Mind-reaching machine could soon turn your secret thoughts into speech
The device that eavesdrops on the voices in your head:
Mind-reaching machine could soon turn your secret thoughts into speech
Scientists want reproduce speech from brain recordings in
real-time
Goal is to help those affected by motor disease such as
Lou Gehrig's
Such a novel device would communicate people's intended
thoughts via an electronic speaker or writing device, the say
By ELLIE ZOLFAGHARIFARD FOR DAILYMAIL.COM
PUBLISHED: 16:15 EST, 27 May 2016 | UPDATED: 11:38 EST,
28 May 2016
A mind-reaching machine that can translate thoughts into
speech is coming closer to reality.
The research has been ongoing for several years, and
recently, scientists successfully managed to playback a word that someone is
thinking by monitoring their brain activity.
While there remains a long way to go, they say this could
help victims of stroke and others with speech paralysis to communicate with
their loved ones.
Professor Robert Knight and his team at UC Berkeley have
been studying how hearing words, speaking out loud and imagining words involves
brain areas that overlap.
'Now, the challenge is to reproduce comprehensible speech
from direct brain recordings done while a person imagines a word they would
like to say,' said Knight, who is also the Founding Editor of Frontiers in
Human Neuroscience.
Knight says the goal of the device is to help people
affected by motor disease such as paralysis and Lou Gehrig's Disease.
'There are many neurological disorders that limit speech
despite patients being fully aware of what they want to say,' Knight said.
'We want to develop an implantable device that decodes
the signals that occur in the brain when we think about a word, then turn these
signals into a sound file that can be reproduced by a speech device.'
Such a novel device would communicate people's intended
thoughts via an electronic speaker or writing device, but the team still has a
lot more research to conduct.
They have been able to reproduce a word a person has just
heard on a machine, by monitoring temporal lobe activity in a neurosurgical
setting.
Using electrodes placed on the surface of the language
areas of the brain of awake patients, they monitored the pattern of electrical
responses of brain cells during perceived speech.
The scientists then created a computer model that could
match spoken sounds to these signals.
'We recorded electrical signals directly from the human
language areas when a person heard words,' Knight explained.
'We then decoded these electrical signals and were able
to turn them into sound files that reflected what the person heard, with
remarkable accuracy.'
Remarkably, the team was then able to decode speech when
a person thinks of a specific word, from direct brain recordings.
'The new techniques and mathematical processing of the
brain signals got us closer to the details we need to extract the signals that
are relevant for reproducing speech,' he said.
The researchers took a clever approach to overcome some
important limitations.
For example, they accounted for the natural differences
in sound timing when one is producing the same word twice, such as when
thinking of the word then by uttering it.
'We applied a temporal realignment procedure that
improved our accuracy in classifying words that are spoken or imagined,' Knight
explained.
The team's approach is based on evidence that the brain
evolved to sense the physical properties of the sounds produced by human voice,
and then process them into meaningful elements of language, such as words,
despite their high variability.
'Our work showed us it is possible to capture the brain
signals that represent an intended word,' he said.
Such substantial progress brings the team closer to
building an effective prosthetic device, but the work must continue.
'Better understanding of language organization and better
recording devices will allow us to achieve useful implantable, wireless and
battery-powered speech prosthesis,' said Knight.
So far, the work is based on rare data collected from
patients that have been scheduled for neurosurgery for a non-related reason,
such as to treat epilepsy.
'Our ultimate goal is to create a small device that can
be used in everyday life,' he said.
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