Some rough and ready philosophical background is required here. Don't quote this in your essays.
Until the early 1900s, the philosophical consensus was that there was Mind and there was Body and they were two distinct kinds of things. This position is called Dualism.
In the early to mid 1900s, some people denied that there was Mind at all, only Body and Behavior (which is observable). This is called Behaviorism.
In the 1950s, two chaps in Adeliade, Australia (Ullin Place and Jack Smart) put forward the theory that there is Mind, there is Body, and that Mind just IS Body. That is, the mind is a perfectly normal physical thing like a pulse or body temperature. This is called Identity Theory (the two are quantitatively identical, that is, one and the same thing). It is now the most widely accepted of these three approaches in contemporary philosophy.
Here's U.T. Place:
And here is his brain:
U.T. Place died in 2000. He left his brain to the university, which has housed it thus:
It asks, "Did this brain contain the consciousness of U.T. Place?"
According to Identity theory, the answer is, not quite. Rather that the consciousness of U.T. Place was
one and the same thing as the activities of this brain.
One of the drawbacks of Identity theory is that you don't get to believe in life after death. I guess this is the consolation prize.