Until recently, scientists believed our brains were fixed, their circuits formed and finalised in childhood, or "hardwired". Now we know the brain is "neuroplastic", and not only can it change, but that it works by changing its structure in response to repeated mental experience.
-Norman Doidge, M.D. (2013). Brain scans of porn addicts: what's wrong with this picture?
Wow! I never knew that! You mean the brain can actually learn? And it changes with experience? Really?? Thank you, Norman Doidge, for that brilliant insight, and for many other gems in your wonderful Comment is Free piece on porn addiction in the Guardian.
Let's see what physicians and psychologists of yesteryear have to say about these newly discovered "neuroplastic" brains.
Here it may be asked whether the organs [of the brain] increase by exercise? This may certainly happen in the brain as well as in the muscles; nay, it seems more than probable, because the blood is carried in greater abundance to the parts which are excited, and nutrition is performed by the blood. In order however, to be able to answer this question positively, we ought to observe the same persons when exercised and when not exercised; or at least observe many persons who are, and many others who are not, exercised during all periods of life.
-J.G. Spurzheim (1815). The physiognomical system of Drs. Gall and Spurzheim; founded on an anatomical and physiological examination of the nervous system in general, and of the brain in particular; and indicating the dispositions and manifestations of the mind.
The question is not whether neural events change the status of the tissue in which they occur. The only question which may still be debated is: whether such changes as do undoubtedly occur have the permanence and those other properties which we must attribute to memory-traces. According to our present knowledge the primary effect which nerve impulses produce in ganglionic layers is chemical activity. . .
-Wolfgang Köhler (1938), The Place Of Value In A World Of Facts.
These quotes were taken from a 1964 review paper by Edward L. Bennett, Marian C. Diamond, David Krech, and Mark R. Rosenzweig. The title? Chemical and Anatomical Plasticity of Brain.
Changes in brain through experience, demanded by learning theories, are found in experiments with rats.
Fig. 1 (Bennett et al., 1964). Animals in Environmental Complexity and Training Cage.
The authors compared the brains of rats exposed to complex, enriched environments to those housed in isolated cages. They found increases in cortical thickness, increases in cortical tissue weight (not related to overall brain or body size), and in increases acetylcholinesterase activity in rats who had lived in the fun and social cages. The project was launched 60 years ago, in 1953... so it's a bit disingenuous for Dr. Doidge to call neuroplasticity a "recent" discovery.
Furthermore, Doidge's Freudian interpretation of porn would be rather quaint, if it weren't so disturbing:
Porn sites are also filled with the complexes Freud described: "Milf" ("mothers I'd like to fuck") sites show us the Oedipus complex is alive; spanking sites sexualise a childhood trauma; and many other oral and anal fixations. All these features indicate that porn's dirty little secret is that what distinguishes "adult sites" is how "infantile," they are, in terms how much power they derive from our infantile complexes and forms of sexuality and aggression. Porn doesn't "cause" these complexes, but it can strengthen them, by wiring them into the reward system.
And of course, reward = dopamine. And we all know that "dopamine is the ultimate feminist chemical in the female brain." Oh wait...
Guess Doidge hasn't watched any feminist porn.
Feminist Dopamine, Conscious Vaginas, and the Goddess Array
Is There Any Evidence for the "Porn-Addicted Brain"?
Neuroplasticity is a dirty word
Neuroplasticity is not a new discovery
BENNETT EL, DIAMOND MC, KRECH D, & ROSENZWEIG MR (1964). CHEMICAL AND ANATOMICAL PLASTICITY of BRAIN. Science, 146 (3644), 610-9 PMID: 14191699