The Brain=Mind Fallacy

[Annik]

can someone define "lessened" and "elevated" regarding brain death?

Allow me to explain myself a touch more simply. Your wording here makes me think you're not understanding exactly what I'm talking about.

In the terms of a biological machine, all living beings are machines. Let's use plants as one level, animals as another and then humans on top (I've left single celled organisms out for the sake of simplicity).
Plants operate almost like a fully mechanized assembly line. They take in sunlight for food and take in carbon dioxide to convert to oxygen. They grow, seed and die.
Animals are a step up (even though humans are animals, we are making a distinction for the sake of the argument). They have brains. These brains are so cool! Instead of automated assembly, we've switched to humans (not real humans, metaphorical humans)! Now, we're unsure if these animals can feel emotion, per-say, but their function is elevated from the cognitive functions of a plant. This is where the word elevate enters my argument. The term is one to describe a step up from mindlessness.
Humans (and other self-aware animals like gorillas and elephants) are one step further. How are they 'elevated' from the animal category we were discussing? It's one letter, one pronoun and it's an incredible one, "I". We can think in terms of "I". We're self-aware, we can conceptualize death, we can conceptualize the universe and our place in it (admittedly, I'm not sure if the non-humans who share self-awareness are quite at this level).
I hope this explained the use of the term 'elevated'.

Now, if those terms needed to be questioned in that sense, I'm sure my argument also is confused.
Everything that makes a person a person is stored in the brain. The brain is where our memories are stored, where sensation is processed and where motor function is controlled. Protect your brain, it's everything you are.
When a person suffers brain death, one of two things happens:
1. The body also dies.
2. The body continues to function, but higher brain function is non-existent.
Regardless of which outcome occurs, brain function is no longer present. All of the things that make a human a person has perished. For this reason, the human body, without the brain, is lessened in standing. We've gone from high cognition to automated assembly line. I'm sure you have heard the common term for these types of people, a "vegetable". No longer does the body think or contemplate, it is reduced to merely processing nutrients.
I hope this has cleared things up.