This article is from WeChat official account:Bring science home (ID: steamforkids) , author: Mirror, title figure from: vision China
Since we were born, we have continuously received sensory stimuli-sight, hearing, smell, taste, and touch have shaped our happiness, anger, sorrow and joy. As they grow older, some people begin to pursue more intense stimulation, such as constantly swiping their phones, watching horror movies, and playing extreme sports, while others are tired of being trapped by the flood of information and want to seek cleanliness.
You don’t need to live in seclusion, the laboratory can create a solitary isolation state for you, but the result may not be what you want.
Scientists have always been curious about how the loss of sensory stimulation will affect people, so they designed a series of sensory deprivation experiments (sensory deprivation), That is to limit one or more of the subjects’ five senses within a certain period of time and observe the subjects’ performance.
Donald Hebb’s Sensory Deprivation Experiment
In the 1950s, McGill University psychologist Donald Hebb first tried sensory deprivation experiments. They let 14 college student volunteers stay in the isolation room for 2 to 3 days. Wearing them can only detectDark translucent goggles, plug ears, and use gloves and wrist guards to insulate the touch. During the experiment, they could not leave the house except eating and going to the toilet.
How can you let go of such a good opportunity to sleep?
The subjects who lost the stimulation quickly became drowsy, but they would wake up after sleeping too much. At this time, we must find a way to kill the boredom.
Although the brain has lost information input, it still functions freely. The subjects started wandering around in their imaginations, setting questions for themselves, and playing brain games.
It’s normal up to this point, but over time, incredible things have happened-The subjects have hallucinations: from simple geometric figures to three-dimensional people and Things, even a whole scene:
“A row of yellow dwarfs wearing black hats and open mouths; a group of squirrels carrying sacks decisively in the snow walked beyond the imaginary snow; prehistoric animals were walking in the jungle. “
Some phantoms are from flat to three-dimensional, and others rotate. These interesting scenes have become the only fun in the boring, but some will also cause confusion to the subjects.
These illusions will not disappear when the researcher is talking to the subject, but will quickly disappear when the subject is performing complex tasks such as mathematical operations.
The discovery of this strange phenomenon made the sensory deprivation experiment a research hotspot in the 1950s and 1960s.
In 1961, scientist John Zobac found that if confined subjects were asked to imagine familiar scenes and faces, they would also have realistic scenes before them, even more vivid than in reality. This phenomenon is more likely to occur on the second or third day of the experiment, and it becomes more prominent as the confinement time increases.
In a sensory deprivation experiment in the 1960s, few people could endure more than 12 hours. | Source: DAVID PORTIGAL AND CO., COURTESY OF UNIVERSITY OF MANITOBA ARCHIVES
But like today’s Internet hotspots, this wave of enthusiasm is gradually cooling down, and some people think that such experiments are inhumane, so there has been no new progress for a long time.
In recent years, some scientists have begun to pay attention to this field. In an experiment with only vision deprivation, 13 volunteers were blindfolded for 96 hours, 10 of them had hallucinations, mostly on the next day, lasting only a few seconds or minutes, but one person Lasted all day.
These hallucinations did not come from their deliberate imagination, nor were they under their control.
Picture source: pixabay
When some subjects shared their hallucinations, it was as if they were describing a fantasy movie—a butterfly became a sunset, an otter, and a flower.
This phenomenon reminds researchers of “Bonner syndrome”, which is a hallucination symptom that appears in visually impaired people. However, like the hallucinations caused by claustrophobia, we still know very little about this field.
Such a fantasy experience, are you eager to try? But just like eating wild Yunnan mushrooms, any wonderful illusion has a price, not to mention whether the illusion is a surprise or a fright.
Psilocybe mushrooms contain hallucinogenic toxins, don’t try it | Source: Wikipedia
In 2008, Professor Ian Robbins conducted a sensory deprivation experiment in an underground nuclear bunker. The 6 volunteers were individually isolated in a small dark room, wearing headphones that play white noise. There was nothing in the room except beds, tables and chairs.
Small rooms and appliances used for isolation | Source: BBC “Total Isolation”
The sensory deprivation of one group was more thorough. They were required to wear eye masks that could only be light-sensitive and a protective cover that blocked the sense of touch. (protection The cover was removed at the later stage of the experiment due to discomfort).
Feeling deprived of experimental equipment | Source: BBC “Total Isolation”
Before the experiment started, psychologists did a series of tests for them to evaluate the synthesis of the central executive system of the brain (central executive) ability. Include:
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Visual memory test: Look at a painting and draw it from memory after 30 minutes.
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Information processing test: Say the color of a series of colored words, such as “Red” written in green ink, say green instead of red.
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Language fluency test: such as reporting as many words as possible that begin with a certain letter.
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Things classification ability test: such as cite as many animals as possible in one minute.
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Language suggestion test: Listen to a story and answer related questions after 30 minutes, but the questioner will deliberately mislead the other party, and the subject needs to be screened.
Before the experiment started, everyone’s test results were good.
Memory test results before experiment (left)| Source: BBC “Complete Isolation”
During the next 48 hours of confinement, they experienced restlessness, self-entertainment, confusion and hallucinations (snakes, oysters, etc.) Etc.).
