The Compass of Pleasure

January 24, 2011
By merging an evolutionary perspective with cutting-edge research in neuroscience, Linden, a professor of neuroscience at Johns Hopkins University School of Medicine, addresses provocative questions about the relationship between pleasure and addiction while exploring many of the broader implications of the nexus of the two. "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." Linden (The Accidental Mind) is admirable at explaining complex scientific concepts for the nonspecialist. He focuses most of his attention on the role played by the small portion of our gray matter known as the medial forebrain pleasure circuit and demonstrates how both behavior and chemistry can activate its neurons. He also discusses the somewhat counterintuitive conclusion that addiction is often associated with decreased pleasure. Linden's conversational style, his abundant use of anecdotes, and his successful coupling of wit with insight makes the book a joy to read. Even the footnotes are sprinkled with hidden gems.

January 15, 2011

Journal of Neurophysiology editor in chief Linden (Neuroscience/Johns Hopkins Univ.; The Accidental Mind: How Brain Evolution Has Given Us Love, Memory, Dreams, and God, 2007) probes the anatomy of pleasure in this review of what happens in the brain when we "feel good."

The author notes that it was back in the 1950s that McGill University scientists discovered that rats with electrodes implanted in a specific part of their brains would press a lever repeatedly to stimulate the area, to the exclusion of food, water or sex. The human equivalent of this pleasure circuit is the ventral tegmental area (VTA). When certain neurons in this area are excited, they release dopamine to target neurons in the prefrontal cortex and in selected emotional, motivational and memory centers. A dopamine transporter takes up the released dopamine so the cell can fire again. (Cocaine and other drugs block this re-uptake, flooding the circuitry with dopamine to increase the "high.") Linden details brain-imaging experiments which indicate that the VTA is activated not only to aid human survival by affording the pleasures of eating and the joys of sex, but also in connection with behaviors ranging from consuming fatty foods, charitable giving, exercise, gambling and certain types of learning and ideas. In some people, such behaviors can progress to addiction, a pathological process that changes the structure and function of the VTA, transforming pleasure to craving. The author suggests that the genetic risk of addiction may be as high as 50 percent and involve gene variants in dopamine types and receptors. While this may offer strategies for drugs to fight addiction, it also raises legal and ethical issues should genetic testing be proposed. Linden is clear that there are many unanswered questions. One issue is the concept of pleasure itself. We can define pain with physical descriptors and emotional words, but how and why such a wide range of information inputs and memories should stimulate the VTA is not clear. Regardless, the author is optimistic that eventually technology will refine our understanding.

In the meantime, Linden provides a fresh perspective on pleasure and confirms that those who suffer addictions are truly ill and not just weak-willed losers.

(COPYRIGHT (2011) KIRKUS REVIEWS/NIELSEN BUSINESS MEDIA, INC. ALL RIGHTS RESERVED.)

March 15, 2011
Conventional wisdom advises, If it feels good, stop it. If it tastes good, spit it out. But why? Because indulging pleasurable excess, whether of drugs, food, or sex, has an unforgiving downside. The biology of how we know this is the topic of Lindens fascinating, by turns technical and entertaining effort. It turns out there is a pleasure center in our brains, a very specific locus that spreads joy when it is tickled by stimuli such as sweet, fatty foods or cocaine. Obviously, some things stimulate our pleasure center for a solid reasonsurvival. If sex didnt feel good, we might not propagate the species. Likewise, the pleasure we get from eating encourages us to live long enough to reproduce. But what of vodka and heroin? What about addictions in general? These are a bit more complicated, but Linden is a proficient guide. He even concludes with an educated prediction of a future that promises round-the-clock, unbridled access totheoretically, at leastguilt-free pleasure through a specially wired baseball cap.(Reprinted with permission of Booklist, copyright 2011, American Library Association.)