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Percepción auditiva significativa (lenguaje,
emociones y música), en niños con IC: papel
de la plasticidad en el desarrollo del sistema
auditivo
Meaningful auditory perception (language,
emotion and music) after CI in children: the
role of plasticity in the development of the
auditory system
Blake Papsin Programa de Implantes Cocleares. The Hospital for Sick Children
Departamento de ORL, University of Toronto
Toronto, Canadá
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Reassembling the Auditory
Environment in Children with
Cochlear Implants
Page 3
Paolo Campisi
Vicky Papaioannou
Mark Crawford
Maureen Dennis
Gina Sohn
Naureen Sohail
Cochlear Implant Research Team
DIRECTORS
Karen Gordon
Blake Papsin
RESEARCH
ASSISTANTS
Jerome Valero
Stephanie Jewell
STUDENTS
Daniel Wong
Claire Salloum
Sho Tanaka
Patrick Yu
Brad Hubbard
Lauren Schofield
Brittany Harrison
Brooke Allemang
Laurie MacDonald
Mary Lynn Feness
Pat Di Santos
Nancy Greenwald-
Hood
Susan Druker
Local - external
Sandra Trehub
Frank Russo
International
Robert Cowan
Richard van Hoesel
FELLOWS
Talar Hopyan
Neil Chadha
James Ramsden
COLLABORATORS
Local - SickKids
Bob Harrison
Tracy Stockley
Susan Blaser
Adrian James
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Paolo Campisi
Vicky Papaioannou
Mark Crawford
Maureen Dennis
Gina Sohn
Naureen Sohail
Cochlear Implant Research Team
DIRECTORS
Karen Gordon
Blake Papsin
RESEARCH
ASSISTANTS
Jerome Valero
Stephanie Jewell
STUDENTS
Daniel Wong
Claire Salloum
Sho Tanaka
Patrick Yu
Brad Hubbard
Lauren Schofield
Brittany Harrison
Brooke Allemang
Laurie MacDonald
Mary Lynn Feness
Pat Di Santos
Nancy Greenwald-
Hood
Susan Druker
Local - external
Sandra Trehub
Frank Russo
International
Robert Cowan
Richard van Hoesel
FELLOWS
Talar Hopyan
Neil Chadha
James Ramsden
COLLABORATORS
Local - SickKids
Bob Harrison
Tracy Stockley
Susan Blaser
Adrian James
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The Three Questions
do I run from it?
do I eat it?
do I mate with it?
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Evolution in Our Time?
Biston betularia f. carbonaria Biston betularia f. typica
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Human = Information Processor
olfaction
vision
motor skill
audition
linguistic ability
executive function
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Human = Information Processor
olfaction
vision
motor skill
audition
linguistic ability
executive function
Page 9
Human = Information Processor
olfaction
vision
motor skill
audition
linguistic ability
executive function
Page 10
Reduced
activity
Activity no
longer reduced
Lee, et al., Nature, 2001
Auditory Cortex in Silence
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Reorganization of Auditory Cortex
Fine, et al., 2005
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Reorganization of Auditory Cortex
Fine, et al., 2005
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Human = Information Processor
IQ = 107 IQ = 7
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Auditory Plasticity (Learning)
↑ representation of 8-16 kHz octave band
(Stanton & Harrison 1996)
13
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Capitalizing on Plasticity
Age (months)
0 10 20 30 40 50
IT-M
AIS
score
(%
)
0
20
40
60
80
100
6-12 months
12-18 months
19-23 months
Normal hearing
6-12 months
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Developmental Plasticity
adult map reorganization reported:
If animal is trained to attend to the stimulus
15
(Polley, Steinberg & Merzenich, 2006)
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Senses
collect data
extract data
orient
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Senses
illusory
reassemble the
world – most
probable state
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Vision and Audition
fundamentally different
bilateral pathways
temporal relationships
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Vision and Audition
fundamentally different
bilateral pathways
temporal relationships
visual time
Auditory time
d
e
c
i
s
i
o
n
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Spot the Difference
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Spot the Difference
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Visual Attention
saccades scan visual
environment
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Auditory Processing
must process
environment in one
pass
extract
identify
categorize
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Feature Extraction
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Feature Extraction
key to extraction missed by
Euclid, Archimedes, Da Vinci,
Newton
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Feature Extraction
key to extraction missed by
Euclid, Archimedes, Da Vinci,
Newton
Wheatstone 1838
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Feature Extraction
key to extraction missed by
Euclid, Archimedes, Da Vinci,
Newton
Wheatstone 1838
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Feature Extraction
key to extraction missed by
Euclid, Archimedes, Da Vinci,
Newton
Wheatstone 1838
“there is an essential difference
between the impressions on the
organs of sensation”
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Importance of Stereoscopy
the slight differences between the two
eyes define orientation in space
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Development of Stereoscopy
altricial
Hubel and Wiesel
patched one side
= all input neurons to one eye
patched both sides
= all inputs neurons active
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Can You Patch an Ear?
