Hoffmann Rebekka, Valgeirsdóttir Vigdís Vala, Jóhannesson Ómar I, Unnthorsson Runar, Kristjánsson Árni
Faculty of Psychology, School of Health Sciences, University of Iceland, Reykjavik, Iceland.
Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, University of Iceland, Reykjavik, Iceland.
Exp Brain Res. 2018 Dec;236(12):3405-3416. doi: 10.1007/s00221-018-5387-z. Epub 2018 Oct 6.
Vibrotactile displays can compensate for the loss of sensory function of people with permanent or temporary deficiencies in vision, hearing, or balance, and can augment the immersive experience in virtual environments for entertainment, or professional training. This wide range of potential applications highlights the need for research on the basic psychophysics of mechanisms underlying human vibrotactile perception. One key consideration when designing tactile displays is determining the minimal possible spacing between tactile motors (tactors), by empirically assessing the maximal throughput of the skin, or, in other words, vibrotactile spatial acuity. Notably, such estimates may vary by tactor type. We assessed vibrotactile spatial acuity in the lower thoracic region for three different tactor types, each mounted in a 4 × 4 array with center-to-center inter-tactor distances of 25 mm, 20 mm, and 10 mm. Seventeen participants performed a relative three-alternative forced-choice point localization task with successive tactor activation for both vertical and horizontal stimulus presentation. The results demonstrate that specific tactor characteristics (frequency, acceleration, contact area) significantly affect spatial acuity measurements, highlighting that the results of spatial acuity measurements may only apply to the specific tactors tested. Furthermore, our results reveal an anisotropy in vibrotactile perception, with higher spatial acuity for horizontal than for vertical stimulus presentation. The findings allow better understanding of vibrotactile spatial acuity and can be used for formulating guidelines for the design of tactile displays, such as regarding inter-tactor spacing, choice of tactor type, and direction of stimulus presentation.
振动触觉显示器可以补偿视力、听力或平衡存在永久性或暂时性缺陷的人的感觉功能丧失，并可以增强虚拟环境中用于娱乐或专业培训的沉浸式体验。这种广泛的潜在应用凸显了对人类振动触觉感知背后机制的基本心理物理学进行研究的必要性。设计触觉显示器时的一个关键考虑因素是通过实证评估皮肤的最大通量，或者换句话说，振动触觉空间敏锐度，来确定触觉电机（触觉器）之间的最小可能间距。值得注意的是，这种估计可能因触觉器类型而异。我们评估了三种不同触觉器类型在胸部下方区域的振动触觉空间敏锐度，每种触觉器以4×4阵列安装，触觉器中心到中心的间距分别为25毫米、20毫米和10毫米。17名参与者进行了一项相对的三择一强制选择点定位任务，对垂直和水平刺激呈现都进行了连续的触觉器激活。结果表明，特定的触觉器特征（频率、加速度、接触面积）会显著影响空间敏锐度测量，突出表明空间敏锐度测量结果可能仅适用于所测试的特定触觉器。此外，我们的结果揭示了振动触觉感知中的各向异性，水平刺激呈现的空间敏锐度高于垂直刺激呈现。这些发现有助于更好地理解振动触觉空间敏锐度，并可用于制定触觉显示器设计指南，例如关于触觉器间距、触觉器类型选择和刺激呈现方向。
