What we know about sex offenders, especially child sex offenders, is that they frequently have a cognitive distortion that their desire is the victim's desire. They often will say that the reason they did this is because she wanted it. This cognitive distortion is a very common thing that those who treat sex offenders have to first address. That is one of the reasons adults who show children adult pornography are doing this. The pornography excites the adult, and in their cognitive distortion they think it will excite the child as well, when in fact that's not the case.
The other question you asked me was about mirror neuron research. This started around 2007 from Italy. Researchers began to notice from functional MRI studies and others that when people were looking at something, multiple parts of the brain were lighting up as compared to just the eyeball and the optic nerve going to the back of the brain. These other parts of the brain, the temporal part, the frontal part, they thought had nothing to do with vision. They were absolutely right. It helped us to recognize that what those mirror neurons taught us is that when we see something, our body starts to react in many ways. Our heart rate can increase and our blood pressure can go up, because our body becomes convinced we are experiencing what we are seeing at those moments.
This is relevant when we talk about the role of Internet pornography whether it's youth or adults. It causes the body to have a reaction that is much more than what you see. Now there are over 1,000 papers written about mirror neuron research, and I definitely encourage you to look into it.