paths cross early
hearing occurs in
utero
conductive loss
models
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Can You Patch an Ear?
paths cross early
hearing occurs in
utero
conductive loss
models
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Can You Patch an Ear?
paths cross early
hearing occurs in
utero
conductive loss
models
Page 36
Auditory Brainstem Development
Ear and Hearing, 2003
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Auditory Brainstem Development
Ear and Hearing, 2003
Simultaneous bilateral
Sequential bilateral
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Simultaneous bilateral
Sequential bilateral
-0.10
-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
long delay short delay simultaneous
La
ten
cy
re
lati
ve
to
Rig
ht
(ms
)
Wave eV, Electrode 20
0
0.25
0.75
Device activation 3 months bilateral use 9 months bilateral use
Otology & NeuroOtology, 2007
Asymmetry at the Lateral Lemniscus
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Studying Binaural Perception
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Studying Binaural Perception
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Lateralization Index = (R-L)/(R+L)
Studying Binaural Perception
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Lateralization Index = (R-L)/(R+L)
Left Auditory Cortex Right Auditory Cortex
“Patching” the Ear
Normal
Hearing
Unilateral
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Lateralization Index = (R-L)/(R+L)
Left Auditory Cortex Right Auditory Cortex
“Patching” the Ear
Normal
Hearing
Simultaneous
Unilateral
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Lateralization Index = (R-L)/(R+L)
Left Auditory Cortex Right Auditory Cortex
“Patching” the Ear
Normal
Hearing
Simultaneous
6-12 months
delay
Unilateral
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Lateralization Index = (R-L)/(R+L)
Normal
Hearing
Simultaneous
6-12 months
delay
> 2 years
delay
p = 0.01
Left Auditory Cortex Right Auditory Cortex
* Unilateral
*
*
*
“Patching” the Ear
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Effect of Unilateral Stimulation
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Effect of Unilateral Stimulation
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Effect of Unilateral Stimulation
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Effect of Unilateral Stimulation
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Effect of Unilateral Stimulation
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Effect of Unilateral Stimulation
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Effect of Unilateral Stimulation
R L
Long Delay (> 2 yrs)
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Hubel and Wiesel
explained their “patching” experimental
outcomes
“…early in life the functional integrity of the
pathway may depend not only on the
amount of afferent impulse activity, but also
on the interrelationships between the various
sets of afferents.”
