Acupuncture has been practiced in China for centuries, but American scientists were largely skeptical of its efficacy when they were widely exposed to it in the early 1970s. Chinese doctors explain the phenomenon using a conception of the body unfamiliar to Westerners. Western physiologists, at first largely baffled, have in the past few decades been able to explain the startling analgesic effects of acupuncture in their own terms. I show how a teacher may effectively use the contrasting explanations and research practice, east and west, to teach the cultural contexts of science.
Imagine yourself, for example, as an American physician visiting a Beijing hospital in 1971. A traditional Chinese doctor there tells you that they can alleviate pain by inserting needles at specific points in the skin and then twirling them slowly. The points are sometimes quite remote from the source of pain. Should you believe them?
Next, you witness a surgery where the main source of pain control is from a needle inserted in the patient's forearm. During the operation, the surgeon makes a 14-inch incision around the left side of the thorax, cuts two ribs, and removes a lobe of a tuberculosis-infected lung. Meanwhile, the patient--still conscious--chats with the surgeon. At the end of the 2-hour procedure, the patient sits up and leaves the operating table under his own power, brandishing a copy of Mao's "little red book." Is seeing believing? What did you see?
Finally, the doctor, who knows some Western medicine, explains that it is all quite reasonable if you understand traditional Chinese medicine. The needling, the doctor explains, redirects the flow of the life force through the body, balancing the potentially painful influence of the incision. Does the explanation affect the status of your belief? How? Why?
The use of needling as a form of medicine--a practice known as acupuncture--extends back for over 2000 years in China (Lu and Needham 1980). Acupuncture only received widespread exposure in the U.S., however, in the early 1970s when President Nixon began to reestablish U.S. diplomatic ties with the People's Republic of China. American physicians were at first largely baffled by how acupuncture could suppress pain. It followed no known physiological mechanisms. Indeed, it seemed contrary to scientific and common-sense notions about pain and the body in general. The Chinese explanation was incredible by their standards, but there was no satisfactory Western alternative. What would have been an appropriate `scientific' repsonse in 1971? This case poses penetrating questions for students, introducing them to the problems of science in two cultures.
The spectacle of surgery done under acupuncture startled many Western physicians. But Chinese doctors reported further that they used acupuncture to alleviate other sorts of pain as well, such as headaches, toothaches, lumbago, and chronic pain in joints and muscles. They inserted needles at different points specific for each treatment, as prescribed by their many centuries of experience. The Chinese even used needling to treat general ailments: hiccups, insomnia, asthma, muteness and blindness, ulcers, vitamin E deficiency and, more recently, drug addiction and smoking habits. That was quite an extraordinary list for such a modest procedure.
It is hardly surprising that some American doctors doubted the Chinese claims. For them, acupuncture was unscientific. They alleged fraud, suggesting that the "demonstrations" for Western physicians had been staged merely to promote China's communist regime. They warned of possible abuse by "quackupuncturists". In fact, many acupuncture clinics that opened in the U.S.--and some that had existed previously in various Chinatowns in major U.S. cities--were soon closed by government authorities.
Only when U.S. doctors began to replicate the effects of acupuncture in American hospitals did such criticism abate. The historical case allows the teacher to introduce fundamental questions about how scientists judge the crediblity of claims, especially indirectly through the credibility of other researchers. Western physicians were clearly accorded more authority than Chinese physicians. Why? In what ways were their judgments justified or unjustified? Students may best appreciate the problem by considering the Chinese perspective: how would a Chinese physician--credible among Chinese peers--have established credibility in a community of Western scientists?
Many people acknowledged the positive effects for persons treated with acupuncture, but they were nonetheless unimpressed. Two reasons were given. First, in about one-third of all cases, a patient recovers from his or her condition even without treatment. For these cases, they argued, it would be inappropriate to credit acupuncture. The historical context of skepticism, here, provides an opportunity to underscore (in a constructivist sylte) the role of controlled experiments. In other words, students might well recognize on their own that to assess the effect of the needling alone, you would need to compare patients treated with acupuncture with those who received no treatment.
