Is television good for us?

Does television make you stupid?

Speechless in front of the telly: Watching TV for too long may damage verbal memory - especially in older people. In a large long-term study, watching TV for more than 3.5 hours a day led to significant deficits in remembering spoken information - regardless of other influencing factors. How and why television affects verbal memory is still unclear, as the researchers report in the specialist magazine "Scientific Reports".

Many people can no longer imagine life without television. But the effects and side effects of TV consumption is controversial. Watching TV can certainly contribute to education or even promote language development. On the other hand, however, excessive TV consumption seems to have had negative consequences, especially with children: They later have problems at school and show deficits in social behavior, as studies show.

How does television affect memory?

But what about older people? After young people, they belong to the age group that watches a lot of television. So far, however, hardly any research has been carried out into the consequences of TV consumption for seniors. However, some smaller studies have found evidence that long television viewing can impair working memory and may even promote dementia.

Daisy Fancourt and Andrew Steptoe from University College London have now tested this hypothesis in a six-year long-term study. The participants were 3,590 healthy men and women aged 50 and over, around 30 percent of whom still worked full-time or part-time. The researchers examined the state of health and cognitive performance at the start of the study and over the course of the six years, and asked about the subjects' daily television consumption. After six years, Fancourt and Steptoe evaluated the data.

Bad memory for words

The result: Depending on TV consumption, there were significant differences in verbal memory. "The participants who watched TV for more than 3.5 hours a day had worse verbal memory after six years than participants who watched TV less," the researchers report. The affected seniors found it significantly more difficult to remember previously heard lists of words.

The problem with this is that verbal memory is crucial in order to grasp and process linguistic messages. We need it, for example, in order not to lose the thread in a conversation or to memorize directions or important announcements. If verbal memory is impaired, this becomes increasingly difficult and verbally conveyed content is no longer processed correctly.

Effect independent of other influencing factors

The study showed: The memory-impairing effect of TV consumption is retained even if other influencing factors such as state of health, age, social circumstances or lifestyle are taken into account. A lack of exercise due to watching TV was only partly responsible. "These factors explained 44 to 55 percent of this relationship, but not the rest," said the researchers. "Therefore, this effect must be independent of it."

According to the researchers, there is something else that speaks for the fact that TV consumption plays a role in these memory deficits: "This connection was dose-dependent," report Fancourt and Steptoe. The more television the seniors watched every day, the more pronounced was their verbal memory degradation.

Why does television work that way?

But what is the cause? So far, the researchers have only had guesses: “Laboratory experiments have shown that television leads to a more alert but less focused brain,” they report. Among other things, the EEG shows fewer alpha waves, a type of vibration that is important for learning. Another factor could be visual and emotional stress caused by TV viewing, as stress can also disturb memory.

And there is another possible explanation: "Excessive TV consumption could have a negative effect on memory because it suppresses other, beneficial activities such as reading, playing together or cultural activities," say Fancourt and Steptoe. "Then the observed effects would not be caused by television itself, but by the reduced time that people spend on memory-enhancing activities."

Just relax

As the researchers emphasize, many questions still remain unanswered about the effect television has on memory. “For example, do different programs have different effects on cognitive decline? And could watching TV be a risk factor for developing dementia? ”These questions must now be investigated in follow-up studies.

In the meantime, however, a simple precautionary measure helps: "In order to stay mentally fit for a long time, older people in particular should refrain from watching too much television," says the DGN expert. (Scientific Reports, 2019; doi: 10.1038 / s41598-019-39354-4)

Source: Nature, German Society for Neurology

April 15, 2019

- Nadja Podbregar