From: joedees@bellsouth.net
Date: Sat Feb 02 2002 - 00:33:41 MST
On 2 Jan 2002 at 11:45, Peter Webster wrote:
> The essential religion of modern times might be called NothingBut-ism. It
> is invoked to pacify every doubt, disperse every mystery...
>
> Pubdate: Tue, 01 Jan 2002
> Source: Chicago Tribune (IL)
> Copyright: 2002 Chicago Tribune Company
> Contact: ctc-TribLetter@Tribune.com
> Website: http://www.chicagotribune.com/
> Details: http://www.mapinc.org/media/82
> Author: Ronald Kotulak
>
> SEEING MORE THAN MEETS EYE
>
> Science Finding Hallucinations May Be Reflection Of Brain Pathways
>
> Near-death experiences, in which people believe they see the bright
> light of heaven at the end of a tunnel, may be nothing more than the
> brain cells that process vision lighting up in such a way so as to
> reveal the circular pattern of how they are wired together.
>
> New research also indicates that prehistoric cave and rock art
> depicting spirals, zigzags and other geometric forms may have been
> done by artists experiencing the same kind of drug-induced
> hallucinations that people today have when they take LSD, mescaline,
> Ecstasy and other psychedelic compounds.
>
> A visual hallucination is defined as seeing something that's not
> there. They are relatively common, and almost all cultures from
> prehistoric times on have used drugs to induce hallucinations for
> religious, healing and artistic purposes.
>
> But science now suggests that near-death images and other
> hallucinations involving geometric patterns are really there-- on the
> inside of the brain.
>
> Inducing Creative Mood
>
> People like Arthur Conan Doyle, Aldous Huxley, Cary Grant, Allen
> Ginsberg, Tallulah Bankhead, the Beatles, Charles Dickens, Timothy
> Leary and Salvador Dali, who used hallucinogens in the hopes of
> inducing a creative mood, were actually lighting up their brain wiring.
>
> "[It] surged upon me an uninterrupted stream of fantastic
> [kaleidoscopic-like] images of extraordinary plasticity and
> vividness," is how Albert Hoffman, the brilliant Swiss chemist,
> described his first experience with LSD, a compound he had synthesized
> in 1938.
>
> Hallucinations can also be caused by anesthetics, fatigue, hunger,
> stress, alcohol, fever, adverse drug reactions, sleep deprivation,
> bright flickering lights and even pressure on the eyeballs.
>
> Normally, the 100 million neurons of the credit-card size visual
> cortex at the back of the head convert what our eyes see into edges
> color, depth and other features, and then reassemble the pieces into
> recognizable scenes of the outside world.
>
> The process works fast. About 40 milliseconds after seeing an object,
> edge detectors are activated and in another 40 milliseconds the edges
> become pieced together into contours and the beginnings of surfaces.
> This information goes to other parts of the brain to be compared with
> stored memories.
>
> In far less than a second you've basically solved the problem of
> vision, of remembering, recognizing and sorting out what the object
> is.
>
> In the case of a hallucination, this does not happen. Through the
> action of drugs or other influences, the edge detectors become
> disengaged from the rest of the network and begin firing on their own.
>
> The resulting hallucination reflects the pinwheel pattern of brain
> cells that process lines, curves and other geometric shapes, providing
> a remarkable view of the physical architecture of the visual cortex,
> according to recently published findings by Jack Cowan of the
> University of Chicago and Paul Bressloff of the University of Utah.
>
> "It's almost like seeing your own brain through a mirror," Cowan said.
> "You're basically seeing patterns that your own brain is making."
>
> 4 Basic Groups
>
> Cowan, who is a mathematician and a neurologist, has been studying
> hallucinations for 20 years. He was intrigued by the work of another
> U. of C. scientist, Heinrich Kluver, who in the 1920s and 1930s
> classified the drawings of people experiencing drug-induced
> hallucinations into four basic categories--tunnels and funnels;
> spirals; lattices; and cobwebs.
