Saturday, March 26, 2005

Higher Brain Death and Personhood

The question of what "personhood" is, is one of the more difficult, and more central questions raised by many of today's ethical dilemmas. Obviously, it is at the center of the abortion debate, and as the Terri Schiavo case has made clear, it is also the primary question raised by the definitions of "life" and "death." For better or worse, this is a question that medicine and science cannot answer for us. This means that we have to come up with definitions which, while they may be based on empirical facts, also include interpretations of those facts that are not strictly scientific. In a previous post, I stated unequivocally that I believe that cases of obvious higher-brain death (i.e., when it is physically impossible for a person to ever have any higher-brain functioning again), there is no reason to use the modifier "higher-brain." The "person" is simply "dead." Brandon of Siris disagrees, and in two posts, has presented well-reasoned arguments for his position. In the first, he wrote:
Claims, then, that higher-brain death is death simpliciter, that a person who has ceased having higher-order brain functions is no longer a person, appear to me to be utterly irrational and arbitrary. They are a denial of the fairly obvious fact that human personhood is exhibited in all our vital functions. They are a flight from human animality, a pretense that higher-order thought is all that there is to being a human person. (It is an old story. The excuse that some human persons should not be regarded as persons because they do not properly exhibit rationality is one of the oldest moral dodges in the book; it has been used to justify slavery, racism, sexism, sterilization of the mentally disabled, and the like. If you are going to go this route, you had better have a damn good argument for doing so.)
Brandon considers the higher-brain death position (my position) to involves treating the forebrain as the homunclar center of personhood. In the second post, he wrote:
[The higher-brain death view] is essentially a view under which a person is a humunculus in the brain; the humunculus is the person, and because of this, when the humunculus goes away, the person goes away.
Ultimately, I don't think that Brandon can treat the higher-brain death position as arbitrary without treating his own as arbitrary as well. The reason he fails to see this is that he misunderstands the higher-brain death position. Ultimately, the only difference between them is that they take different views of personhood from the start, but the higher-brain death position does not take the one that Brandon claims. At least, it does not do so in my own version of it, which I do not think is all that idiosyncratic.

An individual human person is differentiated from other human individuals, as well as nonhuman individuals, by a collection of memories, beliefs, knowledge, skills, and tendencies. In other words, what defines an individual person is a history. That history is, by and large, contained in the cerebral cortex and surrounding brain areas, along with the cerebellum. The hind-brain and mid-brain structures that may survive higher-brain death may contain some simple motor programs and associations, but for the most part, they contain innate reflexes and other programs that, while they allow the body itself to survive, do not provide for any real differentiation between individuals. In higher-brain death, then, all that survives is the basic functioning of the organism, while all of the properties that comprise a particular self, a particular person, are gone. Sure, the physical appearance remains, as do the internal bodily idiosyncrasies of an individual (if you have a bad liver from years of drinking, the liver will remain damaged even with higher-brain death), but these differences do not make an individual person. They make an identifiable body, and survive even complete brain death.

From an empirical standpoint, both ways (Brandon's and mine) of delineating personhood are arbitrary. Both place the line between life and death at empirically verifiable boundaries. What criteria, then, can we use to decide between them? My reason for requiring the possibility of higher-brain functioning is this: I believe that to define personhood as the basic functioning of the organism (e.g., breathing, digestion, blood circulation, etc.), or as anything less than the existence of a neurally-realized history, a set of physical properties of the higher-brain that differentiate and define individuals, is harmful to the dignity of human individuals. It results in the view that all of the things that make us different from one another -- all that makes us who we are -- is superfluous, merely icing on the cake of undifferentiated vital functioning. But ultimately, who we are, what we are, as persons, is more than just breathing, circulation, and digestion; it is a history that is recorded in the configurations of our higher-brain structures. When those are gone, we are not persons; we are merely bodies with life, but no lives.

16 comments:

Brandon said...

