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Posts Tagged ‘brain’

Forgive the crude title, but this is the question I was discussing with a group of healthcare professionals recently. The specific topic was ‘brain death’, which is a phrase so widely used today that it hardly ever gets questioned. If someone’s brain is ‘dead’ then surely the person is dead as well? If the human brain has ceased to function then surely the human being has ceased to be alive? Not necessarily.

Much of the controversy is about organ transplantation. If you are going to take someone’s heart and give it to another person, you have to be sure that they are dead before you remove the heart, otherwise the act of removing the heart will be the very cause of their death. At least, that’s what most ethicists would say. The surgeon wants to know that he or she is taking a heart from a corpse and not killing a person. For many years, it has been assumed that if someone is certified ‘brain dead’ then they are definitely dead, and the transplant can go ahead. But this is being questioned more and more.

E. Christian Brugger, Senior Fellow of Ethics at the Culture of Life Foundation, gives some background:

For purposes of organ removal, there are two commonly accepted sets of criteria for determining that death has occurred: the “cardio-respiratory” standard and the “neurological” standard (sometime referred to as the “whole brain death” criterion). The Uniform Determination of Death Act formulated in 1981 by the President’s Commission and widely adopted throughout the U.S. defines the first as the “irreversible cessation of circulatory and respiratory functions”, and the second as “the irreversible cessation of all functions of the entire brain, including the brain stem.” Although each criterion focuses upon a limited set of critical functions, the state of death of the entire human organism is thought to be able to be inferred by focusing on any one of them.

In his 2000 address, John Paul II says that when “rigorously applied” the neurological criterion “does not seem to conflict with the essential elements of a sound anthropology.” He goes on to say “therefore a health-worker professionally responsible for ascertaining death can use these criteria [i.e., cardio-respiratory and neurological] in each individual case as the basis for arriving at that degree of assurance in ethical judgment which moral teaching describes as ‘moral certainty'” (No. 5).

In other words, the pope states that the neurological criterion seems to be a reliable basis for arriving at moral certitude that a person has died, which is required before harvesting vital organs can be legitimate.

But new questions have come up in the last few years.

Research has emerged in the past decade, especially by D. Alan Shewmon, professor of pediatric neurology at UCLA Medical Center and Consultant for the Pontifical Academy of Sciences, challenging the reliability of the widely accepted neurological standard.

Recall the pope says that death consists in the “disintegration of that unity and integrated whole that is the personal self” (no. 4), and that we can identify biological signs that follow upon the disintegration. It seems to follow that an apparent absence of certain biological signs of somatic (bodily) disintegration can raise reasonable doubts as to whether death has occurred.

Shewmon’s research demonstrates conclusively that the bodies of some who are rightly diagnosed as suffering whole brain death express integrative bodily unity to a fairly high degree.

Brain dead bodies cannot breathe on their own since the involuntary breathing response is mediated by the brain stem, which has suffered complete destruction. So the bodies need to be sustained on a mechanical ventilator, which supports the body’s inspiration and expiration functions (breathing in and out). But with ventilator support, the bodies of brain dead patients have been shown to undergo respiration at the cellular level (involving the exchange of O2 and C02); assimilate nutrients (involving the coordinated activity of the digestive and circulatory systems); fight infection and foreign bodies (involving the coordinated interaction of the immune system, lymphatic system, bone marrow and microvasculature); maintain homeostasis (involving a countless number of chemicals, enzymes and macromolecules); eliminate, detoxify and recycle cell waste throughout the body; maintain body temperature; grow proportionately; heal wounds (i.e., the immunological defense of self against non-self); exhibit cardiovascular and hormonal stress responses to noxious stimuli such as incisions; gestate a fetus (including the gaining of weight, redistribution of blood flow favoring the uterus, and immunologic tolerance toward the fetus); and even undergo puberty.

The data is indisputable. Yet there is considerable disagreement on how to interpret the data with respect to the question of human death. Some scholars such as James M. DuBois, writing in the 2009 “Catholic Health Care Ethics” manual published by the National Catholic Bioethics Center, refer to this long list of functions of brain dead bodies as “residual biological activities” no more expressive of life than the twitching of a lizard’s amputated tail. Others, including scientists and several philosophers and theologians who, with me, accept magisterial teaching, are less comfortable setting them aside as possible signs of true somatic integration.

Although Shewmon’s evidence certainly does not establish that brain dead bodies are the bodies of living (albeit highly disabled) persons, in my judgment, and in that of other competent scholars and scientists, it raises a reasonable doubt that excludes “moral certitude” that ventilator-sustained brain dead bodies are corpses.

It’s not an argument to say that a brain dead person is necessarily still alive – it simply suggests that there are serious doubts and questions about the meaning of brain death. And as long as such questions remain, we shouldn’t pretend that we have absolute confidence that a brain dead person is definitely dead. And if that’s the case, then there are implications for how we continue to care for such persons, and whether or not we transplant their organs.

If you want to follow this up, see this article on the Signs of Life conference on brain death in 2009; Pope Benedict’s 2008 address to a conference about organ transplantation; a Linacre Centre paper that touches on brain death, and another about the definition of death; and the NHS page about brain death, which includes the following uncritical remarks:

Brain death occurs when a person in an intensive care unit no longer has any activity in their brain stem, even though a ventilator is keeping their heart beating and oxygen circulating through their blood.

