Hallucination Types : Introduction To Hallucinatory States

What are Hallucinations ?

Welcome to the hallucination help blog. Hallucinations are essentially a false perception of objects and or events that involve our main senses such as sight, hearing, smell, taste and touch. They are experienced by people of all ages from toddlers to elderly and from all walks of life. There are a number of mental health conditions that are commonly associated with hallucinations including schizophrenia, Alzheimer disease and bipolar disorder.

However, mental states are not exclusively the cause of hallucinations as they may also be experienced by people with brain tumors, viral infections, diabetes or even something as common as a high fever, flu or common cold. Some hallucinations may take months to develop and be noticed while for others, such a elderly people, there maybe a sudden onset.

image of eye hallucinating spots

Hallucinations can be categorized into a wide range of sub groups. A person that experiences hallucinations may experience one or several of the subgroups listed below depending on their individual condition.

Hypnagocic and Hypnopompic Hallucinations 

Hypnagocic forms of hallucinations are those which occur as a result of one's state of consciousness during the onset of sleep when one is half asleep/awake. These are often referred to as "sleep onset dreams" or "half awake dreams" as the person often recalls dream like visions occurring during the time before the sleep period begins. Some common images that people experience during hypnagocic hallucinations include geometric patterns, tunnels of light and phosphenes. One might also experience visions of repetitive tasks from ones daily life during this period such as playing games after a day in which one spent many hours playing computer games. A common experience is that of repetitive manual tasks which reflect one's work environment such as factory work, answering telephones or serving customers.

Hypnagocic  hallucinations have also been linked with the phenomenon of sleep paralysis and visible entities. In this situation a person will believe that there is a presence in the room with them, either beside or at the end of the bed. The person is typically unknown to them and may induce a feeling of tension or fear. During the experience many people report that their body is in a state of paralysis and their speech is either impaired or disabled.

A number of people have reported that the hypnagocic state can heighten levels of creativity. This has been reported by a number of famous people including Mozart, Salvador Dali and Nicholas Tesla.

Hypnopompic hallucinations are essentially the opposite of hypnagocic in that they are experienced during the waking state rather than the falling asleep state. These typically occur because the brain is not fast enough to readjust its functioning to a an awake state from the dream state. Dreams that one is experiencing in the dream-state are thus able to migrate into one's awakened consciousness and form hallucinations in a  half awake to almost fully awake state of being. A major cause of hallucinations while waking up can be attributed to sleep deprivation. Depression and seasonal affective disorder (SAD) are also linked to experiences of hallucinations on waking.

Tactile Hallucinations / Somatic Hallucinations

Tactile hallucinations refer to an imaginary physical feeling of pressure on one's skin or body parts. More commonly it is refereed to as simply a feeling of touch from an object that isn't there. This may include feelings of somebody touching your body, insects walking either on or beneath your skin ( Formication ) and cutting of hair.

An example of such a condition might be a patient who suddenly turns around, convinced that someone has just touched their back, only to find nobody present other than themselves. People who experience formication may be so convinced that insects are crawling under their skin that they scratch so excessively as to induce bleeding or scaring.

Tactile hallucinations can occur within the hypnagogic state in which the person might experience a convincing feeling of falling to the ground before the onset of sleep. The feeling is so real that they report a definite 'hitting' the ground with all the associated body pain one might expect from such an event. Another interesting form of tactile hallucinations is the idea of a "phantom limb" in which somebody who has lost a limb such as an arm or leg due to an accident or health issues, continues to 'feel' the presence of the limb after it has been removed.

At times tactile hallucinations may also be present with a visual one. A person may both see the presence of an angel, alien, snake, spider while also feeling it's touch on their face or body. in some extreme cases people have reported both seeing and feeling sexual interaction with entities. 

The causes of tactile hallucinations can be classified into two broad categories - mental/health illness and drug abuse. Dementia, a loss of brain function due to certain diseases, is a condition that may cause feelings of tactile hallucinations. People who suffer nerve disorders and immune system problems such as Fibromyalgia (FMS) and Multiple Sclerosis have also reported cases of tactile hallucinations. As for substance abuse, sugar, caffine, cocaine, amphetamines, crystal meth, ectasy ( mdma ), Ritalin, Tridil, Welbutrin, Zyban and some eczema medication have all been implicated in the occurrence of tactile hallucinations.

