Received: by alpheratz.cpm.aca.mmu.ac.uk id PAA27254 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-majordomo@mmu.ac.uk); Tue, 9 Jan 2001 15:07:33 GMT Subject: Fwd: Looking for clues in the world's biggest brain bank Date: Tue, 9 Jan 2001 10:03:29 -0500 x-sender: wsmith1@camail2.harvard.edu x-mailer: Claris Emailer 2.0v3, Claritas Est Veritas From: "Wade T.Smith" <wade_smith@harvard.edu> To: <skeptic@listproc.hcf.jhu.edu>, "memetics list" <memetics@mmu.ac.uk> Content-Type: text/plain; charset="iso-8859-1" Content-transfer-encoding: quoted-printable Message-ID: <20010109150154.AAA12811@camailp.harvard.edu@[128.103.125.215]> Sender: fmb-majordomo@mmu.ac.uk Precedence: bulk Reply-To: memetics@mmu.ac.uk
Looking for clues in the world's biggest brain bank
http://www.boston.com/dailyglobe2/009/science/What_makes_us_tick_P.shtml
By Raja Mishra, Globe Staff, 1/9/2001
Brains aren't gray.
They're tan, almost yellow. The sliced-up example sitting on Dr. John
Hedreen's cutting board has the consistency of mushrooms, maybe something
else.
''It's like hard Jell-O,'' he says.
He slices the brain into quarter-inch slivers with a kitchen knife. Days
ago, this brain was thinking. It was remembering. It was feeling.
Perhaps, close to death, it conjured up a lifetime of accomplishments, of
regrets, of loves.
Now it is meat.
''A very highly organized mushroom,'' says Hedreen, slicing away.
The 1990s were dubbed the ''Decade of the Brain'' by President George
Bush. Science made enormous leaps in understanding how the components of
the brain work. Treatments for fearsome degenerative brain diseases now
seem attainable. Hedreen works at McLean Hospital's brain bank, also
known as the Harvard Brain Tissue Resource Center, which sends scientists
brain samples to conduct research on these illnesses.
But what of consciousness?
What is it about that 3-pound hunk of meat that gives rise to the sense
that our thoughts and feelings and perceptions are unified into one
bundle that is us? It is a phenomenon so central to life - it's always
there - yet so elusive. For all our advances, consciousness defies
explanation.
In fact, the millennium-long argument over consciousness has grown
particularly heated in the last decade. Neuroscientists state that they
can explain consciousness in the familiar language of chemistry and
biology. Philosphers retort: Foolishness! Theologians fret that God's
handiwork is being diminished by the whole debate.
Thinking on the issues basically divides into two camps: Those who argue
neuroscience will one day figure out the biochemical mechanisms that give
rise to consciousness, and those who state that the very nature of
consciousness resists scientific explanation.
The only consensus is that there is no consensus.
Hedreen lines up the brain slivers on his cutting table. He points to the
corner of one, a swirl of tan and yellow.
''That's the basal ganglia,'' he says, explaining that it is the part of
the brain that atrophies during Huntington's disease, eventually causing
dementia.
Just a slight change in the consistency of this rubbery little item can
decimate a lifetime of thoughts and habits.
''You can tell just by looking at its colors and shape'' whether the
brain's former owner had Huntington's, Hedreen says.
''This one seems OK.''
A brain ''junkyard''
Six freezers line each side of a narrow room in the basement of one of
the buildings on McLean's vast campus. There is scarcely room for two
people between the rows.
Blowing air creates a noisy hum. The freezers' temperature gauges read
minus 77 degrees Centigrade, or minus 106.6 Fahrenheit.
This is the vault, in a manner of speaking, of the world's largest brain
bank, where hundreds of brains - many of them once belonging to people
who suffered from dementia or other mental illnesses - are stored.
Opening one of the freezers reveals dozens of clear lunch-bag-size bags
filled with brain slivers. The frozen slivers are orange. On each bag is
a hand-scrawled number in black Magic Marker.
''This is like a junkyard,'' says Dr. George Tejeda, assistant director
of the brain bank. ''If someone says, `I'm looking for a carburetor,' I
tell them: `This is what we have.'''
What makes cars go can be explained. The internal combustion engine is
understood from top to bottom. Each function of a car - air filtering,
steering, exhaust - is easily explained by the engineer, as is the way in
which they work to together to make the car move.
Some hope the same one day will be said about the brain and its most
obvious product - consciousness.
''We are quite certain that a naturalistic, mechanistic explanation of
consciousness is not just possible. It is fast becoming actual,'' Tufts
University philosopher Daniel Dennett told the Royal Institute of
Philosophy in England in a millennial lecture last year.
Dennett is perhaps the most eminent proponent of this view. It holds that
science will eventually uncover enough about the brain and body to
explain consciousness. Indeed, neuroscientists are preparing for a
dramatic increase in brain research in the coming years, including more
than $350 million for new neuroscience centers at the Massachusetts
Institute of Technology alone.
Already, the mechanisms behind many of the bedrock aspects of our
existence, like emotion and memory and sensory perception, are reasonably
well understood by scientists, neurologists say. The brain has been
mapped. The chemicals that influence the brain are being uncovered.
But how it all combines to create a sense of self - consciousness - is
still a mystery.
