NOTE: The following is taken from Jan Dirk Blom’s A Dictionary of Hallucinations (pp. 188-9), which is designed to serve as a reference manual for neuroscientists, psychiatrists, psychiatric residents, psychologists, neurologists, historians of psychiatry, general practitioners, and academics dealing professionally with concepts of hallucinations and other sensory deceptions.
Fasting-Induced Hallucinations: A term used to denote a hallucination evoked or facilitated by fasting. A conceptual distinction can be made between fasting for dietary reasons, anorexic fasting, forced fasting, and ritualistic fasting. In any case, fasting is a powerful mechanism that can facilitate the mediation ofa hallucinatory state, especially in combination with other facilitating mechanisms such as * sleep deprivation, isolation, * sensory deprivation, and the use of laxatives. The pathophysiological mechanism underlying fasting–induced hallucinations is basically unknown. However, it has been suggested that a fasting–induced hyperexcitation of the dopaminergic system may play a part in their mediation. Fasting–induced religious, mystical, and hallucinatory experiences have been reported since ancient times. Conversely, fasting and food refusal (i.e. sitophobia) are sometimes attributed to the influence of * imperative hallucinations, usually of an auditory nature, which forbid the individual to eat or warn him or her that the food is poisoned or unclean. For example, * visual hallucinations involving snakes or eyes seen by the affected individuals in the meals offered to them have been reported. In addition, it is known that * olfactory and * gustatory hallucinations may convince the affected individual that food is not to be trusted. It is not inconceivable that in such cases the ensuing reactive type of fasting aggravates the hallucinatory state.
In a book entitled The Biology of Belief: How Our Biology Biases Our Beliefs and Perceptions, the third chapter deals with The Biology of Belief Manipulations. Joseph Giovannoli writes:
Psilocin, a molecule found in certain mushrooms, is similar to serotonin and can bind to serotonin receptors. Eating psilocin-containing mushrooms will cause psilocin to bind serotonin sites in the thalamus. The thalamus, like a switching station, determines which sensory information reaches various parts of the brain. The prefrontal lobes are the part we use to reason and make decisions. Anything that disrupts the thalamus can disrupt the flow of sensory information to the prefrontal lobes. This in turn can cause abnormal thoughts to occur in our minds. If enough psilocin binds to serotonin sites in the thalamus the excessive sensory impulses flowing to the prefrontal lobes cause them to manufacture thoughts. In other words, if you eat enough psilocin-containing mushrooms, you will hallucinate. During dream sleep, blood flow to the thalamus increases while flow decreases to the complex thinking areas in the frontal brain. This combination, it is theorized, reduces our sense of time and self-awareness during dreaming, and contributes to our forgetting dreams on awakening.
When mushrooms or other plants containing serotonin equivalents are used in a religious context, the hallucinations make imagined images more vivid and therefore more believable than those of a vague dream. The hallucination becomes a transcendent experience, but thought in this mental state is illusion. Instead of using psilocin, the same result can be achieved through sensory deprivation. Sensory deprivation is thought to increase the number of serotonin receptor sites in the thalamus, causing an otherwise normal level of serotonin to disrupt the thalamus and allow excessive sensory impulses to reach prefrontal lobes. The following passage from the ancient philosophical writings of India, the Upanishads (800-500 BC), describes what we know today as a fasting-induced hallucination:
For a fortnight one must fast, drinking only water; then the mind, so to speak, is starved into tranquility and silence, the senses are cleansed and stilled, the spirit is left at peace to feel itself and that great ocean of soul which it is a part; at last the individual ceases to be, and Unity and Reality appear. For it is not the individual self which the seer sees in this pure form of inward seeing; that individual self is but a series of brain and mental states, it is merely the body seen from within. What the seeker seeks is Atman, the Self of all selves, the Soul of all souls, the immaterial, formless Absolute in which we bathe ourselves when we forget ourselves.
An alternative explanation would be that the subject’s interpretation of events in ways consistent with his or her beliefs has combined with a fasting-induced hallucination or dream state to create a dream or illusion consistent with the hallucinator’s beliefs. Hallucinations are typically achieved by meditating, rhythmic rituals, ritual fasting, fatigue, or drugs. Hallucinations resulting from smoking opium introduced the phrase pipe dreams into our vocabulary.
Another example of how brain chemistry can manufacture “reality” is found in near-death-experiences. Unlike prefrontal lobe hallucinations, near-death experiences occur when your brain is deprived of oxygen—as can occur during surgery. When oxygen levels begin to decrease across your vision-processing neurons at the back of the brain, the neurons activate, and their output is the same as if you were seeing a white light. It is like an incandescent light bulb flashing as it burns out, except that the light lasts longer. You first “see” a white dot that gets larger as more and more of your vision neurons are deprived of oxygen. The tunnel perception is created because the neurons that are not yet deprived of oxygen do not activate, and you perceive their output as black. Seeing a small white spot on a black background reminds you of being in a black tunnel and seeing the small bright tunnel opening. As more neurons are deprived of oxygen you see the white spot grow larger. It reminds you of getting closer to a tunnel opening. Ultimately, when all your vision neurons are deprived of oxygen, you “see” only white. You have reached the tunnel opening. Further evidence of the biological origin of near-death experiences is that they also occur in people who have been physically incapable of sight from birth.
