One thing I've noticed in the past few years is that because of chemicals in our atmosphere, EL Frequencies, other causes or a combination thereof, we have had changes in the seratonin levels of many people. Other physical conditions that are more prevalent nowadays is known to be caused by a lack of another chemical in the brain. Well, there has been some speculation that because of various factors, there has been an increase in the hallucinogen DMT within the brain, and this increase has been causing hallucinations of experiences with alien beings; DMT is made naturally in the brain. Following is an excerpt from Chapter 30 of the book "Hunt for the Skinwalker" by Colm Kelleher, Ph.D., and George Knapp[brackets mine]:
Psychiatrist Rick Strassman has done experiments with DMT and monitored its effects on humans. In one of the few scientific studies of its kind, Strassman studied the effects of injecting DMT into sixty volunteers at the University of New Mexico between 1990 and 1995. Strassman was startled to discover that a large number of his subjects experienced meetings with "alien bengs" and nonhuman intelligences following injections of DMT. The details of these meetings were remarkable consistent among the subjects, though none of these experimental volunteers were allowed to compare notes prior to being interviewed.
To Strassman, the almost identical "hallucinations" experienced by different subjects in their encounters with the "aliens" seem to imply that the subjects experienced some kind of objective reality as a result of the DMT injections. He hypothesized that perhaps DMT was able to open a perceptual doorway into other "dimensions" where the human mind could meet and communicate with the denizens of these realities. In strassman's words. He stated "I suggest DMT alters the receiving qualities of the brain, an employ a television analogy. Personal healing occurs by an enhancement of 'contrast and focus'; invisible worlds and entity contact takes place by changing reception of 'channels' to include dark matter and parallel universes."
Strassman speculates that perhaps, under certain circumstances, in certain states, the human brain might increase its levels of endogenous DMT and so make it easier for the "alien abduction" experience to take place. Or could an external agency manipulate the DMT levels in the human brain in order to make journeys to other worlds possible, or alternatively, such that the denizens of other worlds could cross over into ours?[as I mentioned above(in some cases)] Shamans, who apparently have the ability to cross over into other worlds at will, also report having DMT-like experiences.
No. Close encounters occur when people meet extra terrestrial visitors. There are many testimonies relating to this from across the world over the last 70 years in particular. DYOR.