Gustatory Hallucinations 

Gustatory hallucinations relate to ones sense of taste. In this situation a person will essentially taste something that isn't there. This can occur when one's mouth is completely empty or when one's mouth does contain food and the person experiences a different taste to what is considered normal.

Some commonly reported taste sensations include onions, metal, tobacco, fruit as well as a general "bad taste". Approximately seven percent of people diagnosed with schizophrenia experience gustatory hallucinations. They are also experienced by people who suffer from uncinate gyrus seizures which result from an impaired function of the brain uncus region responsible for taste and smell. That being said, there is also a small percentage of the normal population that experience gustatory hallucinations at some point in their life without any reported mental disease or impairment.

As an interesting side note, a non-mental related olfactory hallucination can be induced through the consumption of so called "miracle fruit" which is native to parts of Africa and has now been commercially cultivated in the U.S. resulting in a tablet form of the active ingredient. The fruit, when ingested, causes subsequent consumption of bitter food to taste sweet. The effects can last for up to one hour after ingestion of the fruit in either natural or tablet forms.

Visual Hallucinations 

One of the most commonly reported types of hallucinations, visual hallucinations refer to the phenomena of seeing imaginary objects in the visual field with eyes open or closed without any external stimulus. These hallucinations mimic visual perception. The cause of visual hallucinations are typically related to mental disorders ( schizophrenia, depression, bipolar, delirium, dementia, Parkinson's, stroke, Lewy Body Dementia ), shifts in consciousness ( eg. sleeping states / waking states ) , drug use or medical issues such as postpartum psychosis, tumors ( against optic nerve ), stroke, food poisoning, toxic poisoning ( e.g lead ), high fever, stress, migraine headaches or fatigue ( sleep deprivation ).

The most common visual hallucinations range from the low-level in which the person sees dots, a distorted shape, colors or patterns to very complex high-level visual hallucinations in which the person's perception of their environment is so complete as to feel like they are in another world.

The mental condition Schizophrenia is typically known for producing auditory ( hearing ) hallucinations however visual hallucinations may be experienced as well. Patients with schizophrenia can experience what they believe to be profoundly real hallucinations. Examples of schizophrenic hallucinations include seeing people in the same room who are typically not familiar, animals in motion, movement in the periphery of vision or shadowy figures ( shadow people ) .

Another mental condition which involves vivid hallucinations is Penducular Hallucinosis. In this condition, a person will see detailed hallucinations of people or environments that are actually familiar to the
m. The hallucinations take on a rather normal appearance without any extreme morphing of the visual field. For this reason, a sufferer of Penducular Hallucinosis may find it very difficult to distinguish the hallucination from reality.

Visual hallucinations are commonly attributed to mental dysfunction however there are a number of physical conditions that may result in visual hallucinations when no apparent mental disorder is present. Sleep deprivation is a well documented case in which people begin to see things that are not there after a prolonged period without rest.

Shadows, insects ( spiders, bees) , blurred shapes on the horizon, tiled patterns and floating people are some of the typical reported hallucination seen due to a prolonged lack of sleep. It has been suggested that visual hallucinations during sleep deprivation are centrally caused due to stress on the eyes. This is consistent with the finding that visual acuity is unimpaired during sleep deprivation. In most cases of sleep deprivation hallucinations, there appears to be no permanent damage to brain function and a normal state is restored once regular sleep is attained.

Ultra-marathon runners have been known to experience vivid hallucinations of people and animals while competing the later stages of a race as their body becomes extremely fatigued and shows signs of dehydration. Related to this is the condition of hyponatremia - an electrolyte disturbance in which the body show low levels of sodium. Low sodium levels can lead to fatigue, confusion, loss of appetite, hallucinations and even coma. 

High blood sugar levels such as those experienced by people with diabetes can lead also lead to dehydration and induce hallucinations.

