2013-08-26
Cognitive aspects of
auditory plasticity
across the lifespan
MARY RUDNER1 AND THOMAS LUNNER1,2
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INTRODUCTION
• Speech is the main mode of communication
• Hearing impairment (HI) can be compensated
Linnaeus Centre HEAD, Linköping University, Sweden
Eriksholm Research Centre, Oticon A/S, Denmark
SPEECH COMMUNICATION UNDER ADVERSE CONDITIONS
– unfamiliar language
– unfamiliar speaker characteristics – noise and reverberation
– HI ‐ masking, filtering, distortion – fatigue and – load – (Mattys et al., 2012). – Techn: hearing aids (HA)
– Sociocultural: sign language
• Plasticity arises from
– HI
– Compensation
Confidential Conversation (1661)
Quirijn van Brekelenkam
SPEECH COMMUNICATION UNDER ADVERSE CONDITIONS
• Hearing aids – May counteract some adverse conditions for persons with HI
– But signal processing may actually generate adverse conditions (e.g. distortion) Netherlandish Proverbs (1559)
Pieter Bruegel the Elder
SPEECH COMMUNICATION UNDER ADVERSE CONDITIONS
• …demands high level cognitive resources such as working memory (WM)
…
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WORKING MEMORY FOR COMMUNICATION
• short‐term maintenance and processing of relevant information
• limited capacity
• Individual differences WORKING MEMORY FOR COMMUNICATION
• Simple span tasks
– E.g. digit span
– Storage capacity only
• Predict performance on challenging language tasks? • Complex span tasks
– E.g. reading span
– Simultaneous storage and processing capacity
The-car-drove-fast ”Yes”
The-birch-tree-sang” ”No”
…
”Fast, sang, …”
WORKING MEMORY FOR COMMUNICATION
• Episodic buffer (Baddeley, 2010)
HEARING AIDS AND SPEECH PERCEPTION IN NOISE • Wide Dynamic Range Compression (WDRC)
– integration of multimodal representations
– Improved speech intelligibility depends on adjustment to individual characteristics • RAMBPHO • WM
(ELU, Rönnberg et al., 2013)
– Rapid, Automatic, Multimodal integration of PHOnology
– Background noise
– Speech material
– Plasticity over time
The Suitor's Visit (c.1658)
Gerard Terborch
HEARING AIDS AND SPEECH PERCEPTION IN NOISE • Independently measured WM (reading span)
• Poor SNRs
• Ecological validity?
• Cognitive Spare Capacity (CSC)
– Ability to maintain and process audible information
COGNITIVE SPARE CAPACITY
•
•
Elsa had five green bowls
•
Peter had six pink rings
•
Participants
– Experienced HA users
Material
– HINT sentences
Task
– Recall final word
Results
– Noise reduced recall despite high intelligibility.
– Noise reduction processing (Wang et al., 2009) restored performance – Influence of WM
Ng, Rudner, Lunner, & Rönnberg (under review)
Ng, Rudner, Lunner, Syskind Pedersen & Rönnberg, IJA, (2013)
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2013-08-26
COGNITIVE SPARE CAPACITY
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•
•
•
Participants
– Adults with NH
– Adults with HI
Materials
– Audio(visual) 2‐digit numbers
Task
– Updating (e.g. highest in series)
– Inhibition (e.g. only a particular voice)
Results
– Visual cues reduced performance in quiet for NH but not in noise or for HI.
– Effect of memory load and noise greater for HI than NH.
PHONOLOGICAL DISTINCTIVENESS
• Phonology
– Distinct representation gives faster lexical access
– Severe, long‐term HI gives indistinct representation
• Poorer visual rhyme judgement:
• Poorer verbal fluency
Classon et al., (2013) a Speech Lang Hear;
b Frontiers Aud Cogn Neurosci; c J Com Dis
Mishra, Lunner, Stenfelt, Rönnberg & Rudner (2013), JSLHR;
under review; in prep.
PHONOLOGICAL DISTINCTIVENESS
• Visual rhyme judgement
in persons with HI
– ERP signature
– Poorer performance compensated by WM
…but at the cost of poorer long term storage
R+O+, korp – torp, [kår:p] - [tår:p]
R+O-, helg – välj, [hel:j] - [vel:j]
R-O+, sant – saft, [san:t] - [saf:t]
R-O-, bröd – spik, [brö:d] - [spi:k]
SEMANTIC CONTEXT
• …can facilitate speech understanding under adverse conditions • Hagerman sentences
– Coherent – Low redundancy
• HINT sentences – Coherent – High redundancy
Daddy’s going to mend my armchair
The lady goes shopping once a week
Classon et al., (2013) a Speech Lang Hear;
b Frontiers Aud Cogn Neurosci; c J Com Dis
THE AGING BRAIN
• Sensory and cognitive functions decline with age
• Persons with HI have increased risk of congitive impairment (Lin et al., 2013)
• Hearing decline associated with long term (LTM) but not WM decline
MODALITY SPECIFICITY
• Early deafness results in recruitment of auditory cortex for visual processing (Fine et al., 2005; Lomber et al., 2010)
• While observing sign language
– Auditory deprivation ‐> recruitment of right hemisphere
– Sign language experience ‐> recruitment of both hemispheres
• Sensory function changes but cognitive function of language processing is preserved. Rönnberg et al., 2011, JSLHR
Cardin, V., Orfanidou, E., Rönnberg, J., Capek, C.M., Rudner, M. & Woll, B. (2013).
Nature Communications.
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CONCLUSIONS 1
• Cognition is vital for speech communication under adverse conditions
• Economic use of cognitive resources may be facilitated by
– Phonological distinctness – Semantic coherence – Well fitted hearing aids
• Most important in older adults? Dante Illuminating Florence with His Poem,
Domenico di Michelino
CONCLUSIONS 2
• Neurocognitive organisation in deaf native signers –
benchmark for understanding the complex interactions between age‐
related sensory and cognitive decline as well as audiological, cognitive and social interventions aimed at supporting speech communication.
Confidential Conversation (1661)
Quirijn van Brekelenkam
Collaborators
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Jerker Rönnberg, HEAD
Stefan Stenfelt, HEAD
Ingrid Johnsrude, Queen’s University and HEAD
Adriana Zekveld, VU Amsterdam and HEAD
Carine Signoret, HEAD
Lisa Classon, HEAD
Elaine Ng, HEAD
Sushmit Mishra, HEAD
Bencie Woll, UCL UCL
Velia Cardin, UCL and HEAD
Eleni Orfanidou, University of Crete
Cheryl M. Capek, University of Manchester
• T
Thank you!
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