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Time (Yrs)
0 1 2 0 1 2 0 1 2
R L
Simultaneous (0 yrs) Short Delay (< 1 yr) Long Delay (> 2 yrs)
Abnormal cortical organization is promoted
by unilateral cochlear implant use
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Binaural Hearing
sounds reach:
one ear before the
other
at different levels
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Binaural Hearing
binaural processing
occurs first at the level
of the brainstem
timing and level
differences are
compared (sound
localization)
Lateral
Lemniscus
(V)
Inferior
Colliculus
Superior Olivary
Complex
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Cochlear Implants and Binaural Hearing
effects of inter-implant place
effects of inter-implant level cues
effects of inter-implant timing cues
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Right Stimulation
Left Stimulation
Binaural Stimulation Left + Right Added
Binaural Interaction
Binaural Interaction
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Binaural Interaction
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Binaural Interaction
Device activation 3 months bilateral use 9 months bilateral use
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
long delay short delay simultaneous
Late
ncy r
ela
tive t
o R
igh
t (m
s)
0
0.25
0.75
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Development of Stereoscopy
Hubel and Wiesel
patched one side = all input neurons to one eye
patched both sides = all inputs neurons active
eso- or exotropia resulted in amblyopia
the eye still could “see” but the cortex couldn’t
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Development of Stereoscopy
Hubel and Wiesel
patched one side = all input neurons to one eye
patched both sides = all inputs neurons active
eso- or exotropia resulted in amblyopia
the eye still could “see” but the cortex couldn’t
Page 63
Development of Stereoscopy
Hubel and Wiesel
patched one side = all input neurons to one eye
patched both sides = all inputs neurons active
eso- or exotropia resulted in amblyopia
the eye still could “see” but the cortex couldn’t
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Coding of Inter-Implant Place
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Coding of Inter-Implant Level
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Development of Stereoscopy
Hubel and Wiesel
patched one side = all input neurons to one eye
patched both sides = all inputs neurons active
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0.2 ms 0.6 ms
0.2 ms
ITD=0 ms
ITD=-0.4 ms (R leads L)
ITD=+0.4 ms (L leads R)
Coding of Inter-Implant Timing
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Coding of Inter-Implant Timing
0.2 ms 0.6 ms
0.2 ms
ITD=0 ms
ITD=-0.4 ms (R leads L)
ITD=+0.4 ms (L leads R)
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Coding of Inter-Implant Timing
0.2 ms 0.6 ms
0.2 ms
ITD=0 ms
ITD=-0.4 ms (R leads L)
ITD=+0.4 ms (L leads R)
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Coding of Inter-Implant Timing
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Coding of Inter-Implant Timing
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Coding of Inter-Implant Timing
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Coding of Inter-Implant Timing
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Binaural Perception
Hubel and Wiesel
in the blind eye edge
perception still possible!
primary processor still
perceives edge
cortex stereo blind
edges in audition are
coded by timing
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Behavioural Implications
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Behavioural Implications
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Reassembling the Auditory
Environment
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Emotion in Faces But Not in Speech
= p < .001
Hopyan et al. (2009), Child Neuropsychology
ANGRY SAD
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Normal Hearing
n=25
Cochlear Implant
n=23
Mean age =
11. 7 years
Enhanced Use of Visual Input
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Auditory only Auditory-visual
Normal Hearing
n=25
Cochlear Implant
n=23
Mean age =
11. 7 years
Reaction Time & Visual Input
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2
3
4
5
6
7
8
9
10
EYES OPEN EYES CLOSED
Tim
e (
se
c)
2
3
4
5
6
7
8
9
10
EYES OPEN EYES CLOSED
Tim
e (
se
c)
Standing on one foot Standing on one foot
on a balance beam
VISION*GROUP INTERACTION
p=0.88
IMPLANT CONTROL
Impact of vision
Page 83
2
3
4
5
6
7
8
9
10
EYES OPEN EYES CLOSED
Tim
e (
se
c)
2
3
4
5
6
7
8
9
10
EYES OPEN EYES CLOSED
Tim
e (
se
c)
Standing on one foot Standing on one foot
on a balance beam
VISION*GROUP INTERACTION
p=0.88
IMPLANT CONTROL
Impact of vision
Page 84
p=0.01 *
NORMS
CONTROLS
8
9
10
11
12
13
14
15
16
17
ON OFF
Me
an
Sc
ale
Sc
ore
(m
ax
=3
0)
Implant ON vs. OFF
Page 85
p=0.01 *
NORMS
CONTROLS
8
9
10
11
12
13
14
15
16
17
ON OFF
Me
an
Sc
ale
Sc
ore
(m
ax
=3
0)
Implant ON vs. OFF
Page 86
Summary
sequential bilateral cochlear implantation
allows asymmetric auditory development
alters but does not eliminate binaural processing in
the brainstem
compromises binaural processing in the auditory
cortex
facilitates perception of inter-implant level, but not
timing, cues
Page 87
Summary
simultaneous bilateral cochlear implantation
allows symmetric auditory brainstem
development
protects the auditory cortex from reorganized
lateralization
Page 88
Conclusions
there are multiple sensitive periods in
auditory development
duration of both bilateral and unilateral
auditory deprivation should be limited in
children