False Perception is a general term that includes any experience in which there is a mis-perception of a stimulus. This mis-perception may be due to properties of the stimulus and its surrounding context that make it more likely that it will be incorrectly perceived (i.e., an illusion). Mis-perception also occurs when there are internal psychological factors that cause the sensory/cognitive system register a perceptual experience that has no external referent (hallucinations). (There are also instances of the opposite happening - i.e., negative hallucinations- where real referents are not perceived, but that is rare and takes us too far afield)

True hallucinations by definition are always accompanied by the false belief that what is being perceived is veridical (real, true). Hallucinations that are not accompanied by such belief are called pseudo-hallucinations. Many of the so-called hallucinations experienced under the influence of a psychoactive substance like LSD are actually pseudo-hallucinations.

It is generally assumed that hallucinations are not uniquely associated with psychopathology. In fact hallucination-proneness seems to exist on a continuum in the general population, and most of us have experienced hallucinations (or pseudo-hallucinations) on going to sleep (hypnogogic hallucinations) or waking up (hypnopompic hallucinations) at some point in our lives.

Illusions, on the other hand, are a type of false perception that are dependent upon the existence certain stimulus conditions, and once those conditions obtain, most individuals will be susceptible to mis-perceiving (regardless of their hallucination.

Hope this helps,

M

False Perception is a general term that includes any experience in which there is a mis-perception of a stimulus. This mis-perception may be due to properties of the stimulus and its surrounding context that make it more likely that it will be incorrectly perceived (i.e., an illusion). Mis-perception also occurs when there are internal psychological factors that cause the sensory/cognitive system to register a perceptual experience that has no consensually validated, external referent (hallucinations). (There are also instances of the opposite happening - i.e., negative hallucinations- where real referents are not perceived, but that is rare and takes us too far afield)

True hallucinations by definition are always accompanied by the false belief that what is being perceived is veridical (real, true). Hallucinations that are not accompanied by such belief are called pseudo-hallucinations. Many of the so-called hallucinations experienced under the influence of a psychoactive substance like LSD are actually pseudo-hallucinations.

It is generally assumed that hallucinations are not uniquely associated with psychopathology. In fact hallucination-proneness seems to exist on a continuum in the general population, and most of us have experienced hallucinations (or pseudo-hallucinations) on going to sleep (hypnogogic hallucinations) or waking up (hypnopompic hallucinations) at some point in our lives.

Illusions, on the other hand, are a type of false perception that are dependent upon the existence certain stimulus conditions, and once those conditions obtain, most individuals will be susceptible to mis-perceiving (regardless of their hallucination proneness level)

Hope this helps

Eyewitness accounts are notoriously unreliable. Is this fact due to a process of misperception, selective attention, or other personal biases?

A mixture of all three. although false memories play a key role here - you may be interested in the work of elizabeth lofus who documents Several studies which have been conducted on human memory and on subjects’ propensity to remember erroneously events and details that did not occur. She performed experiments in the mid-seventies demonstrating the effect of a third party’s introducing false facts into memory

http://agora.stanford.edu/sjls/Issue%20One/fisher&tversky.htm

We all see a mere fraction of the visible spectrum, hear an even smaller band of the auditory spectrum and every thing we see is through the personal blinkers and filters of social conditioning, education, past experience, personal truth and degree of trust.

Instead of asking what is wrong with them and their memories ask the person themselves if they are aware they appear to see things differently. Ask them why they are frightened or fixated about different issues. Be careful you are not leading with the questions as this is a powerful way to actually create false memories. When you understand the individual context and the sensitivity that hyper-awareness brings to the altered state of consciousness (psychosis) maybe there are good reasons for them to be paranoid or see events unfolding in a different context to others.

The difference lies in "association"

bearing in mind, that our memories relate to the last memorized "try", not the original experience.. See this research: http://www.sciencedaily.com/releases/2012/09/120919125736.htm

Heather is right to flag up the issue of leading questions, as when psychiatrists ask patients "Do you hear voices?", when they should be fishing for auditory hallucinations, ie noises, music or voices. But asking "them why they are frightened or fixated about different issues" is also a leading question. A misperception may just be a misperception, nothing to do with subconscious motives or cognitive biasses.

