Hallucination, the ability to sense things absent from the external environment, has nothing to do with imagining things
Take Mr X, a normal human being leading his ‘normal’ life. We can visualize him (a) as having a brain, possessing a conscious and an unconscious module, (b) in his external varied environment, ranging from a most colourful one to a very dull, monotonous, boring one. Sub-serving those two are (c) his sense organs, which may be perfectly normal or defective.
Hence the possibilities he can present to us are: (1) he is normal, awake and exposed to everyday sensory experiences coming from the exterior which normally displace his brain’s unconscious minor workings to the background. (2) or Mr X is walking kilometers in the white Arctic or on a deserted road, or flying in a blank, dull sky for hours, or goes through the monotonous desert of Sahara for hours — all alone; his senses may become completely numb, because of lack of contrasts, and lose all bearings, leading him to hallucinate. (3) Another possibility is Mr X is fully awake, exposed to a normal external environment, but his sense organs themselves are diseased due to cataracts, deafness, or total loss of smell.
In spite of his handicap, the deaf Mr X may hear real music, or if he is blind he may see real people (Charles Bonnet syndrome). Or (4) Mr X, just before falling off to sleep, or waking up in the morning, may see flitting shadows outside his window or hear creaking doors opening by themselves as he starts to hallucinate; but gradually as sleep deepens dreams take over. (5) Mr X is healthy, fully awake and well-oriented, but is now placed in an anechoic chamber where all his normal senses cannot register external inputs; in this case suddenly those daily ‘insignificant’ dormant minor unconscious brain workings assume importance and rise into his consciousness and cause hallucinations!
Anechoic Chamber (AC)
To test the noise level of their products industrial enterprises isolate the latter in very silent chambers to come up with a stable standard and reference values. This AC is a scientifically designed environment where there is extreme silence, to the extent that the background noise level is at negative decibel!
We are in an anechoic chamber. That’s where some medical researchers and psychologists have decided to place human subjects and study their reaction.
Silence reigns supreme, and with the light switched off. Suddenly, for the first time since our babyhood, we are cut off from our senses. Two possible options open up: we may discover that our brain’s “dormant” reverie will spill over into our consciousness, or we may hear blood coursing through our ears, our gurgling stomach or creaking lungs and our beating heart. We would mistakenly interpret them as coming from outside. After 20 minutes a new eerie feeling will creep over us: we have started to hallucinate! “Not only do people hear their heartbeat, they have trouble orienting themselves and even standing. How you orient yourself is through sounds you hear when you walk. In the anechoic chamber, you don’t have any cues.”
Such sensory deprivation is a totally new experience to us!
Yet hallucination, the ability to sense things absent from the external environment, has nothing to do with imagining things, because experiments carried out in an MRI app has found that people who hallucinate, for example seeing a face, have a definite activation of part of the brain which lights up again when exposed to that face for real! Religious followers who claim to have seen some godly deities are hallucinating — but they are not lying: their brains get activated and come up with the image for them, once they are in a very quiet corner, when their senses are withdrawn from the external world.
Some workers have challenged that finding and refused to ascribe an anechoic chamber’s capacity to produce hallucination; they maintain that those who hallucinate are prone to it. This has motivated other researchers to prolong the time inside the AC from 20 to 45 minutes. And lo! It seems that everyone, whether prone or not, pressed the button to run out fast, the experience inside being too distressing.
As we gradually fall asleep, our consciousness fades, but part of our brain does not sleep. It goes on analyzing all the incoming sensations that have been experienced during the previous hours. Some of them escape and emerge into our failing consciousness to produce some hazy, bizarre and totally disconnected unreal dreams. In fact it is believed that while our senses are sleeping part of the brain is always preparing our body to react to imminent danger. But could these dreams be part of a hallucination process? Or vice versa?
About 5% of normal people will hallucinate sometime, specially after the age of 60. But persistent hallucination will demand a visit to the psychiatrist as it could be a sign of schizophrenia. Another category of patients who are so afflicted are the drug addicts. Generally our main senses of vision, hearing and smell are well isolated from each other. But in a brain MRI app drug addicts are found to have these sensory areas encroaching on each other, which this would explain the description of their bizarre experiences leading to a distorted external reality.
In addition, hard drugs, like LSD, switch off partly those regions of the brain that create the feeling of a united self, thereby producing a sense of a disintegrating self –distressing and disturbing experience typical for LSD users. The question has been asked whether hallucination of normal individuals in an AC is similar to drug addicts’ experience?
Oliver Mason, a psychologist experimenting with AC, believes that the generated hallucinations could lend support to the concept that they arise from a faulty source monitoring… That is, the brain misidentifies the source of its own thoughts as arising from outside the body. The rapid psychosis inducing effect of sensory deprivation in an AC is said to be analogous to the effect of drugs such as cannabis and ketamine, especially in those prone to psychoses. Could mental illness and normality occur on a continuum? The evidence is pointing in that direction.
And are hallucinations and external reality part and parcel of the same process?
One test carried out was to give someone a degraded version of a speech. He will not understand it, but if he had heard the original good version previously then his mind picks sensory information from memory to make its prediction — and create meaning. When external stimulations are deficient our brain puts together previous knowledge and experiences to fill in the gap. It creates its own sensations from previous experiences and projects them as internal conscious perceptions. That’s what it does when we hear some old melodies or tunes, we guess rightly what the next wording or tune will be! That’s how we can indulge in a fluid conversation in our own language; if it is a foreign one the brain has no bearing and gets stuck.
“Our reality is merely controlled hallucinations reined in by our senses,” says Anil Seth, a neuroscientist from Sussex University.
For us laymen, we can only guess what hermits, yogis and other individuals can experience when they isolate themselves in remote caves or mountainous secluded places to meditate; of course all will depend on how many of their usual senses they would obliterate and to what degree. The sound of the wind blowing, the radiance of the dawn or dusk light, the soothing cool pure air of the mountain will keep them connected to the world outside. They attempt to rein in the sensations coming from the outside world and the disturbances coming from inside. They have come to seek the silence of the mind… but may experience something very different. Could be a case of hallucination, for many of our cave dwelling prophets have claimed that they have seen or heard God talking to them?!
* Published in print edition on 19 October 2017