Re: Why Can Some Blind People Process Speech Far Faster Than Sighted Persons.


Carolyn Arnold
 

It's a matter of exercising, so if a certain part of the brain is needed for something, using that develops its strength, just like taking exercise does muscles, regardless of other issues.

So, yes, some blind people are good musicians, but sighted people are too, al la Jerry Lee Lewis, Mickey Gilley, Fats Domino, and Floyd Cramer.

-----Original Message-----
From: main@TechTalk.groups.io [mailto:main@TechTalk.groups.io] On Behalf Of Gene Warner
Sent: Monday, September 19, 2022 7:26 PM
To: main@TechTalk.groups.io
Subject: Re: [TechTalk] Why Can Some Blind People Process Speech Far Faster Than Sighted Persons.

This is not surprising when you consider that blind people are much more dependent on their hearing than sighted people are, so of course their brains are going to rewire themselves to get more out of what they hear than sighted people ever will.

Interesting article though.

Gene...

On 9/19/2022 7:03 PM, Janet wrote:
I was reading this article and thought some of you might want to read
it as well. There is a link to the original article below. I find
it to be quite interesting.

Why Can Some Blind People Process Speech Far Faster Than Sighted Persons?

Functional brain imaging has revealed that some blind people's brains
rewire themselves, giving them extraordinary auditory comprehension

By R. Douglas Fields on December 13, 2010

SAN DIEGO—Books fly from the shelf as Superman fans the pages in a
blur devouring the information at blinding speed. Superhuman mental
powers, including his extraordinary sense of hearing and blazing
speed-reading, are as vital to Superman as his bullet-beating velocity
and steel-bending strength. But it seems Superman isn't the only being
with the gift of quickness. Neuroscientists reported in November at
the Society for Neuroscience's annual meeting in San Diego that they
have found an interesting group of real individuals with such
superhuman mental abilities—blind people. Moreover, functional brain
imaging now reveals how they achieve their extraordinary cerebral feats.

A popular notion is that blind people sharpen their remaining senses
to compensate for lost vision. Blind musicians, such as Stevie Wonder
and Ray Charles, may excel in music because of their highly developed
sense of hearing. Researchers from the Hertie Institute for Clinical
Brain Research at the University of Tübingen in Germany have found
scientific support for this belief. Blind people can easily comprehend
speech that is sped up far beyond the maximum rate that sighted people
can't understand. When we speak rapidly we are verbalizing at about
six syllables per second. That hyperactive radio announcer spewing
fine print at the end of a commercial jabbers at 10 syllables per
second, the absolute limit of comprehension for sighted people. Blind
people, however, can comprehend speech sped up to 25 syllables per
second. Human beings cannot talk this fast. The scientists had to use
a computerized synthesizer to generate speech at this speed. "It sounds like noise,"
Ingo Hertrich, one of the scientists involved in the research told me.
"I can't understand anything…maybe it sounds like some strange foreign
language spoken very rapidly." (To hear what speech at 16 syllables
per second sounds like, listen to a sample recording the scientists
used in their experiments.)

Hertrich and his colleagues Hermann Ackermann and Susanne Dietrich
wanted to find out what was going on inside the brains of blind people
that gives them this "superpower" to understand speech at ultrafast
rates. Examining brain regions activated by blind and sighted people
while they listened to ultrafast speech and laid inside a (functional
magnetic imaging, or MRI) brain scanner revealed that in blind people
the part of the cerebral cortex that normally responds to vision was
responding to speech.

No wonder blind people seem to have superhuman powers of high-speed
listening comprehension. Normally, this brain region, situated at the
back of the skull and called V1, only responds to light. Vision is
such an important sense for humans that a huge portion of the brain is
devoted to visual processing—far more gray matter than is dedicated to
any other sense. In blind people all this brain power would go to
waste, but somehow an unsighted person's brain rewires itself to
connect auditory regions of the brain to the visual cortex.

Ackermann explained that the age at which a person loses sight is
likely to be critical in rewiring brain regions controlling hearing to
the region that normally processes vision. In people who are born
blind the visual cortex is completely unresponsive to any auditory or
visual stimulation. This region of the brain becomes functionally
disconnected because visual input is necessary early in life to wire
up visual brain circuitry properly. Younger people who lose sight
after these connections formed, however, are able to reroute them to
process auditory information after becoming blind. On the other hand,
people who lose sight late in life are also less able to rewire their
brains, because the critical period during which visual experience can
influence this process is limited to earlier years in life. (All the
subjects in this study had lost their sight between two and 15 years
of age.)

But how do brain regions connected to the ears get rewired to brain
regions that are normally connected to the eyes? The fact is that most
of our senses have some interacting circuitry between them, which is
called cross modality. There are some connections between the brain's
auditory and visual regions, because the two senses must work together.
Seeing a person's lips move helps comprehension of speech. We also
need to orient our visual and auditory attention to the same events
and to the same place in space, so there is an exchange of information
between the auditory and visual cortices. Nerves from muscles that
control our eye movements, for example, connect to the brain's hearing
centers as well. These connections between visual and auditory regions
of the brain become strengthened after losing sight. Also, some
regions of cerebral cortex that border visual and auditory
cortices—the left fusiform gyrus, for example—expand territory in
blind people to make use of the idle circuitry in visual cortex.

Interestingly, the researchers found that blind people only use the
right visual cortex for understanding ultrafast speech. Ackermann
suspects that this may be because the right brain is specialized for
processing low-frequency information, which is typical of speech, but
this theory is still unproved. What blind people might use the left
visual cortex for is something the group is investigating and hopes to
report at next year's meeting.

The main interest of the researchers is in brain stroke. By
investigating how the blind brain rewires itself to compensate for
lost function, the researchers hope to discover new information that
can be helpful to patients recovering from stroke. But Ackermann also
stresses that an important outcome of this research is the help it can
provide the blind. Whereas it is always better to be sighted than not,
people who have lost vision do have certain extraordinary abilities
that can give them advantages over sighted people. He finds that blind
people are able to turn up the rate of text-to-speech converting
computer programs to read three books in the time it would take a
sighted person to read one. This extraordinary ability will benefit
blind people in processing large amounts of written information in
textbooks for study at school, and perhaps open new job opportunities
to exploit their high-speed reading skills for translation or other
auditory comprehension at blazing speeds that to Lois Lane and the
rest of us mere mortals sounds like babble.

Rights & Permissions

ABOUT THE AUTHOR(S)

R. Douglas Fields is a senior investigator at the National Institutes
of Health’s Section on Nervous System Development and Plasticity. He
is author of Electric Brain: How the New Science of Brainwaves Reads
Minds, Tells Us How We Learn, and Helps Us Change for the Better
(BenBella Books, 2020). Credit: Nick Higgins

The Original Article can be found at

https://www.scientificamerican.com/article/why-can-some-blind-people-p
rocess/#:~:text=Interestingly%2C%20the%20researchers%20found%20that,th
is%20theory%20is%20still%20unproved
<https://www.scientificamerican.com/article/why-can-some-blind-people-process/#:~:text=Interestingly%2C%20the%20researchers%20found%20that,this%20theory%20is%20still%20unproved>.

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