Agree even frightened and fixated are judgmental and leading words... My brief personal experience of psychosis would be better described as fascinating, fun and spiritual. Point being the assumed world of 'losing it' from a professionals perspective is coloured by media driven associations and fear. For some people you have to 'lose it' to 'find it' and this is worth the messy bits in between. After all we endure pain, loss of dignity and mess to give birth, who said spiritual and emotional growth had to be smooth and drama free?

Heather,

Fun and psychosis are not typically two words I would use together, as in "fun psychosis." It has been my consistent clinical experience in a number of different settings that psychotic individuals do not find psychosis fun. In fact, they find hallucinations scary and even terrifying.

But I can also concede that it may be possible for a person to have unusual sensory experiences that may be considered by a person (without a psychiatric history) to be fascinating or even spiritual. Again, we may have an issue with definitions and sematics operating in this discussion.

Coming back to the original question, I think the cognitive processes involved in perception, misperception, illusion and hallucination are the same. What differs is the quality of the perception and the context. I have not fully checked the literature on visual hallucinations, but for Charles Bonnet syndrome is is probable that eye disease is necessary, or even sufficient. In other words, the "hallucinations" arise out of false perceptions, possibly with an added delusional component, so are really illusions. An excellent description of Sir Robert Liston's CB syndrome can be found in Edin Med J 1836;46:334.

With respect to auditory hallucinations, I think I have been guilty on RG of loose semantics and definitions, since I actually don't think there is such a thing as an auditory hallucination. They are basically illusions, or elaborated misperceptions. There is either a genuine external noise, as when someone hears birds singing, which transforms into birds talking, called a "functional hallucination". Or an internal noise (tinnitus). If it is established that there are persons with perfectly normal ears who deny tinnitus, a third possibility is that their AHs develop from subliminal cochlear signals (which have been physiologically demonstrated in normals).

Agreed Neil psychosis is not fun when it is triggered by fear but at other times it is triggered by elation. It can be very funny to think in rhyme for no reason, to notice things you have never seen before and look at life from a different perspective. Rapture if celebrated rather than medicated might only last a short time.... A. Maslow said that if your only tool is a hammer then every thing looks like a nail. Context is everything and I am asking how much does media and industry conditioning about 'terrible diseases of the mind' influence the professional person when the patient could be having a wacky, perhaps inconvenient but not so terrible experience.

Anthony I did not believe in auditory hallucinations until a voice directed me to break into a distant friends home and save her from attempted suicide. I was not psychotic at the time. The voice was clear, firm and not coming from background noise, nor do I have tinnitus. Many famous people claimed to hear voices including Gandhi and Socrates. 80% of elderly people hear or see a departed spouse within a year of widowhood. We are more than a sum total of organs and medical knowledge to date because medicine is ignoring other systems such as electromagnetic and so much more is yet to be discovered.

Thanks Heather for describing one (?) of your auditory hallucinations. It would help me if you could confirm you have never had dizziness, tinnitus, sensitivity to noise, distorted hearing, ear fullness, motion sickness or ear infections as a child.

I suspect widow hallucinations may be a myth. If these are Googled, all you get on page one is Rees 1971, where there was no control group. "Hallucinations" (undefined) were commoner in older widows, where ear and eye disease would be commoner as well. I am not aware of any decent study in the last 50 years on this matter.

G'day,

There is a great deal of imprecision in the way these terms are used interchangeably in normal conversation.

Marina, I do like your way of defining these terms.

If I understand correctly, you are suggesting that an illusion occurs primarily because of something unusual that is happening outside of your skull, while misperceptions and hallucinations also involve unusual things happening internally?

Some examples-

-Illusion-

I was driving along the coast a few days ago, and a limestone island 18 km off-shore looked like it was floating above the horizon, and it's low white sandy beaches looked like the white cliffs of Dover.

It was about 36 degrees C, humid, and the air was still. An inversion layer was trapping an 18 km wide "bubble" of hot moist air in the lower levels of the atmosphere, directly between my eyes and the island, and this lensing was causing a visual illusion.

This sort of illusion is like looking at a carnival mirror. My eyes were receiving light that was being unusually distorted by the atmospheric conditions. The image I perceived in my mind was (to the best of my knowledge) an entirely accurate representation of the information my eyes were collecting and communicating to my brain.

