Home > The Loom
A Blog About Life, Past and Future

Winner of the American Association for the Advancement of Science’s 2004 Science Journalism Award

Scientific American Science and Technology Awards 2005

About this Author
Carl Zimmer Carl Zimmer is the author of several popular science books and writes frequently for the New York Times, as well as for magazines including The New York Times Magazine, National Geographic, Science, Newsweek, Popular Science, and Discover, where he is a contributing editor. Carl's books include Soul Made Flesh,, Parasite Rex and Evolution: The Triumph of An Idea. His latest book is Smithsonian Intimate Guide to Human Origins. Please send newsworthy items or feedback to blog-at-carlzimmer.com.
The Latest on Human Evolution!
Smithsonian%20small.jpg Smithsonian Intimate Guide to Human Origins
More on the book...

Test calendar
Recent Newspaper & Magazine Articles
."Children Learn by Monkey See, Monkey Do. Chimps Don' t "
The New York Times, December 13, 2005

."A Pair of Wings Took Evolving Insects on a Nonstop Flight to Domination "

The New York Times, November 29, 2005

."From the Mouths of Lizards Spew Clues to the Origin of Snake Venom "
The New York Times, November 22, 2005

."In Give and Take of Evolution, a Surprising Contribution From Islands"
The New York Times, November 22, 2005

."Down For the Count "
The New York Times, November 8, 2005

."The Neurobiology of the Self "
Scientific American, November 2005

."Can Chimps Talk? "
Forbes.com, October 24, 2005

."DNA Studies Suggest Emperor Is Most Ancient of Penguins "
The New York Times, October 11, 2005

."The History of Chromosomes May Shape the Future of Diseases "
The New York Times, August 30, 2005

."Building a Virtual Microbe, Gene by Gene by Gene "
The New York Times, August 16, 2005


Soul Made Flesh
A 2004 New York Times Notable Book of the Year

evocover.jpg Evolution: The Triumph of an Idea (2001)

prexcover.jpg Parasite Rex (2000)

watercover.jpg At the Water's Edge (1998)

"...among the joyous, heartless, ever-juvenile eternities, Pip saw the multitudinous, God-omnipresent, coral insects, that out of the firmament of waters, heaved the colossal orbs. He saw God's foot upon the treadle of the loom, and spoke it; and therefore his shipmates called him mad."
--Moby Dick


By submitting a comment, you grant Carl Zimmer permission to quote or republish this comment without restriction, notification, or compensation. Also, you acknowledge that you alone are fully responsible for (and bear full legal liability for) the content of this comment – including inaccuracies or potentially libelous statements. You certify that in this comment you have disclosed no proprietary or confidential information. This agreement applies even if you choose to post anonymously or supply false or incomplete identification.

Spirited debate is welcome, but comments that are spam, off-topic, seriously offensive, or otherwise inappropriate will be removed at my discretion. Comments may take up to a day to be posted, due to filtering, although usually they will be posted immediately. I do not fact-check, spell-check, or otherwise verify or correct comments.

Starting Points and Old Favorites
Eyes, Part One: Opening Up the Russian Doll

Eyes, Part Two: Fleas, Fish, and the Careful Art of Deconstruction

Florida, Where The Living Is Contradictory

The Chromosome Shuffle

Of Stem Cells and Neanderthals

Taking the Plunge

Your Loss is Your Gain

Divine Worms

Recent Trackbacks
› Chaotic Utopia:
Weird weather and bifurcations

› Watermark:
CUTE! Cats

› Critical Biomass:

› MonkeyFilter:
Cat Family Tree

› Pharyngula:
It's good to know…

› 無修正動画の楽しみ方:
無修正 画像の楽しみ方

Subscribe with Bloglines

Creative Commons License
In the Pipeline: Don't miss Derek Lowe's excellent commentary on drug discovery and the pharma industry in general at In the Pipeline

The Loom

February 08, 2005
Consciousness and the Culture Wars, Part ThreeEmail This EntryPrint This Entry
Posted by Carl Zimmer

Scientists studying people in minimally conscious states have published the results of brain scans showing that these people can retain a surprising amount of brain activity. The New York Times and MSNBC, among others, have written up accounts.

