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

Soyka F, Bülthoff HH, Barnett-Cowan M - PLoS ONE (2015)

Bottom Line: Discrimination thresholds for eccentric rotations reduced with increasing radii, indicating that additional tangential accelerations (which increase with radius length) increased sensitivity.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.

View Article: PubMed Central - PubMed

Affiliation: Max Planck Institute for Biological Cybernetics, Department: Human Perception, Cognition and Action, Tübingen, Germany.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Conditions.Description of the experimental conditions as they were presented to the participants.
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pone.0136925.g001: Conditions.Description of the experimental conditions as they were presented to the participants.

Mentions: In this study, we used a direction discrimination task in which participants had to judge whether a motion was leftward or rightward and thresholds were measured for translational motions, head-centered rotations and eccentric rotations (Fig 1). Eccentric rotations (also known as off-center rotations) are motions with a circular trajectory in which the center of rotation is located behind the participant and participants are facing away from the center of rotation. Such motions include both translational and rotational cues and are therefore well suited for studying potential cue integration, or dominance.


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

Soyka F, Bülthoff HH, Barnett-Cowan M - PLoS ONE (2015)

Conditions.Description of the experimental conditions as they were presented to the participants.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555836&req=5

pone.0136925.g001: Conditions.Description of the experimental conditions as they were presented to the participants.
Mentions: In this study, we used a direction discrimination task in which participants had to judge whether a motion was leftward or rightward and thresholds were measured for translational motions, head-centered rotations and eccentric rotations (Fig 1). Eccentric rotations (also known as off-center rotations) are motions with a circular trajectory in which the center of rotation is located behind the participant and participants are facing away from the center of rotation. Such motions include both translational and rotational cues and are therefore well suited for studying potential cue integration, or dominance.

Bottom Line: Discrimination thresholds for eccentric rotations reduced with increasing radii, indicating that additional tangential accelerations (which increase with radius length) increased sensitivity.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.

View Article: PubMed Central - PubMed

Affiliation: Max Planck Institute for Biological Cybernetics, Department: Human Perception, Cognition and Action, Tübingen, Germany.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus