www.cs4fn.org
Searching to Speak:
From locked-in syndrome
to cyborgs
Paul Curzon
Queen Mary,
University of London
Created by Paul Curzon of
Queen Mary, University of London
As part of the cs4fn project
with support from EPSRC and Google
Locked-in Syndrome
• A person with locked-in
syndrome is totally
paralyzed except
perhaps being able to
move an eyelid
• They can see, hear and
think but they cannot
communicate back
• Their intelligent mind
is trapped inside a
useless body
Could you write a book if you
had locked-in syndrome?
• Jean-Dominique Bauby
did…
• Describing what his life
was like with locked-in
syndrome
• It is described as
“one of the greatest
books of the century”
• How did he do it?
Communicating with
Locked-in Syndrome
• The helper reads the alphabet a letter at a
time
– Is it A?
– Is it B?
– Is it C? etc
• Blinking means yes, not blinking means no
• The helper writes the letter down.
• Then starts again with the next letter
Try it yourself
What are the problems?
How fast is that?
How fast is it?
• It is very slow
• It takes on average 13 questions for
every letter
• At worst it takes 26 questions
Computer Scientists
do it better
• Any Computer Scientist knows it can be
done in…
5 questions per letter at worst
How?
Winning at 20-Questions
• Do you ask questions
like
–
–
–
–
–
–
Is it Lady Gaga?
Is it Will Smith?
Is it Lara Croft?
Is it Gandhi?
Is it Gromit?
Is it Beyonce?
• That would on average
take billions of
questions
– you have only 20!
Locked-in Syndrome
Again
• How do we locate the correct letter in
the alphabet with only 5 blink/no blink
questions?
Locked-in Syndrome
Again
• Ask questions about which half of the
remainder of the alphabet the letter is in.
– so we rule out half the letters with every question
– not just 1!
Search Algorithms
• We have looked at two different ways of
searching for information
• Two different algorithms
– Linear search
• One by one
– Binary search
• Divide and conquer
• Halving search
Algorithms first …
• Now we have a better
solution we can think
about programming
it…and using a
particular technology to
replace the human
helper
• For example,
– computer detecting blinks
– brain implants or scalp
electrodes to read
thoughts
The First Cyborg…
• Prof Warwick of
Reading University
had a chip implanted
in the nerves of his
arm
– A computer read the
signals between his
brain and hand…and
sent them over the net.
– The technology that
helps the disabled
could give “superhuman powers”.
Future computers
will need emotions too
QuickTime™ and a
YUV420 codec decompressor
are needed to see this picture.
1
Computers and People
• Before you come up with solutions …you
must make sure you understand the problem.
– That usually means understanding people as well
as computers.
• Only then can you work on ways to improve
things.
• That is what computer science is about
…thinking out of the box…doing things
better… that couldn’t be done before…
improving life for all … changing the future.
If you want to
make a difference:
Work hard, have fun and change the
future…
More of the
Fun side of Computer Science
and Computer Engineering @
www.cs4fn.org
Thank you…any questions?