addiction

is not about a chemical that causes desire but creates a disposition toward 'craving' which is not an instrumental desire a desire for pleasure, or relief, or what have you. Rather, it generates an intrinsic motivation and issues in an impulse that, unless checked by an exercise of self-control, leads to action.

Richard Holton, an influential moral philosopher, and Kent Berridge, a neuroscientist whose work on addiction is widely discussed, contribute the third of the three papers focusing on the dopamine signal. They reject the view that the dopamine signal causes valuing or desires. Rather, it plays a role in the generation of a disposition to experience cravings, where a craving is a state midway between a desire and an intention. A craving is not an instrumental desire a desire for pleasure, or relief, or what have you. Rather, it generates an intrinsic motivation and issues in an impulse that, unless checked by an exercise of self-control, leads to action. Holton and Berridge argue that work by Wyvell and Berridge (2000) demonstrates that dopamine generates cue-conditioned cravings rather than an expectation of reward. Wyvell used amphetamines to sensitize rats to a sugar reward. Sensitized rats who learned to associate a tone with the availability of sugar pressed the lever to deliver sugar frantically, but sensitized rats who simply had the lever made available to them did not press it any more frequently than control rats. Since there is no reason to think that rats in either condition had different expectations about how rewarding sugar would be, the tone seems to be a direct cause of motivation, independent from beliefs or expectations. Since cravings can cause behavior that is at variance with agents' beliefs, Holton and Berridge reach a conclusion that is directly in conflict with Yaffe's: (some) addicts act akratically.

Richard HoltonThinkers

Richard Holton