Egocentric and allocentric representations in auditory cortex
A key function of the brain is to provide a stable representation of an object’s location in the world. In hearing, sound azimuth and elevation are encoded by neurons throughout the auditory system, and auditory cortex is necessary for sound localization. However, the coordinate frame in which neuro...
| Main Authors: | , , |
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| Format: | Article |
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Public Library of Science
2017
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| Online Access: | https://eprints.nottingham.ac.uk/44271/ |
| _version_ | 1848796877256916992 |
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| author | Town, Stephen M. Brimijoin, W. Owen Bizley, Jennifer K. |
| author_facet | Town, Stephen M. Brimijoin, W. Owen Bizley, Jennifer K. |
| author_sort | Town, Stephen M. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | A key function of the brain is to provide a stable representation of an object’s location in the world. In hearing, sound azimuth and elevation are encoded by neurons throughout the auditory system, and auditory cortex is necessary for sound localization. However, the coordinate frame in which neurons represent sound space remains undefined: classical spatial receptive fields in head-fixed subjects can be explained either by sensitivity to sound source location relative to the head (egocentric) or relative to the world (allocentric encoding). This coordinate frame ambiguity can be resolved by studying freely moving subjects; here we recorded spatial receptive fields in the auditory cortex of freely moving ferrets. We found that most spatially tuned neurons represented sound source location relative to the head across changes in head position and direction. In addition, we also recorded a small number of neurons in which sound location was represented in a world-centered coordinate frame. We used measurements of spatial tuning across changes in head position and direction to explore the influence of sound source distance and speed of head movement on auditory cortical activity and spatial tuning. Modulation depth of spatial tuning increased with distance for egocentric but not allocentric units, whereas, for both populations, modulation was stronger at faster movement speeds. Our findings suggest that early auditory cortex primarily represents sound source location relative to ourselves but that a minority of cells can represent sound location in the world independent of our own position. |
| first_indexed | 2025-11-14T19:54:58Z |
| format | Article |
| id | nottingham-44271 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:54:58Z |
| publishDate | 2017 |
| publisher | Public Library of Science |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-442712020-05-04T18:50:16Z https://eprints.nottingham.ac.uk/44271/ Egocentric and allocentric representations in auditory cortex Town, Stephen M. Brimijoin, W. Owen Bizley, Jennifer K. A key function of the brain is to provide a stable representation of an object’s location in the world. In hearing, sound azimuth and elevation are encoded by neurons throughout the auditory system, and auditory cortex is necessary for sound localization. However, the coordinate frame in which neurons represent sound space remains undefined: classical spatial receptive fields in head-fixed subjects can be explained either by sensitivity to sound source location relative to the head (egocentric) or relative to the world (allocentric encoding). This coordinate frame ambiguity can be resolved by studying freely moving subjects; here we recorded spatial receptive fields in the auditory cortex of freely moving ferrets. We found that most spatially tuned neurons represented sound source location relative to the head across changes in head position and direction. In addition, we also recorded a small number of neurons in which sound location was represented in a world-centered coordinate frame. We used measurements of spatial tuning across changes in head position and direction to explore the influence of sound source distance and speed of head movement on auditory cortical activity and spatial tuning. Modulation depth of spatial tuning increased with distance for egocentric but not allocentric units, whereas, for both populations, modulation was stronger at faster movement speeds. Our findings suggest that early auditory cortex primarily represents sound source location relative to ourselves but that a minority of cells can represent sound location in the world independent of our own position. Public Library of Science 2017-06-15 Article PeerReviewed Town, Stephen M., Brimijoin, W. Owen and Bizley, Jennifer K. (2017) Egocentric and allocentric representations in auditory cortex. PLoS Biology, 15 (6). e2001878/1-e2001878/34. ISSN 1545-7885 http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2001878 doi:10.1371/journal.pbio.2001878 doi:10.1371/journal.pbio.2001878 |
| spellingShingle | Town, Stephen M. Brimijoin, W. Owen Bizley, Jennifer K. Egocentric and allocentric representations in auditory cortex |
| title | Egocentric and allocentric representations in auditory cortex |
| title_full | Egocentric and allocentric representations in auditory cortex |
| title_fullStr | Egocentric and allocentric representations in auditory cortex |
| title_full_unstemmed | Egocentric and allocentric representations in auditory cortex |
| title_short | Egocentric and allocentric representations in auditory cortex |
| title_sort | egocentric and allocentric representations in auditory cortex |
| url | https://eprints.nottingham.ac.uk/44271/ https://eprints.nottingham.ac.uk/44271/ https://eprints.nottingham.ac.uk/44271/ |