Depictions of hallucinations usually portray them as sight and sound, but they can also be flavors, scents and feelings. Some can even convince a blind person that they can see! This article looks as hallucinations across the five senses, including:
Hearing Voices...Auditory hallucinations can include hearing voices talking to or about you, animal sounds, footsteps and music. Speech-based hallucinations can also be positive or negative in nature, offering support or even directing curses at you. The "identity" of the speaker can be anything from a family member to a stranger from a foreign land speaking in snippets of "their" own language... and the attitude and intensity of the voices can change in stressful situations.
There's also some evidence that your background has some effect on any hallucinatory voices you might hear. Luhrmann and colleagues interviewed 60 people with schizophrenia in different regions, finding that the hallucinations in:
While hearing unexplained voices is typically a stressful experience, Yale researchers have suggested that people who believe themselves to be psychic may be channeling auditory hallucinations into a positive experience.
Teeple and colleagues note that visual hallucinations have been linked to brain abnormality via genetics and injury, neurotransmitter imbalances and even the unconscious mind bleeding over into the conscious. Like auditory hallucinations, stress, illness and substance abuse can all play a part in triggering this phenomenon, with migraines, epilepsy and Creutzfeldt-Jakob (mad cow disease) all capable of causing them.
One extremely unusual kind of hallucination is Anton's Syndrome, in which an individual with damage to the occipital lobe of the brain (containing the visual cortex) becomes clinically blind but refuses to admit it. Sufferers hallucinate their surroundings based on their memory, confusing observers as the seemingly sighted individual bumps into moved objects, closed doors and other people.
There's also prosopometamorphopsia, a condition which distorts human faces. Prosopometamorphopsia is so rare that fewer than 100 cases have been recorded since 1904. Strangely, only in-the-flesh faces get distorted and photographs seem unaffected.
Feeling the False...Hallucinations aren't limited to audio and visual - they can also take the form of olfactory, gustatory and tactile sensations.
Olfactory hallucinations (sometimes called phantosmia) take the form of smells ranging from garbage to flowers. In addition to the usual causes, polyps growing in the nose, exposure to solvents, insecticides, COVID 19 or even smoking can lead to these hallucinations. These phantom scents can be very distressing - imagine being treated to the odor of a rubbish dump for 20 minutes at random intervals!
Strange and unexplained flavors are the hallmark of gustatory hallucinations. Little research has been done on these, but one thing we do know is that individuals diagnosed with epilepsy commonly experience them. Gustatory hallucinations can lead to the sufferer avoiding food... which is obviously bad for their long term health and survival.
Tactile hallucinations can include the feeling that someone or thing is touching your skin, that insects or animals are crawling around inside you (formication) a sensation of falling or even that your internal organs are shifting around inside your body. These can be deeply disturbing - people suffering from formication have been known to self harm in an attempt to remove the hallucinatory bugs. Perhaps the most extreme form is "phantom limb", a condition in which an amputee hallucinates what the missing limb is feeling... including pain.
On the flip side, a very common tactile hallucination is the hypnic jerk - a sudden feeling of falling while you are partially asleep (and thus have relaxed muscles) that makes you jerk awake. Perhaps it's an ancient reflex from our arboreal forebears, intended to save us from falling out of a tree!
- Hearing voices - and how your background affects what they say
- Seeing the unreal - including distorted faces and sight-by-memory
- Feeling the false - hallucinatory scents, flavors and feelings
 |
| Research suggests that 1 in 10 people hear hallucinatory voices... (TRAPHITHO) |
Hearing Voices...Auditory hallucinations can include hearing voices talking to or about you, animal sounds, footsteps and music. Speech-based hallucinations can also be positive or negative in nature, offering support or even directing curses at you. The "identity" of the speaker can be anything from a family member to a stranger from a foreign land speaking in snippets of "their" own language... and the attitude and intensity of the voices can change in stressful situations.
There's also some evidence that your background has some effect on any hallucinatory voices you might hear. Luhrmann and colleagues interviewed 60 people with schizophrenia in different regions, finding that the hallucinations in:
- America - San Mateo: Often advocated violence, were viewed as illness or intrusive thoughts.
- West Africa - Accra: Were usually viewed as spiritual, sometimes depicted a conflict between a "good" and "bad" entity.
- India - Chennai: Tended to be of family (living or dead) offering guidance - either good or bad.
While hearing unexplained voices is typically a stressful experience, Yale researchers have suggested that people who believe themselves to be psychic may be channeling auditory hallucinations into a positive experience.
Seeing the Unreal...
Covering everything from indistinct lights and blurry objects in your peripheral vision all the way up to large animals and complex scenes, visual hallucinations are the "classic" in most people's eyes. There's also the hallucination-adjacent palinopsia (an image persisting despite the object being removed from the field of view) and pareidolia (the tendency to "see" meaningful patterns in objects such as the classic man-in-the-moon) that are present in almost everyone.Teeple and colleagues note that visual hallucinations have been linked to brain abnormality via genetics and injury, neurotransmitter imbalances and even the unconscious mind bleeding over into the conscious. Like auditory hallucinations, stress, illness and substance abuse can all play a part in triggering this phenomenon, with migraines, epilepsy and Creutzfeldt-Jakob (mad cow disease) all capable of causing them.
One extremely unusual kind of hallucination is Anton's Syndrome, in which an individual with damage to the occipital lobe of the brain (containing the visual cortex) becomes clinically blind but refuses to admit it. Sufferers hallucinate their surroundings based on their memory, confusing observers as the seemingly sighted individual bumps into moved objects, closed doors and other people.
There's also prosopometamorphopsia, a condition which distorts human faces. Prosopometamorphopsia is so rare that fewer than 100 cases have been recorded since 1904. Strangely, only in-the-flesh faces get distorted and photographs seem unaffected.
 |
| Hypnic jerks may be a holdover from our tree-dwelling forebears... (jhenning) |
Feeling the False...Hallucinations aren't limited to audio and visual - they can also take the form of olfactory, gustatory and tactile sensations.
Olfactory hallucinations (sometimes called phantosmia) take the form of smells ranging from garbage to flowers. In addition to the usual causes, polyps growing in the nose, exposure to solvents, insecticides, COVID 19 or even smoking can lead to these hallucinations. These phantom scents can be very distressing - imagine being treated to the odor of a rubbish dump for 20 minutes at random intervals!
Strange and unexplained flavors are the hallmark of gustatory hallucinations. Little research has been done on these, but one thing we do know is that individuals diagnosed with epilepsy commonly experience them. Gustatory hallucinations can lead to the sufferer avoiding food... which is obviously bad for their long term health and survival.
Tactile hallucinations can include the feeling that someone or thing is touching your skin, that insects or animals are crawling around inside you (formication) a sensation of falling or even that your internal organs are shifting around inside your body. These can be deeply disturbing - people suffering from formication have been known to self harm in an attempt to remove the hallucinatory bugs. Perhaps the most extreme form is "phantom limb", a condition in which an amputee hallucinates what the missing limb is feeling... including pain.
On the flip side, a very common tactile hallucination is the hypnic jerk - a sudden feeling of falling while you are partially asleep (and thus have relaxed muscles) that makes you jerk awake. Perhaps it's an ancient reflex from our arboreal forebears, intended to save us from falling out of a tree!
Thanks for reading - for more, try...