Cocaine users' brains unable to extinguish drug associations
Their study, published September 5 in Addiction Biology , finds that chronic users have a "global impairment" in the ventromedial prefrontal cortex (VMPFC), an area of the brain that is linked to impulse and self-control, and is responsible for the kind of learning that assigns value to objects and behaviors. The Mount Sinai study investigated a specific type of learning called extinction -- the process by which a new, affectively neutral, association replaces an old, affectively arousing association -- to identify the neurobiological mechanism that underlies the persistence of drug seeking in addiction despite negative consequences and a reduction in the drug's rewarding affects. To investigate these questions, the research team collected functional magnetic resonance imaging (fMRI) data on a three-phase classical conditioning paradigm in individuals with a history of chronic cocaine use and healthy control individuals without the drug habit. They found that in dr...