Funneling in the Nervous System and its Role in Loudness and Sensation Intensity on the Skin

The relation between the subjective intensity of a vibration on the skin and the physical amplitude of the vibration is different for the different parts of the skin, for example, the finger tip and the shoulder. The reason for this is that the sensation of vibration “loudness” is a complex interaction of summation and inhibition along the stimulated skin surface. Both summation and inhibition vary with the amplitude of the vibration, the distance between the stimulated areas, the slope of the spatial distribution of the stimulus along the surface of the skin, its time pattern, and the density of the innervation. I have tried to describe these relations as variations in “funneling action” of the nervous tissues in the hope that this terminology will lead to a better understanding of the various phenomena.A series of experiments was designed to establish rules for the estimation of the funneling action. For this purpose (1) the vibration loudness produced by a point vibrator was compared with the loudness ...