Given the difficulties of random blinding, and the long-term (decades-long) duration of the research, studying that aspect (with the same post hoc brain morphology analysis) might help assess causality.
There was some exclusion of other factors in the study per TFA.
Additional areas: South Africa and Tanzania saw television introduced relatively recently, 1975 and 1994 respectively. Those would be larger populations, though confounded by other factors (poverty, racism, higher early-adult mortality due to HIV/AIDS).
I'd thought of some other remote island locations as well, though most have quite small populations. That would make large-scale studies challenging.
Slightly orthogonal: Simon Winchester's book Outposts details many of these, including aspects of their cultures, though I don't recall if he dwelt long on the specifics of television or its lack.
Ascension Island and the Falkland Islands seem to have reasonable broadcasting because they have major military bases on them. Diego Garcia would be the same. The Falklands have a substantial civilian population, but Ascension has almost no one who can be classed as a kind of native. (Tristan Da Cunha and Saint Helena both do.)
Somewhere like Bermuda or certain smaller Caribbean Islands will have had decent service due to being tax havens (Cayman Islands, Virgin Islands) or major tourist destinations (St. Barts, Bahamas, Barbados). (Jamaica, Cuba, Trinidad & Tobago, and Hispaniola all have large populations.)
I was in Nepal in the early 1990s and there was a surprisingly limited service within Kathmandu (mostly satellite), and none up in the hills. I imagine that has changed a lot since then. I am friendly with a Nepali family here and they watch a lot of Hindi soaps and Bollywood, because they can understand the language. I'm sure Nepal is swamped with "global" content now and is no better for it.
I don't think these are a good comparison. The nature documentaries are primarily visual (and since it's Attenborough involve a lot of Foley work). His docs are extremely well made, but you could still use them as wallpaper as I have seen some do.
Maybe the same could be said about the Marvel films. You don't have to concentrate much, but you are guessing some of what is going on.
Some programmes do require some more imagination or interaction. A murder mystery, if it's any good will get you wondering whodunnit. If you are watching a better quality gameshow, you may be at least attempting to answer the questions. Or both may be wall paper.
>Strikingly, the sedentary element of TV watching didn’t appear to be the main driver for these changes.
>Those who reported high amounts of sitting at work actually had larger frontal and occipital lobes, as well as reduced white matter hyperintensity volumes, indicating better brain health than among those who sit to watch TV. This could be due to the intellectually stimulating nature of many sit-down jobs, say the study authors.