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Actively speaking two languages protects against cognitive impairment

uoc.edu

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Re: Actively speaking two languages protects against cognitive impairment

#3
> They recruited 63 healthy individuals, 135 patients with mild cognitive impairment such as memory loss, and 68 people with Alzheimer's – the most prevalent type of dementia – in four hospitals in Barcelona and the metropolitan area

Wait so, N = 266? All from Barcelona?

C'mon.

Re: Actively speaking two languages protects against cognitive impairment

#4
Interesting and suggestive, but difficult to interpret from the publicly available information. Actively speaking two languages no doubt implies complex correlations between wealth, status and circumstance.

The paper abstract doesn't mention controlling for location. That would also be an interesting thing to test.

Re: Actively speaking two languages protects against cognitive impairment

#7
post #4

Interesting and suggestive, but difficult to interpret from the publicly available information. Actively speaking two languages no doubt implies complex correlations between wealth, status and circumstance. The paper abstract doesn't mention controlling for location. That would also be an interesting thing to test.

One of the first things it mentions is controlling for location -- they were all in Barcelona.

Re: Actively speaking two languages protects against cognitive impairment

#8
post #3

> They recruited 63 healthy individuals, 135 patients with mild cognitive impairment such as memory loss, and 68 people with Alzheimer's – the most prevalent type of dementia – in four hospitals in Barcelona and the metropolitan area Wait so, N = 266? All from Barcelona? C'mon.

With proper random sampling you only need something like N = 27 (I forget exactly) to reach p = 0.05

Assuming random sampling, it's a misconception that you need ten thousand participants to have a useful study.

Re: Actively speaking two languages protects against cognitive impairment

#9
post #8
post #3

> They recruited 63 healthy individuals, 135 patients with mild cognitive impairment such as memory loss, and 68 people with Alzheimer's – the most prevalent type of dementia – in four hospitals in Barcelona and the metropolitan area Wait so, N = 266? All from Barcelona? C'mon.

With proper random sampling you only need something like N = 27 (I forget exactly) to reach p = 0.05 Assuming random sampling, it's a misconception that you need ten thousand participants to have a useful study.

Cue “p = 0.05 is a random choice” and a big thread about p-hacking. Any takers?

It feels like everything to say has already been said about the bias of small sample sizes and the dangers of p-hacking. But it also seems like the discussion is inevitable here.

I wonder if there’s a new insight to glean, somehow...

For a background on why p-values are misleading, see https://youtu.be/42QuXLucH3Q which is excellent. He points out that 0.05 was selected by Ronald Fischer in 1925, and people have gone with it since.

Re: Actively speaking two languages protects against cognitive impairment

#10
post #8
post #3

> They recruited 63 healthy individuals, 135 patients with mild cognitive impairment such as memory loss, and 68 people with Alzheimer's – the most prevalent type of dementia – in four hospitals in Barcelona and the metropolitan area Wait so, N = 266? All from Barcelona? C'mon.

With proper random sampling you only need something like N = 27 (I forget exactly) to reach p = 0.05 Assuming random sampling, it's a misconception that you need ten thousand participants to have a useful study.

Isn't the crux just that, "proper random sampling" can be quite hard. Assumptions are fine in theory, in reality, they can seriously throw us for a loop.
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