Transcript

I think one of the most important findings in the last few years in neuroscience is that while the molecule dopamine is associated with reward, it's more about motivation and craving. There's a really classic experiment now that people use to demonstrate this. Take two rats, and the rats independently separate cages. Can lever press for food, or when they can access food, there's a little bit of dopamine that's released anytime they get some food. So we always thought that food, like many other rewards, like food, sex, warmth when you're cold, cool when you're too warm, is triggering the release of dopamine.

But someone had the good idea to deplete dopamine in one of those animals, and then what you find is that the animal without dopamine still enjoys food, still enjoys other pleasures. So dopamine is not really involved in the enjoyment of those pleasures. It's involved in motivation. Because if you make the animal have to move just one rat's length, believe it or not, to get to that lever, the animal with dopamine will work to go get that thing. It will work through some effort to go get the reward. Whereas the animal, or it turns out the human, without much dopamine, can still experience pleasure. They can sit on their couch and cram their face with pleasure inducing calories or what have you watch pleasure inducing things on the television, but they have very little motivation to go pursue things that will deliver them pleasure. It's actually what's really driven the forward evolution of our species has been the desire to go seek things beyond the confines of our skin.