Today, many neuroscientists don’t even call it a persistent vegetative state. The new term is disorders of consciousness. One neuroscientist recounts,

In the past 20 years, advances in neuroimaging techniques have allowed us to explore brain functions in these altered states of consciousness. One breakthrough study conducted at our lab, in collaboration with the University of Cambridge in the United Kingdom, involved 54 DoC patients. The researchers asked the patients to perform two mental-imagery tasks while they lay in a brain scanner. In the first, they were asked to imagine playing tennis; in the second, to imagine walking from room to room in their home – mental tasks that are associated with contrasting patterns of neural activity. Remarkably, five patients were able to wilfully modulate their brain activity, suggesting that, though unable to express any outward signs of consciousness at the bedside, they could understand and follow the researchers’ instructions.

Inspired by these findings, the researchers conducted further repeated behavioural assessments on these five patients and managed to observe outward signs of awareness in three of them. Yet still, no voluntary behaviour could be detected in the remaining two patients. This was the first large, multi-patient study to demonstrate that a small proportion of patients who are entirely unresponsive when assessed at the bedside do, in fact, have some residual awareness and cognition.

This was a dramatic result, making us realise that some unresponsive patients are more conscious than we thought…

Aurore Thibault, “Consciousness regained” at Aeon

The mind is not merely the brain humming along.

Further reading:

Can loved ones in a coma hear us? Yes, generally, they can. Modern brain imaging studies show that very often they can. And, with help from new technology, they can answer us too.

and

Four researchers whose work sheds light on the reality of the mind The brain can be cut in half, but the intellect and will cannot, says Michael Egnor. The intellect and will are metaphysically simple