Spatial processing is frequency specific in auditory cortex but not in the midbrain

Sollini, J., Mill, R. and Sumner, C.J. ORCID: 0000-0002-2573-7418, 2017. Spatial processing is frequency specific in auditory cortex but not in the midbrain. The Journal of Neuroscience, 37 (27), pp. 6588-6599. ISSN 0270-6474

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Abstract

The cochlea behaves like a bank of band-pass filters, segregating information into different frequency channels. Some aspects of perception reflect processing within individual channels, but others involve the integration of information across them. One instance of this is sound localization, which improves with increasing bandwidth. The processing of binaural cues for sound location has been studied extensively. However, although the advantage conferred by bandwidth is clear, we currently know little about how this additional information is combined to form our percept of space. We investigated the ability of cells in the auditory system of guinea pigs to compare interaural level differences (ILDs), a key localization cue, between tones of disparate frequencies in each ear. Cells in auditory cortex believed to be integral to ILD processing (excitatory from one ear, inhibitory from the other: EI cells) compare ILDs separately over restricted frequency ranges which are not consistent with their monaural tuning. In contrast, cells that are excitatory from both ears (EE cells) show no evidence of frequency-specific processing. Both cell types are explained by a model in which ILDs are computed within separate frequency channels and subsequently combined in a single cortical cell. Interestingly, ILD processing in all inferior colliculus cell types (EE and EI) is largely consistent with processing within single, matched-frequency channels from each ear. Our data suggest a clear constraint on the way that localization cues are integrated: cortical ILD tuning to broadband sounds is a composite of separate, frequency-specific, binaurally sensitive channels. This frequency-specific processing appears after the level of the midbrain.

Item Type:	Journal article
Publication Title:	The Journal of Neuroscience
Creators:	Sollini, J., Mill, R. and Sumner, C.J.
Publisher:	Society for Neuroscience
Date:	5 July 2017
Volume:	37
Number:	27
ISSN:	0270-6474
Identifiers:	Number Type 10.1523/jneurosci.3034-16.2017 DOI
Rights:	This is an open-access article distributed under the terms of the Creative Commons Attribution License Creative Commons Attribution 4.0 International, which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
Divisions:	Schools > School of Social Sciences
Record created by:	Jonathan Gallacher
Date Added:	27 Feb 2019 09:25
Last Modified:	27 Feb 2019 09:25
URI:	https://irep.ntu.ac.uk/id/eprint/35821

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