The key to this question can be found mixing some concepts of anthropological psychiatry with the concept of "Functions of the self" that was used by Bleuler. The self has four basic conditions: we are only one (unicity), we are always the same person (identity), we have power over our actions (sovereignty) and we are distinct from the external world (limits of the self). The four elements are, more or less, affected always in schizophrenia. That's why, for example, an schizophrenic patient can be multiple persons at the same time (recently; we saw one patient that was a complete team of soccer himself!). They are not affected, by the contrary, on personality disorders, except sometimes identity in dissociative states.

Has any of you asked himself why schizophrenic patients have auditory but NOT VISUAL hallucinations? (I know some of you will disagree with this, but that was what I was taught by my masters, and I can say that, again and again, when I have seen a patient diagnosed of schizophrenia, that had TRUE visual hallucinations, there was a comorbidity with an organic disease, or, simply, the patient was NOT schizophrenic when adequately studied).

Auditory hallucinations follow a simple pattern: first, the patient begins to hear his own thoughts. As the identity of the self becomes blurred, the patient starts to experience them as voices distinct from himself, And then, finally, when the limits of the self dissolves, voices are experienced as from outside. So, from this point of view, schizophrenic patients does not really have alterations of perception, because all the phenomena origins from the thought itself.

At the same time this is happening, sovereignty of the self also is diminished. So, every action of the senses that usually happens in active form (I hear, I see, I touch, etc), changes to a passive status, giving rise to all the phenomena we usually call "alterations of sensoperception":

"I hear" gives rise to "I'm heard", so everyone can know what he's thinking.

"I talked" gives rise to "I'm talked", which is lived in two forms: the first, the "auditory hallucinations" we talked early, and the second, one aspect of self-reference: "they talk about me".

"I see" changes to "I'm observed", giving rise to another aspect of reference phenomena: "They are seeing me, and they follow me".

"I touch" changes to "I'm touched", giving origin to "kinestesic" hallucinations.

So, when nearly examinated, auditory hallucinations in schizophrenia are not really alterations of the sensoperception, but expressions of thought disorder and blurring of the self.

I find more difficult to differentiate auditory hallucinations of dissociative states and those which are of organic origin, because in both cases they tend to be single voices, personalized and to have external projection. Probably the best way to differentiate them are that (in the case of temporal lobe epilepsy) they are stereotyped and repetitive, and are not exclusively affected by emotional factors (don't forget that organic diseases are also affected by emotions), and they tend to follow a "delirium" pattern, usually having exacerbations at night.

The first person to have asked why auditory and not visual hallucinations were commoner in psychosis was probably Benjamin Rush. His explanation, which I believe is correect, is that ear disease is commoner than eye disease in psychotics. Have you checked, Rodrigo, whether AHs start with faint or ambiguous noises in the ear? You also seem to be describing depersonalisation, which is probably of vestibular origin, and can be induced by running hot or cold water into the ear.

In the same line to Moskowitz and Corstens, recent comparative studies to psychotic symptoms in borderline personality disorder (Associated with childhood trauma and dissociative symptoms) and schizophrenia, it's not possible Concluded distinc pyschotic hallucinations. Moreover dissociative hallucinations to have a clear overlap between the two entities. Since it is common for people affected by dissociative disorders present command hallucinations, and general schnneiderian's symptoms.

Moreover, several studies have found in schizophrenic patients with a history of child abuse, that hallucinations have high rates of dissociative symptoms. Getting itself to postulate that the hallucinations would be a partial depersonalization, in which the person is distanced from traumatic memories and thoughts.

Thank you to all for your answers. I hope a hot debate here. Is interesting that in some comparative studies between psychotic and dissociative disorders, as Helga point, is very difficult to distinguish between this samples based to symptoms. The answer of Rodrigo appoint to self and consciousness they are continua functions, as psychotic symptoms (e.g., Strauss, 1969, and mnay studies by van Os and his colleagues). Result an rare thing to speak of a continuum in self and consciousness? Obviously, they are two constructs very difficult for to operationalize. I think that Anthony charge a great weight in ear disease as causal factor; in this sense I think this (see the attachment down). I know the Occam's razor argument, but I think that razor is a point of view or perspective, not a onthology.

https://www.researchgate.net/post/Why_there_are_more_auditory_hallucinations_than_visual_hallucinations_in_functional_psychiatric_disorders?ev=tp_feed_post_xview

I understand the model of "deficit" as a way to explain some kind of alterations of sensoperception. The more classic (and illustrative) example is Charles Bonnet Syndrome, or, as it has been sometimes called "psychosis of the blind". In this disease, complex visual hallucinations occur, just the sensorial modality that has been lost. Another classic example can be "phantom limb", in which cynestesic hallucinations appear in a severed extremity. Both are examples that can be homologated with auditory hallucinations in the hearing-impaired.

