<s>
The	B-Application
McGurk	I-Application
effect	I-Application
is	O
a	O
perceptual	O
phenomenon	O
that	O
demonstrates	O
an	O
interaction	O
between	O
hearing	O
and	O
vision	O
in	O
speech	O
perception	O
.	O
</s>
<s>
If	O
a	O
person	O
is	O
getting	O
poor-quality	O
auditory	O
information	O
but	O
good-quality	O
visual	O
information	O
,	O
they	O
may	O
be	O
more	O
likely	O
to	O
experience	O
the	B-Application
McGurk	I-Application
effect	I-Application
.	O
</s>
<s>
Many	O
people	O
are	O
affected	O
differently	O
by	O
the	B-Application
McGurk	I-Application
effect	I-Application
based	O
on	O
many	O
factors	O
,	O
including	O
brain	O
damage	O
and	O
other	O
disorders	O
.	O
</s>
<s>
This	O
effect	O
was	O
discovered	O
by	O
accident	O
when	O
McGurk	O
and	O
his	O
research	O
assistant	O
,	O
MacDonald	O
,	O
asked	O
a	O
technician	O
to	O
dub	O
a	O
video	O
with	O
a	O
different	O
phoneme	B-Language
from	O
the	O
one	O
spoken	O
while	O
conducting	O
a	O
study	O
on	O
how	O
infants	O
perceive	O
language	O
at	O
different	O
developmental	O
stages	O
.	O
</s>
<s>
When	O
the	O
video	O
was	O
played	O
back	O
,	O
both	O
researchers	O
heard	O
a	O
third	O
phoneme	B-Language
rather	O
than	O
the	O
one	O
spoken	O
or	O
mouthed	O
in	O
the	O
video	O
.	O
</s>
<s>
This	O
effect	O
may	O
be	O
experienced	O
when	O
a	O
video	O
of	O
one	O
phoneme	B-Language
's	O
production	O
is	O
dubbed	O
with	O
a	O
sound-recording	O
of	O
a	O
different	O
phoneme	B-Language
being	O
spoken	O
.	O
</s>
<s>
Often	O
,	O
the	O
perceived	O
phoneme	B-Language
is	O
a	O
third	O
,	O
intermediate	O
phoneme	B-Language
.	O
</s>
<s>
Vision	O
is	O
the	O
primary	O
sense	O
for	O
humans	O
,	O
but	O
speech	O
perception	O
is	O
multimodal	B-Application
,	O
which	O
means	O
that	O
it	O
involves	O
information	O
from	O
more	O
than	O
one	O
sensory	O
modality	O
,	O
in	O
particular	O
,	O
audition	O
and	O
vision	O
.	O
</s>
<s>
The	B-Application
McGurk	I-Application
effect	I-Application
arises	O
during	O
phonetic	O
processing	O
because	O
the	O
integration	O
of	O
audio	O
and	O
visual	O
information	O
happens	O
early	O
in	O
speech	O
perception	O
.	O
</s>
<s>
The	B-Application
McGurk	I-Application
effect	I-Application
is	O
very	O
robust	O
;	O
that	O
is	O
,	O
knowledge	O
about	O
it	O
seems	O
to	O
have	O
little	O
effect	O
on	O
one	O
's	O
perception	O
of	O
it	O
.	O
</s>
<s>
Wareham	O
and	O
Wright	O
's	O
2005	O
study	O
showed	O
that	O
inconsistent	O
visual	O
information	O
can	O
change	O
the	O
perception	O
of	O
spoken	O
utterances	O
,	O
suggesting	O
that	O
the	B-Application
McGurk	I-Application
effect	I-Application
may	O
have	O
many	O
influences	O
in	O
everyday	O
perception	O
.	O
</s>
<s>
Both	O
hemispheres	O
of	O
the	O
brain	O
make	O
a	O
contribution	O
to	O
the	B-Application
McGurk	I-Application
effect	I-Application
.	O
</s>
<s>
In	O
people	O
that	O
have	O
had	O
