Members of cave experiment team on the experience

Ever wonder what it would feel like to unplug from a hyperconnected world and hide away in a dark cave for 40 days?

Fifteen people in France did just that, emerging Saturday from a scientific experiment to say that time seemed to pass more slowly in their cavernous underground abode in southwestern France, where they were deprived of clocks and light.

With big smiles on their pale faces, the 15 left their voluntary isolation in the Lombrives cave to a round of applause and basked in the light while wearing special glasses to protect their eyes after so long in the dark.

"For once in our life it is as if we could press pause," said 33-year-old Marina Lançon, one of the seven female members in the experiment.

For 40 days and 40 nights, the group lived in and explored the cave as part of the Deep Time project.

There was no sunlight inside, the temperature was 10 degrees Celsius (50 F), and the relative humidity stood at 100%.

The cave dwellers had no contact with the outside world, no updates on the pandemic nor any communications with friends or family.

Scientists at the Human Adaption Institute leading the 1.2 million-euro $1.5 million) project say the experiment will help them better understand how people adapt to drastic changes in living conditions and environments.

As expected, those in the cave lost their sense of time, with most team members estimating they had spent from 23 to 30 days underground.

Johan Francois, 37, a math teacher and sailing instructor, ran 10-kilometre circles in the cave to stay fit.

He said he sometimes had "visceral urges" to leave.

In partnership with labs in France and Switzerland, scientists monitored the 15 members' sleep patterns, social interactions and behavioural reactions via sensors.

One sensor was a tiny thermometer inside a capsule that participants swallowed like a pill.

It measured body temperatures and transmitted data to a computer until it was expelled naturally.

The team members followed their biological clocks to know when to wake up, go to sleep and eat.

They counted their days not in hours but in sleep cycles.

On Friday, scientists monitoring the participants entered the cave to let the research subjects know they would be coming out soon.

"A bit of sadness to leave this world, where we lived in for so long," said Deep Time project director Christian Clot after emerging. "But also real pleasure to find blue skies, greenery and loved ones again."