Influence of scaling range on vibrotactile power function exponents for the tongue and hand

Intramodal range has been studied by R. Teghtsoonian (1973), who found that for magnitude-estimation procedures an increase in the scaling range will cause a decrease in the exponent of the power function. For magnitude production procedures, an increase in the scaling range will decrease the magnitude of the exponent of the power function (Teghtsoonian, 1973). The purpose of this pilot study was to investigate the influence of scaling range on the psychophysical functions obtained by the method of magnitude production for vibrotaction. Twenty subjects were randomly selected and divided into two groups of 10 subjects each. Subjects' ages ranged from 17 to 23 yr. A detailed description of the vibrotactile equipment can be found elsewhere (1). The psychophysical method of magnitude production was used to establish suprathreshold magnitude functions from the anterior midline section of the tongue dorsum and the thenar eminence of the right hand. Each subject in Group 1 received a random order of six numbers (5, 10, 15, 20, 25, 30) and was asked to adjust the magnitude of the stimulus that he was feeling to the number being presented. Each subject in Group 2 received the same random series of six numbers as Group 1, but other numbers were also randomly interspersed above, between, or below the series of six to present an expanded range of numbers for scaling. For both groups the randomized series of numbers was presented three times at each test site.(ABSTRACT TRUNCATED AT 250 WORDS)