Magnitude estimation by the non-pacinian I tactile channel

Abstract

Psychophysical responses to mechanical stimuli were measured to study the sense of touch. By using a forward-masking procedure on eight subjects, magnitude estimation was performed by activating the Non-Pacinian I tactile channel. For each subject, 40-Hz and 250-Hz absolute thresholds were found. Additionally, the 250-Hz masking stimuli that were required to mask the Pacinian channel for selectively activating the Non- Pacinian I channel were determined. The masking stimuli were applied before the test stimuli to find the masked thresholds at 40 Hz. In the final set of experiments, suprathreshold stimuli were used to find magnitude estimation values. These values fit power functions well. Experimental results were compared to neural simulated population responses to study the origins of the power law. The model simulations that used the total number of spikes as the intensity code predicted the experimental results better.|Keywords: somatosensory, mechanoreceptor, power law, masking, Meissner corpuscles