symptoms
Understanding Hallucinations and Other Misperceptions
Misperceptions
To illustrate this phenomenon, consider one of my personal experiences. One cool autumn afternoon in the horse barn, I experienced the following perception. I was convinced that I saw a chubby white-footed field mouse scurry along the wall of the barn out of the corner of my eye.
At least this was the most logical interpretation my brain could make of the limited data it had received and processed. As it turned out, the object in my peripheral vision was actually a brown leaf that had silently travelled along the wall, driven by an anomalous fall breeze.
My brain had provided (added) information that had not come directly from my senses. Instead, my brain fabricated information so that it could make sense of the event. My brain concluded that the brown object was a mouse (ruling out the possibility that it could be a leaf, since it was moving). My brain further surmised that the mouse was hurriedly moving from one location of concealment to another.
This phenomenon (misperception) is a common experience for most of us and is in no way suggestive of disturbed thinking.
Illusions
By far the best example of this occurrence is the impression that we see water pooled on the surface of the pavement on a hot summer day as we speed along the highway in our automobile.
We quickly discover that this water does not exist as we reach the point on the road where the water should be. Even though our brain plainly and squarely received all of the data from our eyes necessary to construct the image of water in our visual cortex, our brain was mistaken.
In this case, the brain was not required to add any data, but merely interpret it; and yet erroneously concluded that we had seen water.
From a scientific perspective we understand this phenomenon to be a product of the convection of air, warmed by the hot asphalt, and changes in the air’s density. These factors allow the altered air to form a make-shift lens that refracts light and creates the image that our eyes reliably receive.
Synthetic Hallucinations
Unfortunately, many of our patients with Schizophrenia are familiar with this type of hallucination from their recreational or experimental drug use. These experiences with hallucinogenic drugs do offer an excellent opportunity to consider visual experiences that, to most, are clearly hallucinations.
Under the influence of LSD or other hallucinogens, we might perceive individuals with putrid green faces and dangling long hair comprised of dark brown kelp.
Further scrutiny of the environment might disclose the presence of puffs of vividly colored exhaust from the tail pipes of automobiles passing on the street. These colored fumes are present even though we are experiencing them in the heat of summer, when nothing more than the shimmering hot air and steam from exhaust should be detected.
Logic tells us that our experience is an hallucination. These hallucinations are so bizarre or far fetched to be easily recognized as hallucinations.
This ability to reliably distinguish these altered perceptions from reality is reassuring to the “tripper” and undeniably provides some protection from a transition to a “bad trip” that might leave them irreparably damaged.
Please be aware that LSD is a potent brain toxin, one that sometimes unexpectedly produces severe and permanent brain damage. This damage is totally unpredictable and can occur with the first or the fiftieth experience.
Since in this case the hallucinations are unbelievable, they serve to illustrate that within the brain, where all perceptions ultimately come to their final realization, these synthetic perceptions (hallucinations) are indistinguishable from perceptions that originate, unaltered, directly from our senses.
Perspective
Consider hearing a knock at the door of your doctor’s office. Your doctor might rise from his chair and answer the door. To his surprise, he may find that his sister was knocking at the door. This might be possible, but unlikely, since the doctor’s sister lives in Seattle and has never been to his office.
If the visitor at the door was the doctor’s mother, rather than his sister, this should cause the doctor to question the validity of the image that had formed in his brain, as his mother passed away years ago.
At this juncture, the doctor is at least able to make a decision regarding the validity of this perceived event. Either this represents an hallucination, which is the more likely, although distressing, explanation; or less likely, and even more distressing, the doctor’s dead mother has come to call.
This illustration creates an opportunity for people with Schizophrenia to appreciate an ability that they all possess. They can critically examine what appears to be a “real” experience. Most importantly, they can learn to employ reason in an effort to distinguish between hallucinations and reality.
Provided the patient is not seriously disturbed, this often allows them to more effectively deal with otherwise disturbing experiences in those instances where even the use of potent medications or large does of medications have not completely eliminated hallucinations.
Many patients are able to reflect on their experiences and compare them with what would be logical under the circumstances. If the experience seems to be illogical, they can conclude that it may very well be an hallucination.
If the doctor, or the patients in their own scenarios, chose to embrace the presence of a dead loved one at the door and consider it to be “real”, they may form a delusion (a fixed false belief) related to this experience. As a consequence of this acceptance, it may be incorporated into their system of delusions.
Hallucinations
Hallucinations, as experiences, are indistinguishable from other perceptions in the brain, unless reason dictates that they are unlikely to be reliable perceptions.
An understanding of hallucinations also demonstrates that delusions are always difficult, if not impossible, to distinguish from reality. They appear in the mind in precisely the same form as do any of our other thoughts.
Our brain automatically and unquestionably accepts them. Only a very determined query of their validity is likely to result in their being categorized as questionable, or eventually, as false beliefs.
This is particularly true if these experiences seem to originate in our senses. To complicate matters further, the patient’s hallucinations and delusions become “systematized”, added to the evolving framework of similar thoughts, that each, in turn, reinforce one another.
Conclusion
In terms of experience, hallucinations cannot be easily distinguished from reality. We can critically examine them and conclude that they are not real. While it would be difficult to ignore them, this process may make them less distressing. Many patients accomplish this with practice. When the hallucinations are entirely plausible, this becomes much more difficult.
(Sources: This article is a translation of an excerpt from a novel, entitled “Vagaries”, written by the author.)
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