callosotomies	O
done	O
,	O
the	B-Application
McGurk	I-Application
effect	I-Application
is	O
still	O
present	O
but	O
significantly	O
slower	O
.	O
</s>
<s>
People	O
with	O
lesions	O
in	O
the	O
left	O
hemisphere	O
of	O
the	O
brain	O
show	O
a	O
greater	O
McGurk	B-Application
effect	I-Application
than	O
normal	O
controls	O
.	O
</s>
<s>
In	O
people	O
with	O
right	O
hemisphere	O
damage	O
,	O
impairment	O
on	O
both	O
visual-only	O
and	O
audio-visual	O
integration	O
tasks	O
is	O
exhibited	O
,	O
although	O
they	O
are	O
still	O
able	O
to	O
integrate	O
the	O
information	O
to	O
produce	O
a	O
McGurk	B-Application
effect	I-Application
.	O
</s>
<s>
Therefore	O
,	O
there	O
is	O
a	O
McGurk	B-Application
effect	I-Application
exhibited	O
in	O
people	O
with	O
damage	O
to	O
the	O
right	O
hemisphere	O
of	O
the	O
brain	O
but	O
the	O
effect	O
is	O
not	O
as	O
strong	O
as	O
a	O
normal	O
group	O
.	O
</s>
<s>
Dyslexic	O
individuals	O
exhibit	O
a	O
smaller	O
McGurk	B-Application
effect	I-Application
than	O
normal	O
readers	O
of	O
the	O
same	O
chronological	B-Application
age	O
,	O
but	O
they	O
showed	O
the	O
same	O
effect	O
as	O
reading-level	O
age-matched	O
readers	O
.	O
</s>
<s>
The	O
smaller	O
McGurk	B-Application
effect	I-Application
may	O
be	O
due	O
to	O
the	O
difficulties	O
dyslexics	O
have	O
in	O
perceiving	O
and	O
producing	O
consonant	O
clusters	O
.	O
</s>
<s>
Children	O
with	O
specific	O
language	O
impairment	O
show	O
a	O
significantly	O
lower	O
McGurk	B-Application
effect	I-Application
than	O
the	O
average	O
child	O
.	O
</s>
<s>
Children	O
with	O
autism	O
spectrum	O
disorders	O
(	O
ASD	O
)	O
showed	O
a	O
significantly	O
reduced	O
McGurk	B-Application
effect	I-Application
than	O
children	O
without	O
.	O
</s>
<s>
Younger	O
children	O
with	O
ASD	O
show	O
a	O
very	O
reduced	O
McGurk	B-Application
effect	I-Application
;	O
however	O
,	O
this	O
diminishes	O
with	O
age	O
.	O
</s>
<s>
It	O
has	O
been	O
suggested	O
that	O
the	O
weakened	O
McGurk	B-Application
effect	I-Application
seen	O
in	O
people	O
with	O
ASD	O
is	O
due	O
to	O
deficits	O
in	O
identifying	O
both	O
the	O
auditory	O
and	O
visual	O
components	O
of	O
speech	O
rather	O
than	O
in	O
the	O
integration	O
of	O
said	O
components	O
(	O
although	O
distinguishing	O
speech	O
components	O
as	O
speech	O
components	O
may	O
be	O
isomorphic	O
to	O
integrating	O
them	O
)	O
.	O
</s>
<s>
Adults	O
with	O
language-learning	O
disabilities	O
exhibit	O
a	O
much	O
smaller	O
McGurk	B-Application
effect	I-Application
than	O
other	O
adults	O
.	O
</s>
<s>
Therefore	O
,	O
people	O
with	O
poor	O
language	O
skills	O
will	O
produce	O
a	O
smaller	O
McGurk	B-Application
effect	I-Application
.	O
</s>
<s>
In	O
patients	O
with	O
Alzheimer	O
's	O
disease	O
(	O
AD	O
)	O
,	O
there	O
is	O
a	O
smaller	O
McGurk	B-Application
effect	I-Application
exhibited	O
than	O
