I have two Ag/AgCl electrodes and a circuit to obtain SCL signal. While doing experiments I observed that when I left electrodes open and used two fingers and touched on two electrodes, it took a period of time for SCL signal to rise a stable value (let's call it rising time). The curve is similar to the capacitor voltage vs. time in RC circuit. When I used the inner side of a palm to touch on these two electrodes it took much longer time to rise to a stable level. During the experiments, there was no stimulus hence, the rising time was not the 1-3s rise time of SCL signal after the appearance of a stimulus. I think it's because of the capacitance of the skin. However, I am not sure which part of the finger or palm (skin or inner tissues) causes that. Is the simplified equivalent circuit of the electrodermal system explained in http://www.bem.fi/book/27/27.htm sufficient enough?

Could anyone help me to answer this question?