> May I translate: They saw improvements in things they could easily measure. They hope this translate into improved cognitive ability. But it actually didn't. But they still hope it'll do that later.

I find your translation misleading. They did see improved cognitive ability, just not superior to the conventional fitness program at the time of measuring. Increased BDNF, which stands for brain-derived neurotrophic factor, is actually pretty significant so they are not pulling potential future development from thin air.

Mind you the sample population is the elderly, for which the prospect of neural growth/protection is pretty important, and this might have further applications to other populations such as recovering alcoholics, methamphetamine users, and even depression/anxiety sufferers where hippocampal volume decrease is indicated.