July 5, 20117/5/11 0 comments
“We humans have a complicated and ambivalent relationship to pleasure, which we spend an enormous amount of time and resources pursuing. A key motivator of our lives, pleasure is central to learning, for we must find things like food, water, and sex rewarding in order to survive and pass our genetic material to the next generation,” says David Linden, professor of neuroscience at the Johns Hopkins University School of Medicine and the chief editor of the Journal of Neurophysiology. His new book, The Compass of Pleasure: How Our Brains Make Fatty Foods, Orgasm, Exercise, Marijuana, Generosity, Vodka, Learning and Gambling Feel So Good, explores what it really means for the brain to experience pleasure.
In a nutshell, Linden says our genes have variants that mute the function of dopamine signaling that converge on a “small group of interconnected brain areas called the medial forebrain pleasure circuit” – the “tiny clumps of neurons” where human pleasure is felt. People who carry these rain-on-your-parade variants experience blunted pleasure circuits, which in turn might lead to their overindulging to reach the same degree of pleasure achieved by others.
“In order to get to that same set point of pleasure that others would get to easily — maybe with two drinks at the bar and a laugh with friends — you need six drinks at the bar to get the same thing,” Linden recently told Terry Gross, host of the NPR program Fresh Air.
Linden goes on to explain that our pleasure circuits involve multiple factors, including genetics, stress and life experience; understanding that biology is important in treating addiction, which he calls the “dark side of pleasure.” And while “addiction” shouldn’t be used to justify inappropriate behavior, he argued on Fresh Air that true addicts aren’t just resorting to vices because of desire. Rather than seeking pleasure, he added, true addicts are fulfilling the need we all have for pleasure.
Okay, so I won’t use addiction to justify that one too many glass of wine or just one more piece of chocolate cake. But I admire Professor Linden for reframing the topic in a way that helps inspire advanced ways of understanding the brain.
“I like to tell the students in my lab that the golden age of brain research is right now, so it’s time to get down to business,” he writes in The Compass of Pleasure. “Our accumulating understanding of neural function, coupled with enabling technologies that allow us to measure and manipulate the brain with unprecedented precision, has given us new and often counterintuitive insights into behavioral and cognitive phenomena at the levels of biological processes…Understanding the biological basis of pleasure leads us to fundamentally rethink the moral and legal aspects of addiction to drugs, food, sex, and gambling and the industries that manipulate these pleasures in the marketplace. It also calls for a reformation in our concepts of such virtuous and prosocial behaviors as sharing resources, self-deprivation, and the drive for knowledge…Perhaps, most important, analysis of the molecular basis of enduring changes in the brain’s pleasure circuitry holds great promise for developing drugs and other therapies to help people break free of addictions of many sorts, to both substances and experiences.”
I’m raising a glass – err, giving a cheer to everyone who is working to better understand the human brain. What do you want to know about what makes us tick?