The Making of the Mind: The Neuroscience of Human Nature (22 page)

BOOK: The Making of the Mind: The Neuroscience of Human Nature
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Another way is to reduce, if not eliminate, self-talk altogether. The relaxation response is a reduction of the arousal associated with emotion. It can be induced through meditation methods that concentrate executive attention away from distracting thoughts and replace the usual worrisome chatter of the interpreter with a mental focus on a single word or phrase. For example, in a type of Kundalini meditation in yoga practice, meditators “passively observed their breathing and silently repeated the phrase ‘sat nam’ during inhalations and ‘wahe guru’ during exhalations.”
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The goal is to focus attention on a single bodily process—breathing in and out—rather than allowing the contents of working memory to wander aimlessly. At the same time, the attributions,
explanations, and narratives of the inner voice are at least partly silenced by the repetition of the chosen phrase. Brain alterations seen in functional magnetic resonance images taken during the relaxation response included changes in the amygdala, reflecting control of emotional arousal, and changes in the prefrontal cortex associated with the executive attention network.
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To produce the relaxation response, a variety of such phrases can be used, including simply repeating the word “one” or “relax.”
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If the mind wanders from focusing on breathing and repeating the phrase, the meditator simply returns attention and starts over again. It is important not to worry about the mind wandering, because that will only invite the interpreter to assign blame and generate negative self-talk. For example, after realizing that the focus from breathing and word repetition has been lost, the meditator might say, “Oh well” and return to repeating the word or phrase.

The findings on meditation indicate that human working memory and the inner voice of the interpreter are interlocked with emotional arousal. By practicing focused attention on the process of breathing—an elemental, life-sustaining bodily process that typically unfolds outside of awareness—the contents of working memory are directly altered. By thinking about breathing, the usual wandering of thoughts that pop in and out of working memory is diminished. As for verbal working memory, the inner dialogue of the interpreter is replaced with a simple word or phrase. The usual commentary of the interpreter is in part silenced by redirection. Meditation can take a variety of forms beyond those discussed here, but in general it can be seen “as a family of complex emotional attentional regulatory strategies developed for various ends, including the cultivation of well-being and emotional balance.”
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As such, it elegantly demonstrates how the advanced working memory and the interpreter of the human mind are intertwined with emotion.

The most astonishing example of how the interpreter can affect health through positive illusions is the placebo effect.
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If the brain's interpreter infers that a pill, a potion, a prayer, a ritual dance, or any other medical procedure—whether from the canon of modern medicine, alternative medicine, or shamanistic medicine—is curative, then it can actually work, just because the person holds and activates a strong belief in its power. The placebo effect, then, is a positive illusion generated by a belief and an interpretation. Remarkably,
these mental events by themselves can activate events in the brain and body, including the immune system and the pain perception system. Sham pain pills, sham acupuncture, and even sham surgery supposedly undertaken to correct a source of chronic pain have been shown to produce effective analgesia, based on the patient's interpreting the treatment as real and believing in its effectiveness.

A placebo was once conceived as an inert substance with no specific effect. Thus, any benefit from the placebo must come solely from the patient's belief that it can cause a reduction in pain or a reversal of some disease process. Today, medical researchers think of a placebo as a simulation of an active therapy, a way of invoking the benefits of a real medication through a ritual that engages the patient's hopes and expectations. Shelley E. Taylor, in
Positive Illusions
, observed that “the placebo effect is most likely to take place when it is introduced into a carefully crafted theatrical production designed to enhance unrealistic optimism.”
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The doctor or other health practitioner who expresses confidence in the effectiveness of the treatment can slip similar thoughts into the patient's self-talk. To the extent that the left-brain interpreter assigns a causal role to the value of the treatment and begins to narrate its benefits, it can in fact induce the brain to respond positively. Placebos “clearly achieve their greatest success in the absence of real physical disorders,” a fairly common circumstance, in that physicians have estimated “that about 65 percent of the patients who seek treatment actually have problems that are primarily emotional in origin.”
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The power of the placebo effects is well understood by pharmaceutical researchers investigating new medications. The benchmark for establishing effectiveness is comparison of the new medication to a placebo. In other words, some patients receiving placebos get better, too. Only active medications that perform better than a placebo are worth pursuing, particularly because active medications generally carry some risk of side effects whereas placeboes do not. The individual receiving the placebo must expect it to be an active drug and believe that it will work effectively. Thus, in research testing, the effects of new medications are carried out under blind conditions. For ethical reasons, participants in the research are aware that some recipients will get active medication and others will not. But the recipients are blind to which condition
they have been assigned. Moreover, the best research design involves double-blind conditions, in which both the person administering the treatment and the recipient are unaware of its true content. By taking this precaution, any expectations about the possible benefits of the treatment are not communicated in subtle ways, through spoken words or through nonverbal body language and gestures.

Looked at from a different perspective, it is understood that a portion of the benefit from a medical intervention comes from the placebo response, the belief that the treatment will help. For example, the use of morphine and other opioid drugs as pain killers is most effective in managing postoperative pain when the patient receives the medication in an open manner.
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That is to say, the patient knows when the medication is given and knows it is morphine for the purpose of relieving pain. The clinician injects the medication in full view of the patient and verbally suggests that it will help to reduce pain. These contextual elements activate the patient's belief that morphine will quickly bring on a reduction in pain. By contrast, when the same dose of morphine is given under hidden conditions—administered by a machine without the patient's awareness—it is less effective in reducing pain. Similarly, smaller doses of the analgesic medications can achieve pain management more successfully when given openly than when hidden from the patient. The ritual of administering a pain palliative draws the attention of the interpretive system, initiating a placebo response on top of the purely pharmacological effects of the drug on the pain-perception system. What is more, the open administration can further strengthen the patient's belief regarding the effectiveness of morphine as an analgesic. Once the pain begins to fade after receiving the drug, the interpreter would seek an explanation. With open administration it is easy to assign the cause of pain relief to the morphine injection. With hidden administration, the interpreter is left to wonder exactly what caused the reduction in pain; the inference that morphine must have been injected and must have caused the reduction in pain is less certain.

