University of Washington researchers have designed a
computer-interfaced drawing pad that helps scientists see inside the brains of
children with learning disabilities while they read and write.
The device and research using it to study the brain patterns
of children will be presented at the Organization for Human Brain Mapping
meeting in Seattle. A paper describing the tool, developed by the UW’s Center
on Human Development and Disability, was published this spring in Sensors, an
online open-access journal.
“Scientists needed a tool that allows them to see in real
time what a person is writing while the scanning is going on in the brain,”
said Thomas Lewis, director of the centre’s Instrument Development Laboratory.
“We knew that fibre optics were an appropriate tool. The question was, how can
you use a fibre-optic device to track handwriting?”
How it works
To create the system, Lewis and fellow engineers Frederick
Reitz and Kelvin Wu hollowed out a ballpoint pen and inserted two optical fibres
that connect to a light-tight box in an adjacent control room where the pen’s
movement is recorded.
They also created a simple wooden square pad to hold a piece
of paper printed with continuously varying colour gradients. The custom pen and
pad allow researchers to record handwriting during functional magnetic
resonance imaging, or fMRI, to assess behaviour and brain function at the same
Other researchers have developed fMRI-compatible writing
devices, but “I think it does something similar for a tenth of the cost,” Reitz
said of the UW system. By using supplies already found in most labs (such as a
computer), the rest of the supplies – pen, fibre optics, wooden pad and printed
paper – cost less than $100.The device connects to a computer with software
that records every aspect of the handwriting, from stroke order to speed,
hesitations and liftoffs.
Understanding how these physical patterns correlate with a
child’s brain patterns can help scientists understand the neural connections
Researchers studied 11- and 14-year-olds with either
dyslexia or dysgraphia, a handwriting and letter-processing disorder, as well
as children without learning disabilities. Subjects looked at printed
directions on a screen while their heads were inside the fMRI scanner. The pen
and pad were on a foam pad on their laps.
Subjects were given four-minute blocks of reading and
writing tasks. Then they were asked to simply think about writing an essay
(they later wrote the essay when not using the fMRI). Just thinking about
writing caused many of the same brain responses as actual writing would.
“If you picture yourself writing a letter, there’s a part of
the brain that lights up as if you’re writing the letter,” said Todd Richards,
professor of radiology and principal investigator of the UWIntegrated Brain
Imaging Center. “When you imagine yourself writing, it’s almost as if you’re
actually writing, minus the motion problems.”
Richards and his staff are just starting to analyse the data
they’ve collected from about three dozen subjects, but they have already found
some surprising results.
“There are certain centres and neural pathways that we
didn’t necessarily expect” to be activated, Richards said. “There are language
pathways that are very well known. Then there are other motor pathways that
allow you to move your hands. But how it all connects to the hand and motion is
still being understood.”
Besides learning disorders, the inexpensive pen and pad also
could help researchers study diseases in adults, especially conditions that
cause motor control problems, such as stroke, multiple sclerosis and
“There are several diseases where you cannot move your hand
in a smooth way or you’re completely paralysed,” Richards said. “The beauty is
it’s all getting recorded with every stroke, and this device would help us to
study these neurological diseases.”
The work was supported by a grant from the National
Institutes of Health. Other UW collaborators on the project are Peter Boord,
Mary Askren and Virginia Berninger.