On average, Australians watch two hours and 39 minutes of broadcast television in their home every day.

That number has declined slightly from six years ago, where it was more than three hours.

We’re also using more screens than ever – the average Australian home has more than six screens, most of which are able to be connected to the internet.

The power of television to provide rapid, engaging stimuli while requiring little or no input from the viewer has made it an object of interest for researchers interested in working out how prolonged viewing can affect the brain.

That’s in part because it involves sedentary behaviour – sitting and watching – which is thought to influence cognitive health. But some sedentary behaviours, like browsing the internet, are thought to actually protect against cognitive decline. So what’s going on?

British research used data from the English Longitudinal Study of Aging, which follows adults who were more than 50 years old at the start. They looked at more than 3,500 people who at first didn’t have dementia. They asked them how much television they watched each day, sorting people into different groups based on their viewing habits.

They also did cognitive tests – in particular, for verbal memory (that’s your ability to recall words and pair words that may be abstractly linked) and semantic fluency (where you have to come up with words linked to a given topic within a certain amount of time).

The cognitive tests were done when the study started, and then again six years later. The average age of a study participant was 67.

The study found that television watching was gendered – women watched more than men – and those who didn’t have a partner, those who didn’t work and those of a lower socio-economic background were also likely to watch more.

When it came to verbal memory (word recall), there was a clear link between longer viewing times and poorer results. Particularly, watching for more than 3.5 hours a day was associated with poorer verbal memory.

People who watched more than 3.5 hours a day saw a decline in their verbal memory skills.

There seemed to be a ‘dose response’ – that is, the more television you watched beyond that point, the greater the effect on verbal memory. The researchers did also see a relationship between television viewing and semantic fluency, but the link seemed to go away once they’d taken into account demographic factors like wealth and education.

Implications

There seem to be a host of reasons for reducing screen. The authors say that watching television can have benefits – learning opportunities, cultural experience and escape from stress. But it can also displace other beneficial activities, like reading, exercise and socialising with friends.

Last Reviewed: 24/01/2020

© Norman Swan Medical Communications.



References

For reference: Fancourt, et al (2019). Television viewing and cognitive decline in older age: findings from the English Longitudinal Study of Ageing. Scientific Reports doi: 10.1038/s41598-019-39354-4.