A high fever is another non dysfunctional mental state that may result in seeing false imagery. High fever hallucinations are varied in scale and details. They range from simple fuzzy vision to full on imaginary scenes. Some examples of reported high temperature hallucinations include seeing one's room flipped over 180 degrees, visions of angels or the grim reaper, room items disappearing and reappearing, flashes of light, historical figures and even shrinking pillows while the patient is recovering in bed. These images, which may appear frightening especially to young children, disappear as the person recovers from the fever.

picture of man with a high fever

Stress is another physical state of being that can cause or exacerbate both visual and audio hallucinations. Extreme levels of stress can lead to anxiety, depression and in some cases schizophrenia at with point hallucinations are noticed. For patients of mental disorders on medication, stressful events can increase the frequency and level of visual apparitions. Reports have noted that excessive caffeine consumption can also lead to increased stress levels with result in hallucinations.

A rather interesting form of visual hallucinations in the sane are those that occur during a period of bereavement ( after the death of a loved one ). In a number of cases people who have lost a lifelong friend, a marital partner of many years , a parent or child, experience grief and may see the person present in the same room some hours, days or even months after their death. These are known as bereavement, post-bereavement or grief hallucinations. Research conducted by Agneta Grimby at the University of Goteborg concluded that 82% of the elderly subjects experienced hallucinations of their deceased spouse at 1 month, 71% of the subjects at 3 months, and 52% at 12 months after death.

Migraine headache sufferers also experience hallucination on occasion. These typically take the form of aura ( scintillating scotoma ) like flashes of light at the periphery of vision, jagged patterns of light in a kind of z-type shape or sawtooth shaped spinning wheels. Some migrane sufferers also report experiencing problems with depth perception.

Visual hallucinations are often reported by people of old age after going through surgery. Elderly patients are more susceptible to post operation hallucinations due to the levels of stress involved and inflammation around the brain. 

Perhaps the most direct form of hallucinations in the sane are those experienced while under the influence of psychedelic drugs or medication. Some of the more well known drugs that are known to create visual hallucinatory effects include illicit substances such as Lysergic acid diethylamide ( LSD ), heroin, cocaine, psiolcybin ( magic mushrooms ), melcalin ( peyote cactus ), marajuana, salvia, dimethyltryptamine ( DMT ) and alcohol.

There are also a large number of medications and prescription drugs that cause disturbed sensory perceptions such as Amitriptyline, Diazepam, Amantadine, Eszopiclone, Diethylpropion, Acetaminophen, Levodopa, Donezepil, Pethidine, Ciprofloxacin, Diphenhydramine, Lyrica, Alprazolam, Chlordiazepoxide, Buspirone, Lunesta, Hydroxyzine ( Atarax ), Amobarbital, Butabarbital and a number of SSRI drugs.

Visual hallucinations are not limited to an open eyed experience. Hallucinations are also seen by people with their eyes closed ( closed eye visuals - see below ) and also are seen in a number of cases by people who are visually impaired or completely blind. Known as Charles Bonnet Syndrome, patients with visual loss experience hallucinations much the same as people who have perfect eyesight. 

Auditory Hallucinations

Auditory hallucinations relate to the perception of certain sounds without any external sound source. Classic, complex auditory hallucinations take the form of voices, music, animal sounds or the sounds of vehicles. Statistics vary, but it’s generally accepted that between 3 and 10 percent of the population hear voices that other people don’t.

Auditory hallucinations are commonly experienced by people diagnosed with psychiatric problems such as Schizophrenia. Approximately 70% of schizophrenia patients have reported experiencing auditory hallucinations in some form or other. 40% of bipolar disorder patients and 40% of post traumatic stress sufferers also report experiencing a distorted audio sense.

picture of women covering ears as a result of auditory hallucinations

There are a number of non psychiatric conditions that also may induce auditory hallucinations including temporal lobe epilepsy, brain lesions, tumors and infections ( eg viral encephalitis ). Stress, anxiety, trauma and depression are also sometimes associated with this problem. They have also been reported when people feel overly tired or exhausted. Drug use or withdrawal from drugs such as alcohol, cocaine, amphetamines, ecstasy and lsd have also been shown to result in this condition.

