Orotactile Sensation, Gustation and Palatability: A Pilot Study

Abstract

The hypothesis that deficits in orotactile sensitivity may affect gustation and palatability is not new. It is supported by animal models employing deafferentation; however, little direct evidence supports the application of the model to humans. Indirect evidence comes from four separate fields: (1) neuroanatomy, (2) physiology, (3) developmental biology, and (4) learning theory. The results of a pilot study with humans provide additional direct evidence that implicates the role of orotactile sensitivity in human gustation. In this pilot study, the oral cavity was topically anesthetized to determine whether gustation would be compromised to a similar extent as orotactile sensitivity. The time course of the degree of anesthesia was determined by prior measurements of oral-tactile sensitivity using an oral air-based aesthesiometer. Different concentrations of NaCl-solution were presented to subjects in order to determine gustatory thresholds before and after anesthesia. Analysis of magnitude-estimation data indicated that there were statistically significant decreases in gustatory sensitivity after anesthesia. Basic and applied implications of this area of research are discussed.