15 French Volunteers End Their 40-Day Isolation Study

The entrance to the Lombrives Cave: the widest cave by volume in Europe. (Wikimedia Commons)

Volunteers ages 27 to 50 emerged from the Lombrives Cave in southwestern France led by their leader, French-Swiss explorer Christian Clot, after they finished participating in the 40-day isolation study on April 24. They wore special sunglasses to protect their eyes from the natural sunlight but were otherwise healthy.

The 15 members who participated in the scientific experiment, part of the 1.2 million to 1.5 million euro “Deep Time” project, spent their days isolated in their own spots within the cavernous region at temperatures of 12 degrees Celsius and humidity of 95 percent without any sunlight or electronics. Unable to connect with the outside world, scientists left the subjects to rely on their very own biological clocks to understand and determine the beginning and end of each day.

The Human Adaptation Institute hosted the project with the goal of measuring how humans change to drastic changes in their living conditions. Volunteers had to generate their own electricity via a pedal bike and had to draw water from a well 45 meters below the earth. One volunteer, Johan François, a 37-year-old math teacher and sailing instructor, remarked that he ran 10-kilometer circles around his space in order to stay fit, confessing that he occasionally had “visceral urges” to leave the cave.

Marina Lançon, one of the seven female members, stated she felt “no rush to do anything” while spending her time in the cave. She admitted that she will wait a few more days until opening back up her smartphone in order to avoid any whiplash.

Labs in France and Switzerland monitored the volunteers’ sleeping patterns, social interactions, and behavior reactions via sensors that volunteers swallowed like a pill. Scientists entered each participant’s cave on April 23 in order to inform them of the study’s upcoming end. Most of the volunteers misjudged the number of days that they had spent in the cave, underestimating the time, thinking they had 7 to 10 more days to go.

Once their time came to a close, two-thirds of the participants expressed their desire to stay in the cave for a few days longer in order to finish group activities and projects. However, they all left with pale, smiling faces, greeted by a round of applause.