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Central Auditory Processing Disorders (CAPD): A Key Factor in Developmental
Disorders
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Complete
On-line AIT Checklist
by Rosalie
Seymour, SLP/A, Berard AIT Practitioner
Detailed scientific
information on Central Auditory Processing Disorders taken from a PowerPoint Slide presentation.
Central
Auditory Processing Disorders as a Key Factor in Developmental Language
Disorders with implications for:
- Specific Language Impairment
- Dyslexia
- Autism
(ASD)
- Attention Deficit Disorder (ADD, ADHD)
- Developmental Language Disorders
Saying More Than We
Know: Is Auditory
Processing Disorder a Meaningful Concept?
Norma Rees, 1981
Outline of this presentation:
- Brief overview of research
- The question of assessment:
- How do we interpret the test results
- Intervention planning
Three Stages in the Adoption of New Ideas
- Ignored
- Vehemently opposed
- Accepted as self-evident
Historical
- “Dyslexia due to problems with the perception
of auditory information” Orton 1937,
Monroe 1932
- 1968:
The first postmortem of a dyslexic brain: “there are structural differences
in the left temporal region associated with language.”
What is Central Auditory Processing Disorder
(CAPD)?
Jack Katz,1983
“the
least restrictive definition allows us the greatest flexibility and
permits the greatest learning.”
Katz 1983: Before it can be understood,
input must be:
- Located
- Attended to (vigilance)
- Differentiated
- Integrated
- Coordinated with other sensory input
- Stored
- Retrieved
Keith 1980
- Localization
- Attention span
- Discrimination
- Behavioral synthesis (binaural)
- Figure-ground/Competing tasks
- Binaural separation
- Memory
- Blending
- Closure
- Cognition/Comprehension
What is Central Auditory Processing Disorder
(CAPD) ASHA 1996 Task Force
- This definition is inclusive,
and recognizes the neuro-cognitive, attentional and auditory factors
- Sound localization & lateralization
- Discrimination
- Pattern recognition
- Temporal aspects
(including
resolution, masking, integration ordering)
- Auditory performance decrements with competing
acoustic signals
- Auditory performance decrements with degraded
acoustic signals
- An accelerating accumulation of research
- Educational
- Psychological
- Audiological
- Linguistic/SLP
- Neurological
- Neurphysiological
- Neurbiological
- What we have learned from the research since
1970
- All the things we did wrong!
- Inappropriate to apply concepts from adult
models to child models of language, auditory processing, neuro-physiology….Lasky
& Katz ’83, Protti ’83.
- Inappropriate to apply site-of of-lesion
concepts to developmental disorders of children unless lesions are
proven anatomically…Rees ’81,Protti
’83, Shield et al ’96.
- What we have learned from the research
since 1980
- Inappropriate to draw conclusions for speech
sound processing from non sound processing
from non-speech data.
Protti ’83.
- Inappropriate to expect to find modality-specific
processing once the auditory signal has entered processing
once the the brainstem. Luria
- The whole is more than the sum of its parts.
Rees ’81, Luria.
- Let’s not abandon the concept…let’s keep
looking!
The Focus of Assessment of Central Auditory
Processing Disorder (CAPD)
- “The aim of attempting to identify APD is to
determine to what extent it is
to determine to what extent it handicaps
or restricts the person.” Katz 1987, Bellis ’02, Lessler ‘72.
- “Just establishing the presence or absence
of CAPD is not enough to chart a rehabilitation program“.
- Statistical significance does not reflect clinical
significance. Bellis '02.
Assessment of Central Auditory Processing
Disorder (CAPD)
- Audiology
- SLP
- Neuro-physiology
- NO ONE TEST NOR BATTERY
OF TESTS IS 100% RELIABLE
- Singer et al ’98,
Bellis ’02, Delb et al ’03, Kelly ’01 move to end of this segment
- Behavioral
- Psychological
- Educational
- "“intervention should
not be withheld simply because of an inability to test an
inability to test reliably." Bellis
'02.
- Behavioral Indicators & checklists
- Multi-disciplinary Test batteries
- Background information
The Impact of Background Information on Central
Auditory Processing Disorder (CAPD)
Rees ‘81: “No one
has developed an intelligible account of how these central processing
skills relate to language acquisition or academic learning.”
And yet…
- Specific Learning Disabilities:
- Reading - Monroe
’32, Orton ’37, Sawyer’81, Shankweiler & Liberman ’89, Moncrieff
‘03
- Spelling - Bannatyne and Wichiarajote '69
- Communication Disorders - Tallal
’76, Lasky & Cox '76, Lasky & Cox ’83, Young 83, Liberman ’67, Cutting
‘77
- Schizophrenia - Yozawitz
et al '79
- ADD - Ludlow
et al ’83
- Prison population -
Katz et al ‘88
- Autism
(ASD)- Courchesne, Wong & Wong
The Impact of Central Auditory Processing
Disorder (CAPD)
- No one feature is common to all with supposed
CAPD.
