"Most people who do hear voices are not schizophrenic."
"One does not see with the eyes, one sees with the brain."
"When the brain is released from the constraints of reality, it can generate any sound, image, or smell."
Oliver Sacks is a professor of neurology at the New York University School of Medicine and the author of a dozen books, including Awakenings, The Man Who Mistook His Wife for a Hat, and Seeing Voices. He writes frequently for The New Yorker. In this latest book he describes the various kinds of hallucinations that can afflict both normal and ill people.
He defines hallucinations as percepts that are projected into external space. They arise in the absence of any external reality: they are things that are seen or heard but are not there. They are a unique and special category of consciousness and mental life that can startle, excite, bewilder, terrify, or inspire. Sacks believes they underlie much of the myth and folklore found in every culture.
Hallucinations can occur in normal people with sensory deprivation, with prolonged sleep deprivation, or when falling asleep or awakening. They can occur in certain medical conditions, such as blindness, Parkinson's, migraine, seizures, the delirium of high fever, or with drug or alcohol toxicity. Vivid hallucinations can occur with meditation, with spiritual exercises, and with ecstatic drumming or dancing.
Sacks notes that 10 to 20 percent of those with blindness gain a secondary visual world, one of complex visual hallucinations. Known as Charles Bonnet syndrome, these are a reaction of the brain to the loss of eyesight. They often consist of blobs or clouds of intense color, can be rich in detail, and can have repetition and multiplication. They may have mosaics, squares, hexagons, honeycombs, checkerboards, or more elaborate figures with rich robes and elaborate headgear. They are different from dreams because insight is preserved: the subject realizes they are not real.
Sacks says that brilliantly colored hallucinations known as "the prisoner's cinema" can appear to those kept in isolation or in darkness. They can also be caused by any visually monotonous task, and have been reported by polar explorers, by sailors who have spent days looking at a becalmed sea, by high-altitude pilots flying for hours in an empty sky, and by long-distance truckers focused for hours on an endless road.
The hallucinations that can accompany immobilization were seen during the tragic polio epidemic, when polio victims lay motionless in coffin-like "iron lungs." They also occur with post-encephalitic Parkinson's patients enclosed in immoveable Parkinsonism.
In addition to their scintillating scotomata, migraine patients can experience hallucinations that commonly have simple patterns of zigzags and checkerboards, lattices, cobwebs, or honeycombs. Or they can have complex human figures, faces, or landscapes. Sacks notes that migraine-type patterns are seen in the art and crafts of every culture, going back tens of thousands of years.
Epilepsy was known to Hippocrates as the sacred disease since it was thought to be a disorder of divine inspiration. Its partial or focal seizures can cause dreamlike fantasies or complex sensory hallucinations of sight, sound, or smell.
The musical, visual, or tactile hallucinations seen with delirium generally indicate a medical problem, such as high fever or alcohol toxicity. They disappear as soon as the medical problem is corrected.
Sacks notes that hypnagogic (just before sleep) images are similar to hallucinations and are estimated to occur in the majority of people. They can have brilliant, exaggerated colors. The hypnopompic hallucinations that come upon awakening are often seen in bright illumination with open eyes, and can be terrifying. They occur in normal people and can constitute a severe challenge to one's belief system, or can even challenge reason itself. For example, visions of angels and devils may engender belief in their physical reality and reinforce a belief in the supernatural.
He says hallucinations from whatever cause can create a world of imaginary beings. The folklore of every culture includes supernatural figures like the incubus and succubus, which assault the sleeper sexually, or the Old Hag, which paralyzes its victims and sucks their breath away.
Hallucinations, like Sacks's other books such as Musicophilia, Migraine, and A Leg to Stand On, is delightful, informative, and highly recommended.
Jerome C. Arnett, Jr., M.D.
|Printer friendly Cite/link Email Feedback|
|Author:||Arnett, Jerome C., Jr.|
|Publication:||Journal of American Physicians and Surgeons|
|Date:||Jun 22, 2015|
|Previous Article:||The window of opportunity to save independent medical practice is closing.|
|Next Article:||Climate of Corruption: Politics and Power behind the Global Warming Hoax.|