So, in this schema, an 'illusion' is due to something outside of the person who perceives it. If another person is placed in exactly the same spot, under the same circumstances, they will also perceive a very similar illusion.

-False Perception-

As a young man, I spent a fair bit of time in remote wilderness country on my own. I've had the experience several times of misperceiving sounds- (typically water babbling in a stream, or the wind). Most healthy adults experience these sorts of phenomenon to some degree as youngsters...

Go out in the bush, (sorry- I'm an Aussie- go out in the woods or the forest or the jungle or the fields or the mountains or the desert or the scrub or them thar boondocks), BUT whatever natural environment you go out into, do it by yourself...

Sit.

Wait.

If you are all alone. after a while, you will hear murmuring voices in the constant white noise of these environments, (wind, flowing water, leaves rustling, waves, rain, birdsong etc).

This is normal.

Your nervous systemn is a machine, built by boot-strapping adaptive mechanisms, perfectly evolved to detect signals amongst noise.

Our nervous systemns are over-responsive to potential signals, rather than under-responsive, largely because for the vast majority of our evolution, it has been adaptive to treat every rustle in the bushes as a potential ambush predator (think tigers. leopards. jaguars, lions) and counterproductive to ignore such noises, (even if 99% were false alarms).

When someone's "threat detectors" are over active, (as in psychosis) then even the background noise of an airconditioner quietly humming in the ceiling is actually a hub-bub of ranting voices.

If you dehydrate, malnourish, and/or sleep deprive yourself for several days, (or take large doses of stimulants like caffeine, amphetamine, or cocaine) you are much more likely to experience such misperceptions.

So, in this schema, a false perception is different to an illusion, because it is an internal event. It is based on real sensory input, but the perception and/or interpretation of that information is skewed by personal, internal factors. Someone else in the same place may or may not experience a similar misperception.

As Anthony suggests, someone who experiences chronic tinnitus might end up experiencing auditory hallucinations, (probably in exactly the same way that if I sat on a mountain for 5 days listening to nothing but the wind, I'd start hearing voices whispering).

This sort of misperception is a product of our nervous systemn desperately seeking a signal in constant chaotic noise. Clinically, it is how people understand and respond to these symptoms, not whether they experience them or not, that's important.

-Hallucination-

I have experienced visual hallucinations induced by psilocybin, mescaline, and LSD. Also through sleep deprivation, trance, chanting and repetitive rhythms, and through chronic methamphetamine use. (I participated in informal, old-school, "participant-observer" "action research").

Some of these hallucinations seem similar to be a very similar phenomenon to false perceptions, in that a real stimulus is distorted by the way your brain is processing information- (faces morph and transform into animal forms that still resemble the person, moving light or shadows appear to take on physical form, or patterned fabric turns into a vibrant pulsing animation).

But some hallucinations are quite clearly entoptic geometry or similar internal forms that arise spontaneously. http://www.viewzone.com/entopic.gif

Again, if you know that you are misperceiving things this is probably not a problem. (Indeed, as a young man I found psychedelics to be both enjoyable and occasionally quite instructional). But if you don't realise that you're hallucinating, you are probably going to have an exceedingly unpleasant time.

Now I'm going to speculate

I'd suggest that (using Marina's schema) illusions are different to hallucinations and misperceptions. I'd also suggest that the latter two may form a continuum, where an initial misperception can grow into delusions that then "feed" more elaborate hallucinations.

Paul.

Under False Perceptions , Paul is describing two different processes:

Misinterpretation: As when you go and sit in the outback or deep cave. Signals from your sense organs remain normal, but after a while the brain starts to get confused and offers alternative scenarios, the speech analysis system switches on, the wind seems to start whispering, etc

Signal error: Triggers of this state, dehydration and drugs, are exactly the same triggers for Meniere spectrum disorder, ie overactivity of the inner ear, the main senses affected being the vestibular and auditory. I do not think there is evidence for threat detectors being overactive in psychosis, not is it necessary to postulate this, since the normal brain mechanisms as shown in the first process also come into play here.(Incidentally, if there is a condition of overactive auditory threat detectors due to brain abnormality, the condition is misophonia).

P.S.

Hi Anthony,

I have had personal experience of visual, auditory, and tactile hallucinations when I was younger.

