31-03-2004, 05:30
*makes you want to hallucinate for science
>
>January 09, 2002 -- UNIVERSITY OF UTAH MEDIA ADVISORY
>The news release below was issued recently by the University of Chicago
>and features work done in colloboration with University of Utah
>mathematics professor Paul Bressloff. We are relaying it to Utah news
>media with the permission of the University of Chicago. Below the news
>release is a copy of a Chicago Tribune story on the research.
>
>HALLUCINATIONS PLUS MATHEMATICS PLUS ANATOMY
>EQUALS INSIGHT INTO BRAIN ARCHITECTURE
>
>CHICAGO, Jan. 3 -- Scientists are deducing the internal circuitry of the
>visual brain by mathematically reproducing the geometric hallucinations
>people see when they ingest mind-altering drugs, view bright, flickering
>lights or encounter near-death experiences.
>
>The findings by the University of Chicago's Jack Cowan, the
>University of Utah's Paul Bressloff and three of their colleagues provide
>new insights into the complexities of vision, the workings of the brain and
>even the origins of art.
>
>"We take it for granted, but seeing is an amazing process," said
>Cowan, a professor in mathematics and neurology. "In something less than
>a second, we can see objects and classify them under all kinds of
>differing illumination from very dim to very bright. We're just
>scratching the surface of what's going on."
>
>The mathematical study of vision and the brain has been accepted for
>publication in the journal Neural Computation. Co-authoring the study
>were Martin Golubitsky, University of Houston; and two of Cowan's former
>graduate students, Peter Thomas, Salk Institute for Biological Studies; and
>Matthew Wiener, National Institutes of Health.
>
>"We're trying to understand how the intrinsic circuitry of the
>visual cortex of the brain can generate patterns of activity that underlie
>hallucinations," Bressloff said. These geometric hallucinations take the
>form of checkerboards, honeycombs, tunnels, spirals and cobwebs, a
>phenomenon originally studied as early as the 1920s and 1930s by the
>late Heinrich Kluver, a pioneering University of Chicago neurologist.
>
>"Because we know how the eyes are wired to the visual cortex, we can
>calculate what the patterns actually look like there," said Cowan. "They
>correspond very closely to the patterns that people report seeing."
>
>A technique called "perturbation theory" proved crucial to
>reproducing the geometric patterns, Bressloff said. Also crucial was an
>understanding, based on recent advances in brain anatomy and physiology,
>of the strong short-range connections and weaker long-range connections
>between neurons in the visual cortex.
>
>"It is a situation where you have something strong and something
>else that's weak, so it perturbs the system," Bressloff said.
>
>The mathematics that models the perturbation is, coincidentally,
>similar to that used in calculating the Zeeman Effect in quantum
>mechanics, which describes the physics of the subatomic world. "If you
>take hydrogen atoms and you put them in a weak magnetic field, their
>spectrum changes in ways that can be calculated," Cowan explained. "It's
>called the Zeeman effect." Bressloff noted, however, that "there's no
>quantum mechanics involved in the actual working of the brain."
>
>Academically trained in physics and electrical engineering, Cowan
>may be the world's only university faculty member who holds dual
>appointments in mathematics and neurology. In 1986, he organized one of
>the founding workshops of the Santa Fe Institute, a private, non-profit
>research and education center devoted to the study of complexity and
>complex adaptive systems. He became interested in geometric
>hallucinations in the late 1970s, when he realized that they may provide
>clues regarding the brain's circuitry.
>
>"Producing hallucinatory images in the brain could be understood in
>terms of spontaneous pattern formation in the brain," Cowan said. "The
>brain makes patterns of activity when it goes unstable." Such instabilities
>follow the ingestion of substances such as LSD, psilocybin and cannabis,
>which act on control networks in the brainstem that secrete noradrenalin,
>seratonin and dopamine, which in turn control brain states.
>
>"If there's any noise-random fluctuations of brain activity-in the
>brain, it is amplified into a pattern that reflects the architecture of the
>brain. The brain just takes the noise and shapes it into a pattern," Cowan
>said. "In the case of geometric visual hallucinations this is a direct
>consequence of the pattern of connections in the visual cortex."
>
>Some researchers foresee the day that blind people will see again
>following the implantation of a vision computer chip in the brain. "We're a
>long way from that," Cowan said. "So far we've only described the
>interactions between edge detectors in the visual brain, but there are all
>kinds of things going on in the visual cortex. There's detection of color
>and movement and depth and texture and surfaces. The circuitry involved
>in all of that is complicated and needs to be worked out."
>
>Cowan, Bressloff and their colleagues are ready to continue the
>work. Bressloff said, "It's just the beginning of a long program of
>studying more and more complex hallucination patterns, trying to see how
>far we can go with deducing the intrinsic circuitry of the cortex."
>
>As for the origins of art, last June Cowan participated in a
>conference on the topic in Montana. Geometric designs are a common
>design element in cave paintings and prehistoric rock art the world
>over. Some experts trace the prehistoric origins of art to
>hallucinogenic experiences.
>
>"A lot of the imagery is clearly related to what people report seeing
>when they take hallucinogens," Cowan said.
>
>NOTE TO EDITORS: The u in Kluver takes an umlaut. The diacritical mark
>cannot be transmitted.
