Vestibular perceptual thresholds measure vestibular sensory and perceptual noise by quantifying how small of a passive self-motion an individual is able to reliably perceive. Vestibular thresholds have clinical and operational relevance, as they are elevated in vestibular migraine patients, and even healthy individuals with higher (i.e., worse) thresholds have degraded balance. Vestibular thresholds have been quantified across a range of frequencies (motion durations) for rotations and translations, with differences identified for different motion directions (e.g., up/down thresholds are higher than those for left/right motions). While roll tilt thresholds have been well quantified, pitch tilt thresholds have not. Here we aim to quantify pitch tilt thresholds across a range of frequencies and test whether they are higher than in those for roll tilt. In ten normal subjects, we found pitch tilt thresholds at 0.15, 0.2, 0.5, and 1 Hz averaged 1.66, 1.61, 0.99, 0.51 degrees, respectively. Using a general linear model, we found subjects' pitch tilt thresholds were slightly, but significantly, higher than their roll tilt thresholds across all frequencies tested. These differences were approximately 10% at 0.15, 0.2, and 1 Hz and 3% at 0.5 Hz. Pitch tilt thresholds exhibited a similar frequency response as in roll tilt (decreasing a higher frequencies). They also had substantial inter-individual variability, which correlated across pitch tilt frequencies and between pitch and roll tilt thresholds. We discuss why pitch tilt thresholds might be higher, including the pitched-up orientation of the utricular plane of the otoliths, compared to previous studies, and discuss functional implications.

中文翻译：

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在一定频率范围内，俯仰倾斜的人前庭感知阈值比侧倾倾斜的感觉阈值稍差。

前庭知觉阈值通过量化个体能够可靠感知的被动自我运动量来测量前庭感觉和知觉噪声。前庭阈值具有临床和操作相关性，因为前庭偏头痛患者的前阈值升高，甚至阈值较高（即较差）的健康个体的平衡能力也下降。已经针对旋转和平移在一定频率范围内（运动持续时间）对前庭阈值进行了量化，并针对不同的运动方向确定了差异（例如，上/下阈值高于左/右运动的阈值）。尽管侧倾倾斜阈值已得到很好的量化，但俯仰倾斜阈值却尚未确定。在这里，我们旨在量化整个频率范围内的俯仰倾斜阈值，并测试它们是否高于侧倾倾斜阈值。在十个正常受试者中，我们发现在0.15、0.2、0.5和1 Hz的俯仰倾斜阈值分别平均为1.66、1.61、0.99、0.51度。使用通用线性模型，我们发现受试者在所有测试频率上的俯仰倾斜阈值均略微但显着高于其侧倾倾斜阈值。这些差异在0.15、0.2和1 Hz时约为10％，在0.5 Hz时约为3％。俯仰倾斜阈值表现出与侧倾倾斜相似的频率响应（降低更高的频率）。它们之间也存在很大的个体差异，这些差异在俯仰倾斜频率之间以及俯仰和侧倾阈值之间相关。我们讨论为什么俯仰倾斜阈值可能更高，