These experiences occurred in varying contexts, such as;

extreme sleep deprivation,

serious dehydration,

malnutrition (3 to 5 days without any food),

sustained ritual drumming and chanting,

sensory deprivation (soundproof float-tank heated to body temperature),

hallucinogen or dissociative intoxication,

chronic stimulant use,

and also

withdrawal from dependent use of stimulants (that is my only experience of tactile hallucination- "formication").

My visual acuity has always been good, my history of eye disease is nil.

(One of my childhood nicknames was "Hawkeye". At age 18 I used to have 20/10 vision. That means I could see details at 20 feet that most people could only see at 10. I'm in my late 40s now, and so starting to lose my near vision, which is inevitable but still rather annoying).

History of ear disease or tinnitus, also nil. (As I age my hearing is starting to degrade, and injury has resulted in me loosing some frequencies in my left ear, but at the time that I abused myself in various ways enough to experience auditory hallucinations, my hearing was excellent).

I have no personal or familial history of mental illness.

I do agree when you state that if something is unusual or defective in the organs perceiving any stimuli, misinterpretation of that stimulus is far more likely. However this is not the only source of misperception or hallucination. There are many ways that very accurate sensory input maybe misperceived or misinterpreted by your nervous systemn, due to intoxication with psychoactive substances or other factors that disrupt normal brain function and/or cognition.

Hi Neil,

Working in mental health gives us a biased sample. Symptoms of psychosis are not always experienced as unpleasant, but people who seek help for these symptoms are almost always having an unpleasant time. In my work I've met quite a few people who hear helpful friendly voices, and report no associated discomfort or problems.

Paul.

Hi Anthony, I have great hearing with nil injury or even childhood ear infections although I do notice that if I am stressed my ears do ring and use this as a first sign to address the stress... I am shortsighted but I see well with my contact lenses.

A more probable explanation for some of the weird experiences I have had is mercury poisoning. Amalgam fillings are made from 50% mercury and the rest is silver, zinc, copper and tin. There have been 3 times in my life when I have struggled... when the school dental nurse filled every one of my molar teeth, when I broke fillings while pregnant and amalgam poured down my throat and when I had amalgam removed unsafely. (See the list of mercury poisoning symptoms at the end of this) However this does not explain why I heard a voice direct me to saving a life. And I did not even for a moment think that this was anything apart from a spiritual intervention that did not require any explanation, it just was, life would be boring with no mystery.

Paul, I have greater appreciation of your opinion now that I know you have taken yourself to the 'edge'. And you are right psychosis is not always unpleasant but if the first time was unpleasant the family and medical support assume that every 'speed bump or aftershock' that follows is. If you are a non responder to medication and going psychotic (for me this was once each winter for 4 years, less severe each time) then where is the harm in learning to enjoy the experience that other people spend large amounts of money to achieve?

And I could stop the experience in a few days, not with medication but large doses of Vit C, B3, D, EMPowerPlus and omega 3 oils, good food, supportive friends, music and long walks. People deserve a choice to be self responsible as part of their recovery and to learn to be safe and comfortable even if the experience is not understood by anyone apart from people who have taken psychedelics. Dr Daniel Fisher's research shows 80% of people recover from mental health issues yet are treated as if they are the 20% who don't, and most recover faster with less drugs.

Common Symptoms of Chronic Mercury Poisoning

Emotions; Aggressiveness, Anger (fits of), Anxiety, Confusion, Depression, Fear and nervousness, Hallucination, Lethargy, Manic depression, Mood swings, Shyness

Energy Levels; Apathy, Chronic tiredness, Restlessness, Insomnia

Neurological/Mental; Fine tremor, Lack of concentration, Learning disorders, Memory loss, short and long term, Numbness, Slurred speech, Psychosis.

Head; Dizziness, Faintness, Headaches (frequent), Ringing in ears, Excessive blushing, Hair loss, Vision problems, Tunnel vision.

Nose; Inflammation of the nose, Sinusitis, Excessive mucus formation, Stuffy nose, Loss of sense of smell

Skin problems; Allergies, Excessive perspiration, Skin cold and clammy

Oral/Throat; Bad breath (halitosis), Gingivitis/bleeding gums, Inflammation of the gums, Leukoplakia (white patches), Mouth inflammation, Metallic taste, Sore throats, Ulcers of oral cavity, Burning sensation.

