Television, Computers and the Aging Mind: What You Do on a Screen May Matter

Most of us spend part of every day in front of a screen. For many people over 50 the evening television is a small pleasure, and the computer or tablet is how we stay in touch, pay bills and look things up. We are often told to cut down on screen time, but "screens" cover a lot of different activities.

A new study suggests it may be worth asking a different question: not only how long we look at a screen, but what we are doing while we look.

What the researchers did

The study was published at the end of September in the journal npj Digital Medicine by a team led by Zhong and colleagues. It drew on information from nearly 9,000 older adults in four large studies of ageing, in Europe and in the United States. The average age in the groups ranged from the late sixties to the mid-seventies.

Participants had reported how much television they watched and how much they used a computer, and they had taken tests of thinking skills, including memory and the ability to name as many animals as possible in a short time. The researchers compared the two habits with these results. They also used a genetic method that looks at inherited variations linked to a habit, which is one way of trying to get a little closer to the question of cause.

What they found

In these groups, more television viewing went with poorer overall thinking scores. Computer use went the other way: people who used a computer had better overall scores. The best results appeared at moderate amounts. In three of the four groups, the strongest link was at two to three hours of computer use a day, and in the fourth it was at an hour or less.

The genetic part of the analysis pointed to a possible clue in the brain. Genetically predicted television viewing was linked to a smaller left insula, a brain area involved in attention and in tuning in to our own body. This difference accounted for an estimated 14.8 percent of the link between television and thinking scores, which means most of the link was left unexplained.

It is also worth noticing how common television is. Depending on the group, between 40 and 49 percent of people watched four hours or more a day, while 30 to 40 percent did not use a computer at all.

What this does and does not mean

This is an association, and it should be read as one. People who watch a lot of television may differ from other people in many ways that the study could not fully capture, such as health, energy, mood, income or how much they get out of the house. It is also possible that people whose thinking is already changing drift towards the sofa and away from the keyboard, rather than the other way round.

The genetic method is designed to reduce this kind of doubt, but it does not remove it. The study cannot say that television harms the brain, or that sitting at a computer protects it.

The honest limits

The authors point out several limits themselves. The questionnaires recorded how long people used a computer, but not what they used it for, so an hour of online banking, a video call with a grandchild and an hour of scrolling all count the same. Smartphone use was not measured in a comparable way across the groups. The genetic data came mainly from people of European ancestry, so the results may not apply equally to everyone. And the analysis could not fully capture patterns that are not a simple rise or fall.

A gentle way to use this

None of this is a reason to feel guilty about an evening programme you enjoy. Television can bring laughter, company and conversation. What the study invites is a small, curious look at the balance of the day.

Some people find it helps to choose programmes on purpose instead of letting one run into the next, to get up and move around at the end of each one, or to talk about what they watched with someone. Others like to spend part of the time they would have spent in front of the television on something that asks a little more of them, such as a letter, a crossword, a video call with family or learning something new on the computer. These are ideas to try, not findings of the study.

A small, steady habit

Treeny is built around the idea that active time on a screen can be something you choose and enjoy. The daily exercises are short, and Flo, the coach inside the app, adjusts them to how you are doing each day. It is one gentle way to use a few minutes of screen time actively. It is not a treatment, and it is not a substitute for anything described in this article.

A note on how to read this

This article describes research and is not medical advice. The study discussed shows associations and cannot show that television causes poorer thinking, or that computer use protects it. If you are worried about your memory or thinking, speak to your doctor, who knows your situation in a way no article can.