Rutgers researchers have used neuroimaging to demonstrate that cocaine addiction alters the brain’s system for evaluating how rewarding various outcomes associated with our decisions will feel. This dampens an error signal that guides learning and adaptive behavior. The observed changes likely propagate a mysterious aspect of some addictive behavior—the tendency to keep doing harmful things that sometimes have no immediate benefit. Those changes also make it harder for long-term users of cocaine to correctly estimate how much benefit they’ll derive from other available actions. To read the full story.