From a traditional Chinese perspective, however, the mere idea of such an experiment posed an ethical problem: why would you refrain from a treatment that your expreience showed was effective? Chinese medicine stresses the result for the patient. Research is secondary. Therefore, you would not withhold a treatment just for the sake of a test. For the traditional Chinese, if you already knew how to help a patient recover, you did not also need to know why the procedure worked, especially if your research would likely cost patients their well-being. While a Chinese scientist might not disagree with the reasoning behind the design of the controlled experiment, it would be outside proper science. What is the boundary of science and can it vary culturally?
A second reason for disregarding acupuncture, according to some critics, was that pain might be suppressed merely through psychological suggestion--not a method worthy of serious medical attention. In other words, pain control might have resulted from some "unscientific" influence, such as hypnosis, not by the needling itself. In 1972 one doctor asserted, `the "needlism" merely acts as a reinforcing stimulus as well as a diversionary maneuver to disguise the presence of a subtle placebo effect'. There was, he claimed, `a misdirection of attention' (Kroger 1972). Many Westerners were especially suspicious when they discovered that the Chinese tended to screen patients: not all were deemed eligible for acupuncture. Indeed, the Chinese had considered the attitude of the patient towards acupuncture as early as the Han period (2nd century B.C.). At the same time, Chinese doctors did not distinguish so sharply between psychological and physiological mechanisms. The treatment itself was effective. A Chinese doctor might have replied: is psychosomatic healing not healing? Chinese and Western standards for "good" medicine and science emphasized different values in this instance.
Of course, one could test for the effect of suggestion--and a teacher can invite students to design such a test. They might imagine, for example, that you could check acupuncture on a person or organism that can feel pain but that is not susceptible to suggestion. Both infants and animals, in fact, respond to acupuncture. Illustrations of acupuncture charts for horses, pigs, water buffalo, camels and other animals dating back to the Yuan period (14th century--before the European Renaissance) offer striking images of the Chinese tradition. Students might be able to interview local veterinarians who now use acupuncture (see Schoen 1994).
Another approach to testing suggestibility, commonly used in drug trials, is to prevent the patient from knowing whether he or she is receiving treatment. Some researchers have used "sham acupuncture," needling at non-acupuncture points. Others have used "treatments" of needles taped to the skin. Students may interpret the results themselves (reviewed in Pomeranz 1987). In various lab studies in the past few decades, acute pain stimuli (such as intense heat or sharp objects) were given to humans, mice, cats, horses, rats and rabbits. Needling of true points clearly suppressed pain, while needling of sham points produced very weak effects. In the case of chronic (long-lasting) pain, such as backaches or arthritis (studied clinically), results were more complex (the differences between groups are statistically significant):
|placebos of needles taped to the skin||30%-35%|
Philosophers and sociologists have viewed `organized skepicism' as a hallmark of (Western) science for some time). This case allows one to assess the role of such skepticism. What may have motivated such strong criticism and concerns about fraud in this case? Given the 2000-year tradition of practice in China, were additional tests warranted? In what ways, if any, did the early criticisms contribute to developing scientific knowledge? Students may consider how incentives or institutionalized checks and balances can either encourage or suppress such motivations. Teachers may invite them to devise a system that might positively regulate their effect.
The flow of qi along the meridians is how the Chinese traditionally explain health and illness. When the flow is impeded or imbalanced, disease, malfunction or pain results. To restore the balance, needles are inserted at points along the appropriate meridian. The needles either promote or impede the flow of qi, reestablishing the balance of yin and yang.
The concepts of qi and meridians are problematic from a Western perspective because no anatomical structures define the meridians, and no measurable force can be identified as qi. A Westerner may thus be inclined to think that the notions of meridians and qi are superfluous--perhaps relics of an ancient and discredited cosmology. But the concepts are essential from the perspective of actual practice. Acupuncturists use meridian maps to assess where needles should be placed. Indeed, part of the acupuncturist's skill is diagnosing which meridians have been affected and where along those meridians needles should be placed.
