Integration of Semi-Circular Canal and Otolith Cues for Direction Discrimination during Eccentric Rotations

Humans are capable of moving about the world in complex ways. Every time we move, our self-motion must be detected and interpreted by the central nervous system in order to make appropriate sequential movements and informed decisions. The vestibular labyrinth consists of two unique sensory organs th...

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Main Authors:	Soyka, Florian, Bülthoff, Heinrich H., Barnett-Cowan, Michael
Format:	Online
Language:	English
Published:	Public Library of Science 2015
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4555836/

id	pubmed-4555836
recordtype	oai_dc
spelling	pubmed-45558362015-09-10 Integration of Semi-Circular Canal and Otolith Cues for Direction Discrimination during Eccentric Rotations Soyka, Florian Bülthoff, Heinrich H. Barnett-Cowan, Michael Research Article Humans are capable of moving about the world in complex ways. Every time we move, our self-motion must be detected and interpreted by the central nervous system in order to make appropriate sequential movements and informed decisions. The vestibular labyrinth consists of two unique sensory organs the semi-circular canals and the otoliths that are specialized to detect rotation and translation of the head, respectively. While thresholds for pure rotational and translational self-motion are well understood surprisingly little research has investigated the relative role of each organ on thresholds for more complex motion. Eccentric (off-center) rotations during which the participant faces away from the center of rotation stimulate both organs and are thus well suited for investigating integration of rotational and translational sensory information. Ten participants completed a psychophysical direction discrimination task for pure head-centered rotations, translations and eccentric rotations with 5 different radii. Discrimination thresholds for eccentric rotations reduced with increasing radii, indicating that additional tangential accelerations (which increase with radius length) increased sensitivity. Two competing models were used to predict the eccentric thresholds based on the pure rotation and translation thresholds: one assuming that information from the two organs is integrated in an optimal fashion and another assuming that motion discrimination is solved solely by relying on the sensor which is most strongly stimulated. Our findings clearly show that information from the two organs is integrated. However the measured thresholds for 3 of the 5 eccentric rotations are even more sensitive than predictions from the optimal integration model suggesting additional non-vestibular sources of information may be involved. Public Library of Science 2015-08-31 /pmc/articles/PMC4555836/ /pubmed/26322782 http://dx.doi.org/10.1371/journal.pone.0136925 Text en © 2015 Soyka et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Soyka, Florian Bülthoff, Heinrich H. Barnett-Cowan, Michael
spellingShingle	Soyka, Florian Bülthoff, Heinrich H. Barnett-Cowan, Michael Integration of Semi-Circular Canal and Otolith Cues for Direction Discrimination during Eccentric Rotations
author_facet	Soyka, Florian Bülthoff, Heinrich H. Barnett-Cowan, Michael
author_sort	Soyka, Florian
title	Integration of Semi-Circular Canal and Otolith Cues for Direction Discrimination during Eccentric Rotations
title_short	Integration of Semi-Circular Canal and Otolith Cues for Direction Discrimination during Eccentric Rotations
title_full	Integration of Semi-Circular Canal and Otolith Cues for Direction Discrimination during Eccentric Rotations
title_fullStr	Integration of Semi-Circular Canal and Otolith Cues for Direction Discrimination during Eccentric Rotations
title_full_unstemmed	Integration of Semi-Circular Canal and Otolith Cues for Direction Discrimination during Eccentric Rotations
title_sort	integration of semi-circular canal and otolith cues for direction discrimination during eccentric rotations
description	Humans are capable of moving about the world in complex ways. Every time we move, our self-motion must be detected and interpreted by the central nervous system in order to make appropriate sequential movements and informed decisions. The vestibular labyrinth consists of two unique sensory organs the semi-circular canals and the otoliths that are specialized to detect rotation and translation of the head, respectively. While thresholds for pure rotational and translational self-motion are well understood surprisingly little research has investigated the relative role of each organ on thresholds for more complex motion. Eccentric (off-center) rotations during which the participant faces away from the center of rotation stimulate both organs and are thus well suited for investigating integration of rotational and translational sensory information. Ten participants completed a psychophysical direction discrimination task for pure head-centered rotations, translations and eccentric rotations with 5 different radii. Discrimination thresholds for eccentric rotations reduced with increasing radii, indicating that additional tangential accelerations (which increase with radius length) increased sensitivity. Two competing models were used to predict the eccentric thresholds based on the pure rotation and translation thresholds: one assuming that information from the two organs is integrated in an optimal fashion and another assuming that motion discrimination is solved solely by relying on the sensor which is most strongly stimulated. Our findings clearly show that information from the two organs is integrated. However the measured thresholds for 3 of the 5 eccentric rotations are even more sensitive than predictions from the optimal integration model suggesting additional non-vestibular sources of information may be involved.
publisher	Public Library of Science
publishDate	2015
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4555836/
_version_	1613471341001834496

Integration of Semi-Circular Canal and Otolith Cues for Direction Discrimination during Eccentric Rotations

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