Lungs; Asthma/bronchitis, Chest congestion, Shallow respiration, Shortness of breath, Chronic coughing

Digestive System; Colitis, Diarrhea/constipation, Loss of appetite, Weight loss, Nausea/vomiting.

Heart; Anemia, Chest pain, Heartbeat rapid or irregular

Muscles & Joints; Cramping, Joint aches, Muscle aches, Muscle weakness, Stiffness

Other; Water retention (edema), Renal failure, Bone loss, Anorexia, Genital discharge, Gland swelling, Hypoxia, Hypothyroidism, Illnesses (frequent)

Hi Anthony,

and >.

Thanks for calling me up on that, and clearly making that distinction.

>

Again, point taken. Although...

>

http://www.sciencedirect.com/science/article/pii/S0149763404000351

.

However that was a sloppily imprecise use of language on my part. What I meant to refer to was the fact that over-active or dysregulated dopamine-bearing systemns, (whether this overactivity or dysregualtion is due to a psychotic disorder, or due to stimulant intoxication/toxicity, or due to extremely stressful situations such as anxiety + fear, pain, sleep deprivation, dehydration etc) encourages the person to see salience in noise, and connections between random pieces of information- (People in these states may decide that random events must contain meaning, and often develop the paranoid ideation that such events must be related to them personally, and they also exhibit an increased tendency to connect "A" with "D" when any sober sane person would see no connection).

I am suggesting that similar processes may underlie visual and auditory misperceptions, and that if these misperceptions are experienced chronically they may lead to the development of complex delusional architectures.

Paul.

Thanks Heather for giving me the information that no psychiatrist would obtain. Tinnitus is not a symptom of stress or anxiety (unless someone hyperventilates). The only cause of tinnitus known to me is an inner ear or auditory nerve disorder, especially Meniere spectrum disorder when it is fluctuant. In this state of cochlear hypersensitivty, a whole range of different drugs now irritate the ear still further, inducing auditory hallucinations.

The best model for paranoia is that deriving from hearing disorder. Clinically this was noted by Kraepelin and others; experimentally, Zimbardo induced paranoia in normals by inducing a hearing loss in them. There are some excellent descriptions on the internet of persons hearing weird noises, in fact tinnitus, but who cannot be dissuaded from the suspicion that they come from the CIA instead, or from some electronic device.

Tinnitus activates the brain dopamine circuits, especially the nucleus accumbens. There is a current paper in Science noting that music also boosts up the NA, producing a dopamine rush. So any increase in auditory salience as in psychosis does not have to be due to any criterion shift, the sounds may simply be more prominent.

Hi Anthony,

I am aware of the literature showing strong associations between musical hallucinations (specifically) and tinnitus/progressive deafness.

Can you provide a reference for this statement;

?

I have met many people who believe their internal voices/noises were external, and most were people you might suspect had something unusual about da regulation in their na. But I have no idea what percentage of them suffered tinnitus.

>

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=403786

.

Half the patients in this study experienced auditory hallucinations but had no signs of tinnitus or ear disease. Instead, their auditory brain-stem responses were abnormal.

Regards,

Paul.

You are welcome Anthony, so are you saying 'ringing in the ears ears' a listed symptom of mercury poisoning would raise dopamine?

I did learn the other day from my wellness doctor that mercury slots into the same receptor site as progesterone. This would cause many disruptions to both male and female metabolism as it plays many important roles apart from reproductive.

This doctor also told me why root canaled teeth are dangerous to health... living teeth have a positive internal pressure which flushes through a matrix of small natural holes. However a dead tooth has bacteria invade those holes and then produce toxic waste products which can adversely affect health.

I really do think that many small physical and emotional stressors add up over time causing 'breakdowns' rather that non evident and non contagious disease which happens to strike when a person is exhausted, nutritionally depleted and overwhelmed. This was was documented in the 1930's depression when doctors knew that a few good meals and some sleep restored many wandering, muttering and aggressive homeless people.

Opps I wrote ears twice, oh well there are two of them lol.

