As the theory
goes, there is a place (or places) in the medial forebrain
that, when stimulate
d, produces a pleasure
for a person. This has been demonstrated in rats
, which will push a lever -- more than 6000 times an hour, depending on the parameters of the experiment
-- that stimulates their so-called pleasure center
. Some experiments in human
s have been less promising, with stimulation causing only slight feeling. Others have been better, with the sensation likened to orgasm
, and the subjects developing romantic attraction
to the experimenter. The field is still wide open, though, as there are at least five dopaminergic pathway
s, each of which can be stimulated to various degrees and can be stimulated at the same or different times.
The stimulation is instantly psychologically addictive, as it effortlessly produces a reward stimulation that could otherwise only be reached through a lot of hard work (via an orgasm, or whatever). To be of any use besides turning people into wire junkies, it would have to be addressable as a gradient. That is to say, the device doing the stimulation would need to be able to cause a little bit, a good amount, or a great deal of pleasure. Then it could be used safely -- in small amounts -- as an instantaneous reward for an action that would ordinarily produced a delayed reward. Discovery of the groups of neurons that are needed for this effect could prove very useful in many fields. I have a few examples below, and there are countless more to be found.
First off, it could be used as a learning aid. Intuitive learning is already somewhat pleasurable, as evinced by the feeling you get when fixing a difficulty or solving a puzzle. Memorization based learning, like cramming for a test or reading research papers, is not nearly as much so, as the reward for it is delayed. Upon solving a problem, you feel good about your accomplishments, whereas upon committing some facts to memory, there is no immediate accomplishment, and thus, no immediate reward. Both experiences, however, store events to long-term memory through the same vector, NMDA induced long-term potentiation. If there were sensors implanted to determine when learning was happening -- by sensing levels of glutamate or acetylcholine, perhaps -- they could be set to trigger a tiny bit of pleasurable stimulation. You could effectively addict yourself to learning things well, thus improving your memory and possibly your intelligence.
PC stimulation would also be useful to ease the intense craving of drug withdrawal. Addictive drugs (cocaine, nicotine, and the opiates, specifically) desensitize the dopamine responsive areas of the brain, which in many cases are also responsible for pleasure. Thus it is hard for somebody addicted to one of those drugs to get pleasure out of anything at all while not under the influence. Direct PC stimulation could be used to replace that feeling. Over the course of a month or two, the stimulation could be ramped down, and ultimately turned off. While this wouldn't stop the horrible physical aspects of withdrawal, it would at least allow the person to experience pleasure without the drug.
In tandem with a NMDA inhibitor, strong stimulation could be the basis of a fast, effective, low risk general anesthetic. The NDMA inhibitor would stop the person from forming thought or memories about anything that happened, and keep pain from seeming "real" to the person experiencing it. This has been shown in the use of ketamine, dizocilpine, and other dissociatives, which are all NMDA blockers. The problem with their use as human anesthetics comes from the effects of regaining normal consciousness and memory, which can cause paranoia and psychotic breaks in people who aren't prepared for them. Giving very strong PC stimulation for the duration of the inhibitor's peak and ramping it down as the inhibitor leaves the system, would probably stop these "emergence phenomena" all together. This possibility is worth investigating because the damage done by chemicals that inhibit NDMA is much less worrisome than the dangers -- like, say, death -- associated with modern general anesthetics.
Going along with that idea, the PC could be excited during any instance of artificial paranoia or psychosis, helping the person regain control and realize that everything is allright. In fewer words, it could reverse a bad trip. This is very good the first time or two it is used, and spares the user needless psychological trauma. It is very bad, however, when it becomes a habitual part of psychedelic use (see: wireflipping). From there it's only a short step to using it when not using psychedelics, and ending up a wire junkie.
Having a reward sensation available would be good for all kinds of conditioning, good and bad. It could be administered voluntarily to teach a person to stop overeating, exercise regularly, or even brush and floss at night. Frighteningly, though, it could also be used to make someone an efficient killer, or willing to sacrifice themselves for another. Worst of all, it could be given full force for a week or so to somebody being interrogated, and then withdrawn altogether until that person gave up whatever information was being looked for. Reverse torture, if you will.