The Meditation Debates
Sarah Lazar debates the Issue with Dr. Mezmer
Sarah Lazar
VS. Dr. MezmerInstructor in Psychiatry/Bad Psychology Expert
Harvard University/Academy of Lagado
Pretty smart lady/Pretty smart ass guy
Meditation Expert/Expert on experts
(an actual email exchange on the topic of meditation between an expert on meditation and an expert on laughing at the experts)
The Question
The fmri (functional magnetic resonance imaginge) has of late been used as a tool to measure the physiological correlates of meditation or meditative like behaviors, yet I have only been able to find one study that compares subjects who are instructed to rest (think of nothing with their eyes closed) with subjects that are attending to a simple visual stream (or otherwise meditating). That study found no neurological difference between both groups. The question is, are you aware of any studies that use resting subjects as a control? The reason for this is clear. I do not dispute the importance or effectiveness of meditation, yet the need to posit an evocative stimulus like entity called attention is an issue that has not in my opinion been satisfactorily resolved. If attention is not required to explain the efficacy of meditation, then Holmes' argument (see below) is correct, and core concepts in meditation, namely the need to attend to a simple stimulus, must be abandoned. I have included a very short precis of my argument below.….
It has been well established (Holmes, 1984, 1988) that the 'body' at rest, namely the relaxation of the musculature comes about whether one is focusing passively on a stimulus (meditating) or simply thinking of nothing with one's eyes closed (resting). Recently, fmri studies (Greicius et al. 2003) have demonstrated that the 'brain' at rest during states of no cognitive (i.e. thinking of nothing with eyes closed) or low cognitive (i.e.,passively focusing, or meditation) demand is also the same for both conditions. A key question is how such and 'resting' brain states and muscular relaxation operate in tandem. In Benson's view as well as for meditation researchers in general this correlation is due to the presence of some element of 'attention' that activates a 'relaxation response'. However, this position makes no sense if attentional elements are not necessary to elicit the neurological and somatic events that comprise meditative states. A much more likely possibility is that muscular activity is directly implicated in thinking or problem solving, and that when one is not consciously or non-consciously involved with ruminating about problems, the muscles will revert to a relaxed or resting state. This position incorporates the well-regarded idea (Damasio, 1994) that the activity of the musculature acts to somatically 'mark' choices so as to expedite decision-making, and is a continuous aspect of the conscious and nonconscious deliberations that mark our workaday lives. In other words, differential muscular tension generally occurs not as part of a 'flight or fight' response, but rather because it helps us nonconsciously make effective decisions (i.e. the so-called gut reaction). If follows therefore that when we are placed in a position where there are no decisions to make, as when we think of nothing or events that signify nothing (passive focusing), the musculature will relax. Thus the act of passively attending to a stimulus, or meditating, is no more effective than mere resting (i.e. thinking of nothing with eyes closed) as an independent variable that correlates with or causes relaxed states. Moreover, a default resting state is not equivalent to a relaxation response, since no unique neural, biochemical, or peripheral signal is required to acquire such a state, but rather the absence of such signals. Hence the notion of a relaxation response or unique meditative state must be abandoned.
References:
Damasio, A. (1994) Descartes Error: Emotion, Reason, and the Human Brain.
Avon: New York
Greicius MD, Krasnow B, Reiss AL, Menon V. (2003). Functional connectivity
in the resting brain: A network analysis of the default mode hypothesis.
Proc Natl Acad Sci U S A. Jan 7;100
spnl.stanford.edu/publications/pdfs/61.pdf
Holmes, D. S. (1984). Meditation and somatic arousal reduction. A review of
the experimental evidence. American Psychologist, 39(1), pp. 1-10
www.american-buddha.com/meditation.arousal.htm
Holmes, D. S. (1988). The influence of meditation versus rest on
physiological arousal: a second evaluation. In Michael A. West (Ed.) The
Psychology of Meditation, Oxford: Clarendon Press
(the debate: my comments are in italics; mezmer)
Lazar
You posed an interesting question, but I think you are getting caught in some semantic difficulties, and some common misunderstanding about what meditation is (and isn't). I have tried to address some of the biggest issues here:
First, the work of Holmes is, in my opinion, flawed. The experiments are not well designed and several of his arguments are illogical or are not supported by the data that he presents. There have been literally hundreds of papers that show differences between meditation and rest, his are the only papers I know of that do not.
