STUDIES IN PALLESTHESIA - PALLOMETER THRESHOLD VALUES IN 60 PROVED NORMAL SUBJECTS

[摘要] A new electronic instrument, the Pallometer is described for the precise determination of threshold amplitudes of vibratory appreciation at any selected fixed frequencies. Minute deviations in amplitude levels can be accurately ascertained. Pallometric threshold patterns for the fingertips in 60 proved normal subjects of varying ages and both sexes are presented. Individuals with normal vibratory acuity report differing threshold amplitudes at the various frequencies tested. Amplitude spreads are confined to the narrowest limits so far reported. The form of the mean curve confirms 240 cps as the optimum frequency and reveals a very small elevation from this level at frequencies on either side. Right-handed individuals are shown to be more sensitive on the left index fingertip; left-handed subjects are more sensitive on the right. Left-handed subjects however, have higher threshold levels on both hands. Repeated testing of normal individuals reveals fluctuations within the limits of the normal amplitude range. Threshold amplitudes apparently are easily influenced by changes in environmental temperature and by the smoking of a single cigarette. Determination of normality of vibratory acuity based upon levels of appreciation at 1 or 2 frequencies may be misleading. It is essential that only subjects with proved normal Vibratory acuity be used as controls for vibratory sense studies.