Dopamine: Novelty, Salience, Violation of Expectations
Dopamine has many functions which include measuring reward value, motivation, learning & memory, sexual desire. Dopamine dysregulation is the hallmark of all addictions, including porn addiction. Dopamine is stimulated by novelty. This is important because novelty is what makes Internet porn different from magazines or a rented DVD. Each click, each search, each moment of anticipation leads to a squirt of dopamine. Endless novelty-and-variety is the key addictive feature of the Internet and especially Internet porn. Imagine having the same Playboy magazine as your only stimulation for a month worth's of masturbation. Would you develop an addiction, or porn-induced ED from 30 days of the same static centerfold? No way.