enables you to ramp up or down the activity in the pleasure center. Want to get a bit more out of yo

enables you to ramp up or down the activity in the pleasure center. Want to get a bit more out of your dinner, a movie, tennis stroke, work, or sex? Flip the switch. Want to buffer yourself from the pain of ostracism, a romantic break up, or a colonoscopy? Flip the switch. Would you buy it? Ifso, what would you use it for, and would you be a habitual user? Would you worry about any side effects? Might using this device become addictive, or worse, either destroy the feeling of pleasure altogether or push you into a never-ending quest for satisfaction, with each dollop of pleasure leaving you wanting a bigger dollop next time around. This may seem like science fiction, but it’s closer to non-fiction. Over fifty years ago, scientists working with rats, implanted electrodes into in a region of the brain called the nucleus accumbens. The electrodes were connected to a switch. If the rat pressed the switch, it activated the electrode and thus stimulated this brain area. The rats indeed pressed, over and over again, some at a rate of 2000 presses per hour, with no external reward or threat of punishment. Pressing the switch was the reward, or at least the vehicle to what appeared to be the experience of reward. Pressing the switch was addictive. These scientists had discovered a critical part of the circuitry of pleasure, in rats! The rats discovered a pleasure switch, something they wanted to experience over and over and over again. Soon after this discovery, clinicians started using deep brain stimulation to treat individuals with neurological complications, including Parkinson’s patients suffering from loss of motor control, patients experiencing sustained pain, Tourette’s patients suffering from motor tics and obsessive-compulsive problems, and even a patient in a coma who had lost, but then slowly recovered the capacity to name and grasp objects. Similar to the rat work, the technique involves implanting an electrical pulse generator within a targeted brain region. When the generator is turned on, it stimulates activity in previously malfunctioning regions. But as with genetic manipulations and the unknown space that characterizes the genomic universe, so too is the situation unchartered in the neuronal universe. Two patients suffering from chronic pain were implanted with impulse generators and subsequently developed profound addictions to the stimulation. In addition to relatively successful pain reduction, both patients experienced an enhanced desire for sex, including erotic feelings. One of these patients self-stimulated so often that she forgot to wash, change clothes, and adhere to family commitments. What happened? Did the clinicians treating these patients hit the pleasure center? When stimulated, what actually changed in the minds of these patients? Did they simply want more sexual arousal, suggesting that stimulation turned up the gain on their desire for sex? Or, did stimulation change what they /ike, a shift in the sense of pleasure that accompanies sex, and in this case, the anticipation of sex? Or perhaps it changed both wanting and liking, especially since we often want things we like? These observations of how humans and rats respond to brain stimulation show that particular areas of the brain are linked to pleasure, especially the motivation to obtain rewarding experiences. These Hauser Chapter 2. Runaway desire 57 HOUSE_OVERSIGHT_012803