Chris,

Thanks for the (very, very helpful) reply. A few points:

* I don't define 'person' in terms of basic functioning but as a subject with a particular sort of nature (this becomes important in a clarification below).

* How does your view avoid saying that a human person is merely one part of a human animal? If a person is completely comprised of a collection of memories, skills, &c., then something like this would seem to be the case: it seems to create a sort of materialist dualism in which the person is a subject of activity directing another subject of activity (the non-personal body). It's precisely for this reason that I called the cruder view I originally set out a humunculus theory of personhood. On my view, this doesn't arise because the human person is simply the same thing as the human organism or animal - called a 'person' for different reasons than they are called an 'organism' or 'animal', but if the concepts are qualified by 'human' they have the same extension. On a view such as the one you give it looks to me like the extensions of 'human person' and 'human organism' (or 'human animal', as I tend to put it) will always differ; 'human person' will never refer to an animal organism: Human persons will always be distinct from human animals in the way that parts are distinct from wholes. Am I missing something?

* The human dignity issue is an interesting one, which I'll have to think about at greater length. I do agree that persons are more than just functioning; I regard them as examples of a particular kind of thing: in our case, human. As I see it, it is in virtue of being subjects having a human nature that we have our human dignity. But it doesn't seem plausible to me to say that higher-brain death puts an end to our being the sort of thing that is human, so that to call something 'human' both before and after brain-death is an equivocation.

So there are still perplexities here for me. But, again, this is a great post.

Chris said...

Brandon, to answer your second point, it might help if I redescribe my definition. An individual person is defined by a set of necessary and sufficient features, which include:
1.) A body that is alive (which includes being capable of being kept alive artificially, e.g., with a respirator).
2.) A history.

Without 1., there is no 2., but with 1. but no 2., there is no person. The body can survive without the brain, but all traces of the individual person are lost in such cases. So, a person is a brain and the rest of his or her body, but the person only exists when the two are together (it is not yet possible to have only a higher-brain, and it's not clear that it will ever be; in fact, I think there are good empirical reasons to doubt the possibility of a brain in a vat, for instance).

Anonymous said...

I comment with trepidation, because I'm way out of my league here ... but I wondered how Chris deals with the personhood of newborns. Do they yet have a neurally realized history that endows them with the dignity of personhood? If so, at what point does this occur? I guess since you raised the abortion debate at the beginning of the post, I'm asking where you draw the line at the other end of life, and how.

A less serious question is whether a person who suffers global amnesia becomes a different "person." That is, can the "history" you refer to be lost without the loss of higher-brain function?

(You can read that, if you like, as a request for more information about global amnesia: I found your post a while back on your agnosticism about the recovery of repressed memories very interesting).

Unknown said...

I tried to leave a comment about Brandon's post on his website, but as a non-team member, I'm not allowed. Since I really read about his post here, I'll try to comment here.

"What makes a person a person, traditionally, is being an individual example of the general sort of thing that usually exhibits rationality."


I think you are conflating higher brain function with rationality, and I think that's misleading/ incorrect. If we are ever rational, that rationality is only one of countless other functions of "the higher brain". (Which Chris could probably elaborate for us...)

Yes, "rationality" is the traditional definition of personhood (from Western philosophy), but I think that is a hugely mistaken (and outdated) characterization of human beings. Being human is not acting "rationally", it's acting "humanly." I am not being glib when I say that I RARELY see human beings acting rationally (and that those rare, fleeting rational acts I do observe are often of an order not so very different from what a dog (a non-human) can figure out ie. i need to do "this" if i want "this". )

I would like to add that we know from evolution that the differences between humans and other animals are an issue of quantity, not quality.

Chris said...

caleb, very good questions. the global amnesia case can be dismissed, because a history isn't simply explicit memory. I would argue that extreme rhetrograde amnesia creates a different "self" for the individual, because the conscious self is largely mediated by explicit memory, but doesn't make the person a new person.

As for the infant, it already has a set of tendencies (not all of which are fully realized, or fully determined) which differentiate it from other human persons.

