One of the famous line drawings of the artist M. C. Escher
portrays a realistically drawn hand holding a pencil. The line drawn by the pen turns out to be the cuff of a
shirt sleeve, from which emerges a second hand. . . which grows out of the
paper somehow and holds a pencil, whose line is the cuff of a shirt sleeve,
from which emerges the first hand.
Escher’s “Drawing Hands” came to mind when I read of a planned
initiative by the Obama administration to promote a decade-long project to map
the human brain.
Officially, the project is still under wraps until the
President announces his budget priorities later this month. But according to a New York Times report by John Markoff, plans include increased
federal funding for neurological research directed at mapping increasingly
complex brains, ranging from those of a fruit fly up to the world’s smallest
mammal, a type of shrew. But the
ultimate goal is to learn how essentially every neuron in the human brain is
connected, and how the whole thing works:
a wiring diagram of the brain, if you will. Hopes are that such knowledge could lead to new therapies
for presently incurable brain disorders such as Alzheimer’s disease and other
forms of dementia.
Inevitably, this project has been compared to the Human
Genome Project, which was completed about a decade ago at a cost of under $4
billion. Some estimates say that
the information gained from that project has returned up to $140 for every
dollar spent. Aside from the
purely economic results, the mapping of the human genome was a landmark
scientific achievement in its own right, which has led to further questions and
discoveries in an already burgeoning field.
Does the human-brain mapping project hold the same amount
of promise, either economically or scientifically? The first question that should be asked is, “Can it
work?” And some scientists are
already voicing doubts.
Markoff quotes neuroscientist Donald G. Stein as saying, “I
believe the scientific paradigm underlying this mapping project is, at best,
out of date and at worst, simply wrong.”
Apparently, the old analogies of the brain as a massive kind of
telephone switchboard, or even a “wet computer,” fail to capture essential
aspects of an organism which can develop new neurons in response to external
stimuli, and has recently proved to be much more plastic than earlier theories
supposed. To the extent that the
project imposes an outdated brain model on researchers, it will not
succeed. But every researcher
knows that what you say you are going to do in order to get research money, is
not necessarily the thing you actually end up doing, so this concern is
probably not as great as you might think.
What is of greater concern now is the question of
basic feasibility. When Dr. Rafael
Yuste of Columbia University was asked at a September 2011 conference about
what he would really like to be able to do with the brain, he replied, “I want
to be able to record from every neuron in the brain at the same time.” Simply storing the data that would
result from such an instrument is a brain-boggling proposition. One estimate is that you would need the
data-storage equivalent of about 600 million hard drives the size of the one on
my personal computer (500 gigabytes) to store all the neurological activity
that goes on in only one brain for a year. The next time you say “nothing’s on your mind,” think about
that.
Of course, data storage has been getting more
efficient for decades, and it will probably continue to do so for a while. But storing the data is nowhere near as
hard as obtaining it in the first place.
Right now, the only way to monitor individual brain neurons is to
connect wires to them, which requires opening the skull. There are various means to monitor the
brain non-invasively, but at present they have a fairly poor resolution, on the
order of a millimeter at best. And
there are thousands of neurons in each cubic millimeter of brain. Futuristic plans to send molecule-size
data recorders into the brain and record the results on DNA are still purely
drawing-board notions, and it is not clear they will ever work.
When the Human Genome Project began, we knew that DNA
sequencing was possible—it was just very slow and tedious. Rapid advances in technology enabled
the project to finish ahead of schedule.
It is by no means clear that massive monitoring of individual brain
neurons is even theoretically possible. And unmentioned so far is the question brought up by the
Escher drawing: can the brain
really understand itself? In
particular, what would happen if Dr. Yuste gets his wish and one day he sits
down at a computer monitor that shows him the output of his own brain in some
meaningful way. If you’ve ever
pointed a TV camera at a monitor showing the camera’s own field of view, you have
seen some weird patterns show up.
It’s not pleasant to contemplate what it might mean for your own brain
to watch itself in action.
As with any great leap in scientific knowledge these
days, the rationale for it is that it may lead to practical benefits such as cures
for diseases like Alzheimer’s and autism.
While we can’t discount these possibilities, neither can we discount the
notion that once it’s possible to exhaustively monitor the activity of the
human brain, it may be possible to read thoughts in a way that would amount to
the ultimate invasion of privacy.
At the very least, this possibility raises concerns that should be taken
seriously. So far, everyone whose
brain has been monitored has given consent to the process, we hope. But the molecule-size brain monitors
could be delivered without the patient’s knowledge or consent.
So far, this kind of thing is in the realm of science
fiction rather than fact. But
before it becomes fact, let’s hope that we have a full public discussion of the
potential downsides as well as the benefits of a map of the human brain,
assuming such a thing is even possible.
Sources: John Markoff’s article
“Obama Seeking to Boost Study of Human Brain,” appeared in the online edition
of the New York Times on Feb. 17,
2013, at http://www.nytimes.com/2013/02/18/science/project-seeks-to-build-map-of-human-brain.html. He followed it with an analysis piece
on the same subject on Feb. 24 at http://www.nytimes.com/2013/02/26/science/proposed-brain-mapping-project-faces-significant-hurdles.html. I relied on both of these pieces for
this article. The M. C. Escher
work “Drawing Hands” can be viewed at http://kafee.files.wordpress.com/2009/10/drawing_hands.jpg
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