A professor spent 5 days alone in complete darkness, then started seeing her dead grandmother sitting in the cave with her

Dr Kiana Aran spent five days isolated in a dark cave in Poland to test how sensory deprivation impacts the human mind and body. This experiment, which took place in November 2024, resulted in the bioengineering professor experiencing vivid hallucinations, including seeing her deceased grandmother sitting with her.

As reported by LADbible, Dr Aran, who serves as a professor at the University of California, initially entered the cave to find a way to quiet her racing thoughts. As someone constantly juggling academic responsibilities, she found that her brain never seemed to switch off. 

She noted, “As a faculty, my mind has been always racing. I have tried yoga, meditation to just calm my brain down, because I’m constantly thinking of, ‘Okay, what’s next, what’s next, what’s next.’ I cannot sit still, and sometimes it gets too much.”

There was no light or entertainment available

The setup for the experiment was stark. While she had access to a bed, a shower, and a bathroom, there was absolutely no light or entertainment available. Researchers tracked her body with sensors, and her only connection to the outside world was food delivered once a day at unpredictable times. This lack of a schedule made it impossible for her to track whether it was day or night.

By the second day, the reality of the isolation set in, and she found the experience incredibly difficult. She described the ordeal as “a torture, sort of” and admitted she was desperate to leave early. She recalled the struggle by saying, “How am I going to stay another three days here? Because I was doing nothing.”

The psychological and physical toll manifested in some bizarre ways. Dr Aran reported seeing her mother, cousin, and grandmother, who had passed away years prior, sitting together and watching an iPad. She found it impossible to distinguish between a dream and a hallucination. 

Beyond these visions, she reportedly began to perceive outlines of objects despite the total darkness surrounding her. Her senses also shifted, with her food tasting much more intense. Testing later confirmed that her saliva actually contained increased levels of taste receptors. Researchers monitoring the experiment also discovered significant changes in her internal body clock, her gut microbiome, and her immune response. 

Despite the intensity of the experience, Dr Aran walked away with a profound shift in her perspective. She reported feeling much more patient, grateful, and compassionate toward her surroundings. She still carries those feelings with her and noted, “I appreciate everything I have right now all around me.”

Writing about the experience in Nature, she described the moment she finally returned to the world. She explained, “When I finally emerged from the cave on the fifth day, I embraced those waiting anxiously for me; the colleagues, the friends, the ones who had made this opportunity possible. In that moment, wanting to feel everything at once, I ran to the frozen lake nearby and dove in. The icy water bit into my skin, but after five days of darkness, it was the most vivid reminder that I was alive.”