Interestingly, the sort of higher-brain function that we would associate with higher-brain life (the opposite of higher-brain death) doesn't really come around until well into the second trimester.

As for a post on amnesia, I would be happy to write one. Memory is my favorite topic, after all (well, maybe analogy, but I view most forms of memory as a forms of analogy). I'll try to do it sometime this week. There are several kinds of amnesia, so it may take a few posts.

Macht said...

"An individual human person is differentiated from other human individuals, as well as nonhuman individuals, by a collection of memories, beliefs, knowledge, skills, and tendencies. In other words, what defines an individual person is a history. That history is, by and large, contained in the cerebral cortex and surrounding brain areas, along with the cerebellum."

What do you mean, exactly, that this history is "contained" in the cerebral cortex and surrounding brain areas? Isn't this history closely associated with an individual's entire body? Is my skill of being able to, say, dribble and shoot a basketball "contained" in the brain or is it a skill that my entire body possesses? It seems to me that things like muscle development and other similar things should be just as much a part of this "skill history." I guess I have the same problem as Brandon in that I don't see why the entire body's history shouldn't be included in the history that you say makes up the person. In other words, what differentiates my self from your self is not only my cerebral cortex (and surrounding areas) history, but my entire body's history. I agree that who we are is more than just breathing, circulation, etc. But it is also more than just the "history that is recorded in the configurations of our higher-brain structures."

I also don't see how viewing a person as a kind of "bodily history" will be harmful to the dignity of individuals. Just the opposite since it avoids the problems you spoke of - instead it treats the entire body as "all that makes us who we are."

Chris said...

Macht, see my comment above (the second comment) for your question about the body. A person's history is, in part, contained throughout the body, but it is unrealizable without higher-brain function. It turns into mere surface difference.

Macht said...

But you are assuming in that comment the very thing that I'm questioning. To say "A person's history is, in part, contained throughout the body, but it is unrealizable without higher-brain function" is to assume that the person's history is "contained" in the cerebral cortex and surrounding areas. In particular, I'm questioning your phrase "[without a brain] all traces of the individual person are lost."

It isn't clear to me why we should single out the "history that is recorded in the configurations of our higher-brain structures" from the entire "bodily history." To put it another way, in your comment above, what reason do we have for separating 1) and 2) ? I can understand isolating the brain from the rest of the body in order to make studying it easier, but when we are talking about personhood it seems wrong to talk about "a person is a brain and the rest of his or her body" rather than "a person is a body (part of which is a brain)."

Chris said...

Macth,
I'm going to assume, for the moment at least, that you're not being disingenuous (perhaps, for instance, you are a 16th century Frenchman). First, imagine that we remove the entire brain from a body, but keep the body "alive" by artificially pumping oxygen-rich blood, stimulating digestion in the stomach, etc. Is the "person" whose body we are causing to function in the absence of a brain alive? I think even Brandon would say no to this. Now, imagine we ad a hindbrain, so that it performs those functions itself. Is it alive? Brandon would say yes, but even here, at least a part of the brain is required. Now, imagine we add a hindbrain. In doing so, we add not only the storage-place of the person's history, but also the ability to manifest that history. This (the whole system, not just the forebrain) is where I say personhood lies.

Note one more time that the forebrain is nothing without its body. It develops to fit is particular body, and cannot function without it. Thus, while I am requiring a forebrain for personhood, I am not saying that the forebrain and personhood are coextensive. The forebrain is a necessary feature, and so is the body, but neither alone is sufficient.

There are differences in other part of the body that are important, but they are merely like the differences in the condition of the condition of the paint on a barn, or the amount of wood that's been eaten out of its supports by termintes. They make us different things, but they don't, by themselves, make us different persons, because while they alter the way our bodies i react to the environment, even in the absence of a brain (as long as we can keep the body "alive"), they cannot affect the way we act in the world without the brain. In short, the body without the brain is a mere reactive hulk, and with it, it is an active particiant in the world (or, at least, a potential actor, in cases of temporary unconsciousness, e.g.).