One case occurred when a congenitally blind person was deprived of oxygen for minutes in a near drowning accident. People who have had near-death experiences also report having an overwhelming sense of well-being. This occurs because the oxygen deprivation also causes your brain to release a flood of endorphins, which bind with your opiate receptors, producing what is typically described as a runner’s high.
Joseph Giovannoli, The Biology of Belief: How Our Biology Biases Our Beliefs and Perceptions, 2000, pp. 44-48.
Also see: Hallucination: A Normal Phenomenon? http://dujs.dartmouth.edu/fall-2009/hallucination-a-normal-phenomenon#.VMZYHSzCaSo
NOTE: Though fasting and food-deprivation is a very ancient religious technique used in order to produce trance-like states, religious experiences, and in some cases of excessive fasting, divine visions, there are also foods that can be eaten that help induce such states:
1. Chile Peppers: Chile-induced hallucinations, known as heat-induced delirium, are sometimes experienced by those who eat “the world’s hottest” chili peppers. There isn’t much literature available on why eating hot peppers would lead to head trips, but two things seem to be going on. First, there’s the endorphin rush from the pain caused by the hotness of the chile. Beyond that, it’s worth noting that hot peppers are in the same botanical family as potatoes, tobacco, and deadly nightshade. Tobacco’s mental effects might be mild, but overdosing on the fruits of potatoes (rarely seen, but they do have fruit, if you let the stalks grow and flower) and nightshade plants makes you hallucinate, then die. Capsaicin might be the best-known chemical in hot peppers, but odds are some other potent molecules are in the mix as well.
2. Nutmeg: Nutmeg is actually psychoactive, in the right doses. It takes somewhere between 5 and 15 grams of grated nutmeg–about two tablespoons or two whole seeds–to have any effect, and even then it only kicks in three to six hours later. Reports on psychonaut forums indicate that the nutmeg high varies, from “kinda mix between stoned and drunk” to “high as balls…can’t really focus…red eyes…possible nausea” with recommendations to “make sure you have like 36 hours put off from ingestion until you have to do anything. lol.
3. Fish: Hallucinogenic fish are certain species of fish, found mainly in the tropics, that can produce vivid auditory and visual hallucinations if their flesh is ingested. They are also called dreamfish or dream fish.
List of hallucinogenic fish: http://en.wikipedia.org/wiki/Hallucinogenic_fish#Hallucinogenic_species
Ichthyoallyeinotoxism, which you might know better as Hallucinogenic Fish Poisoning, comes from eating certain fish that either produce hallucinogenic toxins themselves or just store them up from eating lots of algae with the stuff. Ancient Romans were known to eat Mediterranean sea bream for recreational tripping purposes back in the day, and the fish is known in Arabic as “the fish that makes dreams.”
Sarpa salpa, known commonly as the Salema porgy, is a species of sea bream, recognisable by the golden stripes that run down the length of its body, and which can cause hallucinations when eaten. It is relatively common off the coasts of South Africa, Tenerife, Malta and Cyprus, but has occasionally been found as far north as Great Britain. Sarpa salpa is not normally psychoactive. It is, in fact, often served as a dish at seafood restaurants in the Mediterranean area. The fish became widely known for its psychoactivity following widely publicized articles in 2006, when two men ingested it at a Mediterranean restaurant and began to experience many auditory and visual hallucinogenic effects. These hallucinations, described as frightening, were reported to have occurred minutes after the fish was ingested and had a total duration of 36 hours. It is believed that the fish ingests a particular algae or phytoplankton which renders it hallucinogenic. The effects described are similar to those of indole tryptamine psychedelics.
4. Rye Bread: Rye grain is occasionally infected with the ergot fungus. Ergot contains several psychoactive chemicals such as ergotamine, a compound used in the synthesis of LSD. Outbreaks of ergot poisoning, which also cause intense convulsions, “gangrenous symptoms,” and death, have dropped off since the 19th century, and the last big one happened in a French village in 1951. (Note: ergotamine is one of the precursor chemicals used to make LSD and not LSD itself).
5. Mulberries: Ingesting large amounts of unripe mulberries can cause moderate hallucinations. Black, red, and white mulberry are widespread in southern Europe, the Middle East, northern Africa and Indian Subcontinent where the tree and the fruit have names under regional dialects. It was much used in folk medicine, especially in the treatment of ringworm. Mulberries are also widespread in Greece, particularly in the Peloponnese, which in the Middle Ages was known as Morea (Greek: Μωριάς, Morias), deriving from the Greek word for the tree (Greek: Μουριά, Μouria).
See: https://www.erowid.org/herbs/mulberry/mulberry_info2.shtml for an explanation and differentiation of the various uses and effects of red, black and white mulberry.
There are numerous other foods that can potentially have hallucinogenic properties as well. The foods listed above are more commonly known and used.