- Auditory memory –somewhat irrelevant to syntax
use and comprehension
- Auditory synthesis and closure – is more metalinguistic
than perceptual...predicts reading not language.
- Negativity
Indicators of Abnormal Mismatch Negativity
- Response –pre-cognitive, pre-attentive auditory
change detection system. (Discrimination)
- Automatic, unaffected by sleep or attention.
- Altered by phoneme discrimination training
- Szymanskyy, Yund & Woods & Woods ’98, Rinne
et al 2001
- N1
N1-P2
P2 reflect stimulus
encoding/detection, Tremblay 02
- Indicators of unusual P300 ERP’s reflect attention/memory
Campbell, Courchesne et al ‘93.
- ERP’s for autistic
vs. control – auditory.
- These indicators are of dysfunctional pre-cognitive
operations.
- These disturbances are speech-sound specific
rather than acoustic.
- Intervention Planning
- Compensatory strategies
- Environmental modifications
- Therapeutic interventions Bellis ’02
- Neural Plasticity
- Listening training involving phonemes causes
lasting neurological change.
- Pre-attentive cortical EP’s reflect speech-sound
training.
- Changes in Neural activity precede behavioral
changes.
- Naatanen & Rinne 2002, Tremblay & Kraus
2002.
- Auditory Structural Plasticity
- Plasticity is greater in the early years.
- There is some degree of alteration in neural
wiring throughout life. Kalil ’89, Merzenich et al ’88.
- Neuromaturation and neuroplasticity dependent
on stimulation.
- Stimulation activates and strengthens neural
pathways, whereas unstimulated pathways atrophy. Aoki ’85, Bellis
'02
- Via the mechanism of Long-Term Potentiation
… increase in synaptic efficiency following strong and repeated
stimulation of the sensory system.
- Cells change in size, and in postsynaptic
density.
- Amplitude after intensive Increase in P3
phonological training.
- Bliss & Lomo L73,
Gustaffson & Wigstrom ’98, Jirsa ’92, Tallal et al ’96, Merzenich
et al ’96.
- Intensive training of the auditory modality
can modify the degree of asymmetry in the posterior auditory region
and increase the size of the auditory region and increase the siez
of the planum temporale.Schlang
et al ’95
- Direct training alters the sensory neural
maps at the single cell level. Recanzone et al ’93.
- Include auditory stimulation in all cases
of CAPD. Chermak & Musiek '92.
- Phonological training if intensive can structurally
alter auditory pathways.
- Listening to altered speech sounds is found
to have the same effect.
- Cetnral Auditory Processing Disorder (CAPD)
and Dyslexia
- “Symptoms which characterize dyslexia appear
indistinguishable from APD’s.” Moncrieff ’03
- IDA 2000: …a language –based disability
of comprehension that affects both oral and comprehension and written language.
“
- “It usually reflects insufficient
phonological processing abilities”
- Dyslexia
- “The core deficit responsible for impaired
learning to read is phonological in nature, and has to do with oral
language rather than visual perception”
- “…the move ahead sound problem of manipulation
of the sound onstituents of oral language “ Habib 2000
- “This difficulty stems from detecting the
auditory stimuli with certain temporal properties…” (especially
severe in competing situations)
- Visual problems usually described in dyslexia
are skills that develop under the influence of reading.
- They reflect the similar disruptive neuro
-integrative pattern.
- Habib 2002, Witton et al 98. Bishop et al
’99, Helenius et al ‘99
- Neurophysiological (p300, MMN, cerebral
bloodflow studies, fMRI)
- Abnormal cortical activation
- Unusual responses to novel auditory and
visual stimuli –greater distractibility, and more effort to re-focus.
- Deviant change detection especially in left
auditory cortex.
- Deficient processing of acoustic changes
of
rapidly occurring sequences
- Helenius et al ‘02,
Russeler et al
’02, Renvall & Hari , 2002, Galaburda et al ’95, Rosen '95
- Atypical brain asymmetry in dyslexia is
specifically linked to phonological
- impairment. Larsen et al ’90.
- The degree of planum temporal asymmetry
is inversely proportional to the degree of the phonological disorder
dyslexia. Habib & Robichon ‘96
Auditory Processing Disorder (APD) and Dyslexia
“Symptoms which
characterise dyslexia appear indistinguishable from APD’s” Moncrieff
’03
- Assessment of Cetnral Auditory Processing
Disorder (CAPD)in Dyslexia
“intervention
should not be withheld simply because of an inability to test reliably”.
Bellis ‘86.
