Originally Posted by
Murray4x5 
So, does this quash the mid-brain AVRT theory, and support limbic system as the source of alcoholic behaviour? Me-thinks it's the limbic system which originates the need for alcohol, which become urges and unwanted intrusive thoughts as they pass through the mid-brain.
Murray
I don't think it matters for the AVRT structural model where precisely in the brain the urges come from.
The structural model is an oversimplification to illuminate the fact that drug cravings are similar to other biological cravings, such as thirst or hunger. The brain, of course, is much more complex.
The "Addictive Voice" of AVRT is just the conscious expression of that biological craving as experienced in our "mind's eye" via thoughts, images, and words.
There have been studies linking the insula, which does not exactly lie in the midbrain, to drug cravings. Former cigarette smokers whose insula was damaged apparently completely stopped having urges to smoke.
Scientists studying stroke patients are reporting today that an injury to a specific part of the brain, near the ear, can instantly and permanently break a smoking habit. People with the injury who stopped smoking found that their bodies, as one man put it, “forgot the urge to smoke.”
One could interpret this insula damage as preventing the higher brain from being able to "read" the cravings generated by the lower functions (the infamous "beast" of AVRT) and then generating the Addictive Voice to bring the cravings to conscious thought.
Articles:
In Clue to Addiction, Brain Injury Halts Smoking A Small Part of the Brain, and Its Profound Effects