HIS is Charles Lax's brain on speed.

Mr. Lax, a 44-year-old venture capitalist, is sitting in a conference for telecommunications executives at a hotel near Los Angeles, but he is not all here. Out of one ear, he listens to a live presentation about cable television technology; simultaneously, he surfs the Net on a laptop with a wireless connection, while occasionally checking his mobile device — part phone, part pager and part Internet gadget — for e-mail.

Mr. Lax flew from Boston and paid $2,000 to attend the conference, called Vortex. But he cannot unwire himself long enough to give the presenters his complete focus. If he did, he would face a fate worse than lack of productivity: he would become bored.

"It's hard to concentrate on one thing," he said, adding: "I think I have a condition."

The ubiquity of technology in the lives of executives, other businesspeople and consumers has created a subculture of the Always On — and a brewing tension between productivity and freneticism. For all the efficiency gains that it seemingly provides, the constant stream of data can interrupt not just dinner and family time, but also meetings and creative time, and it can prove very tough to turn off.

Some people who are persistently wired say it is not uncommon for them to be sitting in a meeting and using a hand-held device to exchange instant messages surreptitiously — with someone in the same meeting. Others may be sitting at a desk and engaging in conversation on two phones, one at each ear. At social events, or in the grandstand at their children's soccer games, they read news feeds on mobile devices instead of chatting with actual human beings.

These speed demons say they will fall behind if they disconnect, but they also acknowledge feeling something much more powerful: they are compulsively drawn to the constant stimulation provided by incoming data. Call it O.C.D. — online compulsive disorder.

"It's magnetic," said Edward M. Hallowell, a psychiatry instructor at Harvard. "It's like a tar baby: the more you touch it, the more you have to."

Dr. Hallowell and John Ratey, an associate professor at Harvard and a psychiatrist with an expertise in attention deficit disorder, are among a growing number of physicians and sociologists who are assessing how technology affects attention span, creativity and focus. Though many people regard multitasking as a social annoyance, these two and others are asking whether it is counterproductive, and even addicting.

The pair have their own term for this condition: pseudo-attention deficit disorder. Its sufferers do not have actual A.D.D., but, influenced by technology and the pace of modern life, have developed shorter attention spans. They become frustrated with long-term projects, thrive on the stress of constant fixes of information, and physically crave the bursts of stimulation from checking e-mail or voice mail or answering the phone.

"It's like a dopamine squirt to be connected," said Dr. Ratey, who compares the sensations created by constantly being wired to those of narcotics — a hit of pleasure, stimulation and escape. "It takes the same pathway as our drugs of abuse and pleasure."

"It's an addiction," he said, adding that some people cannot deal with down time or quiet moments. "Without it, we are in withdrawal."

ACCORDING to research compiled by David E. Meyer, a psychology professor at the University of Michigan, multitaskers actually hinder their productivity by trying to accomplish two things at once. Mr. Meyer has found that people who switch back and forth between two tasks, like exchanging e-mail and writing a report, may spend 50 percent more time on those tasks than if they work on them separately, completing one before starting the other.

As a result, Mr. Meyer said, businesspeople who multitask "are making themselves worse businesspeople."

He says little research has been done into why some people are compulsively drawn to multitasking. But he theorizes that the allure has several layers. Multitasking offers a guise of productivity, a "macho" show of accomplishment, and similarities to a quick amphetamine rush.

"It's related to what happens to skydivers or jet pilots," he said. "They put themselves in situations where, if they don't perform at peak efficiency, they'll crash and burn. In the aftermath there is a rush of chemicals."

Patrick P. Gelsinger, the chief technology officer at Intel, says it is clear that the overall time spent in front of screens — whether desktop computers or hand-held devices — is rising. "Time spent watching television is down," he said. "But over all you see a discretionary increase in the amount of time people are connected to technology."

The presence of such devices, as well as their power, will only grow. Networks that provide wireless Internet access are in their early stages. Intel has put the full force of its science and marketing effort behind wireless devices and the superfast miniature microprocessors that power them.

Intel portrays computers as pushing productivity, and Mr. Gelsinger scoffs at the idea that digital devices have a compulsive or physically addictive draw. "We don't make drugs," he said. "We make technology building blocks that move the world forward in all ways."

But he concedes that there can be a point at which the constant accessibility of information is hard to escape.

In one meeting at Intel, Mr. Gelsinger said he found himself sending an instant message to his boss across the room — a potential distraction, though he argued that by doing so, he did not have to engage in "disruptive whispering." At other times, Mr. Gelsinger has had to remind himself not to use e-mail on his laptop during a meeting because it can send the message that he is not paying full attention.

SOMETIMES, discipline must be imposed from the outside. At a recent technology conference organized by The Wall Street Journal and attended by industry heavyweights like Bill Gates of Microsoft, Steve Jobs of Apple Computer and Stephen M. Case of AOL Time Warner, people were discouraged from using their wireless Internet access during presentations.