Mezmer
David S. Holmes published two controversial papers on meditation in the 1980's in which he did not deny the benefits of meditation. He did however deny the necessity to use focused attention as an independent variable. Quite the contrary to your claim, his main argument was that many meditation studies often did not reflect tight experimental design, and in particular argued for the efficacy of experimental control groups rather than the 'own control' groups that predominated in meditation studies. Your work for example reflects an own control group method. Holmes would argue (and so would I) that an experimental control group wherein a subject was required to rest would have been necessary in order to demonstrate the added or perhaps necessary efficacy of focused attention. Because one, like the devil, can quote statistics and make experiments to serve one's purposes, Holmes discounted many studies that did not meet these exacting procedural standards. Holmes' argument was as much about proper experimental method as it was about meditation, and I believe that his arguments were right were neither illogical or unsupported by the relevant data.
Secondly, Holmes in his major papers did quote an experiment he performed, but these were secondary to an extensive literature review and critique of meditation studies, where he described scores of well controlled experiments that concluded that resting was not distinguishable from meditating. There are indeed hundreds of papers that show differences between meditation and rest, but as you know as well, one good experiment with tight experimental controls is worth a hundred that are performed with flawed procedure and encumbered with misleading interpretations.
Lazar
Second, although in the west the word "meditation" can mean passively viewing visual stimuli, it is not the same thing as Eastern meditation. Although some forms of meditation incorporate visual stimuli, it is generally just one component of what the person is doing at that time. True meditation involves paying attention to the breath and/or bodily sensations and thoughts. The practitioner can make the breath and body their sole focus, or they can simultaneously focus on a word (mantra), or visual stimuli (real or imagined). The mind is not passive or "thinking of nothing" in Eastern meditation. If you sit and watch your thoughts for 10 minutes, you will see that random thoughts constantly appear, and that it takes effort to keep your true attention on the present moment (ie you will start fully focused, and start thinking thoughts like "this is not so hard, I can stay fully focused without any problem...." However, if you keep going, after a few minutes you will probably realize that mind has wandered off onto some other completely unrelated topic and you have forgotten that you were watching your thoughts. With practice, the mind can be trained to stay truly focused, that is the work of Eastern meditation.
Mezmer
I quoted the recent study by Greicius et. Al., that provided fmri mappings of resting (resting with closed eyes) that was followed by passive visual stimulation (staring at checkerboard), but the inference that passive visual stimulation was meditation was mine. In personal conversation recently with Dr. Greicius, he made this telling comment. "Increasingly, I am of the opinion that an eyes-closed rest paradigm is a window on to the "stream of consciousness" rather than true rest or "thinking of nothing". I understand it as a state in which one is recalling recent events and manipulating the information "on line" towards some end. As an example, you could be in the scanner with your eyes closed and call up a recent conversation you had and then begin ruminating on the potential consequences of that conversation. After a few moments you might think of the plans you have for the evening and the possible outcomes, etc..." Greicius' study did not mention meditation once, and the author claimed no knowledge of the literature of meditation. Yet his results and interpretation clearly parallel yours, with the major exception of his identifying neural state effects of meditation with resting, not focused attention. His study is one of the first of its kind on the 'resting brain hypothesis'. His interpretation of rest as a primary independent variable vs. meditator's claims of focussed attention must be reconciled, and I would anticipate they will be soon. Maybe you'll be the one who'll do it!
