Psychedelic-information-theory-Shamanism-in-the-age-of-Reason

at the cortical columns that control optic muscles, generating a chainreaction in neural transduction felt as a muscle twitch or throb.Increasing or decreasing optic pressure naturally produces phosphenes;periodically interrupting the eye’s finely timed saccades with a muscletwitch may have a similar effect. In his experiments with phosphenes inthe mid 1800s, Johannes Purkinje applied an aqueous extract ofbelladonna (scopolamine, atropine) directly to his eye to producephosphenes. Because the effect was localized, Purkinje proposed thatphosphenes may be related to cycloplegia, or partial paralysis of the eyemuscles. 20 Given these reports, it is reasonable to assume that anyinterruption of fine visual motor control, interruption of optic signaltransduction, or change in optic pressure will necessarily producephosphenes.Entopic vs. Eidetic HallucinationGeometric hallucinations, or phosphenes, are considered to beentopic, meaning they are a product of excitation and destabilization inspatial coupling between neural assemblies in the retina and visualcortex, and produce complex patterns similar to fractal recursion.Entopic hallucinations can be contrasted with eidetic hallucinations,which are more fully formed images that appear from visual memory orimagination. Psychedelic eidetic hallucinations are generally moreexplicitly personal than the abstract geometric forms associated withflicker phosphenes. Over the course of a psychedelic sessionhallucinations will start with flicker phosphenes and then increase incomplexity from entopic to eidetic content, often containing a seamlessmixture of the two. It can be assumed that eidetic hallucinations onlybegin once serotonergic modulation of the forebrain has beensufficiently interrupted to allow cholinergic modulation of mid-brainvizualization. 11 The transition from entopic to eidetic hallucination isalso associated with a transition from the high frequency beta orgamma state to a lower frequency alpha or theta state.Meditation and autohypnotic exercises are targeted to producestates of hypnagogia associated with theta waves and entopichallucination. Drugs which naturally drive theta waves in the brain are