Bucking the recent tradition at trade shows and technology conferences, the organizers decided not to provide wireless Internet access inside the conference.

"We wanted people to absorb what the speakers were saying," said Walt Mossberg, a technology columnist at The Journal.

"We decided that if you have Wi-Fi, it would be destructive," he added. "If you have the Internet, it will win out. People imagine they can multitask, but sometimes people overestimate the extent to which they can do it."

If multitasking creates a problem for people, the cause is not the gadget makers themselves, said Jeff Hallock, the senior director for consumer products at Sprint PCS, the mobile telephone carrier. The company has been selling the manna of multitasking: phones that can also take digital pictures, send e-mail and instant messages and download music. But Mr. Hallock says those functions help people stay organized, not make them frenetic.

"We're enhancing people's lives so they can have more control of the flurry of activity that's seemingly coming in," he said.

"You don't have to check your voice mail," he added. "We're giving you the chance to do so."

The notion that using all these devices creates a harmful addiction is absurd to Bruce P. Mehlman, assistant commerce secretary for technology policy and a former executive at Cisco Systems. Mr. Mehlman said the presence of many gadgets in people's lives created not a cacophony, but harmony and balance.

Mobile phones, wireless Internet devices and laptops have liberated executives, he said, allowing them to leave the office and to spend more time at home. The users of these technologies are constantly wired, he said, but to a very positive goal.

"Ten years ago, you had to be in the office 12 hours," said Mr. Mehlman, who said he now spent 10 hours a day at work, giving him more time with his wife and three children, while also making use of his wireless-enabled laptop, BlackBerry and mobile phone.

"I get to help my kids get dressed, feed them breakfast, give them a bath and read them stories at night," he said. He can also have Lego air fights — a game in which he and his 5-year-old son have imaginary dogfights with Lego airplanes.

Both love the game, and it has an added benefit for Dad: he can play with one hand while using the other to talk on the phone or check e-mail. The multitasking maneuver occasionally requires a trick: although Mr. Mehlman usually lets his son win the Lego air battles, he sometimes allows himself to win, which forces his son to spend a few minutes putting his plane back together.

"While he rebuilds his plane, I check my e-mail on the BlackBerry," Mr. Mehlman explained.

Mr. Lax, too, cannot pass up the chance to use every bit of technology that comes his way. A graduate of Boston University who lives outside Boston, he is managing general partner at GrandBanks Capital, a venture investment firm. He serves on the boards of three companies, working to turn them into successful ventures. "I build companies one customer at a time," he said, adding that his investments are up against other well-financed competitors. "It's a race against time."

Mr. Lax uses technology to keep up. He is, by his own admission, "Always On."

On his office desk is a land-line telephone, a mobile phone, a laptop computer connected to several printers, and a television, often tuned to CNN or CNBC. At his side is the aptly named Sidekick, a mobile device that serves as camera, calendar, address book, instant-messaging gadget and fallback phone. It can browse the Internet and receive e-mail. He has been known to pick it up whenever it chirps at him — and he acknowledges having used it to check e-mail while in the men's restroom.

There is no down time in the car, either. "I talk on the phone, but I have a headset," Mr. Lax said. Does he do anything else, like using his Sidekick to read e-mail? "I won't be quoted as saying what else I do because it could get me arrested," he said, laughing.

Mr. Lax said he loved the constant stimulation. "It's instant gratification," he said, and it staves off boredom. "I use it when I'm in a waiting situation — if I'm standing in line, waiting to be served for lunch, or getting takeout coffee at Starbucks. And, my God, at the airport it's disastrous to have to wait there.

"Being able to send an e-mail in real time is just — " Mr. Lax paused. "Can you hold for a second? My other line is ringing."

When he returned, he said he shared this way of working with many venture capitalists. "We all suffer a kind of A.D.D," he said. "It's a bit of a joke, but it's true. We are easily bored. We have lots of things going on at the same time."

The technology gives him a way to direct his excess energy. "It is a kind of Ritalin," he said, referring to the drug commonly taken by people with attention deficit disorder.

BUT he said technology dependence could have its down side. "I'm in meetings all the time with people who are focused on what they're doing on their computers, not on the presentation," he said.

During the Vortex telecommunications conference, held in May in Dana Point, Calif., he and dozens of others were using wireless Internet access. He said that he was paying attention to the speaker, using his Internet connection to look up information about the cable industry.

"I was supporting the effort of the speaker by figuring the elements he was talking about," Mr. Lax said. He paused. "I was also doing e-mail so I guess I wasn't giving 100 percent," he added. "I was 40 percent supporting the effort, and 60 percent doing other things."

Indeed, he said, the technology can be a bit distracting. "But it's not a problem," he said. "Being able to process lots of data allows me to be more efficient and productive."

"It allows me to accelerate success."