Brain Lateralisation and Mindfulness

brain lateralisation

Late last summer, on solitary retreat, I started reading Ian McGilchrist’s book The Master and His Emissary,[1] which sounds like it might be an ironic postmodern novel, but isn’t. It’s a survey of the past, present and (uncertain) future of western civilisation, in terms of the nature and effects of brain lateralisation. If this still sounds like an ironic postmodern novel, you’ll need to know that McGilchrist is a psychiatrist who knows the scientific literature on how the two halves of the brain work differently, and that he started out as an Oxford prof. in English lit. It’s an overwhelmingly ambitious book. Firstly McGilchrist tries to pin down why the human brain has two halves and how they work differently. Secondly he surveys the entire history of western civilisation, from the ancient Greeks onwards, explaining how distinctive attitudes and beliefs of each epoch can be characterised by the relative dominance of one or other half of the brain (the right half is the ‘Master’ and the left is its ‘emissary’). Such an ambitious book has understandably been criticised for imprecision,[2] but for those of us who enjoy intellectual stimulation, and have a concern with the fate of humanity and the planet, it’s a great read.[3] Too much for a solitary retreat, I discovered. I put it aside in favour of something more suitable for meditation (Anālayo’s Perspectives on Satipaṭṭhāna)[4] but picked it up afterwards when I stepped back into the whirling world.

I’ve wanted to write something about The Master and His Emissary since then, neither a ‘review’ (too critical) nor an effusion (too uncritical), but I lacked a prompt. But one arrived last Tuesday when I read a 2011 article by John Teasdale and Michael Chaskalson, two mindfulness teachers and Buddhists, on how the practice of mindfulness transforms suffering.[5] I’ve never before seen an explanation of how the simple practice of mindful awareness can radically change human experience, but this article manages to explain it, by distinguishing two ways in which the human mind cognises, one in terms of ‘propositional meaning’ (factual, conceptual, literal) and one in terms of ‘implicative meaning’ (holistic, metaphorical, poetic). Mindfulness practice encourages the implicative form of cognition, which leads to a reduction of rumination, proliferation, identification with the contents of thought (symptomatic of the ‘propositional’ mode of experience), hence – the transformation of avoidable human dukkha or suffering in the form of mental reactions to painful experience. It occurs to me that McGilchrist’s work on brain lateralisation offers a way to conceive of how Teasdale and Chaskalson’s two modes of cognition are physically realized. Mindfulness amounts to a training in favouring the mode of cognition of the right brain (the ‘Master’) over the left brain (his ‘emissary’).

The fact that the human (in fact, animal) brain is divided into two halves has been known for a long time. It’s not clear why the brain has two halves. It is well known however that the brain is connected contra-laterally with the body: right side of the body hooked up to the left side of the brain, and vice versa. There is a bundle of nerves joining the two halves, to keep up some neural dialogue, but surgeons occasionally cut this corpus callosum to treat severe epilepsy. Amazingly, those whose brains have been so divided seem mostly normal. Hence the idea that the two halves of the brain have distinct and separate functions. In the 1970s the left brain/right brain distinction entered popular culture as a metaphor to contrast rational vs. intuitive personalities, but this was not based on sound research. McGilchrist’s book opens with a massive summary of good contemporary research on how the two hemispheres of the brain function differently. He has given an animated TED talk about this, in which he distinguishes between two kinds of attention.

Whereas the left side of the brain specialises in focussed attention to detail, the right side of the brain maintains a broad general attention. In this way an animal can look for food (narrow focus) while aware of danger (broad vigilance). Hence McGilchrist sees an asymmetry of function in the brain: the two halves do similar and complementary things but in different ways. McGilchrist then builds up a picture of the difference between the ‘worlds’ constructed or revealed by the two halves of the human brain functioning differently. I can’t do justice to his extended discussion, but will draw out one crucial difference. The right brain’s world is one in which things are ‘present in experience, in their embodied particularity, with all their changeability and impermanence, and their interconnectedness, as part of a whole which is forever in flux’ (p.93). In this world we feel connected to what we experience, part of the whole. The left brain’s world is one in which we ‘step outside the flow of experience and “experience” our experience in a special way: to re-present the world in a way which is less true but apparently clearer and therefore cast in a form which is more useful for manipulation of the world and one another’ (p.93). This world is divided up, categorised and lifeless, but we have power over it.

