I do MRI work, and my gut is that none of the claims about dance vs. exercise would replicate. The behavioral data suggests that activity of some type will improve cognitive function (main effects of time). Such beneficial effects of activity on the brain have been shown before, and this is generally accepted. However, the authors' behavioral data doesn't show any difference between the dance vs. exercise groups. Thi…
> The authors' claims about BDNF are supported by a p-value of p = .046, and having main conclusions hinge on p-values of p > .01 usually means the conclusions are rubbish. Your other points I agree with but I actually think the BDNF result has some standing. I'm looking at Fig. 4 and just by an eyeball test there's clear difference in the distributions of the intra-individual BDNF increase. It's not like there's som…
Notably, even if we take this p = .046 as a given, and assume there was no p-hacking, then this type of result implies that statistical power is tiny, and a proper "bigger population" study would likely have to be several hundreds of people. Even a study with 50% power, should have a majority of significant results land p < .01.