remembering George was just fortuitous.
I feel like that a lot. I don't have DID or anything like that, but my memory for experiences and conversations is absolutely abysmal, far, far worse than anybody else's I know. Any question of "Hey, do you remember-" I can usually just cut them off and say 'no'. It's completely frustrating and I don't know why I'm like this.
edit: though I don't cut them off because that would be obnoxious.
> She'd wake up with no memory of what had happened, and wouldn't want to know.
This was probably the most painful part of that whole story. Naturally, I was thinking of my wife and myself as the main characters throughout the whole story, and while it would be incredibly difficult to go through this, it would be harder if she woke up the next morning and didn't want to acknowledge or know about what had happened the night before.
(Unless I'm totally misreading that sentence, and the author is saying something different.)
It's difficult and unpleasant to acknowledge what happened. By doing so they would have to acknowledge and deal with what happened in the past (that caused DID in the first place). Part of therapy is to take them on this road. They're able to cope with reality because they're able to compartmentalize their history. Hearing about it, while necessary, weakens the coping mechanism that helped them survive. So you can imagine why they wouldn't want to hear about it.
And on a far more simple level, disassociating and returning from it is utterly terrifying, and worse still one might know that their loved ones will have also had a very difficult experience
I've seen that "exposure" therapy is often used in the treatment of OCD, another form of anxiety disorder. Patients with OCD often have an anxiety about something and use their quirks and rituals to avoid/ignore the anxiety. To help them cure their rituals, they must actively try to experience the often very extreme anxiety that some situation puts them in. Is the treatment similar in cases of DID?
I dealt with physical illness which caused large amounts of anxiety and stress. If you've recovered from a dehumanizing situation, often you don't want to invite those negative emotions back into your life. You just cross your fingers and hope it doesn't happen again.
>while it would be incredibly difficult to go through this, it would be harder if she woke up the next morning and didn't want to acknowledge or know about what had happened the night before
It's not that bad. Once you go through the exercise a few times, you have strategies that work, and it's about on par with having a sick child, where you might be slightly frustrated that you have to take a day off of work or make other arrangements, but you know the steps to take and get on with the day.
Echoing others, this is very real. I had a girlfriend who did this a few times when we were together for a couple of years, although she never was as bad as this, she for whatever reasons (being brought up early by a couple of loving grandparents?) trusted me. The "parental" role thing is pretty much how it always started, and it ended in exactly the same way, after going to sleep she'd wake up normally and not remember any of it. She did always regress to a previous point in her life, at least at one time associated with a very stressful past event. No drug of any sort associated with it, and I suppose it's good it only happened when at home. There was no obvious trigger.
I'll believe it because I had to be "that person who drives people home after a rave" a few times in my life. There's "I forget my name" drunk, but that's a joke, then there's people who are having a semi-bad trip who literally forget who their friends are. It never got as bad as this fortunately.
Use dissociatives responsibly, be in a familiar environment etc.
I do not agree that having a semi-bad trip makes you forget who your friends are. In fact, I wouldn't call that a semi-bad trip, at all. If someone forgets their friends while tripping (and I assume you mean on acid) they actually, likely, never liked that person enough anyway. Breaking down the barriers and lies is what it does.
I would assume as the poster is talking about raves, they are referencing ketamine or MDMA, and both of these are more than capable of making you forget who you are, let alone who your friends are.
I was curious with the difference between schizophrenia and DID, since most mental illnesses overlap tremendously. If anyone has a better source, you're welcome to elaborate:
"Schizophrenia and dissociative identity disorder are often confused, but they are very different.
Schizophrenia is a severe mental illness involving chronic (or recurrent) psychosis, characterized mainly by hearing or seeing things that aren't real (hallucinations) and thinking or believing things with no basis in reality (delusions). Contrary to popular misconceptions, people with schizophrenia do not have multiple personalities. Delusions are the most common psychotic symptom in schizophrenia; hallucinations, particularly hearing voices, are apparent in about half of people with the illness." (http://www.webmd.com/mental-health/dissociative-identity-dis...)
DID: Alice is talking to Bob. At some point in the conversation Bob "dissociates" and is replaced by Charlie. Charlie is in the exact same place as Bob and sees all the things Bob was seeing, but Charlie wasn't here before so no idea where here is, how he got there, or who is talking to him. Alice doesn't know anything's wrong at first but Bob (now Charlie) seems uncomfortable and doesn't know things Bob does, like where they are, how they got there, or who she is. Sometime later the dissociative episode ends and Bob comes back in place of Charlie. Bob has no idea what transpired during the episode because Charlie was there instead, but recognizes Alice and remembers things they had done together.
