May 17, 2010

Towards a Harmony of the Hemispheres

Posted in Book/article Reviews, consciousness, Pfc tyranny: overview tagged , , , at 3:53 pm by Jeremy

The Master and his Emissary: The Divided Brain and the Making of the Western World

Iain McGilchrist

New Haven: Yale University Press.  2009.

In this blog, I’ve been piecing together what I call a “cognitive history” of human cultural evolution: tracing when, how and where we’ve constructed the thought patterns and underlying worldview that most of take for granted in our daily affairs.  It’s a fairly new approach to understanding our history, so I was intrigued to come across Iain McGilchrist’s book, The Master and his Emissary, which offers a cognitive history (although he doesn’t use that phrase) of the Western world from the perspective of the conflict between the right and left hemispheres of the human brain.

I stumbled across McGilchrist’s book in a New Scientist review written by Oliver Flanagan, a philosopher whose writings I’ve enjoyed and respected.  My pulse quickened a little, as I dove into the article.  What new perspectives would enlighten my mind?  To my surprise and disappointment, the piece read more like an attempted character assassination than a serious review.  Flanagan was so dismissive of McGilchrist’s approach that he seemed to feel that scorn and sarcasm was sufficient for his critique.  For me, this only deepened the mystery.  What had gotten Flanagan so upset?  Was it the contents of the book?  Or was it the approach, the attempt to link neuroscience and history in what I call “cognitive history”?  Not surprisingly, I went straight to Amazon and ordered the book so I could see for myself.

Well, my first takeaway was that McGilchrist had accomplished an extensively researched and impressive analysis which deserved far more respect than the scorn Flanagan had piled on.  (I hope I never get a review from Flanagan when my own book gets published!)  Whatever your viewpoint on McGilchrist’s thesis, I think he shows tremendous intellectual courage in combining the disciplines of neuroscience, history and literature in a unique way, offering perspectives that would not be available through one discipline alone.

So what is McGilchrist’s thesis?  The foundation of his approach is the well-documented difference in the characteristics of the two hemispheres of the human brain.  The left brain is more rational, linear, detail- and narrative-oriented; the right brain is more integrative, fuzzier, emotional and holistic.  This distinction has been noted for a long time, and evidenced by studies of split-brain patients who respond differently to things depending on whether it’s seen by their right or left hemispheres.  It’s also led to a lot of New Age clichés about “right-brain” versus “left-brain” thinking, which may explain part of Flanagan’s scorn and certainly says something for McGilchrist’s courage in attempting a rigorous, intellectual approach to a potentially toxic subject.

McGilchrist interprets this right/left hemisphere distinction as “two fundamentally opposed realities, two different modes of experience” each of which is “of ultimate importance in bringing about the recognisably human world.”  But most importantly, he believes that, although the hemispheres “need to co-operate,” they are in fact “involved in a sort of power struggle” which explains “many aspects of contemporary Western culture.”  This struggle, in McGilchrist’s view, has already been decided and the left hemisphere has won hands down, which is the reason why we live in a society dominated by left-hemisphere values such as systematic and linear thinking, competitiveness and power.  Or, as McGilchrist himself puts it:

An increasingly mechanistic, fragmented, decontextualised world, marked by unwarranted optimism mixed with paranoia and a feeling of emptiness, has come about, reflecting, I believe, the unopposed action of a dysfunctional left hemisphere…

For McGilchrist, it’s pretty clear: the bad things we experience in our modern world can be traced to the dominance of the left hemisphere.  Although McGilchrist disavows the simplistic stereotyping of the New Age right/left hemisphere distinctions, there are times when I feel his contrasts are equally black and white, leaving no room for the complex grays in between that ultimately make our reality so rich when we recognize them.  For example, here’s how he summarizes the right/left contrast:

The world of the left hemisphere, dependent on denotative language and abstraction, yields clarity and power to manipulate things that are known, fixed, static, isolated, decontextualised, explicit, disembodied, general in nature, but ultimately lifeless.  The right hemisphere, by contrast, yields a world of individual, changing, evolving, interconnected, implicit, incarnate, living beings within the context of the lived world, but in the nature of things never fully graspable, always imperfectly known – and to this world it exists in a relationship of care.