Dennett and his allies believe the mystery will yield to decades more of
probing the brain, using various methods of brain imaging as well as the
postmortem research that originates with the brain tissue at the McLean
brain bank.
Just as we progressed from ignorance to general understanding of the
brain during the 20th century, these optimists believe that perhaps the
21st century will produce another leap of knowledge that conquers
consciousness.
In the room next to the freezers is Tupperware. Lots of it. Hundreds of
stacks filled with a yellowish green liquid line rows of shelves. In them
float more brain bits. These are fresh brains, those that arrived so
intact they didn't require freezing.
At 9:30 on a recent morning, Tejada received a call from Arizona. A fresh
brain would arrive within 12 hours. He makes arrangements to staff the
brain bank late into the evening to receive the precious cargo. He calls
this ''The Show.''
In early December, McLean got its 5,000th brain in 22 years of existence.
Workers have ''The Show'' down to a science. The mechanics of it they
understand. But the cargo is a different matter.
''Sometimes in the middle of the night, I think, what made this person
get Alzheimers? Then you're tired and you go home,'' Tejada says.
Mind art
Dr. Tim Wheelock is no artist but you wouldn't know from looking at his
computer screen. It is filled with frames of swirling violet masses with
bluish squiggles. Others are Jackson Pollock-like canvases of red
smudges, black scribbles and orange flecks.
These are images of brain tissue taken through Wheelock's microscope -
local maps of the brain. Wheelock, the brain bank's assistant director of
histopathology, makes these available, via the Internet, to researchers.
He pulls up a photo filled with dull red bundles. They're called tangles,
dead neurons ravaged by Alzheimer's disease.
''Debris, like a skeleton,'' he explains.
When people get enough of these, they start forgetting. But what can
these colorful screens tell us about what it means to be conscious or how
it feels to forget?
''One difference that will never be bridged is direct personal experience
and tissue,'' Wheelock says. In other words, no amount of knowledge about
the brain and its function will ever explain the experience of being
human.
That is the position held by another school of thought. We may be able to
describe the physical parts of the brain, they say, but we will never be
able to articulate how they create consciousness.
In the same way that rats don't understand mathematics, we are unable to
fathom consciousness, some of them argue. Our brains just aren't powerful
enough.
''Consciousness has been discussed for probably thousands of years,''
said Steven Pinker, an MIT psychology professor and author of the book,
''How the Mind Works.''
''But it's not a problem that science is ever likely to illuminate.''
Pinker said he agrees that our minds aren't capable of understanding
consciousness. Another example of such a shortcoming, he explained, is
the Big Bang, which physicists believe created the universe. The natural
question is: What happened before the Big Bang. A physicist would say
that time simply didn't exist and there was no before. But that doesn't
make intuitive sense.
''My own mind is tricking me into thinking that before and after are
relevant to the Big Bang,'' Pinker said.
In similar fashion, consciousness is something beyond our comprehension,
he said.
It may all seem rather esoteric, but anyone who has worked in the brain
sciences profession ponders the issue quite frequently. Just ask those at
the brain bank.
''It's hard to say where consciousness resides at all,'' says Wheelock
sitting in front of his terminal at the brain bank.
But he has his theories. His latest involves the pre-central gyrus, also
known as part of the primary motor cortex or Brodmann Area 4. It begins
at the top of our heads and goes into the center of our brains. This is
where much of our immediate sensory data is processed - where we are, the
temperature, what we are touching.
''It gives us a sense we are in the world,'' he explains.
Wheelock suggests running tests on those with damage to this area, asking
them if their consciousness is impaired. But how would they know? What
would they have to compare themselves to? And how would we know that what
that person was experiencing was a lack of what we understand as
consciousness?
''Yeah, it's complicated, isn't it?'' he says with a laugh.
Ghosts in the machine
''I'll never forget the day I saw my first brain,'' says Dr. Francine M.
Benes, director of the brain bank.
It was 32 years ago and Benes was in graduate school. The brain was in a
bucket, plucked from a man who had just died.
''This organ was capable of thinking thoughts just a few hours ago,'' she
says. ''I thought: `What is it that transformed it from this exquisite
organ to this dead lump?'''
At that time, neuroscience as we know it did not exist. Only a handful of
philosophers pondered consciousness. Serious scientists hardly considered
it. At the time, an idea called dualism by academics reigned. To a great
extent, it still does.
Dualists believe in the soul, the spirit, the ''ghost in the machine.''
It is something that is not matter - and therefore unmeasurable by
science - yet gives us consciousness and makes us individuals.
Most scientists consider this wishful mysticism: How can something not
made of matter influence the matter in our bodies? Yet, absent a
compelling explanation of consciousness, the soul remains a powerful idea
in almost every culture.
In 1978, when the brain bank was founded, most scientists were skeptical
that studying dead brains would produce useful results. It's as if they
were crying: ''What good is a brain without the soul?''
But breakthroughs in the understanding of Alzheimer's disease convinced
skeptics. Now there are about 200 brain banks in the United States. And
that has many scientists optimistic that, once again, science will
triumph.
''I think in my lifetime we'll see big breakthroughs in how the human
brain is wired and how it works,'' Benes said. ''It really is the final
frontier.''
This story ran on page F01 of the Boston Globe on 1/9/2001. © Copyright
2001 Globe Newspaper Company.
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