In this case there is no difference in Bob's or Charlie's ability to perceive the world, nor are either of them perceiving something which Alice could not (barring other conditions). There are no hallucinations or delusions; Bob and Charlie appear to "know" different things, as if they were different people. Of note, Bob and Charlie identify differently but its debatable whether they are (or should be treated as) different persons, hence the change of name.
Schizophrenia: Alice is talking to Bob. Bob is talking to Charlie. Charlie isn't really there, but Bob is either unaware or doesn't mind. Bob's conversation with Charlie may be benign or it may involve plots to take over the world, in either case from Alice's perspective Bob experiencing something which isn't real.
This of course is just a possible scenario for schizophrenia, and if Bob is being treated for schizophrenia he may be better able to control or cope with Charlie. In schizophrenia cases Charlie does not exist to any third party observation; Bob is not identifying as Charlie nor is Charlie an alternate persona. Bob believes he is himself and that Charlie is communicating with him.
In my very limited contact with people who were suffering from schizophrenia, it's clear their minds, their ability to think, is broken in some fundamental way. This is indeed completely different, the person can think properly, it's just that some things are gone. If it's like my girlfriend who had it when with me, this woman regressed in time a bit, not so far she forgot that previous boyfriend, but enough to forget the current one. But I wouldn't be surprised if DID can be more nuanced.
Agreed. I've lost three friends over the years to schizophrenia. I knew them all well before, during and after. Their minds are simply broken, their reality is not the same as ours. One believed he was a ninja protecting the world, another saw himself as the hero of a WWIII future, the third wanted to bind his spirit with alligators to grow his spiritual totem. DID sounds very, very different.
I had a friend who I thought was borderline, and later suspected to have DID. She sometimes said delusional things like she thought she was an alien, or that Jesus was inside her, or that she was a reincarnated dolphin, etc. Other people told me she would get weird in conversations, a lot like the "react oddly in conversations, not respond, or talk to themselves" description in the Wikipedia article. Stuff that schizophrenic people do.
When I asked about it, she said she realized that it didn't make sense that she was a reincarnated dolphin and that she didn't know why she believed those things. Schizophrenic people don't really have that kind of self-awareness.
You can think of schizophrenia as a hardware problem and of DID as a software issue (not bug, but maybe mis-configuration?). With high enough trauma (and applied early enough, while the brain is still developing) anybody could develop DID; some are more prone than others of course.
It does not sound all that unlike certain types of Alzheimer's episodes.
In addition to seeing my Grandmother completely forget who I was from one minute to the next, more bizarrely she would time warp and believe she was 16 years old and seemingly remember everything/everyone at that time of her life very accurately. Not until now, granted I was very young then, did I ever realize that at times she may have not known who she was, but sitting here now I am sure she would have experienced that as well.
That's very interesting. Alzheimer's and this kind of disassociation disorder could be affecting the same "pathway" or something. Thanks for this comment!
There was a novel[1] about a woman with DID and a psychologist who tied that to suppressed memories of sexual abuse. I wondered after reading it whether or not it was a thing or just a creative fiction. I found at least one paper [2] which indicates that DID can be a symptom of prior abuse.
Note that the concept of 'suppressed memories' is not very well accepted by the psychological community. People can be convinced that they remember something they don't, so it's extremely difficult to tell between a 'suppressed' memory and a false one.
Readit News
Maybe memories are stored in some partitioned database, and one of the partitions is always stuff relating to "my identity", and somehow this partition can get unlinked and temporarily re-linked to a blank one, which is discarded after a few hours.
Hmm, maybe this is actually a feature, not a bug. In ancient times people often had to deal with being abused, enslaved, etc. Maybe being able to blank out really unpleasant experiences helped young slaves tolerate their abuse without becoming totally insane or going the route of suicide or rebellion (assuming the latter's success rate was negligible, rebellion would basically be the same as suicide from the standpoint of evolutionary pressures). Which ultimately helped them survive and reproduce.
Then once the mechanism exists, it can still get triggered naturally in modern humans if they're abused, or artificially by drugs.
One thing to keep in mind is that the brain is not an OS, it is more of a FPGA (https://en.wikipedia.org/wiki/Field-programmable_gate_array) that is programmed by experience and life. Memory is very much dissociated all over the brain and in non-intuitive ways. For example the motor cortex deals with voluntary (non-reflexive) movement and is in the cortex near the top of your brain. However, given enough time and practice, these movements become controlled by the cerebellum, that little wrinkly thing hanging onto the back and bottom of your brainstem (https://en.wikipedia.org/wiki/Cerebellum#Learning).