in	O
those	O
without	O
.	O
</s>
<s>
Less	O
influence	O
on	O
visual	O
stimulus	O
is	O
seen	O
in	O
patients	O
with	O
AD	O
,	O
which	O
is	O
a	O
reason	O
for	O
the	O
lowered	O
McGurk	B-Application
effect	I-Application
.	O
</s>
<s>
The	B-Application
McGurk	I-Application
effect	I-Application
is	O
not	O
as	O
pronounced	O
in	O
schizophrenic	B-Application
individuals	O
as	O
in	O
non-schizophrenic	O
individuals	O
.	O
</s>
<s>
Schizophrenia	B-Application
slows	O
down	O
the	O
development	O
of	O
audiovisual	O
integration	O
and	O
does	O
not	O
allow	O
it	O
to	O
reach	O
its	O
developmental	O
peak	O
.	O
</s>
<s>
People	O
with	O
aphasia	O
show	O
impaired	O
perception	O
of	O
speech	O
in	O
all	O
conditions	O
(	O
visual-only	O
,	O
auditory-only	O
,	O
and	O
audio-visual	O
)	O
,	O
and	O
therefore	O
exhibited	O
a	O
small	O
McGurk	B-Application
effect	I-Application
.	O
</s>
<s>
A	O
small	O
study	O
(	O
N	O
=	O
22	O
per	O
group	O
)	O
showed	O
no	O
apparent	O
difference	O
between	O
individuals	O
with	O
bipolar	O
disorder	O
and	O
those	O
without	O
,	O
with	O
respect	O
to	O
the	B-Application
McGurk	I-Application
effect	I-Application
.	O
</s>
<s>
Discrepancy	O
in	O
vowel	O
category	O
significantly	O
reduced	O
the	O
magnitude	O
of	O
the	B-Application
McGurk	I-Application
effect	I-Application
for	O
fusion	O
responses	O
.	O
</s>
<s>
The	B-Application
McGurk	I-Application
effect	I-Application
is	O
stronger	O
when	O
the	O
right	O
side	O
of	O
the	O
speaker	O
's	O
mouth	O
(	O
on	O
the	O
viewer	O
's	O
left	O
)	O
is	O
visible	O
.	O
</s>
<s>
The	B-Application
McGurk	I-Application
effect	I-Application
is	O
weaker	O
when	O
there	O
is	O
a	O
visual	O
distractor	O
present	O
that	O
the	O
listener	O
is	O
attending	O
to	O
.	O
</s>
<s>
A	O
stronger	O
McGurk	B-Application
effect	I-Application
is	O
elicited	O
if	O
the	O
speaker	O
's	O
face/head	O
is	O
motionless	O
,	O
rather	O
than	O
moving	O
.	O
</s>
<s>
A	O
strong	O
McGurk	B-Application
effect	I-Application
can	O
be	O
seen	O
for	O
click-vowel	O
syllables	O
compared	O
to	O
weak	O
effects	O
for	O
isolated	O
clicks	O
.	O
</s>
<s>
This	O
shows	O
that	O
the	B-Application
McGurk	I-Application
effect	I-Application
can	O
happen	O
in	O
a	O
non-speech	O
environment	O
.	O
</s>
<s>
Phonological	O
significance	O
is	O
not	O
a	O
necessary	O
condition	O
for	O
a	O
McGurk	B-Application
effect	I-Application
to	O
occur	O
;	O
however	O
,	O
it	O
does	O
increase	O
the	O
strength	O
of	O
the	O
effect	O
.	O
</s>
<s>
Females	O
show	O
a	O
stronger	O
McGurk	B-Application
effect	I-Application
than	O
males	O
.	O
</s>
<s>
Although	O
,	O
there	O
is	O
no	O
difference	O
in	O
the	O
strength	O
of	O
the	B-Application
McGurk	I-Application
effect	I-Application
for	O
either	O
situation	O
.	O
</s>
<s>
If	O
a	O
male	O
face	O
is	O
dubbed	O
with	O
a	O
female	O
voice	O
,	O
or	O
vice	O
versa	O
,	O
there	O