See here for evidence that the dopamine and tinnitus circuits are the same:

"Tinnitus dopaminergic pathway. Ear noises treatment by dopamine modulation

M.A. Lopez-Gonzalez, F. Esteban-Ortega

Otorhinolaryngology Department, Doctor Fleming Specialties Center, Virgin of the Rocio University Hospital, Juan de Padilla 8, 41005 Seville, Spain

http://dx.doi.org/10.1016/j.mehy.2005.02.016, How to Cite or Link Using DOI

Summary

To date, the neurophysiological model has been used to explain the complexity of tinnitus. However from now on, the tinnitus dopaminergic pathway opens new horizons for ear noises management. Tinnitus perception takes place in prefrontal, primary temporal and temporo–parietal associative areas, as well as the limbic system. Dopaminergic neurotransmitters go through prefrontal, primary temporal, temporo–parietal associative areas and the limbic system. Tinnitus perception and dopaminergic pathway share the same cerebral structures, which control attention, stress, emotions, learning, memory and motivated behavior. Distress of tinnitus emanates from these same cerebral functions. The dopaminergic pathway can be modulated by agonists and antagonists of their receptors and can reduce the perception of tinnitus, such as sulpiride, amisulpride, olanzapine, quetiapine, ziprasidone, zuclopenthixole and aripiprazole, still under investigation, that together with sound treatment as the Sequential Sound Therapy, and a personal contact with the patient, constitute a tinnitus integral treatment."

As for the JLO article abstracted by Paul above, this should should open the debate, not close it. Without going into a detailed critique, two points. Audiology is more than a pure tone audiogram, and why did six of seven schizophrenics with tinnitus have abnormal audiograms? It is fashionable nowadays, even among audiologists, to say tinnitus is a neurological condition (and not that it is an ear disorder with secondary neurological and psychiatric overlay). Kraepelin gave detailed description of auditory hallucinations, many of which were exactly the same as tinnitus as seen by otologists. If psychotics do not have evidence for hearing noises of cerebral origin, who does?

I thought people took hallucinogens to experience the sensory distortions they induced. I would need a lot of convincing that there was still "very accurate sensory input" and that all the misperception started in the brain. Common sense tells me that if senses stray, the first place to look is in the sense organs. No drug known to me or reported in the literature causes musical hallucinations without also causing symptoms of peripheral ear disorder.

Oh dear, now we have a whole new market place for these horrible fluoride laden drugs with all their terrible side effects of impotency, obesity, diabetes and heart failure. Personally I would chose ringing ears....

Surely using the studies of mercury damage which also appear to use the same pathways in the brain (as does the fluorine's) and studies of vaccine damaged kids who become autistic at the time of the third major inoculation we could focus on organic cause. Not everyone is going to be as badly treated by the scientific world as Dr Andrew Wakefield. And we have empirical evidence of recovery from autism through diet and heavy metal elimination. Jenny McCarty (Jim Carrie's wife) is very vocal on that issue after having good success with her own son.

Autistic people themselves report auditory distress. This is not a natural thing for the human in a natural state so why not look at chemical and heavy metal cause? Why is the focus on fixing chemical overload always seem to be add more chemicals? How can the lay person come to any other conclusion other than this is a callous industry looking after its share holders and bottom line well before it looks after the welfare of people.

Hi Heather,

When you wrote "ears" twice, I actually thought you were simulating ringing in the ears, ears. (It worked well, well).

You may have noticed that I use Dr Strangelove as my profile pic, so I DO actually know a thing or two about fluoride!

http://www.youtube.com/watch?v=lfldJIGk7fg

.

Fluoride is lethally toxic in high doses, (5 to 10g in most humans).

Smaller doses can cause some side effects;

http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682727.html#side-effects

.

I do agree that exposing people unnecessarily to antipsychotics is not good practice. In my opinion they most are appropriate for some people who experience psychosis chronically, and for those who represent a serious threat to others when not medicated.

However my concern with unnecessary prescription is not the tiny fluorine content in some atypical antipsychotics (which simply slows the metabolism of the medication, and has no apparent adverse effects).

I'd be worried about the serious side-effects of the antipsychotic molecules themselves, chronically blocking dopamine and serotonin;

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2327229/

.

http://www.aafp.org/afp/2010/0301/p617.html

.

Paul.

G'day Anthony,

Thanks for linking to the paper by Lopez-Gonzalez and. Esteban-Ortega.

Unfortunately all I can access is the abstract, which is rather short on details-

Are they actually (as Heather indicated) suggesting prescribing antipsychotics to treat tinnitus?

