the Ganzfeld experiment

The Ganzfeld experiment tests for extrasensory perception (ESP) by placing a participant in a sensory-reduced environment—usually with halved ping-pong balls over their eyes and white noise or gentle sounds—reducing normal sensory input. Meanwhile, a "sender" tries to communicate a target image or scene to them mentally. The participant then describes any impressions they have. The goal is to see if responses are significantly better than chance, suggesting the possibility of perception beyond the usual senses. Critics argue that false positives and methodological issues challenge its validity, but it remains a well-known method in parapsychology research.