Leech mechanosensory model - Fractional derivative

Ok, now I've incorporated the T cells, but I thought a simple linear filter would enable rates like in the animal. But it wasn't quite right -- the T cells didnt fire on the off phase of the steps. So instead of doing the linear filters, I implemented fractional derivatives for the "filters". So now the P cell filter is the 0.3 order fractional derivative of the sensory signal, and the T cell filter is the 1.6 order fractional derivative.

Figure 1: Sensory signal, P and T cell currents based on fractional derivative of signal.

Figure 2: receptive fields of P and T cells.

Figure 3: P cell responses to sensory signal.

Figure 4: T cell responses to stimulus