So what side would you choose to be on?  Fixed, static, manipulative and lifeless, or evolving, living and caring?  But of course it’s not as simple as that.  For one thing, greater activation of the left hemisphere is associated with more positive affect, leading to an overall sense of happiness.[1] McGilchrist interprets this as inappropriate optimism in a world that’s careening out of control, but I think there’s much more to it than that.  For example, in a detailed review of the neuroscience of meditation, the left hemisphere of the prefrontal cortex is seen to be more heavily activated by experienced meditators and its greater activation has even been correlated with a better immune response to influenza vaccines.[2]

But in spite of McGilchrist’s tendency to see things in stark opposition, I think his overall argument is convincing and compelling, and I fundamentally agree with an underlying current in his thesis: that an ever-increasing imbalance in our collective human consciousness has led to an acceleration of forces that are rapidly driving our world out of control.

Which led me to an interesting internal debate as I read McGilchrist’s book.  (Interesting to me, at least!)  As any casual reader of my blog will know, my own thesis is that the increased domination of the prefrontal cortex (pfc) over our consciousness has led to what I call a “tyranny of the pfc,” with the consequent dire results of our unbalanced global civilization.  Well, doesn’t that sound suspiciously like McGilchrist’s own thesis… just substitute “pfc” for “left hemisphere”?  So, assuming one agrees that a dangerous disequilibrium has arisen in our collective psyche, which is it?  Left hemisphere or pfc?

To a large degree, I have come to believe that the answer is… both.  For example, neuroscientist Michael Gazzaniga, in what is perhaps the most celebrated thesis of left-hemisphere function, describes the left-hemisphere as the “interpreter,” which “creates order out of chaos, and creates a narrative of and explanation for our actions, emotions, thoughts, memories, and dreams.”[3] Now, Gazzaniga’s not talking about the whole left hemisphere, he’s really focusing on the left side of the pfc.  As Goel et al. describe in a 2007 paper:

In terms of hemispheric lateralization, it is widely accepted that the left prefrontal cortex (PFC) has a critical—even dominant (Gazzaniga)—role to play in knowledge-intensive reasoning and decision-making processes.[4]

So the question of pfc vs. left hemisphere is not one of “either/or.”  Instead, it becomes a far more interesting question of how these two different sets of neurological dynamics interact with each other.  How do pfc characteristics relate to right/left hemisphere characteristics?

McGilchrist and I have briefly exchanged e-mails on the subject, in which he agrees with this approach and offers a neuroanatomical explanation, that “the right hemisphere is better connected with, and takes better account of, the subcortical/limbic structures than the left,” and that as a result “the left hemisphere ends up doing the main work for the ‘detached’ aspects of frontal function.”

But how did it get that way?  One way to think about it is that the unprecedented growth of the pfc in human evolution was a major driver of human uniqueness, while the left hemisphere dominance was one of the forms that this dynamic took.  By way of analogy, think of a car driving down the freeway.  Now supposing the driver has his foot down hard on the gas while he’s turning the steering wheel to the left.  Clearly he’s heading for a crash.  But what’s causing the crash… the accelerating engine or the steering?  Both.  If he took his foot off the gas but kept turning sharply, he’d still careen out of control.  If he tried straightening up while still wildly accelerating, he’d still be heading for a crash.  In this analogy, I see the pfc as the car’s engine and the left-hemisphere domination as the steering.  The only hope for the driver is to harmonize his activities, gradually decelerate and straighten out.

Which leads me to something I felt was missing in McGilchrist’s book: a roadmap for getting our cognitive vehicle out of its crash trajectory.  At the very end of the book, McGilchrist touches on a couple of themes that I believe are critical: he mentions that there may be things we can learn “from the East… if we can do so before its cultures are Westernised beyond redemption.”  And he calls for scientific discourse to move “as far as possible” away from “the worn-out mode of scientific materialism with its reductive language.”  I agree wholeheartedly with both of these directions, but I think we have to go deeper to get to the source of our problem.