Our normal experience is of course a seamless combination of these two worlds, based on the separate functions of the two halves of the brain. Each is necessary to make sense of experience and for us to survive. Nevertheless, McGilchrist argues that the two halves of the brain are in competition for dominance, and that the best (for us, for the world) order of things is that the right brain is master; and the left brain is its emissary, its fact-finding, detail-seeking, category-classifying, abstracting representative.

A certain scepticism seems appropriate at this point. How can we possibly know if McGilchrist’s account of these two ‘worlds’ of experience, and his clear preference for right brain dominance, is anything more more than a story, the two halves of the brain being a metaphor for two attitudes or styles of existence? There is some fascinating independent evidence for McGilchrist’s story in Jill Bolte-Taylor’s account of her stroke.[6] Bolte-Taylor is a brain scientist who suffered a left-brain haemorrhage, and not only eventually recovered, but has been able to recount the experience of gradually losing the ‘world’ of the left brain to leave only a right brain experience. She describes the loss of the ability to speak, to distinguish numbers, to read, to organise experience into categories and concepts, and at the same time the appearance of a world in which her ordinary sense of being a separate self melted into an extraordinary and beautiful connectedness, which she describes as ‘nirvana’. And yet, as she explains, despite the profound love, beauty and insight of her exclusively right-brain experience, it is only half of the human experience. Through years of recovery she has had to re-learn the left-brain skills and aptitudes that would enable her to live without a great deal of help. Having regained the functionality of both halves of her brain, she now lives with conscious awareness of the differing worlds created by each half, which she describes in exactly the same terms as McGilchrist.

In their article on how mindfulness transforms suffering, Teasdale and Chaskalson say nothing about brains. After all, we need know nothing about what the grey stuff in our heads is doing to cultivate mindfulness. Teasdale and Chaskalson instead offer a model of how the mind works, a model of cognition which is independent of how it might be physically realized or manifested in our brains. To explain the effectiveness of mindful awareness in reducing symptoms of stress or depression, they characterise mindfulness in terms of the working memory in which we make sense of what is immediately happening.[7] Reading a sentence, for instance, one has to hold in the awareness of working memory the words which make up the sentence, in order to make sense of the sentence as a whole. Likewise one has to be aware of the sentences one has read to have a sense of what the paragraph and the article is ‘about’. This ‘making sense’ of what is happening is cognition. But cognition is not just one process. According to Teasdale and Chaskalson, following previous research in cognitive science, there are different cognitive processes, indeed, there are systems of interacting cognitive processes. The authors choose two for their model of mindfulness. There is an ‘implicative’ cognitive process, which finds implicit and holistic meanings in what is happening. The implicative process finds the meaning of the sentence in a directly intuited web of meanings. The ‘propositional’ process, however, is more specific, concerned with factual and literal understanding. The meaning of the sentence is grasped as the sum of the meanings of its words, as some sort of proposition (about states of affairs, perhaps with an associated truth-value).