The authors make many statements-of-fact but I can't see the full text, and the abstract does not explain how or why they have reached these conclusions, nor what evidence supports them. (I can't even tell what kind of study this is reporting on, or if they are reviewing other people's research, or if it is an opinion piece).

I wouldn't be surprised at all if profoundly sedating dopamine antagonists reduced the perception of tinnitus. But I unless I can find the full text of this article, I can't reach any conclusions based on the abstract. Is there much other published literature on this subject? Has anyone else tried to test this hypothesis since this paper was published?

Hallucinogenic drugs do induce perceptual distortions. The distortion occurs because the drug molecules happen to be a similar shape to naturally occurring neurotransmitters and hormones, and interact with structures that these chemicals would normally engage with. The vast majority of these interactions take place within the users' central nervous system, not within their middle-ears, ears, ears.

Deliriants, hallucinogens, and psychedelics include; 5-HT2A receptor agonists, Tryptamines, Lysergamides, Phenethylamines, Serotonin releasing agents

Substituted methylenedioxyphenethylamines, Cannabinoids (CB-1 receptor agonists), Psychedelic Allylbenzenes, Dissociatives , NMDA receptor antagonists, κ-Opioid receptor agonists and Anticholinergics; and all these different classes of drugs can induce the sorts of symptoms we are discussing.

Paul.

.

Many drugs have been tried for tinnitus, with little success. I am not up to date with the literature, but did find this from a leading ENT journal, which looks promising:

"Sziklai, I., Szilvássy, J. and Szilvássy, Z. (2011), Tinnitus control by dopamine agonist pramipexole in presbycusis patients: A randomized, placebo-controlled, double-blind study . The Laryngoscope, 121: 888–893. doi: 10.1002/lary.21461

Abstract

Objectives/Hypothesis:

Since the concept of tinnitus dopaminergic pathway emerged, studies have been proposed to investigate if dopaminergic agents influence tinnitus. We hypothesized that pramipexole, an agonist on D2/D3 receptors, may antagonize tinnitus in the presbycusis patients (in the frequency range of 250 to 8,000 Hz) in a dose schedule accepted for the treatment of Parkinson's disease in elderly people.

Study Design:

We designed a randomized, prospective, placebo-controlled and double-blind trial.

Methods:

Forty presbycusis patients aged 50 years or older with subjective tinnitus were randomized to two groups (20 patients in both). Patients in the drug group took pramipexole over a period of 4 weeks according to a treatment schedule as follows: week 1, 0.088 mg t.i.d.; week 2, 0.18 mg t.i.d.; week 3, 0.7 mg t.i.d.; week 4, 0.18 mg t.i.d. over 3 days and 0.088 mg t.i.d. the rest of the week. Patients in the second group received placebo. Determination of subjective grading of tinnitus perception, the tinnitus handicap inventory (THI) questionnaire and electrocochleography (ECOG) examinations served as the end points. Subjective audiometry was used to produce secondary data. A significant improvement in tinnitus annoyance is found in the group treated with pramipexole versus placebo with respect to inhibition of tinnitus and a decrease of tinnitus loudness greater than 30 dB. However, neither ECOG nor subjective pure-tone threshold audiometry revealed any change in hearing threshold in response to either pramipexole or placebo.

Conclusions:

Pramipexole is an effective agent against subjective tinnitus associated with presbycusis at a dose schedule used for the treatment of Parkinson's disease. The drug did not change hearing threshold."

The cochlea is full of all sorts of neurotransmitters, so I don't know how anyone can be sure that drugs do not act on neuroransmitters there, especially when no one has tried very hard to check this.

Hi Anthony-

Am I reading that abstract correctly?

It looks like they are reporting that the group who received the active dose of Pramipexole had a significant reduction in their subjective perception of tinnitus symptoms, without any reduction in their hearing threshold. Pramipexole is a dopamine agonist, so they detected the opposite effect of what they had hypothesised, yes?

Paul.

In these sort of drug experiments, especially when considering what might be happening to dopamine receptors, it becomes posible to argue that either inrease or decrease in tinnitus might occur. So the conclusion I would draw, as described in the Objectives, is that dopaminergic agents influence tinnitus, which clearly needs teasing out in further experiments. Their specific hypothesis was that pramipexole would antagonise tinnitus, which turned out to be the case. I am hopefully going to read the full print version tomorrow to check further.

