*****
"There are variants in genes that turn down the function of dopamine signaling within the pleasure circuit. For people who carry these gene variants, their muted dopamine systems lead to blunted pleasure circuits, which in turn affects their pleasure-seeking activities. ... Any one of us could be an addict at any time. Addiction is not fundamentally a moral failing -- it's not a disease of weak-willed losers." -- David Linden
Many of us humans are aware of our personal and ambiguous relationship to pleasure, which we spend a great amount of time and resources pursuing. As we deal with other influencing forces, however, we also tend to regulate pleasure. A key motivator of our lives, pleasure is central to learning, since we find food, water, and sex motivating to survive and pass our genetic DNA onto future generations. Certain varieties of pleasure sensations are regarded as specially guarded areas. Many of our most important rituals involving prayer, music, dance, and meditation create types of transcendent pleasure that has become deeply intrenched in human social and cultural practice. The skillful neuroscientist and articulate author sums it up, "While most people are able to achieve a certain degree of pleasure with only moderate indulgence, those with blunted dopamine systems are driven to overdo it. 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."
Our religions, our educational and legal systems, are all deeply concerned with controlling pleasure, a mind over body notion. But this intrinsic pleasure that can also be initiated or increased by artificial activators like cocaine, heroin, or modest doses of nicotine or alcohol, are located in our brains, transmitting a pleasure buzz from a wide variety of experiences. One can turn to theories of human pleasure and its regulation with support from social history or cultural anthropology, but human pleasure is mostly influenced by tradition and culture. However, The Compass of Pleasure explores a different type of more profound theory based on a cross-cultural biological explanation. The clear and orderly thinking author concludes, "Pleasure must be earned, must be achieved naturally, and it should be sought in moderation. Self denial of pleasure can yield spiritual growth, even while pleasure is transitory."
In this book the author, Dr. David Linden, professor of neuroscience, who likes to tell his students, at the Johns Hopkins University School of Medicine, that the golden age of brain research is right now, argues that most of our lives experiences are transcendent. This applies equally to illicit vices as well as social practices. Various diverse activities as exercise, or socially sanctioned rituals as meditative prayer, or even charitable donations, all fall into this category. Such daily activities trigger an anatomically defined and biochemically determined pleasure circuits in the brain. Shopping, learning, highly caloric foods, gambling, prayer, and browsing on the Internet; all evoke neuro signals that trigger the medial forebrain pleasure circuit, a small group of inter-connected brain areas. These activated tiny clumps of neurons then transmit vague to intense human pleasure signals just experienced.
Linden's theory of pleasure reframes our understanding of the part of the human body that societies are most intent upon regulating. So, "While we might assume that the anatomical region most closely governed by laws, religious prohibitions, and social mores is the genitalia, or the mouth, or the vocal cords, it is actually the medial forebrain pleasure circuit." As societies and as individuals, we are hell-bent on achieving and controlling pleasure, and it is those neurons, deep in our brains, that are the battle ground of that struggle. The dark side of pleasure is, of course, addiction. It is now becoming clear that addiction is associated with long-lasting changes in the biochemical, electrical, and morphological functions of connections within the meddle fore brain pleasure circuit. There is strong support that these changes underlie many of the dark sides of addiction, including progressive tolerance, craving, withdrawal, and relapse. In this sense, pleasure, addiction and memory, are closely related and directly interconnected.
David Linden, in the tradition of great science popularizers of George Gamow and Roger Penrose, like a skillful troubadour who entertains your mind into wonder, iterates, "It would be possible to write a book exploring the brain's pleasure circuits that were free of not only molecules but also basic anatomy,... If you come along for the ride and work with me just a bit to learn some basic neuroscience, I'll do my best to make it lively and fun as we explore the cellular and molecular basis of human pleasure, ..., and addiction."