- Dyslexia as a Multisystem Deficit
- …possibly based on the incapacity of the
brain to perform many tasks requiring processing of brief stimuli
in rapid succession.
- This TEMPORAL PROCESSING IMPAIRMENT THEORY
could account for some of the
- Perceptual,
- Motor,
- Cognitive
- Associated symptoms as yet unexplained
Habib 2000
- Central Auditory Processing Disorder (CAPD)
as a Multisystem Deficit
- ASHA '95: associated factors
95:
(memory, learning, attention, long-term phonological term
representations, higher representaitons, higher-level
neurocognitive processes)...
- “…must be distinguished from AP.
- Not a valid concept in the light of research
implicating the variety and number of neurological systems structures.
It’s not possible to differentiate.
- Lehiste 1972: ”… evidence of connections
between units from subphonemic processing to syntactic processing
taking place at various levels processing
with extensive interaction among them.”
- Role of attention in AP (neurophysiological
studies).
- Four components of Attention
- Arousal
- Orienting
- Selective allocation of attention:
- Different processes
in infants vs children 6+ and adults.
Bellis '96, Sambeth et al ’04, Gomes et al 04, Gaiard et al et al
‘00.
- Central Auditory Processing Disorder (CAPD) relies on:
- Stimulus-determined mesial fields that faithfully
transmit acoustic information.
- Attentionally labile lateral fields that
analyze acoustic features. Petkov
et al ‘04.
- …”suggest attentional phenomena at the auditory
periphery”
- Propose an adaptive filtering mechanism
forselective
auditory attention that can be selective
auditory attention flexibly and
dynamically tuned. Giard et al ‘2000.
- Implications for Intervention:
- (The results of research) … call for integration
of attentional mechanisms into models
of phonetic category
acquision, as well as category modification (sound change). Guion
and Pedersen 2001.
- Luria ‘73: “Communication between the Reticular
Activation System of the
brainstem and auditory fibers
of the central nervous system creates a cortical tone –….a general
activating effect on the cortex that strengthens motoric
reactions to stimuli and sharpens sensitivity.”
- All the features of Central Auditory Processing
Disorder (CAPD) mentioned above CAPD in Autism
(ASD)
- Poor auditory stimulus orientation
- Longer EP latencies
- No habituation or saturation effect
- Storage of information is impaired
- All the features of Central Auditory Processing Disorder
(CAPD) mentioned above CAPD in
Autism
(ASD)
- Garreau et al et al ’94
- Courchesne ’87 +
- Courchesne Lincoln Kilman Galambos ‘85
- Donchin et al ’78
- Bauman & Kemper ’94
- Wong & Wong ’91
- Tanguay & Edwards ’82
- Ceponiene et al ‘03
- Attention and Perception Difficulties: One of the Main
Symptoms of
Autism (ASD)
- Regulation by dopamenergic system
- Sensory overload
- Core improvement on gluten-free diet
- Reorganization of dopamenergic system during
dietary period
- Exisence of opiod-immune relations
- Success with opiod blocking agents has similar
effects on behavioral as diet
- Support for self-injurious behavior opiod
relationship
Research findings and practical implications
for children with Autism
(ASD)
by Paul Whiteley from Sheffield University
We most need a consensus approach to Central
Auditory Processing Disorder (CAPD):
- The issue
is as large as everything put together …
- We will
not comprehend it unless we combine all the information into a NEURO-INTEGRATIONAL
VIEW
Thus to summarize...Concept:
Jack Katz,1983: “the least restrictive
definition allows us the greatest flexibility and permits the
greatest learning.
- Concept #1
- Jack Katz,1983: “the least restrictive
the least restrictive
definition allows us the greatest flexibility and permits
the greatest learning”
- Concept #2
- The
aim of attempting to identify APD is to determine to what extent
it handicaps or restricts the person.” Katz 1987, Bellis ’02, Lessler
‘72.
- Concept #3
- “intervention
should not be withheld simply because of an inability to test reliably.”
Bellis '02.
- Concept #4
- These
indicators are of dysfunctional pre-cognitive operations.
- These
disturbances are speech-sound specific rather than acoustic.
- Concept #5
- Stimulation
activates and strengthens neural pathways, whereas unstimulated
pathways atrophy. Aoki ’85, Bellis 02.
- Concept #6
- "suggest
attentional phenomena at the periphery”
- call
for integration of attentional mechanisms into models of phonetic
models of phonetic
category acquision,
as well as category modification.
- Promising Interventions
employing the above concepts:
- Structured
listening
- Simple
home-based intensive phonological stimulation.
- Berard
Auditory Integration Training: 10 hours of auditory stimulation
with speech-loaded electronically modified music.
-
FastForWord
-
Phonomena
- Earobics
-
Neuro-Cognitive Reconstructive Therapy/Brain Dynamics
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