UCSF
Scientists Take a
Step Toward
Decoding Speech
from the Brain
New study gets closer to restoring
natural communication for those
who cannot speak
STROKE, AMYOTROPHIC lateral
sclerosis and other medical condi-
tions can rob people of their ability
to speak. Their communication is
limited to the speed at which they
can move a cursor with their eyes
(just eight to 10 words per minute),
in contrast with the natural spoken
pace of 120 to 150 words per
minute. Now, although still a long
way from restoring natural speech,
researchers at the University of
California, San Francisco, have
generated intelligible sentences from
the thoughts of people without
speech difficulties.
The work provides a proof of
principle that it should one day be
possible to turn imagined words into
understandable, real-time speech
circumventing the vocal machinery,
Edward Chang, a neurosurgeon at
U.C.S.F. and co-author of the study
published in April in Nature, said in a
news conference. “Very few of us
have any real idea of what’s going on
in our mouth when we speak,” he
said. “The brain translates those
thoughts of what you want to say into
movements of the vocal tract, and
that’s what we want to decode.”
But Chang cautions that the
technology, which has only been
tested on people with typical
speech, might be much harder to
make work in those who cannot
speak—and particularly in people
who have never been able to speak
NEWS
Researchers decoding brain activity
related to speech using an array of
intracranial electrodes similar to this one.