The subject is pacing in the room| Source: BBC “Total Isolation”
After the experiment was over, the same type of tests were repeated. Everyone’s performance deteriorated without exception, with problems such as memory loss, slow response, and unwillingness to think.
Memory test results after experiment (top)| Source: BBC “Complete Isolation”
This is especially true in the information processing test-they tend to read the color words directly, the speed of recognizing colors is slower, and the slowest takes 69% more time than before, and the error rate is also very high.
So if your mind stops for a long time, it will really become stupid
The researcher is most concerned about the language suggestion test. In this test, some subjects became more likely to be misled by suggestive information. For example, when the questioner asks whether the option of A or B is (A and B are both wrong), they no longer point out the story as before There is no A and B, but accept the misleading of the questioner, or start to doubt his own memory.
Interestingly, men are worse than women in this respect, but only two female subjects are not convincing.
Such results have caused researchers to worry that those suspects or witnesses who have been in solitary confinement for a long time may be more likely to be misled during interrogation, shake their original perceptions and give unreliable testimony .
The Central Intelligence Agency (CIA) used sensory deprivation to conduct interrogations. | Source: Pixabay
In the above experiment, the subjects had been confined for less than a day, and they already felt that they were experiencing torture. One can imagine how cruel it would be to imprison for months or even years.
The BBC Horizon section interviewed two victims who had been in prison for a long time: University lecturer Brian Keenan was taken hostage and was imprisoned in a windowless basement for seven or eight months;
Barry Carrige was mistakenly convicted as a murderer, and spent 18 years on and off in a small and dark single cell before being released due to new evidence (U.S. law stipulates that a single solitary confinement cannot exceed 15 days, and there must be at least 4 days in between).
During their imprisonment, their mental state was pushed to the limit, pacing or shaking their bodies constantly, using imagination to fill the void, and even wondering if they were alive. As the length of imprisonment prolonged, their hallucinations became more and more exaggerated. Bryan described one of the terrifying hallucinations:
Picture source: pixabay
“I was alone in the desert, sultry and unbearable. Suddenly, I felt the biting cold wind blown by, as if I was scraping the flesh off my body, leaving only an empty skeleton.”
Brian has also experienced symphonic auditory hallucinations. At first he found it interesting, but the rhythm of the music became faster and faster, and the volume became louder. Brian was forced to hit the wall with his head, trying to get rid of these sounds.
The normal operation of the brain is inseparable from moderate stimulation. After a long period of loss of sensory stimulation, it begins to create hallucinations by itself.
After returning to freedom, it took Brian several months to get used to a normal life. Barry, who has been imprisoned for 18 years, feels that he has completely lost the concept of time, unable to judge the sequence of events; unable to handle tasks that contain too much information; unbearable to drive on crowded streets…even 10 years after being released from prison. in this way.
The brain contains a complex neural network| Source: Pixabay
Researchers speculate that since increasing external stimuli can establish tighter synaptic connections in the brain, sensory deprivation may also cause the original connections to weaken or break. Extreme sensory deprivation will undoubtedly cause indelible harm to the body and mind.
However, a certain degree of restriction of sensory activities within a short period of time also has positive meaning. In this era of information explosion, many people hope that they can temporarily get away from the complicated information. Sleep is undoubtedly one way, and another is to keep the brain awake, but no longer receive external information.
Isolation box
In the early 1960s, researchers specially designed an isolation box (isolation tank) for sensory deprivation experiments. Filled with salt water that can make people float, the temperature is close to human body temperature, and the water tank is closed and soundproof and light-proof. Now, this kind of instrument is mostly used for meditation and recuperation. After tens of minutes in it, the experiencer will feel relaxed and even inspired, but some people find it unbearable, and its actual effect is still controversial.
Actually, for modern people, there is no need to close a small black house, and disconnection from the Internet is enough to be included in the “Top Ten Contemporary Torture”.
Reference materials:
“The Illusion” by Oliver Sachs
BBC Horizon Documentary “Total Isolation”
Feinstein, JS et al. (2018)’Examining the short-term anxiolytic and antidepressant effect of Floatation-REST’, PLoS ONE, 13(2), pp. 1– 24. doi: 10.1371/journal.pone.0190292.
Driller, MW and Argus, CK (2016)’Flotation restricted environmental stimulation therapy and napping on mood state and muscle soreness in elite athletes: A novel recovery strategy?’, Performance Enhancement and Health. Elsevier Ltd, 5(2), pp. 60–65. doi: 10.1016/j.peh.2016.08.002.
Jonsson, K. and Kjellgren, A. (2014)’Curing the sick and creating supermen-How relaxation in flotation tanks is advertised on the Internet’, European Journal of Integrative Medicine .
https://www.canadashistory.ca/explore/science-technology/isolation
http://nautil.us/issue/27/dark-matter/postcards-from-the-edge-of-consciousness-rp
https://en.wikipedia.org/wiki/Sensory_deprivation#Restricted_environmental_stimulation_therapy_(REST)
https://www.medicalnewstoday.com/articles/sensory-deprivation-tank-benefits
https://happiful.com/what-is-sensory-deprivation/
This article is from WeChat official account: scientific home (ID: steamforkids) , Author: Mirror