MONTREAL -- Spending more time indoors has been a harsh reality of the COVID-19 pandemic, but one Montrealer took the lockdown to another level.

Marina Lancon spent 40 days in the Lombrives cave in Ariege, France with no sunlight, WiFi, or even a sense of time.

"I’m not a scientist, I’m an adventure guide. So, for me, getting to know and study how we react in extreme environments is really interesting," she told CTV News Tuesday via videoconference from France.

Lancon was among 15 others who participated in the Human Adaptation Institute's "Deep Time" research project to study the effects on humans in extreme environments without the ability to measure time.

-- Watch the full interview above with CTV Montreal anchor Maya Johnson.