>>13384808The visual area in the brain has several geometric and mathematical principles at the base of its organisation. Makes sense, the 3D world has certain geometric and mathematical properties to it and it makes sense that over the course of evolutionary history visual analysis systems develop/evolve that are continuously better at interpreting and processing that 3D world. But also, your own brain occupies the 3D world, so it also makes sense that computational systems evolve towards maximum efficiency: more processing power in the least amount of space, and this is achieved by "exploiting" the nature of 3D space and conforming to certain geometric properties.
So that is the "what" that you see.
LSD causes unconstrained firing of cells in various stages of visual processing. At the most basic level the information in from your retina that is analysed by the brain is just a collection of very simple shapes and geometries. The geometric layout of cells in early stages of visual processing is very much like how pixels work on a TV screen, but instead of pixels generating colours as variations of R/G/B combinations, retinal input is projected on a "map" of cells with different sensitivities to different orientations (look at the colour description at the top right of pic related). This causes selective firing of very simple orientation-attuned cells, which are pooled to more complex cells which are "composite" shapes, these pool together to even more complex represenations of shape combinations, and so on until actual object representations. So when LSD causes unrestrained firing in early stages of visual processing, cells that represent different basic geometric orientations and shapes start transmitting information in the absence of input.
