Scientists Debate TV's Effect on Brain Development
WASHINGTON--The extent to which television affects the development of young children's brains remains an emotional topic among researchers, and more than 100 of them gathered for a conference here this month to present new findings and wrangle over future directions for research.
The day-long conference, "Television and the Preparation of the Mind for Learning,'' was sponsored Oct. 2 by the administration for children and families of the Health and Human Services Department.
While the neurologists, psychologists, and communications researchers gathered for the meeting clearly parted company on some issues, they found common ground on others.
For one, they agreed that an "enriched'' environment can stimulate not only a child's cognitive skills, but also his brain structure, while an "impoverished'' one will do neither.
The child's ability to develop cognitive functions is greatest in early childhood, because the brain structure is more "plastic'' then, said Marian Cleeves Diamond, a professor of neuroanatomy at the University of California at Berkeley who pioneered brain research in this area 30 years ago.
In her research, Ms. Diamond studied the brain size of caged rats that were given toys to play with, and compared them with those of rats that were without these stimuli.
Ms. Diamond found that the rats in the "enriched'' environment had heavier and larger brains when autopsied and showed the increased nerve branching that allows the cells to communicate better with each other.
Ms. Diamond defines an "enriched'' environment for a child as one in which language skills and creativity are challenged by reading, talking, or playing with toys. The current debate is whether television is an enriching influence that stimulates neurological development or whether it stunts such growth.
Television as 'Hazard'
One side views television as a hazard that, at best, does little to accelerate learning and, at worst, is a catalyst for violent behavior.
The skyrocketing homicide rate in the United States is directly related to the introduction of violence on television, charged Jerome Singer, a psychology professor at Yale University.
Mr. Singer cited studies in the United States and Canada in which
8-year-olds were exposed to television. The more the participants
watched, the more serious the crimes they were convicted of by age 30, which suggests that heavy viewing of certain programs promotes aggressive behavior, he said.
Field studies conducted by Mr. Singer have also concluded that children who watch cowboy, adventure, or detective shows, for example, have less imaginative play and are more aggressive than those who watch other programming.
But, Mr. Singer told participants, this highly entertaining medium is also "dangerous'' to children in more subtle ways.
Children who are heavy viewers tend to understand less of what they read, are slower to develop language skills, and are less able to distinguish between the possible and impossible, he said.
Jane Holmes Bernstein, a neurologist at Children's Hospital in Boston, agreed. In her research she found that teachers reported that it was significantly more difficult for learning-disabled children who watched television to listen and pay attention for extended periods than it was for their peers who did not watch television.
A show's fast-paced format may be the cause of such decreased attention span, according to Jennings Bryant, a professor of communications at the University of Alabama.
Mr. Bryant exposed preschoolers at a day-care center to four weeks of "Sesame Street,'' MTV: Music Television, and network shows in concentrated doses. Although the study was inconclusive, Mr. Bryant found the children who watched MTV more distractible, less vigilant in their tasks, and more aggressive in their play than children who watched the slower-paced shows.
"TV is becoming more frenetic,'' Mr. Bryant concluded.
But Daniel Anderson, a psychology professor at the University of Massachusetts at Amherst, called talk of deadening brain cells "sensationalist'' and said he sees television as a much more dynamic process.
"Television is if anything an enriched experience in terms of brain development,'' said Mr. Anderson.
He presented research concluding that the average child watches television intermittently, fixing his eyes on the screen an average of 10 seconds at a time.
Furthermore, Mr. Anderson asserted to his colleagues, young children watch television while engaging in such other activities as playing with toys or other children and, therefore, diluting the effect of exposure.
While critical of television, many conference participants were wary of using it as a scapegoat for other societal problems.
"It's easy to see TV as a culprit, but it may simply be filling a gap [of free time],'' said Ms. Bernstein. She argued that television is one of dozens of factors such as nutrition and psychological stressors that might affect a child's cognitive development.
"This research can be used to support adverse as well as positive effects on the brain,'' she said because brains are differently affected at different times in different places, which makes it difficult to find conclusive answers in brain research.
Most participants agreed that what children watch also plays a factor in cognitive development and that more inventive, interactive programming is essential.
"If we want our children to be culturally literate, why are we teaching them about Big Bird and Cookie Monster, and throwing alphabet letters at them when we have fables and American history, world history? ...We could be teaching them so much,'' said Jane Healy, the author of Endangered Minds: Why Children Don't Think and What We Can Do About It and the conference's moderator.
The Future of Television
Another environmental variable that is liable to complicate the research further, participants agreed, is the introduction of such new technologies as "virtual reality'' screens--voice-activated computer programs that allow one to design games, choose lectures, investigate history, or play a video musical instrument. Television sets are already blurring the boundary between visual images and reality, they noted.
"This is not just a gadget fetish,'' said Byron Reeves, a professor of communications at Stanford University. "New televisions can dramatically affect people's learning.''
Large screens and added fidelity can make television viewing increasingly lifelike,. "If we are experiencing pictures, they could be defined as a natural experience,'' he said, adding that larger images tend to amplify perceptions, magnifying the both the positive and the negative sensations.
Whether for good or bad, new technologies may eventually invalidate the argument that watching television is a passive activity, some participants said.
Exactly how television might alter the neurological landscape is an
area, all participants agreed, that warrants increased