If the notions of qi and meridians have been unsatisfactory for Westerners, numerous studies over the past few decades have given them a more complete understanding in their own terms. Researchers found relatively quickly, for instance, that acupuncture for acute pain stimulates one particular kind of nerve. Most painful stimuli are carried along small fibers. Acupuncture, though, apparently stimulates larger fibers (type II and III muscle afferents). A theory proposed in 1965 suggested how the two nerve impulses might interact. The interaction was built on a mechanical analogy. According to the theory, there was a figurative "gate" in the spinal cord where the two types of fibers converged. Only one impulse could be conveyed to the brain. As proposed, the large fiber would synapse with the small fibers, inhibit them, and prevent further impulses. This "gate- control" theory could thus explain how gentle needling might "switch" off perceptions of pain--at least where nerves entered the same segment of the spinal cord.
Other researchers, however, noticed that the optimal effects of acupuncture often occur after several minutes--too slowly to be explained by nerve impulses. They wondered if there might be some factor in the blood. Again, students have the opportunity to propose or design possible experiments. In this case, researchers cross-linked the circulation of two rabbits through the veins in their legs. The acupuncture on one rabbit allowed the other to withstand stronger painful stimuli. Cross-injections of cerebral-spinal fluid also worked. They concluded that acupuncture triggered the release of an unknown hormone or similar "messenger" substance.
In 1973, researchers discovered accidentally that the brain releases a class of natural pain- relieving compounds similar to well-known opiate drugs, such as morphine. Among them was endorphin. Was endorophin involved in acupuncture, they wondered. They could study endorphin's possible effects using naloxone, a chemical that inhibited the action of opiates by blocking their receptors on the cell surface. A 1976 study addressed the effects of naloxone injected just prior to acupuncture in rabbits (see Pomeranz 1987, p.9) to see if there WAS pain relief:
|acupuncture at non-points||(sham acupuncture)||No|
|handling & restraint||(no acupuncture)||No|
Again, students may interpret and discuss the results themselves, noting the role of each treatment in reaching their conclusions. How did the controlled experiment contribute to Western understanding here?
Research on pain and acupuncture is far from complete, but the picture is becoming clearer. The system of interactions appears to be quite complex. The "gate-control" theory, for example, now seems far too simple. Numerous nerves originating in the brain and ending at more peripheral points appear to inhibit the transmission of impulses towards the brain. Acupuncture activates many of these inhibitory systems at several levels. In quite different studies, acupuncture has also been linked to increased levels of cortisone, a steroid hormone released from the adrenal cortex. This suggests a link to immune responses. If confirmed, these might help explain acupuncture's other reported health effects in Western terms (Lu and Needham 1980; Pomeranz 1987; Baldry 1993; Liao et al 1994).
Explanation has been another feature typically used to characterize (Western) science. Again, the acupuncture case allows one to assess the precise role of explanation. Both Chinese and Western accounts present themselves as offering causal explanations. Both ostensibly match observations, though there are limits to what can be observed. Both have been revised through time. Although the Western account is well articulated and has been part of a deepening of knowledge about the perception of pain, it has not contributed to the practice of acupuncture. Western findings have yet to benefit or extend traditional treatment methods. An open question is: what have Western explanations achieved regarding acupuncture itself? In what ways are they important? If they are part of what makes science `science', what is the role or significance of science in this case? Are there alternative ways to conceive `science'?
It is worth noting that considerable Western research has been done by native scientists in China itself. Indeed, some of the experiments noted above were done even before the U.S. was introduced to acupuncture in 1971. At the same time, many Chinese have pursued research on the traditional explanations (e.g., Research Group... 1986). The Chinese, at least, do not seem to find stifling contradictions in the two sets of explanations. More generally, the Chinese have adopted Western medicine, though not exclusively. Western and traditional Chinese systems exist side by side. One American acupuncturist trained in China noted, "in China the idea is: they do not only give you Chinese traditional medicine, because if you only learn Chinese traditional medicine, your mind will get stuck." The posture of the Chinese towards the different explanations is itself an interesting feature to provoke student discussion.