Department of Food Science & Technology, The Ohio State University, 2015 Fyffe Rd., Columbus, OH 43210-1007, USA.
Department of Otolaryngology - Head & Neck Surgery, The Ohio State University, 915 Olentangy River Rd., Columbus, OH 43212-3153, USA.
Food Funct. 2022 Jan 4;13(1):64-75. doi: 10.1039/d1fo02460d.
While perception of high-viscosity solutions ( > 1000 cP) is speculated to be linked to filiform papillae deformation, this has not been demonstrated psychophysically. Presently, just-noticeable-viscosity-difference thresholds were determined using the forced-choice staircase method and high-viscosity solutions ( = 4798-12260 cP) with the hypotheses that the tongue would be chiefly responsible for viscosity perception in the oral cavity, and that individuals with more, longer, narrower filiform papillae would show a greater acuity for viscosity perception. Subjects ( = 59) evaluated solutions in a normal, "unblocked" condition as well as in a "palate blocked" condition which isolated the tongue so that only perceptual mechanisms on the lingual tissue were engaged. Optical profiling was used to characterize papillary length, diameter, and density in tongue biopsies of a subset ( = 45) of participants. Finally, psychophysical and anatomical data were used to generate a novel model of the tongue surface as porous media to predict papillary deformation as a strain-detector for viscosity perception. Results suggest that viscosity thresholds are governed by filiform papillae features. Indeed, anatomical characterization of filiform papillae suggests sensitivity to high-viscosity solutions is associated with filiform papillae length and density ( = 0.68, < 0.00001), but not with diameter. Modelling indicated this is likely due to a reciprocal interaction between papillae diameter and fluid shear stress. Papillae with larger diameters would result in higher viscous shear stress due to a narrower gap and stronger fluid-structure interaction, but a larger-diameter papilla would also deform less easily.
当人们推测感知高粘度溶液（>1000 厘泊）与丝状乳头变形有关时，这在心理生理学上尚未得到证实。目前，使用强制选择阶梯法确定了可察觉粘度差异阈值，并使用高粘度溶液（=4798-12260 厘泊）进行了假设，即舌头在口腔中主要负责感知粘度，并且丝状乳头数量较多、较长、较窄的个体对粘度感知的灵敏度更高。受试者（=59）在正常的“未阻塞”状态以及“腭阻塞”状态下评估溶液，后者将舌头隔开，使舌头上的只有感知机制参与。光学轮廓法用于对一部分（=45）参与者的舌活检中的乳头长度、直径和密度进行特征描述。最后，心理物理学和解剖学数据用于生成舌表面作为多孔介质的新型模型，以预测丝状乳头变形作为粘度感知的应变探测器。结果表明，粘度阈值受丝状乳头特征的控制。实际上，丝状乳头的解剖学特征表明，对高粘度溶液的敏感性与丝状乳头的长度和密度有关（=0.68，<0.00001），但与直径无关。建模表明，这可能是由于乳头直径和流体剪切力之间的相互作用。直径较大的乳头由于间隙较窄且流体-结构相互作用更强，会导致更高的粘性剪切力，但较大直径的乳头也不易变形。