I profiled these scientists for a 2003 article in the New York Times Magazine, when they were at an earlier stage in their research. Things certainly have changed since then. When my article came out, hardly anyone had heard of Terri Schiavo, the Florida woman in a permanent vegetative state who is at the center of a battle between her parents, who want to keep her feeding tube in, and her husband, who wants it taken out. Since then, her case has made national headlines, and a law has been passed in her name. I for one will be keeping close attention to how this new paper is received (and used) in the debate over Terri Schiavo, because I had the displeasure of watching my article get pulled into the debate and distorted for political ends.

The key point to bear in mind about this new research is that there's a difference between people in a permanent vegetative state and people in a minimally conscious state. Neurologists have developed bedside tests to determine which state a given patient is in. People in minimally conscious states show fleeting, but authentic, awareness of their surroundings, for example. People in vegetative states do not. Neurologists cannot make this diagnosis from the reports of family members, because it is easy to see awareness in a loved one when there is, in fact, none. That doesn't mean that family members are necessarily wrong if they say a loved one is aware. It's just that a doctor needs to test a patient objectively, using methods that don't rely on his or her own interpretation.

Some people have argued that this test is circular: people are simply defined minimally conscious if they pass a test for minimal consciousness. But the designers of the test have shown that it does have predictive power. For one thing, people who rise to a minimally conscious state have a small but real chance of recovering consciousness (although they may never return to their former selves). People who stay in a permanent vegetative state for many years, by contrast, almost never recover.

The brain scan findings now being reported also strengthen the notion of a minimally conscious state. The researchers scanned the brains of patients diagnosed as minimally conscious, playing the voice of loved ones through headphones, scratching their skin, and doing other tests to check for the function of their brain. They found that the patients responded in important ways. Some patients responded to the recordings with strong activity in regions of the brain involved in language and memory, for example. But in the absence of stimuli, the brains of the patients used less energy than a person would under anesthesia.

On the other hand, earlier scans of people diagnosed as being in a permanently vegetative state showed at most only isolated islands of activity in the cortex, where higher brain functions take place. So the difference detected by bedside tests is mirrored by a difference detected in the brain scanner.

It's crucial neither to overplay or underplay the importance of this work. People who are coping with the staggering burden of a loved one in a truly permanent vegetative state should not see this as evidence that their loved one is conscious and simply "locked in" to an unresponsive body. Nor should pundits raise false hopes by claiming that this is the case.

But it is also true that people with impaired consciousness are not getting the attention they deserve, starting with a good diagnosis. Thirty percent of people in a permanent vegetative state may actually be minimally conscious. It would be fantastic if some day doctors could make a precise diagnosis of brain-damaged patients simply by running them through some tests in a scanner. For now, though, only a handful of people with impaired consciousness in the entire world have been scanned at all. Eventually, it might be possible to use the knowledge gained from these tests to start finding ways to help people recover more of their consciousness, perhaps through brain stimulation. Today there's nothing a doctor can do but wait and watch.

Unfortunately, people with impaired consciousness are more likely to be simply warehoused, getting hardly any attention from a neurologist. Are we, as a society, ready to give these voiceless people the care they deserve?

Category: Brains

David Govett on February 9, 2005 03:03 AM writes...

I can imagine no hell worse than one's ego trapped incommunicado in an increasingly solipsistic environment. Insanity must ensue.

Permalink to Comment
tom on February 9, 2005 02:19 PM writes...

David, I think a kind of insanity does ensue, every night as your brain entertains itself during the 8 hours of solipsism that sleep gifts us. Insanity, but not hell.

Why would a minimally conscious state be any different from this kind of unstructured consciousness? It may last longer, but time is distorted in dreams anyway.

Permalink to Comment

TrackBack URL: http://www.corante.com/cgi-bin/mt/mt-tb.cgi/8870





Remember personal info?

Email this entry to:

Your email address:

Message (optional):