>
> Based on new findings from optical imaging, in which scientists can
> actually see which neurons light up in the visual cortex of cats and
> monkeys when they view different lines and contours, Cowan, Bressloff
> and their colleagues developed a mathematical model that can
> accurately predict the shapes of different hallucinations.
>
> "We calculated that given the kinds of anatomy in the visual cortex,
> there are only four kinds of patterns it will make when it goes
> unstable," Cowan said. "It turns out that those four kinds of patterns
> we get from the math correspond exactly to the four classes of
> patterns that Kluver ended up with based on his looking at the drawings."
>
> Terry Sejnowski, director of the Salk Institute's Computational
> Neurobiology Laboratory, said the work of Cowan and Bressloff could
> have wide application in the areas of artificial intelligence and
> artificial vision.
>
> "They have created a mathematical model which replicates surprisingly
> well the states that the brain gets into when it's having visual
> hallucinations," he said. "These hallucinatory states are really
> abnormal conditions. Sometimes you learn a lot about a complex system
> from the conditions which occur when it breaks down or when it's not
> operating under normal conditions."
>
> The mathematical study of vision is also helping to explain near-death
> experiences. Essentially they are physical representations of
> striplike columns of neurons in the visual cortex that form a tunnel
> pattern.
>
> "What actually happens when somebody takes a drug is the first thing
> they experience is a very bright light in the center of the visual
> field, which is very reminiscent of this sort of light in the tunnel
> when people think they see heaven beckoning in the distance,"
> Bressloff said.
>
> "What seems to happen is that this bright light spreads across the
> visual field and from that state then this structure emerges which is
> the seed for the hallucination pattern," he said.
>
> Drug-Induced Drawings
>
> Since spirals, tunnels, zigzags and other hallucinatory patterns can
> be found in the art of almost all cultures and go back more than
> 30,000 years, many anthropologists speculate that they were done under
> the influence of hallucinogenic drugs or self-induced trances, and
> that these experiences served as the origin of abstract art.
>
> The foremost masters of hallucinogenic experiences are shamans, ritual
> practitioners in hunting-and-gathering societies who enter altered
> states of consciousness to achieve a variety of ends that include
> healing the sick, foretelling the future, meeting spirit-animals,
> changing the weather and controlling animals by supernatural means,
> according to Jean Clottes, scientific adviser to the French ministry
> on prehistoric art, and David Lewis-Williams, professor of cognitive
> archeology at the University of Witwatersrand in Johannesburg, South
> Africa.
>
> In their study of shamans, religious mystics and visionaries around
> the world, Clottes and Lewis-Williams found that while drugs are
> widely used to induce hallucinations, trances are also used to produce
> unusual mental imagery. Trances can be induced through sensory
> deprivation, prolonged social isolation, intense pain, vigorous
> dancing and insistent, rhythmic sound, such as drumming and chanting.
>
> 3 Stages Of Trances
>
> In their book, "The Shamans of Prehistory: Trance and Magic in the
> Painted Caves," Clottes and Lewis-Williams outline three stages of
> trance.
>
> In the first stage trance, people "see" geometric forms, such as dots,
> zigzags, grids, parallel lines, nested curves and meandering lines. In
> the second stage, subjects try to make better sense out of the
> geometric imagery by illusioning them into objects of religious or
> emotional significance, such as construing a zigzag line into a snake.
> The third stage is reached via a vortex or tunnel, at the end of which
> is a bright light. When people emerge from the tunnel they find
> themselves in a bizarre world where geometric patterns become mixed
> with monsters, people and settings. It is in this stage where the
> drawings of humans with animal features occur.
>
> Clottes and Lewis-Williams concluded: "We emphasize that these three
> stages are universal and wired into the human nervous system, though
> the meanings given to the geometrics of Stage 1, the objects into
> which they are illusioned in Stage 2, and the hallucinations of Stage
> 3 are all culture-specific, at least in some measure, people
> hallucinate what they expect to hallucinate."
> __________________________________________________________________________
> Distributed without profit to those who have expressed a prior interest in
> receiving the included information for research and educational purposes.
> ---
> MAP posted-by: Richard Lake
>
>
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