Contemporary researchers have shown they can use a brain-scanning technique known as functional MRI to detect consciousness by indirectly measuring blood flow in the brain,

That doesn’t explain consciousness any better than knowing that the engine makes a car go explains how the engine actually functions.

humans are unique in having a highly developed frontal pole cortex, a part of the brain that researchers have connected with the ability to know what's on one's mind.

All higher animals at least, have an FPC, not as well developed perhaps, but still present. I feel that dogs, cats, horses, other primates, etc. have consciousness, maybe not at the same level, but they do have it. I can’t imagine the cat who just came up to me and requested attention not having any consciousness at all.

Some researchers take things a step further, holding that consciousness is a property of matter so fundamental that even an electron is conscious to a certain extent, a position known as panpsychism

OTOH, it is perhaps going a little too far to say that an electron or a rock is conscious. It’s sort of new-agey, which feels good, but there is rarely much substance to anything new-agey.

Schellenberg said she thinks that a lot of animals have consciousness because "anything that feels pain ... is conscious,

This might be a good point to think about. It might not define consciousness, but it might point to it.