But I don't think it's a model easy to extrapolate to other conditions, nor can be an explanations for auditory hallucinations in schizophrenia. First, because hallucinations can have a lot of etiologies, as there can be a multiple etiologies of psychoses. For example, an olfactive hallucination in temporal-lobe epilepsy is just an epileptic fit, nothing more than a misplaced electrical current. No deficiency is necessary to explain it.

Furthermore, as I explained before, I don't think what we usually call hallucinations in schizophrenia are really hallucinations, because they are not alterations of perception in its origin. So, if we look for causes in the perception pathway, I think we'll never find something satisfactory. But disgregation, alterations of the thought processes, are, in my point of view, the real origin of the so-called "alterations of the sensoperception" (IN SCHIZOPHRENIA, not in other psychoses). So, the answer, at anthropological level, can be found in the blurring of the functions of the self. I know the self itself is hard to comprehend, but that is the reason why we have to observe its functions, because we can only see what it produces, but not the self itself.

And, at a biological level, I think maybe we should search in pathways related not to perception, but to interconnectivity. Why not look at the parietal lobes and corpus callosum?

Can anyone give a light about those two structures and its implications in schizophrenia? I think it should be interesting to talk about them. I know there are alterations of the corpus callosum in schizophrenic patients, but, more than that, I declare myself ignorant in that aspect.

Rodrigo, I'm in full accord with you about your point that hallucinations they not are a perceptual phenomena in "functional" psychosis. In any case, hallucinations have a perceptual dimension, but this not are the hallucination.

Thank you for your question. According to my opinion, there is a big qualitative difference between disociative phenomena and psychotic symptoms like hallucinations in various ways: the qualitative difference is that of experience which is of outstanding importance for differential diagnosis and respective treatment. There is first a qualitative difference with regard to subjective experience but also to the objective observer, as for example the ability to suppress such experiences. But there is also a quantitative difference which is for both types of entities in general relevant. In true hallucinations there is a continuum from illusions to pseudohallucinations to hallucinations as has been shown in experiments and this is relevant for example in cases of schizophrenia which may suffer from true hallucinations and from pseudohallucinations and it is very helpful to differenciate. The former one needs improved neuroleptic therapy whereas the other needs psychotherapy as outlined in a theoretical and case report paper previously (Bechter 1992, "Coincidence of hallucinations and pseudohallucinations in schizophrenia - some implications for theory and therapy." Neurol Psychiatry Brain Res 2: 117-122). The assumption that there is no difference is in my view false, like if you would state that there is no hypertension because all people have some blood pressure. Beyond also in arterial hypertension with dimensional increased blood pressure there will develop qualitative differences. Although, the hypertension model is not perfectly matching the hallucination versus illusion or dissociative phenomena example, in the latter there are more differences even.

Hallucinating, the activity of a hallucinator, is homologous to dreaming, the activity of the dreamer. Psychosis has been defined as dreaming while wide awake.

In the textbooks of psychiatry hallucinating has been erroneously defined negatively, as a disorder of perception. It was Bleuler who later in life coined the concept of DEREISTIC THOUGHT, from de- no, res-thought. Perceptions is of things, dereistic forms of thinking -- dream, hallucination, delusion -- are not about things but about thoughts AND emotions. Freud called it psychic reality, I call it EMOTIONAL REALITY.

Reference:

Lothane, Z. (1982). The psychopathology of hallucinations--A methodological analysis. British Journal of Medical Psychology, 55:335-348.

Henry Zvi Lothane

Hallucinating, the activity of a hallucinator, is homologous to dreaming, the activity of the dreamer. Psychosis has been defined as dreaming while wide awake.

In the textbooks of psychiatry hallucinating has been erroneously defined negatively, as a disorder of perception. It was Bleuler who later in life coined the concept of DEREISTIC THOUGHT, from de- no, res-thought. Perceptions is of things, dereistic forms of thinking -- dream, hallucination, delusion -- are not about things but about thoughts AND emotions. Freud called it psychic reality, I call it EMOTIONAL REALITY.

Reference:

Lothane, Z. (1982). The psychopathology of hallucinations--A methodological analysis. British Journal of Medical Psychology, 55:335-348.

Henry Zvi Lothane

Thank you all for such a fascinating discussion so far. The very different basic views of phenomenology and pathopsychology above illustrate that the area is up for review. I think in some areas of study of aetiology and treatment of personality the ground is shifting towards a more underlying view that dissociation is a key process and occurs when the process of self -integrationis unable to be maintained. This involves "unicity" if you like, but the other Bleulerian functions are relevant and the insult comes from "trauma", overwhelming stress- a theory that is bringing together Jacksonian notions of the hierarchical construction of consciousness and notions of self from James and picking up Janet's notions around dissociation. For a solid thesis and argument on this in Borderline Personality Disorder see Meares, 2012, A Dissociation Model of Borderline Personality Disorder. His thesis however is potentially more broadly applicable to human consciousness and this period of integrative neuroscience research suggests many cognate areas will inform each other in new ways.

I will watch this space with interest.