Maurizio Montalbini

The Italian sociologist Maurizio Montalbini, who died of a heart attack on 19 September in a mountain hamlet near the central Italian town of Macerata at the age of 56, spent months dwelling in caves to study how the mind and body cope with complete isolation.

Montalbini had spent a total of two years and eight months underground since he started his experiments in the 1980s. In 1987 he claimed his first world record after spending 210 days alone in a cave in the Apennine mountains. A year later he led an international team of 14 spelunkers, including three women, to take the world group record with an underground stay of 48 days.

During his endurance experiments Montalbini subsisted mostly on a high-calorie diet of powdered foods and pills similar to those used by astronauts on space flights. Scientists outside monitored him through instruments.

Montalbini's experiments, done in collaboration with Nasa and universities around the world, yielded insights into the effects of isolation including weight loss, changes in time perception and in sleep and menstrual cycles.

For the sociologist, who worked with drug addicts before turning to spelunking, the experiments were also a personal challenge of willpower and endurance.

"One cannot fight solitude, one must make a friend of it," he said after his 1987 exploit. "I succeeded in doing this. I carried everything inside me for seven months – affections, convictions, ideals."

Montalbini broke his solo cave-sitting record in 1993 by living for a year and a day in an underground base built to study the reactions of individuals and crews on simulated space missions. In his last experiment, in 2006 and 2007, Montalbini spent 235 days in a base built in the Apennine Grotta Fredda ["Cold Cave"].