Effects of single-session repetitive judgments on magnitude estimation scales for lingual vibrotactile sensation.

Abstract

The human tongue, because it is mucosal in nature and housed within the oral cavity, presents a unique set of problems for suprathreshold vibrotactile magnitude scaling. It was hypothesized that the ideal response mode when testing the lingual structure would entail a single set of stimulus-level judgments to be made by a subject so that fatigue effects and overall subject discomfort associated with lingual vibrotactile suprathreshold testing could be reduced. The purpose of the present investigation was to study the possible effects that single-session repetitive judgments would have on lingual vibrotactile magnitude estimation outcome. Twenty subjects (M age = 23.25 years) participated in a single-session magnitude estimation paradigm which required them to make three magnitude estimation judgments at each of nine stimulus intensity levels. The three data runs were statistically analyzed using a multivariate mixed-model analysis of variance. There appeared to be no statistical differences between the three magnitude scaling runs at any of the nine sensation levels, whether they were compared separately or in all possible combinations, when alpha was set at .05. The results are discussed as being supportive of the possibility that a single set of response judgments can be employed in lingual vibrotactile magnitude scaling. Factors associated with the single-response set, such as ability to run more subjects in less time, better assurance of open-ended responses from subjects, and the increased likelihood of subject response spontaneity are also discussed.