Learning with a Digital Brain
DURHAM, N.C. -- Imagine how much easier learning the
intricate structures of the brain would be if only you could
carry one around with you to study -- a truly remarkable brain
that you could slice, "unslice" and even reslice in another
plane to explore its complex anatomy. And what if you could
even pick from a list of brain structures -- ranging from the
abducens nerve to white matter -- and instruct your portable
brain to highlight the structure in vivid color amidst its
otherwise undifferentiated beige tissue?
Duke medical students enjoyed just such a capability for the
first time this year, thanks to a new neuroanatomy teaching
program called Sylvius: Fundamentals of Human Neural
Developed by neurobiologist S. Mark Williams with support
from the department of neurobiology and the medical school,
Sylvius was provided on CD-ROM to medical students taking
introductory neuroscience. The program was designed as an
electronic adjunct to the textbook Neuroscience (Sinauer
Associates, Sunderland, Mass., 1997), edited by Dale Purves and
faculty members George Augustine, David Fitzpatrick, Lawrence
Katz, Anthony-Samuel LaMantia and James McNamara.
Duke medical students have given the new program high praise
on feedback forms, using such terms as "very cool,"
"fantastic," "extremely helpful," and "absolutely wonderful
program." One student commented that Sylvius was "Very helpful
in obtaining a visual representation of the three-dimensional
structure of brain structures. Don't know how I'd do it without
the Sylvius program."
Williams named Sylvius for two renowned Renaissance
anatomists who believed in learning body structures by careful
dissection. And dissection is precisely what Williams had to do
in order to produce the images for the Sylvius program.
"Using a human brain specimen from our teaching lab
collection, I sectioned it in one plane and had digital
photographs made of each section. Then for the other two
planes, I glued the sections back together and resectioned them
each time, taking digital images.
The result, said Williams, was that Sylvius was based on
images of the same brain sectioned in three planes, which
greatly simplifies the task of students attempting to
understand brain structure.
"While the gross structure might be the same from brain to
brain, it was very helpful for the students to see the same
brain in different planes," Williams said. "Also, the program
can combine, say, a horizontal section and coronal section to
show a corner, giving the student a greater appreciation for
the three-dimensional organization of structures located deep
within the brain."
Once the images were obtained, however, Williams was still
faced with a considerable challenge in computer graphics to
render them useful.
"By the third sectioning, the brain was basically in cubes,
so there were plenty of cut marks and other defects that I had
to airbrush out to arrive at acceptable images."
Sylvius, includes more than 1,500 such images, organized
into four modules: surface anatomy, sectional anatomy, a
brainstem module and an index listing of some 200 structures.
In the index, mouse-clicking on a structure name calls up an
image with that structure highlighted in color. The program
also includes a "magnifying glass" that users can slide over
the images to see them in greater detail.
According to Williams, Sylvius is quite different from the
several other neuroanatomy programs on the market.
"We show the brain in higher resolution, and our program
gives the user a sense of dissecting the same brain in the
three major anatomical planes," he said. "Also, we
custom-tailored Sylvius specifically to the needs of the
medical students, and it integrates very readily into the
neuroanatomy teaching laboratory."
Not content to rest on his laurels, Williams has already
begun work on an improved version of Sylvius, which he expects
to be ready for the spring semester.
Sylvius 2.0 will include three-D models of individual brain
structures that students can extract from the whole brain for
examination. For this capability, Williams is using data from
National Library of Medicine's Visible Human Project, in which
human bodies were photographed thin section by thin section,
and collaborating with Bradley Smith of the Duke Center for In
Williams is also producing a new set of brain sections that
will be displayed both as photographs and magnetic resonance
images. It will give students side-by-side comparisons of the
same structures visualized with different methods, thanks to a
collaboration with the department of radiology's Gregory
McCarthy, director of the Duke Brain Imaging and Analysis
Center, and James McFall, co-director of the Duke Center for
Advanced Magnetic Resonance Imaging. Developed using the
multimedia software Director, by Macromedia, Sylvius can run on
either a PC or a PowerMac. Sylvius is bundled with the textbook
Neuroscience, and is also sold separately for $29.95 from
Sinauer Associates http://www.sinauer.com.