By far the most common form of hallucinations in people with psychiatric disorders such as Schizophrenia is hearing voices. As such it is used as one of the main diagnosing factors for this illness. Although these voices can be positive they are typically of a negative nature and form commands ( command hallucinations ) that tell the patient that they should do something harmful to themselves or others, that people have other bad intentions towards them, abusive or derogatory accusations ( your are worthless ). Voices may be people they know or complete strangers. There may be just a single voice or a number of different voices present at any one time. Other sounds that people report hearing include a phone ringing, random screaming,

Olfactory Hallucinations

Olfactory hallucinations relate to a sense of smell. People who experience olfactory hallucinations believe they can smell certain scents without the actual scent being present in their environment. This condition is called Phantosmia and can be caused by a number of sources such as brain tumors, seizures in the temporal lobe, trauma, surgery as well as exposure to certain drugs and toxins.

It has been associated with schizophrenia, mood disorders, Parkinson's disease, Alzheimer, epilepsy, neuroblastoma, and migraines. However it is important to remember that even common conditions such as exposure to household bleach or even a simple head cold could also result in phantosmia.

Typically people who suffer from phantosmia will experience unpleasant smells ( cacosmia - a hallucination of an disagreeable odor ).

Some common forms of unpleasant scents that are experienced include tobacco, smoke, hydrogen sulfide (rotten eggs), bad perfume, garbage, a gas leak, wet dog, pungent body odor rotting meat, gasoline, vomit and urine. Very rarely do sufferers report pleasant smells however when they do it typically takes the form of food such as coffee, bakery goods or chocolate.

Why do we smell such unpleasant odors more frequently that say the smell of a rose, perfume or chocolate ? Some researchers believe this might be due to a form of "defense mechanism" and thus scents are more likely to be heightened and that our sense of smell is not so much for pleasure but rather to avoid danger.

Olfactory hallucinations have are reported by up to as much as 65% of pregnant women in a number of studies. As this is a relatively rare medical issue there are very few effective methods of treatment available with the most common being the removal of the olfactory epithelium ( tissue inside the nasal cavity ). A first step that is often recommended before any surgery is available is to make use of nasal sprays such as Oxymetazoline HCl ( Vicks Sinex, Afrin etc ).

Note that phantosmia is different from another disorder of sense of smell, known as parosmia, in which a smell is present in your environment but is distorted.

In general the outlook for people with phantosmia is positive, with most sufferers olfactory senses returning to normal eventually without the need for surgery. Sometimes people think the stink is coming from themselves, which can lead to a condition known as olfactory reference syndrome. Such people will wash frequently and avoid leaving their home. It will start with phantosmia, but then they'll develop secondary paranoia as a result.

Nociceptive Hallucinations

The word nociceptive relates to feeling of pain. People diagnosed with bipolar disease sometime report feelings of random and unexplained pain without any external stimulus or underlying organic cause. This is also sometimes refereed to as psychosomatic pain. The phenomenon of nociceptive hallucinations is not fully understood by medical science. There does appear to be a link between such pain and emotional states and further research is being conducted in this area. However, one should be wary of any literature devoted to medical conditions which are not fully understood as such situations tend to encourage a large amount of speculative writing.

Thermoceptive Hallucinations

This condition relates to our bodies ability to correctly perceive ambient temperature as well as that of solid objects and liquids. A person may report feeling extremely cold or hot when their is no reason for doing so given the current room temperature. Should this occur once or twice it may well be a simple underlying physical problem or viral infection. However a number of people report experiencing thermoceptive issues over an extended period of time in which case the experience may well be categorized as a thermocepetive hallucination. This condition is experienced by a number of schizophrenia patients and also from people who are experiencing drug, alcohol or caffeine withdraw.

Chronoceptive Hallucinations 

Chronoceptive hallucinations relate to a persons ability to accurately judge a passage of time or failing to perceive time as one would normally expect. For example someone may think that a certain event or action occurred over a number of hours with in fact it happened over just a few minutes.

Chronoceptive hallucination are commonly experienced by people under the influence of stimulants, depressants, entheogenic drugs and alcohol. Parkinson's disease, schizophrenia and attention deficit hyperactivity disorder (ADHD) have been linked to abnormalities in dopamine levels in the brain as well as to noticeable impairments in time perception. Neuropharmacological research indicates that the internal clock, used to time durations in the seconds-to-minutes range, is linked to dopamine function in the basal ganglia.

