The human brain is so cunningly designed that accidental damage or malfunctions in the neural network can generate large-scale effects that do not harm a person, but, on the contrary, deliver a lot of new sensations.
We are talking about hallucinations, influences on the sensory system, which stem from the inside of the brain itself. Modern technologies make it possible to purposefully launch such reactions without harm to humans.
The technique of guided hallucinations is based on the Ganzfeld effect, which states that when the brain receives a powerful stimulating signal in only one area, it automatically begins to “think out” signals in other areas.
For example, if you peer into the darkness and listen to white noise, the brain draws an imaginary picture, although the eyes do not receive a single photon of light. And if you run noise on the screen in absolute silence, the brain will complement them with sound hallucinations.
One interesting experiment with guided hallucinations was conducted by TV host and inventor Derek Müller, who locked himself in an anechoic and completely darkened chamber for 45 minutes to conduct a sensory deprivation experiment.
His brain, which at once lost 90% of the signals from the outside world, remained fully functional, and Derek did not go crazy. Moreover, in the absence of external stimuli, he began to feel the subtlest vibrations of his heart and the flow of blood through the veins.
It was not a hallucination, it was just that the brain switched to processing the signals that remained at its disposal, amplifying them and presenting them in the form of sensations understandable to the mind.