Spatial-frequency/Colour synaesthesia
Hello. A slightly odd question, this, perhaps, and I'm not sure if this is the right place to put it...
Has anyone experienced spatial frequency / colour synaesthesia? I hadn't, until recently.
My father, a maths teacher, had given me some posters. Most of them were educational maths posters, but one was a work of art, by Robert Dixon, called 'Wolf Net'. It is entirely black and white, and consists of a tiling of outline hexagons and triangles, but in a space that constricts towards two points in the picture, such that the shapes get smaller, and the lines composing them thinner, as they approach the two centres.
When uninfluenced by any psychoactives other than caffeine and nicotine, it appears to me (and the other five people I have asked) black and white, as it is. However, when affected by cannabis, the picture becomes coloured, in a specific way: as the shapes get smaller (increasing spatial frequency: more stuff going on in any given unit of retinal space) the colours of the lines shift from violet (at low spatial frequency, on the outside) to red (at high spatial frequency, towards the centres), via intervening green and yellow.
This effect, noticeable under cannabis, was markedly stronger under a combination of 2C-B and MDMA (forgive the confound). It appears in the absence of any other notable visual effects on any other object (that I've come across yet). It has replicated in two others that I have asked (without giving them any indication of how it appeared to me), one of them on cannabis, 2C-B and MDMA, and the other on ethanol, 2C-B, and MDMA.
That this effect occurs in a number of people (albeit that 3 is a small sample: to find a shared perceptual experience, identical to such a degree, among three people, is quite suggestive), and appears to be brought out by diverse drugs, leads me to wonder whether some inherent property of typical human visual processing is being amplified. It also makes me wonder what cannabis and either 2C-B or MDMA have in common, in terms of the receptor activity they produce, that they should both produce this striking perceptual illusion.
Also, it may not be spatial frequency that is the key: it's possible that other factors are confounded with it in the picture. I hope to manipulate various parameters to test what factors are crucial to the effect.
If anyone has experienced a similarly consistent (across occasions and people) visual effect of colour evoked by changes in geometric structure (or some other such low-level visual property), or has any ideas about what if anything this might say about human visual processing, or how it relates to what is known about the activity of the drugs that appear to produce the effect, I'd be most grateful and delighted to read what they have to say about it.