In fact, I believe that as long as we maintain a dichotomy of values between right and left orientations, we might be continuing to move in the wrong direction.  If our global culture is to move towards what I call a “democracy of consciousness,” I think we may have to turn our attention to approaches that harmonize the different aspects of our consciousness rather than exacerbate the conflict.  In this view, it’s not about right hemisphere versus left hemisphere – it’s about integration rather than conflict between the hemispheres.  It’s not about the pfc’s conceptual consciousness versus animate consciousness – it’s about harmonizing our conceptual and our animate experience of ourselves into one whole.

McGilchrist might respond to this view by pointing to the fact that the right-hemisphere is characterized by its integrative function, and that this is why he’s arguing for a greater role in right-hemisphere thinking.  Well, that may be true in itself, but I’m proposing a different level of harmonization, one that integrates analytical thought with holistic thought, an approach that I explore in my other blog, Finding the Li.

That may be the reason why those experienced meditators I mentioned earlier showed increased activation of their left-hemisphere pfc.  They’re permitting their entire consciousness to take control of their narrative.  To continue the political analogy, what leads to a stronger, healthier government in the long-term: a well-functioning, harmonious democracy or a tyranny?  The tyranny may appear, temporarily, to be stronger.  Until, that is, it topples.  So if, in our collective consciousness, we are experiencing a tyranny of the left pfc, perhaps the solution is not to fight back with the right hemisphere, but to use the powerful, narrative, cohering function of the left hemisphere to focus our attention better on those other, feeling-laden, instinctual aspects of our being, and learn how to integrate them into a harmony of the hemispheres: a democracy of consciousness.

[1] For example, see Urry, H. L., Nitschke, J. B., Dolski, I., Jackson, D. C., Dalton, K. M., Mueller, C. J., Rosenkranz, M. A., Ryff, C. D., Singer, B. H., and Davidson, R. J. (2004). “Making a Life Worth Living: Neural Correlates of Well-Being.” Psychological Science, 15(6), 367-372.

[2] Lutz, A., Dunne, J. D., and Davidson, R. J. (2007). “Meditation and the Neuroscience of Consciousness”, in P. Zelazo, M. Moscovitch, and E. Thompson, (eds.), Cambridge Handbook of Consciousness. New York: Cambridge University Press.

[3] Gazzaniga, M. S. (2000). “Cerebral specialization and interhemispheric communication: Does the corpus callosum enable the human condition?” Brain, 123(7), 1293-1326.

[4] Goel, V., Tierney, M., Sheesley, L., Bartolo, A., Vartanian, O., and Grafman, J. (2006). “Hemispheric Specialization in Human Prefrontal Cortex for Resolving Certain and Uncertain Inferences.” Cerebral Cortex, 17(October 2007), 2245-2250.


1 Comment »

  1. Thanks for the post.  I agree with much of what you say, as you might expect.  But I’d have to say that your conclusion, contrasting my implied opposition of the hemispheres to your sense of the need for synthesis, is mistaken.  I continually recur to the theme, in both Parts One and Two of the book, that we need both, and that they need to be integrated: synthesis.  The black and white, either/or mode is the mode of the left hemisphere on its own.  I cite Hegel and others on the need for the union of division with union, the integration of differentiation with integration; and in Part Two it is clear that my take on the Ancient World and the Renaissance is that the two worked in balance in each of those ages.  My whole thesis, encapsulated in the metaphor of the title, is that both need to work together.  Both are valuable.  It’s just that in our age, the left has got above itself, and blotted out the whole picture: it is the left hemisphere viewpoint that only one matters.  The right hemisphere knows better than that.

    Incidentally I don’t think it is adequate to say that ‘the left brain is more rational, linear, detail- and narrative-oriented; the right brain is more integrative, fuzzier, emotional and holistic’.  Narrative is definitely something only the right hemisphere can understand.  Emotions are the province of both hemispheres.  The left hemisphere is more rationalistic, but not more rational; and reason is a largely right hemisphere function: deduction, much mathematical thinking, and Vernunft as opposed to Verstand are all right hemisphere mediated.  ‘Fuzzier’ is not a good word for the acceptance of ambiguity and the coincidentia oppositorum, and using those phrases makes it sound as if I am just peddling the old tired stuff about the right hemisphere being pink and fluffy in some New Age way – exactly what I am arguing against – rather than, as I think (and so did Mary Midgley), making some rather subtle points about the nature of thought itself.  But in a short review one ends up cutting corners, and perhaps I am being too pernickety.

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