>
>-30-
>
>January 09, 2002 -- UNIVERSITY OF UTAH MEDIA ADVISORY
>The news release below was issued recently by the University of Chicago
>and features work done in colloboration with University of Utah
>mathematics professor Paul Bressloff. We are relaying it to Utah news
>media with the permission of the University of Chicago. Below the news
>release is a copy of a Chicago Tribune story on the research.
>
>HALLUCINATIONS PLUS MATHEMATICS PLUS ANATOMY
>EQUALS INSIGHT INTO BRAIN ARCHITECTURE
>
>CHICAGO, Jan. 3 -- Scientists are deducing the internal circuitry of the
>visual brain by mathematically reproducing the geometric hallucinations
>people see when they ingest mind-altering drugs, view bright, flickering
>lights or encounter near-death experiences.
>
>The findings by the University of Chicago's Jack Cowan, the
>University of Utah's Paul Bressloff and three of their colleagues provide
>new insights into the complexities of vision, the workings of the brain and
>even the origins of art.
>
>"We take it for granted, but seeing is an amazing process," said
>Cowan, a professor in mathematics and neurology. "In something less than
>a second, we can see objects and classify them under all kinds of
>differing illumination from very dim to very bright. We're just
>scratching the surface of what's going on."
>
>The mathematical study of vision and the brain has been accepted for
>publication in the journal Neural Computation. Co-authoring the study
>were Martin Golubitsky, University of Houston; and two of Cowan's former
>graduate students, Peter Thomas, Salk Institute for Biological Studies; and
>Matthew Wiener, National Institutes of Health.
>
>"We're trying to understand how the intrinsic circuitry of the
>visual cortex of the brain can generate patterns of activity that underlie
>hallucinations," Bressloff said. These geometric hallucinations take the
>form of checkerboards, honeycombs, tunnels, spirals and cobwebs, a
>phenomenon originally studied as early as the 1920s and 1930s by the
>late Heinrich Kluver, a pioneering University of Chicago neurologist.
>
>"Because we know how the eyes are wired to the visual cortex, we can
>calculate what the patterns actually look like there," said Cowan. "They
>correspond very closely to the patterns that people report seeing."
>
>A technique called "perturbation theory" proved crucial to
>reproducing the geometric patterns, Bressloff said. Also crucial was an
>understanding, based on recent advances in brain anatomy and physiology,
>of the strong short-range connections and weaker long-range connections
>between neurons in the visual cortex.
>
>"It is a situation where you have something strong and something
>else that's weak, so it perturbs the system," Bressloff said.
>
>The mathematics that models the perturbation is, coincidentally,
>similar to that used in calculating the Zeeman Effect in quantum
>mechanics, which describes the physics of the subatomic world. "If you
>take hydrogen atoms and you put them in a weak magnetic field, their
>spectrum changes in ways that can be calculated," Cowan explained. "It's
>called the Zeeman effect." Bressloff noted, however, that "there's no
>quantum mechanics involved in the actual working of the brain."
>
>Academically trained in physics and electrical engineering, Cowan
>may be the world's only university faculty member who holds dual
>appointments in mathematics and neurology. In 1986, he organized one of
>the founding workshops of the Santa Fe Institute, a private, non-profit
>research and education center devoted to the study of complexity and
>complex adaptive systems. He became interested in geometric
>hallucinations in the late 1970s, when he realized that they may provide
>clues regarding the brain's circuitry.
>
>"Producing hallucinatory images in the brain could be understood in
>terms of spontaneous pattern formation in the brain," Cowan said. "The
>brain makes patterns of activity when it goes unstable." Such instabilities
>follow the ingestion of substances such as LSD, psilocybin and cannabis,
>which act on control networks in the brainstem that secrete noradrenalin,
>seratonin and dopamine, which in turn control brain states.
>
>"If there's any noise-random fluctuations of brain activity-in the
>brain, it is amplified into a pattern that reflects the architecture of the
>brain. The brain just takes the noise and shapes it into a pattern," Cowan
>said. "In the case of geometric visual hallucinations this is a direct
>consequence of the pattern of connections in the visual cortex."
>
>Some researchers foresee the day that blind people will see again
>following the implantation of a vision computer chip in the brain. "We're a
>long way from that," Cowan said. "So far we've only described the
>interactions between edge detectors in the visual brain, but there are all
>kinds of things going on in the visual cortex. There's detection of color
>and movement and depth and texture and surfaces. The circuitry involved
>in all of that is complicated and needs to be worked out."
>
>Cowan, Bressloff and their colleagues are ready to continue the
>work. Bressloff said, "It's just the beginning of a long program of
>studying more and more complex hallucination patterns, trying to see how
>far we can go with deducing the intrinsic circuitry of the cortex."
>
>As for the origins of art, last June Cowan participated in a
>conference on the topic in Montana. Geometric designs are a common
>design element in cave paintings and prehistoric rock art the world
>over. Some experts trace the prehistoric origins of art to
>hallucinogenic experiences.
>
>"A lot of the imagery is clearly related to what people report seeing
>when they take hallucinogens," Cowan said.
>
>NOTE TO EDITORS: The u in Kluver takes an umlaut. The diacritical mark
>cannot be transmitted.
>
>-30-