He also discusses the disturbing symptoms showing up in some heavy Internet users, the surprising reversal of those symptoms, and the science behind these 21st century phenomena.

Gary is host of www.yourbrainonporn.com. The site arose in response to a growing demand for solid scientific information by heavy Internet erotica users experiencing perplexing, unexpected effects: escalation to more extreme material, concentration difficulties, sexual performance problems, radical changes in sexual tastes, social anxiety, irritability, inability to stop, and obsessive-compulsive symptoms.

As a physiology teacher with a particular interest in the latest neuroscience discoveries, Gary was aware that their symptoms might be the result of addiction-related brain changes. Applying the website's concepts of brain plasticity, many former users have braved withdrawal, reversed their symptoms and restored normal sexual responsiveness.