Abuse has a much longer history than just the social ones the we humans experience. Though your description of the mechanisms that may underlie this and the reasoning behind it is cloudy, I would assume that the evolutionary pressure to disassociate mentally is a preserved one throughout evolution. We can see this most memorably with dogs that learn to roll over or become head-shy, this may be a form of the behavior that has been with mammals and manifests itself similarly though not in the same way for each species. Also, our view of slavery is distorted and brutal, Roman slave laws were permissive in the later years of the empire (https://en.wikipedia.org/wiki/Slavery_in_ancient_Rome#Treatm...) and even allowed legal redress of the slave to the master. If we evolved in this system, then most humans had to be slaves from the point of view of genes. This is possible, though not probable.
I do think being able to blank things out (including times of immense pain) is a feature that increases survival rather than a bug. If you are excessively afraid, your ability to pass on your genes goes down.
Please correct me if I'm wrong, early part of Medical academics is all about studying how a healthy body body works. So that when they start studying the diseases they can learn to distinguish between a disease and a expected behaviour.
So to know if something is an abnormal psychology, you need to first know what is normal.
However, making evolutionary arguments for psychological traits is tricky business and while I'm not a professional evolutionary psychologist myself, I think the explanation you gave violates a fundamental principle of evolutionary arguments.
Imagine gene A confers a fitness advantage because it allows a person to better cope with a selection pressure X, and gene B confers an additional fitness advantage against X, but only if gene A is present, and does nothing otherwise. In this (common) case, gene B will not be selected for unless gene A is already universal in the population. Following the same rules, imagine we then get gene C which is dependent on B, then a variant of gene A called A* which is dependent on B and C, and so on. Eventually, if even one gene is removed (either by sexual reproduction with someone who doesn't have it or by mutation), the whole tower falls down and the entire piece of complex biological machinery is broken.
Basically, there's no way for selection pressure X on a significant chunk but not all of the population to produce a piece of complex machinery (read: involving 2+ interdependent genes) in the first place, and it would be broken beyond all repair in all offspring who didn't have both parents with the full genetic instructions. So the idea that "many humans were abused, enslaved, etc." only works if the selection pressure was on everyone and the adaptation is universal in the human population, unless it's attributed to a single mutation.
The rarity of this condition isn't consistent with it being a feature. Seems like a bug to me.
Hope this was helpful!
Maybe that applies here and so only the emergent behavior was disrupted instead of actually a "piece" of the system?
https://en.wikipedia.org/wiki/Vilayanur_S._Ramachandran
One of their points was that if consciousness is just a representation it should be possible for your brain to alternate between representations, much like as happens in multi-stable perception [2], which would explain DID.
[1] https://www.goodreads.com/book/show/17349805-consciousness-a...
[2] https://en.wikipedia.org/wiki/Multistable_perception
There is a long history of this in Neuropsychology. It's referred to as Double Dissociation [1]. Arguably, this is more about the hardware, but the hardware affects the software ("Brain is the seat of the Mind").
[1] https://en.wikipedia.org/wiki/Dissociation_%28neuropsycholog...
Like a fault attack to reveal the inners of human. Brilliant :)
And I want to say yes! I've read about it somewhere: a region of the brain was damaged on some persons, and they would function normally most of the time, except they couldn't understand metaphors. I can't remember where I read this though...
2) People are being abused at this very moment, it's not something that has only occurred in 'ancient times'.
Eventually, with luck, you can get them to remember who you are reasonably quickly, and things get a lot less complicated - having the intelligence to call her ex as a substitute was a brilliant move on the author's part.
Wife: (looking at me suspiciously)
Me: "Are you confused?"
Wife: (nods yes)
Me: "Do you know who I am?"
Wife: (shakes head no)
Me: "I am your husband"
Wife: (looks at me, wide-eyed, more suspicious)
Me: "Do you have a headache?"
Wife: "Yes..."
Me: "It's going to be okay. This happens when you get bad headaches. I can give you some medicine. Once your headache gets better you will remember everything"
At that point she will usually trust me and the situation becomes much more manageable. In her case, she suffered abuse as a child, and her absentee incidents are always associated with bad migraines. Once we break the migraine, she improves quickly.
Grounding is a common method of dealing with anxiety and other mental health issues. The idea of finding your place, finding familiarity, centring yourself. Something you are very used to doing normally and when safe is important, as is having that also associated very strongly with being safe.
For some people, photos will work well for this - they might capture moments with strong association with safety and happiness. Some people may be able to instead use an object, a talisman of sorts.
For others, or for when the disassociation is worse, a single grounding method may not be enough. It's about building the complete story - getting home and watching something familiar. The grounding only happens from weight of evidence.
Finally, there's something you don't hear talked about much. Coming back around from disassociating can be utterly terrifying in it's own right. Both as one tries to return, and after coming back. Having multiple entirely different means to ground helps with this.