Once a brain stem death has occurred, the person is confirmed dead.

Unfortunately, there is no chance of a person recovering once their brain stem has died. This is because all of the core functions of the body have stopped working and can never be restarted. Although a ventilator can keep the heart beating, the person is effectively dead.

If permission has been given, organs can be removed for transplant and ventilation is withdrawn. Once ventilation is withdrawn, the heart stops beating within a few minutes.

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General Electric Color TV, 1960's by Roadsidepictures.The debate continues about whether allowing young children to watch TV harms their cognitive development or not. It flared up a couple of weeks ago when a report commissioned by the Australian government recommended that children under 2 should be banned from watching TV and electronic media such as computer games. So this is about freedom, censorship, the relationship between the personal and the political, the nanny state, etc., as much as it is about child development.

An article by Patrick Barkham looks at some of the scientific and political issues involved. At the centre of everything is the extraordinary way in which the human brain develops. (I prefer the word ‘mind’ to ‘brain’, because ‘mind’ allows us to appreciate that our cognitive relationship with the world is dependent on much more than the neurological condition of the brain. But the brain certainly plays its part.) Barkham reports the findings of Dr Michael Rich, director of the influential Center on Media and Child Health at Boston Children’s Hospital:

Humans have the most sophisticated brain on the planet because it is relatively unformed when we are born. Our brains triple in volume in the first 24 months. We build our brains ourselves, by responding to the environment around us. The biggest part of this is a process called pruning, says Rich, whereby we learn what is significant – our mother’s voice, for instance – and what is not. “TV killing off neurons and the synaptic connections that are made in order to discriminate signals from ‘noise’,” he says.

Experts in child development have found that three things optimise brain development: face-to-face interaction with parents or carers; learning to interact with or manipulate the physical world; and creative problem-solving play. Electronic screens do not provide any of this. At the most basic level, then, time spent watching TV has a displacement effect and stops children spending time on other, more valuable brain-building activities.

Scientists concede that they do not yet know precisely how TV affects the cognitive development, not just in terms of understanding the inner workings of the brain but because the way we use television and other electronic screens is changing so rapidly that we do not know how it will affect people by the time their brains stop developing in their mid-20s. But the weight of evidence about the deleterious impact of TV on child’s ability to learn is alarming…

A more recent article by Helen Rumbelow steps back and looks at the way theories of child development have changed over the last couple of generations. The 1990s was the decade in which we discovered the importance of the first 24 months, and the idea that the right stimulation could boost your child’s chances. This led to playing Mozart to the child in the womb, flashcards as soon as they popped out, and Baby Einstein videos when they could sit up. Now the tide has turned.

Waching too much TV is bad for your eyes by | spoon |.

I’m not taking sides here – I don’t know enough, and I don’t have children, and I’ve seen plenty of happy and healthy children grow up with a bit of TV. But for all those anxious parents tortured with guilt and uncertainty, Rumbelow provides some consolation with a quote from Dr Martin Ward-Platt. The evidence, he says, is still too equivocal:

 The farther you get away from deprived populations, the less TV gets watched, and the more parental controls there are, so it is hard to disentangle this stuff.

Of course, the thing that really makes the difference for a baby is interaction with a caregiver and there is nothing we can invent as a people substitute. But if a child watches some TV and is exposed to people for the rest of the time, they will do fine. What we don’t know is where the limit is, where you start to hold children back.

If there is no strong evidence either way, we think it’s much better to say we don’t know, and what’s right for you is probably the best thing for your family.

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A new generation of lie detectors is being developed (see Prospect, Oct 09, Lie Detection by Ian Leslie, p66). Remember the scene in Meet the Parents when Robert De Niro wires up his future son-in-law in the basement and interrogates him. This was the old-fashioned polygraph, which works by monitoring stress levels – blood pressure, heart-rate, etc.

wewilltestyourlies by sugarfreak.

The new models work by scanning the brain. When we tell a lie, even if we keep the stress levels down, an extra burst of mental energy is required. This energy is released in the areas of the brain responsible for reasoning and self-control. So if the scanner suddenly spots us thinking hard and carefully as we answer a progression of simple yes or no questions, then we are probably lying.

It could be bunkum. Many neuroscientists question its effectiveness. And a woman in India who was convicted of murder on the basis of evidence from such a lie detection test had her case overturned because there was no material evidence connecting her to the crime.

Supreme Two by YaniG.Why is the thought of an infallible lie detector so unsettling? It’s not because we are all inveterate liars terrified of being exposed. It’s because it makes us appreciate that the truth of another person is not just something that can be ripped out of them and put on display for all to see. Knowledge, when it has to do with another human being, can’t be separated from a relationship.

In ordinary friendships, it is the journey of coming to know someone that is more important than the actual knowledge we come to possess. As I heard in a recent film, the words ‘I’ve never told anyone that before’ are even more important than what was actually told. 

We let someone in gradually. We choose how much to share, and when to share it; and this depends on how much we trust someone, and how much they trust us, and how far along the road we have come together. It’s not that anyone has a right to lie. But we do all have a right to disclose ourselves gradually, on our own terms. Discretion and reticence are the background virtues that allow intimacy and friendship to have any meaning.

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