Central auditory disorders: toward a neuropsychology of auditory objects.
OBJECTIVE
Analysis of the auditory environment, source identification and vocal communication all require efficient brain mechanisms for disambiguating, representing and understanding complex natural sounds as 'auditory objects'. Failure of these mechanisms leads to a diverse spectrum of clinical deficits. Here we review current evidence concerning the phenomenology, mechanisms and brain substrates of auditory agnosias and related disorders of auditory object processing.


RESULTS
Analysis of lesions causing auditory object deficits has revealed certain broad anatomical correlations: deficient parsing of the auditory scene is associated with lesions involving the parieto-temporal junction, while selective disorders of sound recognition occur with more anterior temporal lobe or extra-temporal damage. Distributed neural networks have been increasingly implicated in the pathogenesis of such disorders as developmental dyslexia, congenital amusia and tinnitus. Auditory category deficits may arise from defective interaction of spectrotemporal encoding and executive and mnestic processes. Dedicated brain mechanisms are likely to process specialized sound objects such as voices and melodies.


CONCLUSIONS
Emerging empirical evidence suggests a clinically relevant, hierarchical and modular neuropsychological model of auditory object processing that provides a framework for understanding auditory agnosias and makes specific predictions to direct future work.
Dementia Research Centre, Institute of Neurology, London, UK.
Johanna C
JC
Goll
Sebastian J
SJ
Crutch
Jason D
JD
Warren
D000377:Agnosia / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology*; D001303:Auditory Cortex / Q000503:physiopathology; D001306:Auditory Pathways / Q000503:physiopathology; D001307:Auditory Perception / Q000502:physiology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D006801:Humans; D007805:Language Development Disorders / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology*; D009415:Nerve Net / Q000473:pathology / Q000503:physiopathology; D009484:Neuropsychology / Q000379:methods / Q000639:trends