Friday, March 11, 2005

Three Origamis

Here are three stellated polyhedra I've folded. The left one is a small stellated dodecahedron made of isosceles triangle units, and to the right a small triambic icosahedron with Sonobe units. Each one is composed of 30 modules.

And here's a stellation of the octahedron with 12 Sonobe units:

Thursday, March 10, 2005

Psychoactive plants in Buenos Aires

The Buenos Aires city government did a census of the trees and plants in the city. The census found a few psychoactive plants that have a long history of shamanic use. (Gracias Ibarra!)

Datura arborea (Floripondio or Peruvian trumpets), rich in atropine and scopolamine (especially in the seeds), can be found at: Arquimedes 2258, Caracas 2458, Ferre 2610, Mendez de Andes 764, Mendez de Andes 771, Mom 2868, Puan 566, Quesada 2815, Dr. Nicolas Repetto 561, Tabare 1121, Felipe Vallese 1077, and Zamudio 3042. Regarding the use of these plants, it is worth reading Shulgin's word of caution.

There are also two trees of the Anadenanthera sp. identified as Curupay: Gavilan 4337, and Emilio Mitre 1326. I think this is the same as Cebil (Anadenanthera colubrina var. cebil), and in that case the seeds contain big amounts of 5-HO-DMT (bufotenine). Jonathan Ott has found over 3% bufotenine in Cebil seeds. Its shamanic use in America dates from over 3000 years ago. But bufotenine is not fun. In first place, it seems to be psychedelic only (if at all) at doses close to neurotoxic levels, and in second place the somatic effects are very unpleasant (nausea and suffocation). On the other hand, if it turned out to be Anadenanthera peregrina (Yopo or Cohoba), it should contain mainly 5-MeO-DMT and DMT, and that's a different story.

Other plants in the census that may be psychoactive are cestrum nocturnum (with scopolamine and atropine), and the acacias (some contain tryptamines). And, of course, the ipomoea violaceas growing on my balcony ;)

Wednesday, March 09, 2005

Ragas and Talas

Lately I've grown more interested in Indian music. I've been listening some records by Ravi Shankar, Zakir Hussain, Ustad Allah Rakha and Ustad Sabri Khan. I highly recommend them.

Indian classical music is mostly improvised on the basis of a raga and a tala. Ragas provide a set of rules to construct melodies, while talas define the rythmic patterns.

The sitar is a quite alien instrument to the Western ear. A distinctive feature of the sitar are the sympathetic strings; they are tuned according to each particular raga and resonate in sympathy with the main strings, adding harmonic overtones. Also, very expressive microtonal variations are achieved pulling or bending the strings.

Friday, March 04, 2005

Palais Idéal

Ferdinand Cheval was a French postman who in 1879 tripped on a stone, and the shape of the stone inspired him to build a castle. He spent the following 33 years building his vision with stones collected along the daily mail route. Locals regarded him as a village idiot. His work is the Palais idéal.

Simultaneously, the organic visons of the Catalan architect Gaudí were materializing in Barcelona. Gaudí spent the last years of his life obsessed with the greatest of his works, the still unfinished church La Sagrada Familia.

About a century before Le Palais Idéal and La Sagrada Familia, in the phantasmagoria of an opium-induced dream, Coleridge received a poem, the Kubla Khan, that relates the construction of a palace by mongol emperor Kublai Khan. He awoke and began transcribing it, but someone at the door interrupted him and most of the Kubla Khan was lost for ever. Twenty years later appeared the first Western version of an old Persian book that Coleridge couldn't possibly know, and it read: "To the East of Shangtu, Kublai Khan erected a palace, according to a plan he had seen in a dream and kept in his memory."

Today, a century after Cheval and Gaudi, two centuries after Coleridge, and seven centuries after Kublai Khan, visonary artist Alex Gray is building the Chapel of Sacred Mirrors.

Some links:
El sueño de Coleridge from Other Inquisitions (1952), Borges
Intuit: Center for Intuitive and Outsider Art
Raw Vision magazine (outsider art)
Collection de l'Art Brut
Le Palais Idéal du Facteur Cheval (requires Flash)
Palais Idéal photo gallery
Life and Works of Gaudí
Templo Expiatorio de la Sagrada Familia

Tuesday, March 01, 2005

Endogenous Video Feedback

Entoptic is a general term used to describe endogenous imagery, such as phosphenes or the closed eye visuals produced by many psychedelics. Entoptic images can be shaped as spirals, latices, cobwebs, tunnels, etc, as in the following illustration (from the classification of phosphenes by Max Knoll, 1965):


In the 70s, anthropologist Gerardo Reichel-Dolmatoff noticed entoptic patterns in the art of the Tukano (in Colombia). He extensively documented the images seen in the early stages of the yage (ayahuasca) experience.

In their 1988 article "The Signs of All Times" (Current Anthropology 29:201-245), Lewis-Williams and Dowson postulated entoptic phenomena (experienced by shamans in trance states, possibily induced by psychoactive agents) form the basis for images in Upper Paleolithic cave art.

I have talked about video feedback before (the feedback loop that happens when a video camera is pointed to the monitor). Now, compare entoptic patterns with images produced by video feedback. I think the similarity is remarkable. My idea is that a process equivalent to video feedback might take place in the visual cortex. A biological counterpart of an optoelectronic feedback loop. The image of the homunculus playing with a video camera comes to my mind ;) but what I'm actually suggesting is that perhaps we project back to the striate cortex what we're aware of. If such process occurs within the visual cortex, backprojections from higher cortical areas to V1 must be involved in the generation of entoptic imagery. Supporting this idea, there is evidence that the backprojection from V5 to the V1 is necessary for the perception of moving phosphenes (evoked by magnetic stimulation of V5).

Furthermore, Lewis-Williams and Dowson formulate seven principles of perception for entoptic images: Replication, Fragmentation/Integration, Superpositioning/Juxtapositioning, Reduplication, and Rotation. Those principles are the sort of image transformations that apply in each iteration of a video feedback loop.

Here are some links and references:
Form & Meaning in Altered States & Rock Art
Altered States: The Origin of Art in Entoptic Phenomena
Dr. Tom's Video Feedback Gallery
The Ultimate Video Feedback Page
Daniel A. Pollen, 'On the Neural Correlates of Visual Perception'
Silvanto et al, 'Striate cortex (V1) activity gates awareness of motion'
Juan, Walsh, 'Feedback to V1: a reverse hierarchy in vision'