What's what in auditory cortices?

Retsa, Chrysa (The LINE (Laboratory for Investigative Neurophysiology), Radiology Department and Department of Clinical Neurosciences, University Hospital Center and University of Lausanne, Switzerland) ; Matusz, Pawel J. (University of Applied Sciences and Arts Western Switzerland (HES-SO Valais-Wallis)) ; Schnupp, Jan W.H. (Department of Biomedical Sciences, City University of Hong Kong, To Yuen Street, Kowloon, Hong Kong; Department of Physiology, Anatomy and Genetics, University of Oxford, UK) ; Murray, Micah M. (The LINE (Laboratory for Investigative Neurophysiology), Radiology Department and Department of Clinical Neurosciences, University Hospital Center and University of Lausanne, Switzerland)

Distinct anatomical and functional pathways are postulated for analysing a sound's object-related (‘what’) and space-related (‘where’) information. It remains unresolved to which extent distinct or overlapping neural resources subserve specific object-related dimensions (i.e. who is speaking and what is being said can both be derived from the same acoustic input). To address this issue, we recorded high-density auditory evoked potentials (AEPs) while participants selectively attended and discriminated sounds according to their pitch, speaker identity, uttered syllable (‘what’ dimensions) or their location (‘where’). Sound acoustics were held constant across blocks; the only manipulation involved the sound dimension that participants had to attend to. The task-relevant dimension was varied across blocks. AEPs from healthy participants were analysed within an electrical neuroimaging framework to differentiate modulations in response strength from modulations in response topography; the latter of which forcibly follow from changes in the configuration of underlying sources. There were no behavioural differences in discrimination of sounds across the 4 feature dimensions. As early as 90ms post-stimulus onset, AEP topographies differed across ‘what’ conditions, supporting a functional sub-segregation within the auditory ‘what’ pathway. This study characterises the spatio-temporal dynamics of segregated, yet parallel, processing of multiple sound object-related feature dimensions when selective attention is directed to them.


Keywords:
Article Type:
scientifique
Faculty:
Economie et Services
School:
HEG-VS
Institute:
Institut Informatique de gestion
Subject(s):
Informatique
Date:
2018-08
Published in:
NeuroImage
Numeration (vol. no.):
1 August 2018, vol. 176, pp. 29-40
DOI:
ISSN:
1053-8119
Appears in Collection:



 Record created 2018-11-30, last modified 2018-12-13

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