Imagine you have had an argument, an interchange in which you had a marked and, to you importantly, different point of view to someone else. After the argument, when things quiet down, you attempt to make sense of what happened. The ‘propositional’ process formulates clear verbalized statements: she said this and I think that about it. The ‘implicative’ process tries to understand context and significance: what’s she like and how bruised I feel. The implicative process, therefore, is associated with more ‘felt’ or experienced qualities, whereas the propositional process becomes associated with more ruminative trains of thought. The cultivation of mindfulness, when this means the cultivation of mindful awareness of the implicative kind of meaning of experience, favours the awareness of how experience feels whereas an awareness of the propositional kind of meaning might only favour an awareness of what one is thinking about. Teasdale and Chaskalson propose that the powerfully transformative effect of mindfulness comes from the way in which awareness of implicative meaning is associated with the possibility of ‘holding’ holistic, intuited meaning in such a way that there can be a letting go or release or refreshing of the stories that the propositional cognitive process is telling. ‘We might say that mindfulness allows the poetry of moment by moment experience to rewrite itself’ (p.111).

My point is this. What Teasdale and Chaskalson propose as the different characteristics of the propositional and implicative cognitive processes – the factual, conceptual, literal versus the holistic, metaphorical, poetic – coincides with McGilchrist’s characterisation of the different ‘worlds’ of experience of the left and right halves of the brain. Bolte-Taylor describes the left brain’s aptitude for doing, for analysing information, and for telling stories about what is happening.[8] McGilchrist describes how the left brain re-presents experience in terms of what it already knows, and by contrast, how in right brain experience things present themselves as connected parts of a whole. Might it be, then, that the left and right hemispheres of the cerebral cortex physically realize the functions of propositional and implicative cognition? If this were the case, then cultivating mindfulness – holistic embodied presence to felt qualities of experience – amounts to developing a characteristic function of the right hemisphere. The transformative power of mindfulness should then relate to the prioritisation of the role of the right hemisphere in relation to experience. According to McGilchrist, just this prioritisation of the right hemisphere is necessary for human flourishing, and indeed for the future of human civilisation. McGilchrist himself sees the re-balancing in terms of the possibility of our re-discovery of right hemisphere experience through the body, spirituality and art – three ‘vehicles of love’ (p.445). The cultivation of mindfulness, the Buddha’s ‘direct way’ to the realization of nirvana, might therefore be the secret of all three.

[1] Ian McGilchrist, The Master and His Emissary, Yale University Press 2009. Subtitled The Divided Brain and the Making of the Western World, which would have been a boring title. The paperback is 534 pages long, but printed in very small type. Not for the long-sighted!

[2] Owen Flanagan, an impressive analytic philosopher, concluded: ‘The fact is, hemispheric differences are not well understood. Neither are patterns over 2500 years of western history. Trying to explain the ill-understood latter with a caricature of the former does little to illuminate either’ (Wikipedia).

[3] My own interest was stimulated by a review by my friend Robert Ellis, a philosopher who regards McGilchrist’s work as significant as much for its non-reductive philosophic method as for its ambitious content.

[4] Anālayo, Perspectives on Satipaṭṭhāna, Cambridge: Windhorse, 2014. An excellent companion volume to his Satipaṭṭhāna: The Direct Path to Realization. Reviewed by Ālokadhāra in Western Buddhist Review.

[5] John D. Teasdale and Michael Chaskalson (Kulananda), ‘How Does Mindfulness Transform Suffering? II: The Transformation of Dukkha’, in Contemporary Buddhism 12:1, 2011, pp.103–24. This article is the second of two linked articles in the same issue of Contemporary Buddhism, which itself is devoted to the theme of mindfulness and has been reprinted as a book: Mark Williams and Jon Kabat-Zinn, eds., Mindfulness: Diverse Perspectives on its Meaning, Origins and Applications, Abingdon: Routledge, 2013.

[6] Jill Bolte-Taylor tells her story in a TED talk, and in her book My Stroke of Insight, London: Penguin 2006. McGilchrist does not refer to Bolte-Taylor in his book or in the (massive) full bibliography online.

[7] This description of mindfulness in terms of ‘working memory’ not incidentally connects to the meaning of sati, the Pali word usually translated ‘mindfulness’, which actually means ‘memory’ or ‘recollection’. The Sanskrit equivalent of sati is smṛti, from the verbal root smṛ, ‘remember’.

[8] My Stroke of Insight, pp.142–3.