Proprioceptive Hallucinations 

Proprioceptive hallucinations refer to ones sense of how ones limbs ( arms, legs etc ) are oriented in relative space. The term proprioceptive comes from the Latin words proprius (own) and percipere (to perceive). This category is also sometimes refereed to as posture hallucinations.

In the case of proprioceptive hallucinations, the individual feels that he, or part of himself, is at a different location from the physical body. One might feel phantom limbs or a subjective experience of slipping away from the physical body in what appears to be a phantom body. Subjective experiences of floating, rising and occasionally rolling also occur.

An easily demonstrated illusion of touch is believed to have been discovered by the ancient Greek philosopher Aristotle. It may be produced by crossing the middle finger over the index finger and placing the tips of both fingers on a small, round object, such as a marble. The marble will be felt as two marbles.

Equilibrioceptive Hallucinations 

Equilibrioceptive hallucinations relate to ones sense of balance. Although balance problems are experienced by many people during their lifetime, the majority of balance issues can be connected to underlying psychical illness such as inner ear infections, viral infections or a fever. However for a number of people such balance issues are a form of hallucination and have been reported by people diagnosed with schizophrenia, brain tumors, brain damage and depression.

A form of equilibrioceptive hallucination that can be experienced by anyone is after getting off a merry go round or similar such attraction, one can still feel a sense of movement as if one is still rotating. Another example is the continued "rocking of waves" feeling one gets after disembarking from a long boat ride.

Closed Eye Visual ( CEV ) Hallucinations

Hallucinations which occur only while one has their eyes closed are refereed to as closed eye visuals or CEV for short. CEVs are classified into 5 types depending on the level of hallucinatory images viewed.

The first stage is known as a the visual noise stage and is typified by a dark area of static or noise when one has their eyes closed. This stage is commonly experienced by all people.

The second stage sees the introduction of temporary flashes of light across the back of the eyelids.

The third stage is where patterns begin to take shape with motion and a range of different colors. This stage is experienced by users of hallucinogenic drugs and differs to the experience of such drugs with eyes open. A person under the influence of a drug such as LSD may have little id any form of hallucination with their eyes open but as as they close their eyes the visual field formed on the back of their eyelids instantly becomes a playground of vibrant shifting colors and shapes that often involve repeating geometric forms and fractal like patterns. Stage three is also experienced by people who practice some forms of deep meditation.

The fourth stage sees the introduction of recognizable objects within the visual field. Patterns and colors that often appeared as flat 2D fields in stage three are now elevated to a three dimensional existence. People often report spinning #D objects such as cubes, orbs etc. The objects which are seen with the eyes closed may also evolve further into an entire recognizable scene such as a orb becoming a soccer ball which then generates the visual hallucination of soccer match. As the person opens their eyes, the closed eye scene may then continue into the open eyed state and overlay the current open eyes visual field.

The final stage is the most involved of all stages of CEVs. During the fifth stage the person can no longer distinguish between what is seen with the eyes closed and the rational normal world. At this stage one may well appear to be display irrational behavior while others may appear to be completely unconscious.

Religious Hallucinations

Religious hallucinations relate to peoples experience of contact with gods or religious icons. Some classical examples from history include Joan Of Arc and Gandhi who both claim to have experienced direct communication with God from whom they received their life's calling. Studies have also suggested the the prophet Muhammad's hallucinations of God may well have simply been the result of temporal lobe epilepsy.

Religious hallucinations are often experienced by people with schizophrenia. However researchers, scientists and doctors are all divided as to the true nature of religious hallucinations. On one side, people such as evolutionary biologist and author Richard Dawkins believe that people who experience religious hallucinations are simply insane in a scientific medical sense.

On the other hand we have people such as the late American psychologist Abraham Maslow who say that religious delusions are not a sign of mental illness and are perfectly normal and healthy and that hearing the voice of God is something available to all of us.

Added to this is the idea put forward by authors such as Graham Hancock that religious delusions may be related to fluctuations in our  own levels of the chemical DMT  ( a naturally occurring hallucinogen ). 

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