is	O
still	O
no	O
difference	O
in	O
strength	O
of	O
the	B-Application
McGurk	I-Application
effect	I-Application
.	O
</s>
<s>
Knowing	O
that	O
the	O
voice	O
you	O
hear	O
is	O
different	O
from	O
the	O
face	O
you	O
see	O
–	O
even	O
if	O
different	O
genders	O
–	O
does	O
n't	O
eliminate	O
the	B-Application
McGurk	I-Application
effect	I-Application
.	O
</s>
<s>
Subjects	O
who	O
are	O
familiar	O
with	O
the	O
faces	O
of	O
the	O
speakers	O
are	O
less	O
susceptible	O
to	O
the	B-Application
McGurk	I-Application
effect	I-Application
than	O
those	O
who	O
are	O
unfamiliar	O
with	O
the	O
faces	O
of	O
the	O
speakers	O
.	O
</s>
<s>
Semantic	B-Application
congruency	O
had	O
a	O
significant	O
impact	O
on	O
the	O
McGurk	O
illusion	O
.	O
</s>
<s>
When	O
a	O
person	O
was	O
expecting	O
a	O
certain	O
visual	O
or	O
auditory	O
appearance	O
based	O
on	O
the	O
semantic	B-Application
information	O
leading	O
up	O
to	O
it	O
,	O
the	B-Application
McGurk	I-Application
effect	I-Application
was	O
greatly	O
increased	O
.	O
</s>
<s>
The	B-Application
McGurk	I-Application
effect	I-Application
can	O
be	O
observed	O
when	O
the	O
listener	O
is	O
also	O
the	O
speaker	O
or	O
articulator	O
.	O
</s>
<s>
While	O
looking	O
at	O
oneself	O
in	O
the	O
mirror	O
and	O
articulating	O
visual	O
stimuli	O
while	O
listening	O
to	O
another	O
auditory	O
stimulus	O
,	O
a	O
strong	O
McGurk	B-Application
effect	I-Application
can	O
be	O
observed	O
.	O
</s>
<s>
In	O
the	O
other	O
condition	O
,	O
where	O
the	O
listener	O
speaks	O
auditory	O
stimuli	O
softly	O
while	O
watching	O
another	O
person	O
articulate	O
the	O
conflicting	O
visual	O
gestures	O
,	O
a	O
McGurk	B-Application
effect	I-Application
can	O
still	O
be	O
seen	O
,	O
although	O
it	O
is	O
weaker	O
.	O
</s>
<s>
Temporal	O
synchrony	O
is	O
not	O
necessary	O
for	O
the	B-Application
McGurk	I-Application
effect	I-Application
to	O
be	O
present	O
.	O
</s>
<s>
Subjects	O
are	O
still	O
strongly	O
influenced	O
by	O
auditory	O
stimuli	O
even	O
when	O
it	O
lagged	O
the	O
visual	O
stimuli	O
by	O
180	O
milliseconds	O
(	O
point	O
at	O
which	O
McGurk	B-Application
effect	I-Application
begins	O
to	O
weaken	O
)	O
.	O
</s>
<s>
In	O
order	O
to	O
produce	O
a	O
significant	O
weakening	O
of	O
the	B-Application
McGurk	I-Application
effect	I-Application
,	O
the	O
auditory	O
stimuli	O
had	O
to	O
precede	O
the	O
visual	O
stimuli	O
by	O
60	O
milliseconds	O
,	O
or	O
lag	O
by	O
240	O
milliseconds	O
.	O
</s>
<s>
The	B-Application
McGurk	I-Application
effect	I-Application
was	O
greatly	O
reduced	O
when	O
attention	O
was	O
diverted	O
to	O
a	O
tactile	O
task	O
(	O
touching	O
something	O
)	O
.	O
</s>
<s>
There	O
was	O
no	O
difference	O
in	O
the	B-Application
McGurk	I-Application
effect	I-Application
when	O
the	O
listener	O
was	O
focusing	O
anywhere	O
on	O
the	O
speaker	O
's	O
face	O
.	O
</s>