Hi Anthony,

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If the hypothesis was that Pramipexole would "antagonise the symptoms", then that is using the word "antagonise" in the common English sense of "aggravate":

It means they expected a dopamine agonist would increase Da levels and that this would correlate with increased subjective intensity of the symptoms of tinnitus. But they appear to have found the reverse effect- the "active-dose" group actually reported reduced symptoms, ("a significant improvement in tinnitus annoyance")

Agreed that this still may indicate that dopaminergic agents influence tinnitus.

As all of the test subjects had age-related hearing loss, might an alternative hypothesis be that the tinnitus symptoms they were experiencing were "noise" in the auditory nerve signals (due to hair-cell degeneration in the cochlea and giant-stereociliary degeneration), and that up-regulation of Da was simply over-riding some of these normal, age-related deficits?

Intriguing. Let us know what you can see in the full text.

Paul.

One can argue that a dopamine agonist could have two contradictory effects on tinnitus (or on symptoms of schizophrenia for that matter).

1. Free Da levels increase, and so sequelae of tinnitus increase.

2. The Da from the agonist preferentially binds with the Da receptors, so there fewer receptors left free for the Da from tinnitus, hence tinnitus sequelae decrease.

I have the print paper version right in front of me, and will get back if and when I think I have completely understood it!

In Roget, antagonize means counteract, cancel out, prevent, so they would be misusing the word if they had intended it to mean aggravate.

Sziklai et al state in their introduction ""we examined...whether pramipexole, a dopamine receptor agonist, influenced tinnitus.." , and in the discussion, "It has not yet been defined as to whether dopamine receptor agonists or antagonists might be of benefit for patients with or at risk of tinnitus".

So, contrary to the impression given in the abstract, it looks as if this was basically a fishing expedition. Nevertheless, I think it was quite right to publish it, and further work is indicated.

We do not know yet.

More we learn about new visual pathways not related to vision or to image formation more we understand about abnormal vision symptoms such as Distortions and visual hallucinations as an eye phenomena not mental.

I am an ophthalmologist interested in vision beyond Snellen Visual Acuity. Most of our knowledge (as ophthalmos) is restricted to cortical vision, to the optometric conditions, to the Parvocellular System and the symptoms related to our discussion here is related to the magnocellular pathway. This explain why ophthalmologist do not search and does not understand why a 20-20 patient may present visual complaints. For us, 20-20 means NORMAL Vision System.

We do not know the hidden side of vision, the sub cortical pathways controlling light adaptation, and dozens of sub systems responsible for oculo motility, saccadic movements, fixations, regressions at the level of pre-tectum.

Then, we learned about the IPRGC cells—intrinsically photosensitive retinal ganglion cells reported in 2002 by Provencio. These cells, distinct from the rods and cones in the eye are more sensitive to some wavelengths of light than the other photoreceptors, with particular sensitivity between 460 and 490 nanometers.

The new finding allowed us to understand better photophobia and migraine, which are associated with more than 30 medical conditions, especially mental disturbances. In addition, we learned how to approach photophobia and migraine using spectral filters with a high level of efficacy.

Because the association we have seen more and more cases of schizophrenic and autist spectrum patients with concomitant complaints of photophobia. Moreover, although we do not cover the psychiatric area, we see our patients reporting getting better in their mental picture when treated for the vision complaints with spectral filters. We know by the literature that the IPRGC cells control mood and behavior.

If you, like us, are interested in understanding, better the association of vision and psychiatry, I recommend the access to the article “To see or not to see: that is the question. The Protection-Against-Schizophrenia evidence from congenital blindness and visuo-cognitive aberrations by Landgraf and Osterheider as an introduction.

Concerning our clinical experience, we have been able to treat Photophobia and Migraine using Spectral Filters with a very high level of efficacy. As said, because there is a correlation of these conditions with mental disturbances, we have seen a growing number of psychiatric patients coming for photophobia and migraine.

Spectral filters are custom designed to blocks specified wavelength ranges identified individually as uncomfortable or cause of visual stress. The spectral filters block therefore that portion of the optical spectrum suspected to stimulate photopohobic responses that trigger some, and exacerbate most, migraines.

Ricardo Guimaraes MD PhD

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