You're right, it doesn't appear in the actual paper [ https://www.nature.com/articles/s41598-023-39344-7 ] either, except for this pathetic disclaimer:

    Ethics declarations:
    Competing interests
    The authors declare no competing interests.

There are also no occurrences of the terms "society", "moral", "distress", or "stress".

I'm surprised this work got approval from the Institutional Animal Care & Use Committee.

https://olaw.nih.gov/resources/tutorials/iacufoot.htm

    Criteria for IACUC Review and Approval of Protocols:
    ...
    d. The living conditions of animals will be appropriate for their species and contribute to their health and comfort. ...

I can hardly see how this living brain is having living conditions appropriate to the Sus domesticus (domesticated pig) species. The living conditions are totally unnatural and seem to be in direct violation of item d of the IACUC approval criteria.

> level of consciousness

This was exactly my wondering, as well. It sounds like a really interesting sci-fi horror novel concept to be kept conscious as a brain but unable to interact with the world at all. The idea of being kept alive indefinitely in that state sounds like a fate worse than death.

Also has me wondering: what kind of consciousness is even theoretically possible for a human brain without a body?

If they have bypassed the body entirely, there will at least be reduced hormonal stressors such as adrenaline since those are mostly created in the body on the adrenal glands. Small comfort though as plenty of other stuff is made in the brain.

The brain was anesthetized