Too far, according to an organization of psychologists.

Unlike the players in MTV's reality soap, the five men and four women participating in the program Big Brother will have no contact at all with the outside world for up to three months. And the house they're cooped up in together isn't exactly a swanky London flat.

The long, low, custom-built structure, in a remote part of suburban Almere, looks more like a research facility than a house. Cameras and microphones in every room record the residents' every move as a staff of 110 watches from behind two-way mirrors. Selected moments are broadcast on TV six nights a week. Four webcams are live 24 hours a day.

Producers have done their part to make sure the show will feature plenty of drama. How long each participant will live here depends on when he or she is voted out. Every couple of weeks, each group member has to nominate two others for ouster. Then viewers vote on who to kick out.

Whoever's left standing on 31 December will win US$125,000. But what will be the psychic price for giving one's life briefly to the service of television?

The Dutch Institute of Psychologists for one, was worried enough to issue a press release announcing that the experiment could be dangerous to the participants, who range in age from 20 to 44.

In spite of modern-day fears of surveillance, the cameras aren't what worries the psychologists most.

Wiring a domestic space for TV is just a symptom of the current tendency to make the private public, said psychologist Eric Haas, one of the authors of the statement.

"It has to do with the informalization of public life," Haas said. "People have few problems revealing who they are and their psychological makeup in front of others."

That's not the dangerous part, he said: "That's the reality that we're living in, and we have to cope with it."

The Big Brother participants will get used to the cameras, Haas said, but not to the bizarre social situation: no outside reference points, no reality check, and an authoritative voice issuing occasional directives from an intercom.

Executive producer Paul Rômer says the Big Brother voice -- that of a production staffer -- is used sparingly. It summons people to brief daily chats with the show's editors in a special room. And it instructs them to do other tasks, like carrying out a group project such as inflating and releasing 200 helium balloons with notes attached.

"People are losing the perspective of reality already," Haas said. "The group is the reality, and people are very obedient to Big Brother."

He cited the famous Milgram experiment of the 1960s, in which subjects delivered what they thought were severe electric shocks to strangers when told to by an authority figure.

The press release warned that people participating in Big Brother could "become alienated from themselves and become mentally ill."

Haas likened their isolation to being in a cult. "They're away from their families, with no telephone, no TV, no radio," he said. "They're separated from real life. That makes the perspective of reality very blurred."

Things in the Big Brother house do get solipsistic, with the group often discussing itself. One week into the show, viewers learned that one man was uneasy about another's bisexuality, then saw a woman wiping away tears as she asked others to stop talking about her behind her back.

It's not exactly your typical arid Northern European documentary program.

But it hasn't all been traumatic, if you can believe Martin, the first man voted out. Fresh from a mere week in the Big Brother house, Martin said in an hour-long special broadcast Thursday that he would go back there if he could.

The tensest moments of the announcement ceremony, broadcast live earlier that evening, were replayed, and played up. Cameras lingered on people nervously twisting shirttails and playing with jewelry. In taped statements, two residents said they'd nominated Martin for seeming uncreative and for having little to offer the group.

But Martin's housemates sent him off with hugs, tears, and fervid cheering.

After the bad news came, one woman consoled him: "It's just television. Don't let it make you crazy."

Just in case, psychologists remain on standby, ready to intervene in the experiment "if the tension gets too high and it's too heavy for them," said producer Rômer. "It's in my interest that they stay in the house and don't walk away. So I want them to be happy."