Answers to Yes/No Questions Seen in Pupil Size: Study08/08/13
THURSDAY, Aug. 8 (HealthDay News) -- People who are otherwise
unable to communicate with others can answer yes or no questions
with a simple system that measures changes in the size of their
pupils, researchers say.
The system consists of a laptop and camera and takes advantage
of naturally occurring changes in pupil size that occur when people
do mental arithmetic. No specialized training is required,
according to the study authors.
Along with helping "locked-in" people communicate, the system
might also prove effective in assessing the mental state of people
whose level of consciousness is unclear. Locked-in syndrome is a
rare disorder in which voluntary muscles in all parts of the body
-- except for those that control eye movement -- are paralyzed.
The researchers developed the system in experiments with healthy
people and tested it on seven patients who had stroke-related brain
damage and were unable to communicate. In many of those patients,
their responses to yes or no questions could be determined based on
pupil size alone, according to the study in the Aug. 5 issue of the
"It is remarkable that a physiological system as simple as the pupil has such a rich repertoire of responses that it can be used for a task as complex as communication," Wolfgang Einhauser, of Philipp University of Marburg in Germany, said in a journal news release.
He said further work is needed to improve the system's speed and
accuracy, but added that these technical issues should be easy to
solve. In its current form, the system could already make an
important difference to people who need it most.
For patients in an unresponsive state, "any communication is a
big step forward," Einhauser said.
The U.S. National Institute of Neurological Disorders and Stroke
has more about
Copyright © 2013
. All rights reserved.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.