Stability of magnitude production scales for oral and nonoral vibrotactile mechanoreceptive systems.

The stability of oral and nonoral vibrotactile magnitude scales produced by the method of magnitude production was investigated for 11 adult subjects. Each subject was tested over four sessions separated by 1-wk. intervals. Data analyses included correlations across trials of power function slopes as well as individual adjustments of intensity. Analysis showed a lack of stability over time for the slope functions obtained on the thenar eminence but moderate stability for the functions obtained on the tongue. Individual adjustments on intensity showed consistently high correlations across trials and structures. It was concluded that the subjects' responses were guided by the imposed experimental variables and that each individual's scaling was not necessarily reflected by the correlations based on power function slopes established over the four trials.