Lazar
Third, the work of Benson that you cite was done in the early '70s. Much work since then by him and others has shown that although some physical changes are similar to simple rest, there are several that are not. For instance, Goldberger has shown that meditation can
increase heart rate variability, and recent work by Carlson has demonstrated changes in several immune and endocrine measures (refs below). Although the concept of a relaxation response was convenient as an initial explanation for what was happening, the more recent
work shows that what is happening physiologically is much more complex than a decrease in heart and respiratory rate. Also, it should be pointed out that is some forms of meditation (ie
Mindfulness), physical relaxation is not necessarily achieved (Kabatt-Zinn has argued this extensively in his books and lay articles)
Mezmer
I disagree with nothing here. Again, my argument is that these same results would be observed as well by subjects who were merely instructed to rest. Where are the experiments that provide the experimental controls that would demonstrate the validity or falseness of this claim?
Lazar
Fourth, on the neurological front, we and others have shown that eastern meditation is associated with several changes in neural activity when compared to rest. I have attached our paper, and there are references to others below. The work of Richie Davidson has just
been published this month, showing that resting EEG waves change in subjects after just 8 weeks of regular practice. They also found that compared to a waitlist control group, the subjects had increased antibody titers to influenza shots. The work of Lou shows that
different practices have different neural patterns, but that there is a common set of structures activated during meditation relative to simple rest.
Mezmer
Again, generally I do not disagree. However, do any of these studies implement an experimental control of instructed rest rather than an own control? That is critical to your argument that focused attention in meditation has a special efficacy.
Lazar
Finally, most Americans spend several hours a week sitting and passively viewing their TVs, yet this seems to have a negative impact on health, while meditation promotes good health. It is not really clear yet why or how meditation works. In my opinion it has to do with the self focus. When done well, meditation allows one to become aware of the subconscious (or barely conscious) thoughts and feelings that we all have, and helps us come to terms with biases, negative feelings, inner conflicts which cause stress, etc. These thoughts can contribute to poor health (we all know how are bodies respond when we are under stress or feeling angry). By becoming aware of our more subtle thoughts, we better understand them, which helps us lessen or abolish harmful ones, which presumably ameliorates the negative effects on our health that they were causing. The same is true of physical sensations - with careful attention one can start to notice the tensions and physical postures that we habitually engage in - both the obvious ones and the more subtle ones). And what is really cool, is that we start to notice which subtle thoughts lead to subtle physical tensions, and by properly addressing the negative thoughts, you can get rid of the habitual physical tensions (I have not read all of Damasio's work, so I don't know if he discusses this or not).
Mezmer
Again, I disagree with nothing. Indeed Greicius' study observed the same. I must say in closing that the disagreements we have are quite narrow, and rest squarely on the different independent variables we hold critical to obtain the psychological and physiological effects of meditation. Holmes original argument was that the physiological and psychological correlates of meditation are the same as rest. I believe he is right, and now I am noting that fmri studies are beginning to demonstrate it. Ultimately, this issue will not be solved logically, but empirically; and I believe that you as an objective and skilled scientist are up to that task.
Part 2 of the Great Debate
Lazar
Although I agree with Holmes in that it is important to include on-meditating control groups (and our current study is doing so), disagree that any study that lacks them should be ignored or discounted. In our pilot paper, the subjects went from breathing at 12 breaths per minute down to 4 breaths per minute. Not even during sleep do you see such large changes, and the respiratory physiologists I have talked with have all said that breathing at 4 bpm is extremely rare (and they have spent a lot of time watching people breathe). Also, my subjects returned to 12 bpm during the fixation and control periods, then went back to 4 bpm during meditation, which I don't think would happen if they just lay quietly the whole time. I agree that many of the papers in the literature are not controlled, but like our paper, several find large and unusual changes between rest and meditation that are highly unlikely to occur from simple rest or sleep.
The difference between meditation and simple eyes closed is that during meditation you do not get "caught up" in the stream of consciousness, but rather pull back and become aware of it in a different way. When we begin to ruminate on the days events, there is a tendency for the mind to not stay focused all the way through the event. It begins to dissect an event, but inevitably jumps to a new topic (usually without our really noticing) when it runs into issues that we can't really handle consciously. In the example above, notice that he did not say the brain finishes ruminating on the topic and then logically proceeds to the next, but rather "after a few moments you might be thinking of something else". With meditation practice, one can begin to start noticing that transition, noticing that the transition in thoughts tend to always occur in the same places and also that certain physical sensations tend to also begin to arise when we hit that trouble spot. That is when "insight" happens, and we get a closer look at our psyche, a new perspective on our subtle biases that influence everything that we do without our conscious knowledge. (or we might notice that we tend to have defensive reactions to certain situations, and we start to understand why we have those reactions). That is the key difference between simple rumination and meditation - the meditator becomes aware of their thoughts in a different, more intimate way.