<s>
In	O
order	O
for	O
the	B-Application
McGurk	I-Application
effect	I-Application
to	O
become	O
insignificant	O
,	O
the	O
listener	O
's	O
gaze	O
must	O
deviate	O
from	O
the	O
speaker	O
's	O
mouth	O
by	O
at	O
least	O
60	O
degrees	O
.	O
</s>
<s>
But	O
the	B-Application
McGurk	I-Application
effect	I-Application
's	O
intensity	O
differs	O
across	O
languages	O
.	O
</s>
<s>
Dutch	O
,	O
English	O
,	O
Spanish	O
,	O
German	O
,	O
Italian	O
and	O
Turkish	O
language	O
listeners	O
experience	O
a	O
robust	O
McGurk	B-Application
effect	I-Application
;	O
Japanese	O
and	O
Chinese	O
listeners	O
,	O
weaker	O
.	O
</s>
<s>
Most	O
research	O
on	O
the	B-Application
McGurk	I-Application
effect	I-Application
between	O
languages	O
has	O
been	O
between	O
English	O
and	O
Japanese	O
.	O
</s>
<s>
A	O
smaller	O
McGurk	B-Application
effect	I-Application
occurs	O
in	O
Japanese	O
listeners	O
than	O
English	O
listeners	O
.	O
</s>
<s>
The	O
cultural	O
practice	O
of	O
face	O
avoidance	O
in	O
Japanese	O
people	O
may	O
diminish	O
the	B-Application
McGurk	I-Application
effect	I-Application
,	O
as	O
well	O
as	O
tone	O
and	O
syllabic	O
structures	O
of	O
the	O
language	O
.	O
</s>
<s>
Regardless	O
,	O
listeners	O
of	O
all	O
languages	O
resort	O
to	O
visual	O
stimuli	O
when	O
speech	O
is	O
unintelligible	O
;	O
the	B-Application
McGurk	I-Application
effect	I-Application
then	O
applies	O
to	O
them	O
equally	O
.	O
</s>
<s>
The	B-Application
McGurk	I-Application
effect	I-Application
works	O
with	O
listeners	O
of	O
every	O
tested	O
language	O
.	O
</s>
<s>
The	B-Application
McGurk	I-Application
effect	I-Application
is	O
still	O
present	O
in	O
individuals	O
with	O
impaired	O
hearing	O
or	O
using	O
cochlear	O
implants	O
,	O
although	O
it	O
is	O
quite	O
different	O
in	O
some	O
aspects	O
.	O
</s>
<s>
By	O
measuring	O
an	O
infant	O
's	O
attention	O
to	O
certain	O
audiovisual	O
stimuli	O
,	O
a	O
response	O
that	O
is	O
consistent	O
with	O
the	B-Application
McGurk	I-Application
effect	I-Application
can	O
be	O
recorded	O
.	O
</s>
<s>
The	O
first	O
evidence	O
of	O
the	B-Application
McGurk	I-Application
effect	I-Application
can	O
be	O
seen	O
at	O
four	O
months	O
of	O
age	O
;	O
however	O
,	O
more	O
evidence	O
is	O
found	O
for	O
5-month-olds	O
.	O
</s>
<s>
Through	O
the	O
process	O
of	O
habituating	O
an	O
infant	O
to	O
a	O
certain	O
stimulus	O
and	O
then	O
changing	O
the	O
stimulus	O
(	O
or	O
part	O
of	O
it	O
,	O
such	O
as	O
ba-voiced/va	O
-visual	O
to	O
da-voiced/va	O
-visual	O
)	O
,	O
a	O
response	O
that	O
simulates	O
the	B-Application
McGurk	I-Application
effect	I-Application
becomes	O
apparent	O
.	O
</s>
<s>
The	O
strength	O
of	O
the	B-Application
McGurk	I-Application
effect	I-Application
displays	O
a	O
developmental	O
pattern	O
that	O
increases	O
throughout	O
childhood	O
and	O
extends	O
into	O
adulthood	O
.	O
</s>
