Truly Total Recall

In 1885 German philosopher Hermann Ebbinghaus showed that two thirds of what we learn vanishes from our brains within an hour. That disheartening "forgetting curve" is the reason we paper our computer screens with Post-it notes, mumble mental shopping lists like mantras and consult our PDAs at every opportunity. Sunil Vemuri, a graduate student at the Massachusetts Institute of Technology's Media Lab, is hoping to fill in the holes left by our sometimes fickle minds. How? "Our focus," he says, "is on audio recording everything in our lives."

Vemuri has spent much of the last year and a half strapped to a microphone and PDA, which picks up every word he utters to friends, colleagues and family and beams the information wirelessly to a server. Voice-recognition software converts the spoken word into text and delivers it to his laptop, where it is cataloged along with hourly weather reports, screen grabs, Internet news sites, his e-mail, every item on his daily calendar and--via a Global Positioning System chip in his PDA--his whereabouts in the lab building. Later, when Vemuri is trying to remember something, he finds the passage in any number of ways. He might do a keyword search or look up a particular date.

One of Vemuri's goals is figuring out how best to manage all that data. If you're trying to recall what your wife said in a conversation, are you more likely to remember that you talked while walking through Central Park, that it was 50 degrees and partly cloudy, or that you had stopped to buy coffee beforehand? (So far, weather is proving to be a less important factor than location and timing.)

He's also trying to assess the level of social acceptance for audio recording: are we ready to have people walking around taping every moment of their lives--and ours? We may soon be. As security cameras proliferate, people are growing accustomed to constant video surveillance. In the United States, police departments are already experimenting with neighborhoodwide sound pickups that can transmit audio back to headquarters, which could be useful, say, for pinpointing the location of gunfire.

Would constant audio surveillance be a good thing? Only for some. It could help nostalgia seekers relive their youth, says Vemuri. "My younger sister, who often asks me about our childhood, would have a blast with it. But I'm not convinced everybody would." The technology might also be useful at the office. "Some people work in environments where they're given a lot of information, a lot of to-do lists," he says. "But because of the hectic nature of their jobs, they have an inability to write down notes in a timely fashion. A memory prosthesis would allow them to record it and then, later on, have the ability to retrieve it."

Vemuri hopes his memory prosthesis will one day be a wristwatch-size device. But first, there are plenty of kinks to overcome: voice-recognition software now garbles about 90 percent of what he says, batteries last only two hours and memory chips hold only a fraction of the data he would like to eventually store on them. It will be 10 years, he figures, before technology catches up to his vision. Until then, enjoy the upside of your memory's fallibility: that "automatic erase" function for embarrassing moments.