I'm having some difficulty understanding how the afferent signals are sensed in the finger pads. My understanding is that for mechanoreceptors, as the indenting force increases, their effective response also increases. Additionally, as contact area increases, so does the overall stimulus area and hence a larger response amplitude from the mechanoreceptor afferents should be found.
However, the results shown in this article in the Journal of Neuroscience that discusses this physiology shows contradicting results. In this article, the closer the dot spacing (1 mm or less) and the higher the contact area the lesser the receptors seem to fire, and stop firing altogether at about 1 mm dot spacing?
Why would this occur?