Perception Threshold for Tilt

Abstract

The aim of this study was to determine the thresholds for perception of tilt and translation using 3 motion/tilt profile paradigms. Healthy subjects were submitted to the following: 1) unilateral and bilateral eccentric rotations (centrifugation), 2) whole body translatory decelerations opposite to the movement direction while seated on a linear sled, and 3) discrete slow velocity platform tilts. Subjects were instructed to verbally indicate the perceived direction of tilt or translation. Fifteen healthy subjects (12 male and 3 female subjects, 18-31 yr) without any history or evidence of any ophthalmologic or neuro-otologic disorder participated in this study. Our results from unilateral centrifugation indicate a threshold for body tilt perception of approximately 2 degrees with a substantial interindividual range (1.9-5.6 degrees, 52% interindividual and 34% intraindividual variability), which, to our interpretation, mainly depends on otolithic function. Tilt perception during whole body decelerations and discrete platform tilts mainly depends on somatosensory information, showing the dominant role of the somatosensory system for the perception of body orientation. Thus, tilt sensations during eccentric rotations seems to be a promising tool for the evaluation of utricular dysfunction.

Visual and vestibular perceptual thresholds each demonstrate better precision at specific frequencies and also exhibit optimal integration

“…Our vestibular thresholds as a function of frequency in the dark are very similar to those recently reported for roll tilt by Valko et al (2012), and also quite similar to those recently reported by other groups at 2 Hz (Crane 2012b) and for low-velocity tilts using a detection task (Janssen et al 2011). Another study (Lagace-Nadon et al 2009) reported that visual roll tilt thresholds decreased with increasing temporal frequency, consistent with our findings.…”

“…Roll rotation thresholds ({) are collected with the subject supine, so that the SCC are the primary motion cue. Pseudostatic-tilt thresholds (dashed line) are collected using very slow constant velocity tilts which stimulate primarily the otolith organ and are consistent with "otolith" thresholds determined by others (Janssen et al 2011). At low frequencies, roll tilt thresholds are consistent with the pseudostatic-tilt threshold, suggesting the brain relies primarily on otolith organ cues.…”

Roll aftereffects: influence of tilt and inter-stimulus interval

“…This finding indicates that tilt at the end of a roll adapter causes the RAE to persist. The 9° tilt at the end of the adapting stimulus, although small, is well above the tilt perception threshold (Janssen et al 2011), and prolonged the RAE perhaps by facilitating persistence of the effect of the adapting roll.…”

“…The threshold for perception of static tilt (postural vertical) has been previously measured as 4.4° (Mann and Dauterive 1949; Mann 1950) which is similar to the threshold measured using a centrifuge to change the vertical acceleration vector (Graybiel and Patterson 1955). A more recent study described the threshold of human tilt perception over a group of individuals as 1.9° – 5.6° (Janssen et al 2011). Thus in the current study the thresholds were almost certainly determined by the semicircular canal response to roll rather than by otolith and proprioceptive influences to tilt because at the threshold of roll perception the tilt (0.2°) was an order of magnitude smaller than the previously described thresholds of tilt perception (1.9 to 5.6°).…”

Peripheral Vestibular Dysfunction in Patients With Primary Ciliary Dyskinesia

“…UCF was scored as median SVV angle and gain in each position and utricular percentage weakness. The normal range for static SVV is about 2° [13,16].…”