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

Figure 21. Acetylcholine (ACh) modulates the medial-temporal lobe duringmemory storage, recall, and dreaming. Eidetic imagery in hallucination isassociated with high ACh modulation.The Hippocampus, ACh, Memory, and DreamingThe processes of dreaming, memory storage, and memory recall aremanaged by the hippocampus. 5 The hippocampus receives perceptualinformation from the frontal cortex but is also wired tightly into theemotional limbic system and medial temporal lobe; which is why strongmemories always have an emotional component. 6 Since thehippocampus is central in the formation, consolidation, andreconsolidation of all salient memory, we can also assume it is thesource of salient eidetic hallucination. The hippocampus is most activewhile awake and while dreaming. The process of moving from wakingto sleeping is associated with a move from high beta or alpha activitydown to slower theta and delta ranges. Deep sleep is associated withslow delta waves and low energy activation, while REM sleep anddreaming begin to produce beta activity and energy profiles similar tothose seen in waking activity. 7Nocturnal dream activity is a process of memory consolidation. 8 Indeep sleep and REM the stress chemical cortisol decreasescommunication between the hippocampus and neocortex, 9 and theprocess of REM and dreaming is stimulated by acetylcholine. 10Acetylcholine (ACh) is the primary messenger of the brain’s cholinergicsystem, essential to hippocampal modulation of memory compressionand recall (Fig. 21). Sleep-onset, sleeping, and dreaming are associatedwith an increase in ACh modulation of the brainstem and medialtemporal lobe; this occurs along with a proportional decrease inserotonin, norepinephrine, and aminergic activity in the pre-frontalcortex (PFC). The interplay between these two systems acts like a tidebetween waking and sleeping worlds. Drugs which increase aminergic