When television was in its infancy in the 1950s, most parents warned their children, at least occasionally, "Don't sit so close ... you'll get radiation." Other than worrying that Junior would glow from cozying up to the console, few people back then believed the television could be harmful. On the contrary, it was a novel and entertaining invention that brought families together for a few hours a week of laughter and suspense.

Times have changed. Tuning in for a few hours a week has increased to a few hours a day for the majority of Americans and their children. The single set that was proudly and prominently displayed in the living room typically has multiplied into two or more sets per household. Television has acquired derogatory nicknames such as "boob tube" and "idiot box." And debate over the effect on viewers of its violent, sexually suggestive and lowest-denominator programming echoes from the halls of Congress to scientific laboratories that investigate the problem.

But while TV's programming fuels the most heated of criticism, some social scientists, educators and parents believe that the medium -- not the content -- is the worst of television's messages. Increasingly they advocate unplugging the messenger.

"The fact is that television is the main experience the majority of families are involved in together," says Marie Winn, a control-TV activist and author of Unplugging the Plug-In Drug (Penguin, $7.95), the sequel to her 1977 book, The Plug-In Drug.

While Winn can rattle off a miniseries of scientific findings that indicate the ways television short-circuits our lives, her chief concern is the tube's influence on the family. "Television is the homogenization of family life," she says, "the elimination of that wonderful variety of experiences that are available."

Winn wonders aloud whatever happened to those pre-TV family rituals of reading together, playing games, conversations around the dinner table, "those things families would instinctively do if they weren't watching television." The irony of millions of Americans spending their evenings entranced by shows such as "Family Ties" or "The Cosby Show" -- programs about families that rarely watch television -- isn't wasted on Winn.

"It is just human nature to want to do something easier rather than do something harder," Winn explains. "And TV watching is really easier than anything else. It is entertaining and it is delightful ... But those thousands of hours in front of the TV will have some impact."

Winn's crusade to educate Americans about the TV habit stems from the years her two sons were youngsters watching lots of television with her blessings. As a New York writer and a mother, she often would plant them in front of the set to occupy their time. They sat quietly. She knew what they were doing. And she got some work done herself.

But what seemed like a nice remedy to the ruckus two boys can raise started to worry her when she noticed their dazed look as they sat in the glow of the screen. Was television turning her children into dullards? Her initial research into TV's effects was to make excuses for the medium. Instead, it raised questions about what all those hours of TV-watching were doing to a child's brain and life.

"Even parents with the strongest will in the world won't say 'Okay, let's read a story out loud' when the kids say they want to watch a TV program," says Winn of the TV factor in child rearing -- a larger problem today because of the increase in families with dual wage-earners. "The problem is that many parents may not have the energy to read that story out loud anyway. It is very safe and easy to say, 'Let's all watch "The Cosby Show" instead.' So everyone sits down and plugs in."

Winn contends that parents who allow television to baby-sit their children from an early age -- 2 or 3 years old -- are finding their kids are being socialized by electronic rather than human interaction. The result: Children who aren't easily controllable and parents who are nervous about the well-being of their children when they aren't sedated by television. "There is a general anxiety," says Winn, "that the kids will climb the walls and get into trouble without television."

Few parents would allow a human baby sitter to indoctrinate their children the way television does. But television watching, which now occupies a national average of 24 hours a week of our children's attention, is systematically zonking their consciousness while positive child-rearing strategies are neglected. The "thousands of firm little things parents once said to kids" to motivate them, to make them responsible, argues Winn, no longer accumulate through childhood. "Over a long period," she explains, "you subtract the number of times a parent says, 'You have to play by yourself now,' or 'I can't pay attention to you now but I will later.' Those kinds of little interactions that form a parent-child relationship don't have to happen anymore ... Television is tremendously implicated in a wide-scale loss of parental control."

This month, Winn is heading "a nationwide campaign" designed to raise these issues with parents and children. According to a spokesman at Viking Penguin Inc. -- Winn's publisher -- which is sponsoring the event dubbed "No-TV November" to coincide with the release of her book, students at more than 300 schools have volunteered to give up television for one week. The purpose of a no-TV experiment? " ... to help parents, teachers, and children better understand the role TV plays in their lives," according to the Viking Penguin spokesman, "so they may learn to control it more effectively."

Students enrolled at the Washington Waldorf School in Bethesda already know about minimizing television in their lives. One of the more than 350 independently associated Waldorf schools worldwide that base their approach on the educational philosophy of Rudolf Steiner, the school's policy is to recommend no television for students.

From a Waldorf Schools' brochure: "Virtually all Waldorf teachers would prefer that children not be exposed to TV at all, and would argue that searching out 'good' programs for their age level is somewhat like restricting children to 'good' alcoholic beverages.

"The developing child is simply too young to cope with the physical effects of the medium, not to mention the narcotic impact on the child's own imaginative faculties, its inappropriate models for imitative learning, and its substitution of electronic for human authority ... "

Donald Bufano, the development director at the Washington Waldorf School, doesn't want the school's TV policy to sound dogmatic. "We don't really just say no television," says Bufano, who has taught in the system 10 years and has a background in TV and film production. In Washington, the school doesn't strictly enforce a no-TV policy like some Waldorf schools in Switzerland and Germany. "We don't want to paint people into a corner," says Bufano, who estimates that a third of the school's families have banned television from the home, and the remainder have radically restricted it.

