The study investigated auditory object cognition in patients with dementia syndromes like Alzheimer's disease and primary progressive aphasias. An experimental battery assessed three levels of auditory processing - early perceptual coding, perceptual representations of whole objects, and recognition of object semantics. Results showed distinctive profiles of impaired auditory object processing in different dementia syndromes after controlling for non-verbal working memory performance. The findings suggest dementia syndromes affect auditory object cognition through separable stages of analysis. Future research should study larger cohorts and additional diseases to better understand auditory dysfunction in these disorders.

1. AUDITORY OBJECT
COGNITION IN
DEMENTIA
Johanna C. Golla, Lois G. Kimb, Julia C.
Hailstonea, Manja Lehmanna, Aisling Buckleya,
Sebastian J. Crutcha, Jason D. Warrena (2011)
Presented by
Diana Cordeiro
and
Laura
Gwilliams

2. BACKGROUND
 Deficits people with dementia face have been widely
studied
 Visual object processing deficits are well established
 But the cognition of nonverbal sounds (i.e., auditory
objects) in dementia has been relatively little
explored
 Similarities exist between the two domains, but a
‘visual object’ is much more concrete and easily
defined than an ‘auditory object’

3. AUDITORY OBJECT?
 Auditory objects are made up of acoustic properties
which are processed by the hearer
 Recognise sound characteristics
 And, properties of the object that created the sound
 Unclear how the brain processes an object in the
auditory domain, especially for people with dementia
syndromes

4. WHY STUDY THE AUDITORY DOMAIN?
 1) Clinical Perspective
 Disorders of auditory processing gives rise to a diverse host of
symptoms and deficits
 2) Cognitive Neuropsychological Perspective
 Determine cognitive components required to process an
auditory object
 Relation between these essential components and the study of
damaged brains

5. AIMS
 Build upon previous study:
 1) Extend investigation to include patients diagnosed with
Alzheimer’s disease (AD) and Primary Progressive
Aphasias (PPA)
 2) Assess auditory object cognition while taking working
memory into consideration
 3) Extend analysis of auditory object cognition to include
a wider range of processes including early perceptual
mechanisms
Goll, J. C., Crutch, S. J., Loo, J. H., Rohrer, J. D., Frost, C., Bamiou, D. E., et al. (2010). Non-verbal sound
processing in the primary progressive aphasias. Brain, 133, 272–285.

6. METHOD
 Participants
 20 healthy age-matched controls
 34 patients fulfilling clinical diagnostic criteria for AD or PPA
 Clinically diagnosed with:
 Amnestic Alzheimer’s disease (AD; n-21)
 Progressive non-fluent aphasia (PNFA; n-5)
 Logopenic progressive aphasia (LPA; n-7)
 Aphasia associated with granulin gene mutation (GAA; n-1)
 Pre-experimental assessment
 Peripheral hearing assessment
 General neurological function assessment

7. DESIGN: EXPERIMENTAL BATTERY
 The battery allows assessment of three levels of
cognitive auditory processing:
 1) Early perceptual coding at subcortical level (sub -object)
 i.e., pitch, timbre, auditory size
 2) Perceptual representations (whole object)
 i.e., combined sub-object properties
 3) Recognition of auditory objects (semantics)
 i.e., object -> meaning

8. METHOD: EXPERIMENTAL BATTERY
Experimenters designed a novel battery to probe auditory object cognition

9. RESULTS
Comparisons between syndromes and control
AD PNFA LPA GAA
Pitch change detection Preserved Preserved
Pitch change direction Deficit Deficit
Timbre Preserved Deficit Deficit Preserved
Size familiar Preserved Preserved Preserved Preserved
Size unfamiliar Preserved Preserved Preserved Preserved
Apperceptive Deficit Preserved Deficit
Semantic Preserved Deficit Preserved
After adjusting for non-verbal working memory performance

10. CONCLUSIONS
 Dementia syndromes are associated with impaired
processing of auditory objects
 Separable stages of auditory object analysis
 Separable profiles of impaired auditory object cognition in
dif ferent dementia syndromes
 Working memory was an important aspect of auditory
recognition
 Taken together, results suggest dementia syndromes
are associated with distinctive profiles of auditory
object processing

11. LIMITATIONS
 Small case numbers
 Deficits occurred in context of general auditory
dysfunction and widespread cognitive impairment
 Cannot make direct anatomical and pathological link to
deficits observed
 None of the deficits were restricted to a
particular dementia syndrome

12. FUTURE RESEARCH
 Larger patient cohorts and additional
neurodegenerative diseases
 Clinical perspective:
 Core symptoms of disorders could be better understood with
further study into auditory dysfunction
 Cognitive Neuropsychological perspective:
 Establish relationship between different elements of auditory
object perception
 Explore processes for object segregation in embedded complex
auditory scenes
 Compare mechanisms of object analysis across different
modalities, using appropriate matched tasks in each modality

13. THANKS!
… Questions?