Not everyone responds to placeboes, and the magnitude of response can vary depending on the exact circumstances of its administration. This variability is not surprising when the response is dependent on the interpreter inferring that the treatment is active rather than inert. If an individual is
skeptical about the curative or analgesic properties of a treatment, then his or her interpreter is likely neither to attribute any health improvement to the treatment nor to sustain an inner narrative favoring its continued use.

ADDICTION IN THE MODERN MIND

 

As another example of how parts of the modern mental ensemble alter our emotional experience, consider addiction. The midbrain and limbic forebrain constitute a powerful system of reward that mediates our feelings of pleasure. Rewards are things we seek out because they make us feel good. Sexual orgasm, good-tasting food, and mind-altering drugs such as alcohol and marijuana are some very different examples of rewards that people pursue for the pleasures they provide. Behaviors that are followed by rewards will increase in their frequency—the law of positive reinforcement. As a consequence, behaviors that lead to rewards can readily become habitual. Food and sex are pleasurable because both are needed for human survival and the propagation of the species; yet the same reward system in the brain can also drive substance abuse.

The reward circuit of the mammalian brain, including the human brain, begins in the midbrain, in a region known as the ventral tegmental area, with a neurotransmitter called dopamine.
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This area is the source of the dopamine found in the nucleus accumbens, deep in the forebrain, as well as in the amygdala and hippocampus of the limbic system, and also in the prefrontal cortex. Another supplier of dopamine is the substantia nigra, which furnishes a separate region near the nucleus accumbens called the dorsal striatum. Both natural rewards, like food and sex, and addictive drugs control the frequency of behaviors by increasing the concentration of dopamine in the nucleus accumbens. The dorsal striatum is involved in the reward circuit, too, as a means of consolidating into long-term memory the specific behavioral sequences that led to a reward in the past.

Dopamine is the common denominator of drugs that are abused for their rewards of pleasure.
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However, the opiates (opium, morphine, and heroin), cocaine and amphetamines, nicotine, marijuana, and alcohol each have their own unique signatures composed of other neurotransmitters in addition to dopamine. Addiction means that the user becomes dependent on the drug. This
is contrasted with the overuse or abuse of drugs. Occasional drug use can lead to abuse and possibly even addiction. The key difference is that abuse does not involve dependence on the drug, although abuse can progress to addiction. To illustrate dependence, consider heroin, a highly addictive opiate. Intravenous injection or smoking of the drug causes intense intoxication. The powerful reward of feeling good increases the likelihood of taking the drug again, as the law of positive reinforcement goes to work on the drug taker. Abstinence from the drug produces strong negative feelings of anxiety, restlessness, and dissatisfaction as well as physical discomfort—these are symptoms of withdrawal from the presence of the drug in the brain. During withdrawal, the drug user craves the drug and becomes preoccupied with obtaining it. The negative emotions of withdrawal are associated with a strong increase in cravings for the drug. Over time, the law of negative reinforcement comes into play. In negative reinforcement, a behavior is increased, in this case drug ingestion, to terminate an aversive stimulus, in this case the anxiety and physical discomfort of withdrawal. Regrettably, negative reinforcement teaches the user to take the drug so as to avoid the aversive state of withdrawal. Although addicts start out taking heroin to obtain its powerful positive reward, they end up taking it simply to avoid the pain of withdrawal. The intoxication is no longer as positively rewarding, but avoidance of withdrawal keeps the addict preoccupied with maintaining a constant supply of heroin. In short, the addict has moved from an impulsive stage of drug use driven by positive reinforcement to a compulsive stage driven by negative reinforcement.

Like humans, laboratory rats can become addicted to heroin, cocaine, or alcohol. This is because humans and rats share in common the reward system of the mammalian nervous system. The manner in which positive reinforcement initially drives the impulsive use of drugs to be later replaced by compulsive use maintained by negative reinforcement can readily be studied in the rat. Even so, there are ways in which human addiction is distinctive. A key executive function of human working memory is the capacity to plan and solve novel problems. This capacity of our advanced working memory system enormously complicates the picture of human addiction. Unless drugs are readily available—like they are for a rat in a laboratory cage—human beings do not simply prepare an injection or take a drink whenever they feel like it.
Instead, they often must devote considerable time and effort to finding and purchasing the drug in the first place. Planning to obtain the drug, and overcoming any obstacles to do so, is part and parcel of human addictions, which simply have no parallel in nonhuman species.

Human addicts face a situation different from rats that merely lever-press for drugs…. An addict who steals, another who scams, another who has the money and simply must negotiate a drug purchase—all face new and unique challenges with each new victim and negotiation. Instrumental ingenuity and variation are central to addictive drug pursuit in real life.
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The powerful working memory system of human beings also complicates the experience of cravings for illicit drugs, alcohol, cigarettes, and other addictive substances. As already discussed, craving—the incessant motivation to obtain and ingest the substance—is particularly severe during the compulsive stage of drug addiction. It is also prevalent in compulsive gambling, compulsive sexual behavior, and compulsive eating. For instance, “food cravings have been shown to trigger binge-eating episodes, which in turn contribute to both obesity and disordered eating, especially bulimia nervosa—increasingly serious problems for Western societies.”
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