In the film The Matrix, the hero Neo - as played by Keanu Reeves - could dodge bullets because time moved in slow motion for him. But is this phenomenon confined to the movies? Real-life accident victims often report time "slowing down".

Do they really experience life in slow motion? If so, could we find a way to harness this; a technique to help us think faster and, ultimately, to live longer?

These are questions that fascinate Dr David Eagleman, an assistant professor in the department of neuroscience at Baylor College of Medicine in Houston. In order to see if time could "stretch", he and his colleagues set up a hair-raising experiment involving Suspended Catch Air Device (SCAD) diving, a controlled free-fall system in which "divers" are dropped backwards off a 150-foot-high platform and land in a net. They are not attached to ropes, and reach 70 miles per hour during the three-second fall.

"It's the scariest thing I've ever done," says Eagleman. "But I knew it was perfectly safe, and I also knew it would be the perfect way to make people feel as though an event took much longer than it actually did.

"People commonly report that time seemed to move in slow motion during a car accident. But does that only seem to have happened in retrospect? The answer is critical for understanding how time is represented in the brain."

Eagleman's experiment consisted of two parts. First, he asked participants to estimate how long their own fall seemed to have lasted; then to use a stopwatch to measure someone else's fall. As expected, they remembered their own falls as having taken much longer than those of their compatriots: 36% longer on average.

But was this a slow-motion experience or a trick of the memory? To find out, Eagleman tested whether the terrified fallers could actually see more events happening. He developed a device called a "perceptual chronometer" that was strapped to the volunteers' wrists. Numbers flickered on its screen, and scientists adjusted the speed at which they flickered until it was too fast for them to see. They hypothesised that, if time perception really slowed, the flickering numbers would appear slowly enough for the divers to read while in free-fall. But they found that, while the subjects were able to read numbers presented at normal speeds during the free-fall, they could not read them at faster-than-normal speeds.

"People are not like Neo in The Matrix, dodging bullets in slow-mo," says Eagleman, whose study was published yesterday in the Public Library of Science journal PLoS One. "The paradox is that it seemed to participants as though their fall took a long time. The answer to this is that time estimation and memory are intertwined: the volunteers merely thought the fall took a longer time in retrospect."

During a frightening event, a brain area called the amygdala becomes more active, seemingly laying down a secondary set of memories that go along with those normally taken care of by other parts of the brain. "In this way, frightening events are associated with richer and denser memories," explains Eagleman. "The more memory you have of an event, the longer you believe it took."

This is all related to the well-known phenomenon of time seeming to speed up as we grow older. "When you're a child, you lay down rich memories for all your experiences. When you're older, you've seen it all before and lay down fewer memories," says Eagleman. "Therefore, when a child looks back at the end of a summer, it seems to have lasted forever; adults think it zoomed by."

Yet it doesn't have to be like that, says Steve Taylor, author of a recent book called Making Time. He says we can all extend our lives by "slowing down" time. Clock time might be about minutes and hours, but real time is down to how we experience it - which varies depending on what we're doing.

Just as a lonely rail passenger can experience a longer journey than a couple chatting next to him, so a person who dies at 40 can live a longer life than one who dies at 70. "I don't think it's a delusion," Taylor says. "Time isn't something real or something absolute. It's something created by our minds."

The trick, he says, is to keep seeking novelty; to shun routine and remember to live life in the present. "If you can control time, it is no longer the enemy."