Hess Straumann
Fakultäten » Medizinische Fakultät » Neurologie, Klinik für » Prof. Dr. Bernhard Hess » Hess Straumann
Completed research project
| Title / Titel | Integration of semicircular canal and otolith signals subserves dynamic head-in-space orientation | ||||
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| Abstract (PDF, 14 KB) | |||||
| Summary / Zusammenfassung | Angular acceleration of the head activates the semicircular canals in the inner ear, which evoke a perception of rotation and unconscious compensatory three-dimensional eye movements. If the rotation continuous at a constant velocity (e.g. during a long turn in an airplane), the activation of the semicircular canals, the sensation of rotation and the compensatory eye movements subside. However, if the head rotates around a tilted axis (off-vertical axis rotation), the constant reorientation relative to gravity dynamically activates also the otolith organs in the inner ear. This leads to sustained compensatory eye movements, suggesting that the brain is able to reconstruct the head-in-space motion from dynamic otolith cues. In this project, we test a new motion protocol (“cone motion”), which consists in oscillating a subject simultaneously in the pitch (forward-backward tilt) and in roll plane (right-left tilt) . This maneuver causes the head to move through the same orientations relative to gravity as during off-vertical axis rotation(e.g. starting from nose-up orientation to ear-down, nose-down, etc), thereby creating the same otolith input. Furthermore these oscillations activate the vertical semicircular canals. However, during cone motion, the head does not rotate in the yaw plane (i.e. about the head vertical axis). As there is no activation of the lateral semicircular canals in either paradigm, the only sensory input that would allow discriminating between the two types of motion come from the from the vertical semicircular canals. The questions we study in this project are: Does the brain correctly discriminate between these two motion paradigms, and if so, what are the underlying mechanisms? |
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| Publications / Publikationen | Laurens J, Straumann D, Hess BJM. Spinning versus wobbling: how the brain solves a geometry problem. J Neurosci. 31:8093-8101, 2011Laurens J, Straumann D, Hess BJM. Processing of angular motion and gravity information through an internal model. J Neurophysiol. 104:1370-1381, 2010Laurens J, Hess BJM, Straumann D. Geometrical considerations on canal-otolith interactions during OVAR and Bayesian modelling. Prog Brain Res. 171:287-90, 2008 |
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| Keywords / Suchbegriffe | Vestibulo-ocular reflex, otoliths, 3D eye movements, spatial orientation | ||||
| Project leadership and contacts / Projektleitung und Kontakte |
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| Funding source(s) / Unterstützt durch |
Forschungskredit der Universität Zürich, Foundation |
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| Duration of Project / Projektdauer | Oct 2007 to Dec 2009 |