Meditation is difficult to describe to those who have not practiced (I think it is like trying to explain color to a blind person). I suggest that you find a good teacher and try it for a few weeks some time, perhaps then you will see that it is really not the same as rest.
Mezmer
Holmes noted in his original papers that the effects of meditation were derived from three different methodological approaches: anecdotal studies, own-self controls, and experimental controls. Only experimental control groups could adequately compare meditation vs. rest because only such groups explicitly tested the physiological differences between such variables. Anecdotal and own control group studies could and often did lead to the inference that the physiological effects of meditation were different from rest, however an inference is not proof. Holmes excluded from his survey a certain type of experimental design, not a certain type of experimental interpretation. His decision could not prejudice the results of his survey, since it merely narrowed his literature review to those experiments that explicitly compared resting and meditative states. If indeed experimental control experiments demonstrated that the physiological correlates of meditation were different than rest, then it would be a simple matter for any psychologist to assemble such evidence. None however has been published because in my opinion no such collection of experimental evidence exists.
In neuroscience, the ‘resting brain hypothesis’ exists independently of meditation research, and notes unique neural activation patterns in subjects who are instructed to rest with eyes closed. From my review of the nascent literature on this topic, I do not find much difference in brain activation patterns between those you observed in meditators and those patterns observed for subjects who were instructed to rest. This issue can only be resolved from experiments that compare individuals who meditate and individuals who are instructed to rest with eyes closed. That experiment to my knowledge has not been performed, and should resolve quickly this issue. Such differences cannot be resolved logically, only empirically, and I hope you will consider performing such an experiment.
A few other points. Meditation or the ‘relaxation response’ involves the relaxation of the musculature. Since the musculature needs much less oxygen in a state of repose, breathing rates go down. To note the efficacy of meditation as compared to rest in this matter, I need to see an experiment that has an experimental control. Without that, such observations must be taken with a grain of salt.
A characteristic of 'depth' psychology, long held since Freud, is that the mind had added powers of introspection or insight if placed into a quiescent or otherwise altered state (e.g. hypnosis). The large research literature on the recall and processing of non-conscious information has in general refuted this perspective, and holds that quite the contrary, humans have no access to the nonconscious workings of their brains. Rather, they impose schemas on ambiguous stimuli that give connotations they do not objectively possess. In a major article in the June, 1992 issue of the American Psychologist (and available on the web) on conscious information processes, the psychologist Pawel Lewicki states this position thusly: "It has been demonstrated in a number of studies that when stimuli are ambiguous, encoding algorithms may nonconsciously impose on them preexisting interpretive categories, even if the stimuli "objectively" do not match those categories. The resulting biased interpretation of stimuli, as supportive of the preexisting encoding dispositions has been shown to become a source of subjective experiences that are consistent with these dispositions. This way, the encoding bias may gradually develop in a self perpetuating manner." A good example of this was provided by the comedic-magicians Penn and Teller, who had folks sit down for a taste test of various spring waters, all of which came from the same hidden tap water supply. The exotic waters, all given Spanish or Italian labels which literally meant such poetic things as 'Ass Water' and 'Sewer Water', were consistently given higher ratings than unlabeled tap water. In other words, if the subjects thought they were engaging in a higher gustatory experience, they were, despite the fact that they were objectively all drinking stuff that came from a hose! There is no evidence that meditators are not having their own 'tap water' experience, and to establish that they are having a unique experience requires more than a subjective opinion, it requires demonstrative and unique physiological correlates to the simple act of attentional focusing. To avoid confounding the attention with simple rest, an experimental control group or resting is required. That is critical part of the meditation experiments that you and your colleagues have yet to try.