My wife has these episodes. Evidence-based and logic-based approaches are very ineffective. If I can convince her to go for a ride in the car, and we drive around the city she has lived in her entire life, and drive by the house she grew up in, schools she went to, and get some food from a drive through she's been to hundreds of times, it will reduce her time-to-return by 24-48 hours usually. We can look through several thick photo albums, and at the end she just shrugs and says, "I don't know who any of these people are".
Depends who they are and how and what they forget.
I still don't understand why he didn't have her look for HIM in her phone. Like dude, you know me, look in your phone I'm so-and-so. Look at texts between us. There should be a picture of him too. And why TF was there a picture of her ex in her appartment, but not this guy? This aspect of the story made it seem fake to me, but OK maybe it was very stressful to him and he honestly figured the ex would be more familiar than himself. IDK.
edit: though I don't cut them off because that would be obnoxious.
This was probably the most painful part of that whole story. Naturally, I was thinking of my wife and myself as the main characters throughout the whole story, and while it would be incredibly difficult to go through this, it would be harder if she woke up the next morning and didn't want to acknowledge or know about what had happened the night before.
(Unless I'm totally misreading that sentence, and the author is saying something different.)
It's not that bad. Once you go through the exercise a few times, you have strategies that work, and it's about on par with having a sick child, where you might be slightly frustrated that you have to take a day off of work or make other arrangements, but you know the steps to take and get on with the day.
Use dissociatives responsibly, be in a familiar environment etc.
"Schizophrenia and dissociative identity disorder are often confused, but they are very different.
Schizophrenia is a severe mental illness involving chronic (or recurrent) psychosis, characterized mainly by hearing or seeing things that aren't real (hallucinations) and thinking or believing things with no basis in reality (delusions). Contrary to popular misconceptions, people with schizophrenia do not have multiple personalities. Delusions are the most common psychotic symptom in schizophrenia; hallucinations, particularly hearing voices, are apparent in about half of people with the illness." (http://www.webmd.com/mental-health/dissociative-identity-dis...)
DID: Alice is talking to Bob. At some point in the conversation Bob "dissociates" and is replaced by Charlie. Charlie is in the exact same place as Bob and sees all the things Bob was seeing, but Charlie wasn't here before so no idea where here is, how he got there, or who is talking to him. Alice doesn't know anything's wrong at first but Bob (now Charlie) seems uncomfortable and doesn't know things Bob does, like where they are, how they got there, or who she is. Sometime later the dissociative episode ends and Bob comes back in place of Charlie. Bob has no idea what transpired during the episode because Charlie was there instead, but recognizes Alice and remembers things they had done together.
In this case there is no difference in Bob's or Charlie's ability to perceive the world, nor are either of them perceiving something which Alice could not (barring other conditions). There are no hallucinations or delusions; Bob and Charlie appear to "know" different things, as if they were different people. Of note, Bob and Charlie identify differently but its debatable whether they are (or should be treated as) different persons, hence the change of name.
Schizophrenia: Alice is talking to Bob. Bob is talking to Charlie. Charlie isn't really there, but Bob is either unaware or doesn't mind. Bob's conversation with Charlie may be benign or it may involve plots to take over the world, in either case from Alice's perspective Bob experiencing something which isn't real.
This of course is just a possible scenario for schizophrenia, and if Bob is being treated for schizophrenia he may be better able to control or cope with Charlie. In schizophrenia cases Charlie does not exist to any third party observation; Bob is not identifying as Charlie nor is Charlie an alternate persona. Bob believes he is himself and that Charlie is communicating with him.
So that's why my ex didn't remember things. I read about it, but I could never quite put my finger on what the dissociation stuff was.
I had a friend who I thought was borderline, and later suspected to have DID. She sometimes said delusional things like she thought she was an alien, or that Jesus was inside her, or that she was a reincarnated dolphin, etc. Other people told me she would get weird in conversations, a lot like the "react oddly in conversations, not respond, or talk to themselves" description in the Wikipedia article. Stuff that schizophrenic people do.
When I asked about it, she said she realized that it didn't make sense that she was a reincarnated dolphin and that she didn't know why she believed those things. Schizophrenic people don't really have that kind of self-awareness.
Not sure about the aliens, but the other two are promoted by (different) major world religions.
In addition to seeing my Grandmother completely forget who I was from one minute to the next, more bizarrely she would time warp and believe she was 16 years old and seemingly remember everything/everyone at that time of her life very accurately. Not until now, granted I was very young then, did I ever realize that at times she may have not known who she was, but sitting here now I am sure she would have experienced that as well.
[2] http://www.sciencedirect.com/science/article/pii/01452134939... was cited by a
[1] http://www.amazon.com/Blood-Memory-Greg-Iles/dp/1441808183