If that is how you'd define the mechanism whereby an animal senses and can respond to the stimulation, how is it different in a human?
"If that is how you'd define the mechanism whereby an animal senses and can respond to the stimulation, how is it different in a human?"
It isn’t different in a human machine. It is the same. But the human machine is merely what we occupy. You and I are not the body we occupy any more than we are the car we occupy when we drive. Our feelings of pain are merely via our connection to this body, and our interpretation of the stimulus originating at our nerve endings. And this does not even get into our feelings when shunned by a group, etc. when nothing has been physically done to us. Animals do not contain a human spirit. They are basically automatons.
I think of the human machine as a fighter plane with a pilot, and animals as drone aircraft. What makes the fighter more important to protect is not really the fact that it is more expensive to produce. What makes it more valuable is that it contains a human pilot. What makes a human body more valuable is that it contains a human soul. Once the soul leaves, the body is just so much meat, like a car at a junk yard.