I posted this recently in another thread..check out the link...

"The current porn epidemic gives a graphic demonstration that sexual tastes can be acquired. Pornography, delivered by high-speed Internet connections, satisfies every one of the prerequisites for neuroplastic change [forming new neural circuitry- a key piece in addiction].

Pornography seems, at first glance, to be a purely instinctual matter: sexually explicit pictures trigger instinctual responses, which are the product of millions of years of evolution. But if that were true, pornography would be unchanging. The same triggers, bodily parts and their proportions, that appealed to our ancestors would excite us. This is what pornographers would have us believe, for they claim they are battling sexual repression, taboo, and fear and that their goal is to liberate the natural, pent-up sexual instincts.................
Norman Doidge on pornography and neuroplasticity - worthwhile reading | Reuniting