The big question is whether they remain mentally alert because they engage in these activities, or whether they are able to engage in these activities because they are cognitively intact.

重要的问题在于，他们是否因为参加这类活动而保持了头脑的灵活，或是正因为他们拥有完整的认知能力，所以才有能力参与这类活动。

youdao

My surgery went fantastically well, and a quick series of self-tests performed while still in my hospital bed confirmed my belief that cognitively, I was completely intact.

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