Canal and Otolith Contributions to Visual Orientation Constancy During Sinusoidal Roll Rotation

Abstract

Kaptein, Ronald G. and Jan A.M. Van Gisbergen. Canal and otolith contributions to visual orientation constancy during sinusoidal roll rotation. J Neurophysiol 95: 1936 -1948, 2006. First published November 30, 2005 doi:10.1152/jn.00856.2005. Using vestibular sensors to maintain visual stability during changes in head tilt, crucial when panoramic cues are not available, presents a computational challenge. Reliance on the otoliths requires a neural strategy for resolving their tilt/translation ambiguity, such as canal-otolith interaction or frequency segregation. The canal signal is subject to bandwidth limitations. In this study, we assessed the relative contribution of canal and otolith signals and investigated how they might be processed and combined. The experimental approach was to explore conditions with and without otolith contributions in a frequency range with various degrees of canal activation. We tested the perceptual stability of visual line orientation in six human subjects during passive sinusoidal roll tilt in the dark at frequencies from 0.05 to 0.4 Hz (30°p eak to peak). Because subjects were constantly monitoring spatial motion of a visual line in the frontal plane, the paradigm required moment-to-moment updating for ongoing ego motion. Their task was to judge the total spatial sway of the line when it rotated sinusoidally at various amplitudes. From the responses we determined how the line had to be rotated to be perceived as stable in space. Tests were taken both with (subject upright) and without (subject supine) gravity cues. Analysis of these data showed that the compensation for body rotation in the computation of line orientation in space, although always incomplete, depended on vestibular rotation frequency and on the availability of gravity cues. In the supine condition, the compensation for ego motion showed a steep increase with frequency, compatible with an integrated canal signal. The improvement of performance in the upright condition, afforded by graviceptive cues from the otoliths, showed low-pass characteristics. Simulations showed that a linear combination of an integrated canal signal and a gravity-based signal can account for these results.

Frequency-Selective Coding of Translation and Tilt in Macaque Cerebellar Nodulus and Uvula

“…However, during low frequency movements, linear accelerations in the absence of extra-vestibular cues are typically, and often erroneously (i.e., even when generated by translational motion), interpreted as tilt (Glasauer, 1995; Kaptein and Van Gisbergen, 2006; Merfeld et al, 2005a,b; Paige and Seidman, 1999; Seidman et al, 1998). In fact, these low frequency motions often result in perceptual illusions (“somatogravic/oculogravic” illusion, Graybiel, 1952; Clark and Graybiel, 1963, 1966).…”

Shared Computational Mechanism for Tilt Compensation Accounts for Biased Verticality Percepts in Motion and Pattern Vision

“…These inputs are measured by the (noisy) sensors, which provide two sensory signals ( and r ) to the observer. A major source for the sensory head tilt signal are the otoliths, but other sensory systems, like somatosensory afferents (Bronstein 1999) and the semicircular canals (JaggiSchwarz and Hess 2003; Kaptein and Van Gisbergen 2006;Pavlou et al 2003), may contribute as well. The model assumes that the sensory tilt signal is veridical on average, but rather noisy in comparison with the sensory visual signal r .…”

A Vestibular Sensation: Probabilistic Approaches to Spatial Perception

“…This is due to the fact that canal dynamics are frequency-dependent, such that they reliably encode rotational velocity only above ~0.05 Hz (Goldberg and Fernandez 1971). As a result, the brain often chooses a default solution when experiencing low frequency accelerations: in the absence of extra-vestibular information (e.g., from vision), low frequency linear accelerations are typically, and often erroneously (i.e., even when generated by translational motion), interpreted as tilt (Glasauer, 1995; Kaptein and Van Gisbergen, 2006; Paige and Seidman, 1999; Park et al, 2006; Seidman et al, 1998; Stockwell and Guedry, 1970). …”