Chris said...

Lindsay, I know of some theories that treat pre-cortical areas as integral for certain levels of consciousness -- basic consciousness, with no self-consciousness, autobiographical memory, etc., only a simple sort of brain-world window. These areas include the amygdala, and most importantly, the thalamus. But I'm not sure that they can lead to any level of consciousness without a cortex to input to.

In fact, one way to place someone in a completely unconscious state is to lesion or sever the Intralaminar Nuclei of the thalamus (ILN). These nuclei do two things: send signals from extra-cortical regions (like the amygdala, or pre-cortical sensory regions) to the cortical areas, and from cortical areas to other cortical areas. You can reasonably say that consciousness is not located in any one spot, and is distributed throughout different brain areas, but distributed or not, if you destroy this one brain area, the ILN, there is no evidence of consciousness at any level. And the ILN requires the cortex to work.

Now, parts of the brain can still receive inputs from the body, and send signals back to the body, causing it to react to the environment. This is true of areas like the thalamus and hypothalamus, amygdala, as well as areas in the brainstem, such as the reticular activating system, but I'm not sure that the brain-world interactions you get with these areas alone can be considered any level of "consciousness." I suppose it depends on how we define consciousness.

Chris Wilson said...

What if there's a more pragmatic way to look at this issue?

http://www.enlightenedcaveman.com/2005/03/sanctity-of-life-versus-life-effect.html

Maybe it doesn't matter where we draw the line of life. Maybe we can just be practical enough to realize that sometimes death is better.

Warning - avoid any of the science posts on my site. I've not done the proper due diligence:-)

Macht said...

No, I'm not being disingenuous - just trying to understand your view. I think I do now.

Brandon said...

Chris,

Thanks for the clarification. I'm not convinced; but that's not surprising on a topic like this. If I have time this coming week I might put up a post saying why.

Given the comment about memory as a form of analogy to Caleb, at some point you will certainly have to write a post devoted precisely to that topic.

(If Lizzie is reading this: My comments are Haloscan, so you don't have to be a team member; the comment's there now; Haloscan may just have been a bit flaky when you submitted.)

Anonymous said...

A very interesting set of post and comments.

It is interesting that you bring up the homunculus, Brandon, because if my memory serves me, some proponents held that a little man (homunculus) was inside every sperm, preformed as it were, before conception. Imagine the number of little men who die in order for one to make it!

It might help if we try to separate the definition of personhood from the medical and ethical decisions that are made about what constitutes a merciful prolongation of life or when it is permissable to abort a conception.

The only thing I would add to Chris's naturalist and materialist definition of personhood is that what he is calling the history must be active for a body to be a person. In other words, a person in a deep coma is no longer a person. One could say that. However, if they have the potential of recovering from a coma, then they could be classified as a potential person and given that status.

I'm reminded of the classic comments of Lucretius (materialist): where death is, I am not. Where I am, death is not.

Terry Schiavo is gone, she will never come back. She is not, to paraphrase Lucretius.

Chris is in my view on the right track. Both a body and a working brain are required as is conscious activity for someone to be a person.

In that vein, it is no more humane to pull the feeding tube from the body that is nominally Terry Schiavo than it is to leave the feeding tube in. It is rather a social question and it involves those who are living and conscious today and their relationship to this body, to the personal and social costs of keeping this body alive or letting it die.

I have two more koans or lines from different figures that I think illuminate some of the strangeness of consciousness and that more alien concept or fact if you will of death.

Duchamp: "and anyway, it is only other people who die" downright Epicurean, and follows from Lucretius.

This is a slight modification from Jnaneshwar the 12th century Marathi saint and philosopher:

"If someone is in deep sleep, and no one sees him, is he there?"

Anonymous said...
This comment has been removed by a blog administrator.
Anonymous said...

sorry chris,

blogger was getting flaky on me. they must be having some scaling problems. can you delete the repeat post, thanks.