TL;DR
Turn quiet afternoons into listening time
- Thousands of audiobooks, podcasts and originals
- Listen on your phone, tablet or Echo — also offline
- Cancel anytime
An analysis of four aging cohorts found that older adults who watched more television tended to have lower cognitive scores, while computer use was associated with higher scores. Genetic analyses provided some evidence linking television viewing to cognitive and brain measures, but many findings did not survive statistical correction; the study does not establish that screen habits cause cognitive changes.
A study combining data from four aging cohorts found that television viewing was associated with lower cognitive scores among older adults, while computer use was associated with higher scores. The findings, published in npj Digital Medicine, suggest the type of screen activity may matter when researchers examine screen habits and cognitive aging, but they do not show that changing those habits will prevent cognitive decline.
The observational analysis included 8,996 participants, whose average ages ranged from 69.2 to 76.2 across the cohorts. Researchers examined reported television and computer use alongside measures including memory, processing speed, orientation and verbal fluency. About 40% to 49% of participants in the cohorts reported watching television for at least four hours a day; 30% to 40% reported no computer use.
In the cohort analyses, more television viewing was associated with poorer global cognition, while computer use was associated with higher global cognition. The computer-use association was strongest in estimates for two to three hours a day in three cohorts, and up to one hour a day in the European cohort. Estimates were weaker at four or more hours a day, so the results do not indicate that more computer time was consistently linked with better scores.
The team also used Mendelian randomization, a genetic analysis intended to test potential causal relationships, drawing on results from large genome-wide association studies. These analyses linked genetically predicted television viewing with lower cognitive performance. Computer use was associated with better cognitive performance, but its association with a separate overall cognitive-function measure was not statistically significant. The researchers also tested brain imaging measures and four dementia subtypes.
Different Screen Habits, Different Associations
The findings offer a reason to distinguish what people do on screens when studying cognitive health, rather than treating all screen time as one exposure. Television viewing and computer use showed different associations with cognition in the observational data, and that distinction could help shape future studies of daily routines in older age.
However, the results are not a basis for prescribing a particular number of hours online or in front of a television. People who did not use computers or watched television for longer periods also tended to be older, less physically active, have more chronic conditions, lower cognitive scores and lower socioeconomic status. Those differences may help explain the associations, even after statistical adjustment. The study does not establish that screen use itself produced the cognitive differences.
The distinction matters for readers because screen habits are common, but an association does not tell an individual what caused a score or predict their future cognition. The study measured patterns at a group level. It does not show that replacing television with computer use would improve cognition, nor does it establish an effect on a person’s dementia risk.
Four Cohorts and Genetic Analyses
The researchers combined observational data from the Survey of Health, Ageing and Retirement in Europe, the English Longitudinal Study of Ageing’s Harmonized Cognitive Assessment Protocol, the Health and Retirement Study’s equivalent assessment, and the National Health and Nutrition Examination Survey. They compared reported screen habits with cognitive measures, using adjusted statistical models to account for other factors.
They then examined whether genetic predictors associated with screen-use duration were linked to cognition, brain structure, functional connectivity or dementia outcomes. This method can add evidence about possible causation, but it depends on assumptions about genetic associations and does not replace a randomized trial. The study considered Alzheimer’s, frontotemporal, Lewy body and vascular dementia.
For brain measures, some television-viewing associations with cortical area and thickness were described as nominal, meaning they did not remain statistically significant after correction for testing multiple outcomes. The corrected analysis did find an association with lower left insula volume; evidence for the right insula was weaker. No regional brain-volume association for genetically predicted computer use survived that correction.
““Screen time modalities and neurocognition in older adults: multi-cohort and Mendelian randomization evidence””
— The study authors, in the title of their report
Causation and Long-Term Effects
The observational findings cannot establish whether screen habits affect cognition, whether people with different cognitive or health profiles choose different activities, or whether other factors influence both. The study also does not show whether changing screen habits alters cognitive outcomes over time. The source report describes genetic analyses of dementia subtypes, but the available findings do not specify a convincing association between screen use and any particular subtype.
Some brain-imaging results were nominal and did not survive multiple-testing correction. A result that does not survive this correction is less robust when many outcomes have been tested. The surviving association between television viewing and left insula volume does not by itself establish a meaningful change in everyday functioning. The report also does not provide enough detail to determine how well the findings apply to older adults outside the study populations.
The analysis focused on reported hours of television and computer use, but the available results do not fully describe what participants did on computers, how screen habits changed over time, or whether activities were social, educational or work-related. Those details could matter when interpreting why the two types of use showed different associations.
More Evidence on Screen Activities
Further research will be needed to test whether particular screen activities are linked to changes in cognition over time, and to separate screen habits from health, activity and socioeconomic differences. Studies that track people repeatedly and describe what they do on devices could help clarify the patterns reported here.
For now, the study adds associations across four cohorts and genetic evidence of varying strength. It does not establish a screen-time target or show that reducing television viewing or increasing computer use prevents dementia. The next relevant evidence will come from research that can better establish how screen habits and cognitive changes relate over time.
Key Questions
What did the study find about television viewing?
Across the observational cohorts, more television viewing was associated with poorer global cognition. Genetic analyses also linked predicted television viewing with lower cognitive performance, though the analyses do not establish that viewing caused the difference.
Was computer use linked to better cognition?
Computer use was associated with higher global cognition in the cohort analyses. In genetic analyses, it was associated with better cognitive performance, but not significantly associated with a separate overall cognitive-function measure. These findings do not show that more computer use improves cognition.
How many older adults were included?
The observational analyses included 8,996 participants from four aging cohorts. Their average ages ranged from 69.2 to 76.2 years across the cohorts.
Does the research show that screen habits cause dementia?
No. The study examined associations and used genetic analyses to investigate potential causal links, but it does not establish that television viewing or computer use causes dementia or prevents it.
Source: rss
Evergreen bestsellers Picks
bestsellers
As an affiliate, we earn on qualifying purchases.