Bufano says the Waldorf policy is based on developmental psychology that determines babies and young children to be too wide-eyed and vulnerable to sense perceptions to benefit from a powerful stimulant such as television. As children grow older, they still are unable "to objectify as adults do," says Bufano, "and say 'This is ridiculous.' The child just takes it all in" passively and disengaged, with no mental filter to protect them. For teen-agers, the TV problem is less perceptual and more pragmatic: "They're watching it instead of developing their reading and artistic ills," says Bufano. "It takes up too much time and it dulls teen-agers."

When Kathy and Ivan Charner enrolled their daughter Megan in the Waldorf preschool program, they didn't know the school advised against watching television. "I thought they probably didn't mean public television ... ," recalls Kathy Charner, an editor who works in their Silver Spring home.

But soon the Charners began to reduce their TV fix. Little Megan was resistant and cranky. "I tried to replace it with something that was fun," says Kathy Charner. "We'd go out to the park or we'd make something in the kitchen. It gave me more time with her, which is sometimes a challenge, but it has paid off for us as a family."

Now in the seventh grade, Megan Charner watches almost no television and doesn't miss it. "We and the school want Megan to be fully engaged in her life in whatever she is doing," says Kathy Charner. "TV is not something you are fully engaged in. Rather, it happens to you."

Janet Heirman, whose 9-year-old Sarah is a third-grader at the Washington Waldorf School, baby-sits other children during the day. She says she sees the difference between those who watch a lot of television and those who don't.

"It's very individual," she says, "but some children just seem a bit dull, just not as sparky ... They also tend toward inappropriate play. It makes them a little wilder."

"Visual illiteracy" is TV's influence on children that Mona Brookes says she confronts constantly. The California artist and art teacher who developed a drawing curriculum for children that she outlined in her book, Drawing With Children (Jeremy Tarcher Inc., $10.95) says today's TV-dazzled kids have trouble focusing their visual attention.

"With visual illiteracy, children can be looking straight at an object, but they can't read the information of the shapes they're looking at with their eyes," says Brookes. "With television, they're not participating. People think they're involved in a visual subject but it moves so fast that they're not getting ... any of the detail."

Brookes claims tossing the television out of her house was the best thing she ever did for her then-12-year-old son. "My weaning, so to speak, off of TV came when the cable was turned off and the TV set was still there," recalls Brookes' son, Mark Hall, now a 22-year-old musician and computer program designer in Venice, Calif. Reception in Santa Monica was poor without cable. The picture screen was faint and there was virtually no sound. He remained affixed to the screen anyway. "That really helped to point out what my dependencies were," he recalls.

Marie Winn suspects that distinctive one-way processing by the television of the young mind overexposes children to doses of nonverbal stimulation. "A 2-year-old quickly comes to understand that this humanoid kind of machine will not answer back, that {it} goes on at its own pace," says Winn. "Gradually that child begins to focus some other kind of attention and mental functioning. Part of the evidence of that is when you look at children watching television and they have that trance-like look, glazed eyes and slacked jaws. It doesn't seem to be a state conducive to learning ... "

Winn mentions a mid-'70s Harvard study called Project Zero, which compared the TV-watching experience to the book-reading experience. The set of children who watched a videotape of someone reading a book to them scored lower on retention. The children who listened to stories read to them in person tended to interrupt, expressing their own experiences. "The video kids were passive," says Winn. "The other kids were active."

Two years ago, Dr. William H. Dietz, chairman of the American Academy of Pediatrics Subcommittee on Children and Television and an assistant professor at Tufts University Medical School, reported in the Journal of Pediatrics that children addicted to the tube early in life have an increased chance of growing into overweight teens. Dietz blames snacking in front of the television, the increased likelihood that the snacks are those advertised on television, and the low-to-no energy expended while watching television.

More recently, Dietz has been investigating the metabolic rate in teen-agers. Using "a carefully defined measure," he has found that, "Some kids ... have a lower metabolic rate when they're watching TV than when they're doing nothing. Fidgeting is a minor activity with a major-consequence energy use. Some kids don't even fidget in front of TV."

Peggy Charren, president of Action for Children's Television (ACT), a nonprofit child advocacy group based in Cambridge, Mass., believes one of the most important effects of television on children is what they're not doing when they watch it -- even when they're doing nothing.

"The nothing that you did as a kid was kick stones, look at clouds and think about finding someone to play with," says Charren. "Kids don't do that any more. When there is nothing to do, they turn on the TV set. And they turn it on when there is something to do, too."

Charren mentions a poll 129 students of the Beethoven School in West Roxbury, Mass., conducted on themselves "to see if they would rather watch television or do other things." Top of the list was ride a bike, go to the movies, play with a friend, listen to music. "And, yet, on any particular day," says Charren, "those kids are watching TV instead of doing those things ... I'm worried about what children are missing by spending four hours a day in front of that piece of furniture."

Says Dietz: "I have to wonder whether our children wouldn't be better off spending that time bored rather than watching television ... Boredom generates creativity and self-reliance. As long as we turn on our television sets as an alternative to creativity and self-reliance, we are making a mistake. We are not giving our children what is optimum for their development. At the moment the only alternative that we have as responsible parents is to advise children to turn off the TV set."