[Paleopsych] NYT: It May Look Authentic; Here's How to Tell It Isn't
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Sat Jan 28 20:10:35 UTC 2006
It May Look Authentic; Here's How to Tell It Isn't
http://www.nytimes.com/2006/01/24/science/24frau.html
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By NICHOLAS WADE
Among the many temptations of the digital age, photo-manipulation
has proved particularly troublesome for science, and scientific
journals are beginning to respond.
Some journal editors are considering adopting a test, in use at The
Journal of Cell Biology, that could have caught the concocted
images of the human embryonic stem cells made by Dr. Hwang Woo Suk.
At The Journal of Cell Biology, the test has revealed extensive
manipulation of photos. Since 2002, when the test was put in place,
25 percent of all accepted manuscripts have had one or more
illustrations that were manipulated in ways that violate the
journal's guidelines, said Michael Rossner of Rockefeller
University, the executive editor. The editor of the journal, Ira
Mellman of Yale, said that most cases were resolved when the
authors provided originals. "In 1 percent of the cases we find
authors have engaged in fraud," he said.
The two editors recognized the likelihood that images were being
improperly manipulated when the journal required all illustrations
to be submitted in digital form. While reformatting illustrations
submitted in the wrong format, Dr. Rossner realized that some
authors had yielded to the temptation of Photoshop's image-changing
tools to misrepresent the original data.
In some instances, he found, authors would remove bands from a gel,
a test for showing what proteins are present in an experiment.
Sometimes a row of bands would be duplicated and presented as the
controls for a second experiment. Sometimes the background would be
cleaned up, with Photoshop's rubber stamp or clone stamp tool, to
make it prettier.
Some authors would change the contrast in an image to eliminate
traces of a diagnostic stain that showed up in places where there
shouldn't be one. Others would take images of cells from different
experiments and assemble them as if all were growing on the same
plate.
To prohibit such manipulations, Dr. Rossner and Dr. Mellman
published guidelines saying, in effect, that nothing should be done
to any part of an illustration that did not affect all other parts
equally. In other words, it is all right to adjust the brightness
or color balance of the whole photo, but not to obscure, move or
introduce an element.
They started checking illustrations in accepted manuscripts by
running them through Photoshop and adjusting the controls to see if
new features appeared. This is the check that has shown a quarter
of accepted manuscripts violate the journal's guidelines.
In the 1 percent of cases in which the manipulation is deemed
fraudulent - a total of 14 papers so far - the paper is rejected.
Revoking an accepted manuscript requires the agreement of four of
the journal's officials. "In some cases we will even contact the
author's institution and say, 'You should look into this because it
was not kosher,' " Dr. Mellman said.
He and Dr. Rossner plan to add software tests being developed by
Hani Farid, an applied mathematician at Dartmouth. With a grant
from the Federal Bureau of Investigation, which is interested in
ways of authenticating digital images presented in court, Dr. Farid
is devising algorithms to detect alterations.
His work has attracted interest from many people, he said,
including eBay customers concerned about the authenticity of
images, people answering personal ads, paranormal researchers
studying ghostly emanations and science editors.
For the latter, Dr. Farid is developing a package of algorithms
designed to spot specific types of image manipulation. When
researchers seek to remove an object from an image, such as a band
from a gel, they often hide it with a patch of nearby background.
This involves a duplication of material, which may be invisible to
the naked eye but can be detected by mathematical analysis.
If an object is enlarged beyond the proper resolution, Photoshop
may generate extra pixels. If the object is rotated, another set of
pixels is generated in a characteristic pattern.
An object introduced from another photo may have a different angle
of illumination. The human eye is largely indifferent to changes in
lighting, Dr. Farid said, but conflicting sources of illumination
in a single image can be detected by computer analysis and are a
sign of manipulation.
"At the end of the day you need math," Dr. Farid said. He hopes to
have a set of tools available soon for beta-testing by Dr. Rossner.
Journals depend heavily on expert reviewers to weed out papers of
poor quality. But as the Hwang case showed again, reviewers can do
only so much. The defined role of reviewers is not to check for
concocted data but to test whether a paper's conclusions follow
from the data presented.
The screening test addresses an issue reviewers cannot easily
tackle, that of whether the presented data accurately reflect the
real data. Because journal editors now have the ability to perform
this sort of quality control, "they should do it," Dr. Rossner
said.
The scientific community has not yet come to grips with the
temptations of image manipulation, Dr. Mellman said, and he would
like to see other journals adopt the image-screening system, even
though it takes 30 minutes a paper. "We are a poor university
press," he said, without the large revenue enjoyed by journals such
as Nature, Science and Cell. "If they can't bear this cost,
something must be dreadfully wrong with their business models," he
said.
Science, in fact, has adopted The Journal of Cell Biology's
guidelines and has just started to apply the image-screening test
to its own manuscripts. "Something like this is probably inevitable
for most journals," said Katrina Kelner, a deputy editor of
Science.
She became interested as a quality control measure, not because of
the concocted papers of Dr. Hwang, two of which Science published.
Dr. Mellman says the system would have caught at least the second
of Dr. Hwang's fabrications, since it "popped out like a sore
thumb" under the image screening test.
But other editors are less enthusiastic. Emilie Marcus, editor of
Cell, said that she was considering the system, but that she
believed in principle that the ethics of presenting true data
should be enforced in a scientist's training, not by journal
editors.
The problem of manipulated images, she said, arises from a
generation gap between older scientists who set the ethical
standards but don't understand the possibilities of Photoshop and
younger scientists who generate a paper's data. Because the whole
scientific process is based on trust, Dr. Marcus said: "Why say,
'We trust you, but not in this one domain?' And I don't favor
saying, 'We don't trust you in any.' "
Rather than having journal editors acting as enforcers, she said,
it may be better to thrust responsibility back to scientists,
requiring the senior author to sign off that the images conform to
the journal's guidelines.
Those guidelines, in her view, should be framed on behalf of the
whole scientific community by a group like the National Academy of
Sciences, and not by the fiat of individual editors.
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