“What Do the Two Hemispheres ‘Do'” in The Master and his Emissary by Iain McGilchrist (part II)

These reading notes cover the following sections:

• Context versus abstraction
• Individuals versus categories
• The personal versus the impersonal
• The living versus the non-living
• Reason versus rationality

Context versus abstraction

For the same reason that the right hemisphere sees things as a whole, before they have been digested into parts, it also sees each thing in its context, as standing in a qualifying relationship with all that surrounds it, rather than taking it as a single isolated entity. Its awareness of the world is anything but abstract. (1)

Its either in context or out of context. That’s the principal argument here. My basic claim is that our attention can engage things in their context, or abstracted from the context in which they are found and that tracking the shift between these kinds of engagements is crucial to a robust and mature epistemology, as well as to understanding the nature of scientific investigation. McGilchrist’s argument is that the ability to shift our attention in this way is due to our bihemispheric neurological structure. In this case, the right hemisphere tends to see things in context while the left hemisphere “is the hemisphere of abstraction, which, as the word itself tells us, is the process of wrestling things from their context.” (2)

The left hemisphere can only re-present; but the right hemisphere, for its part, can only give again what ‘presences’. This is close to the core of what differentiates the hemispheres.

Abstraction is necessary if the left hemisphere is to re-present the world. The left hemisphere operates an abstract visual-form system, storing information that remains relatively invariant across specific instances, producing abstracted types or classes of things; whereas the right hemisphere is aware of and remembers what it is that distinguishes specific instances of a type, one from another. The right hemisphere deals preferentially with actually existing things, as they are encountered in the real world. (3)

Individuals versus categories

As mentioned above, part of taking things out of their context is grasping what is invariant across multiple, related instances. In order to identify what is invariant across multiple instances, we must abstract away from that which is variable in those numerous instances. We must ignore certain aspects in favor of others. McGilchrist thinks about abstraction and invariance in terms of individuals versus categories.

At the same time it is the right hemisphere that has the capacity to distinguish specific examples within a category, rather than categories alone; it stores details to distinguish specific instances. The right hemisphere presents individual, unique instances of things and individual, familiar, objects, where the left hemisphere re-presents categories of things, and generic, non-specific objects. In keeping with this, the right hemisphere uses unique referents, where the left hemisphere uses non-unique referents. It is with the right hemisphere that we distinguish individuals of all kinds, places as well as faces. In fact it is precisely its capacity for holistic processing that enables the right hemisphere to recognize individuals. Individuals are, after all, Gestalt wholes: that fact, that voice, that gait, that sheer ‘quiddity’ of the person or thing, defying analysis into parts. (4)

 The personal versus the impersonal

In several posts I’ve spoken about Lonergan’s distinction between things in relation to us and things as they relate among themselves. Lonergan’s distinction is very much like Jordan Peterson’s distinction between the world as meaning and the world as things. This distinction also maps onto the various ways that McGilchrist speaks of the left and right hemispheres. Here McGilchrist speaks of the personal versus the impersonal:

Because the right hemisphere sees nothing in the abstract, but always appreciates things in their context, it is interested in the personal, by contrast with the left hemisphere, which has more affinity for the abstract or impersonal. The right hemisphere’s view of the world in general is construed according to what is of concern to it, not according to objective impersonal categories, and therefore has a personal quality. This is both its strength and its weakness in relation to the left hemisphere. It deals preferentially with whatever is approaching it, drawing near, in relationship with it [i.e. in relation to us]. The right temporal lobe deals preferentially with memory of a personal or emotionally charged nature, what is called episodic memory, where the left temporal lobe is concerned with memory for facts that are ‘in the public domain’ [i.e. similar to things in relation among themselves]. (5)

The living versus the non-living

The continuity from the abstract to the invariant to the impersonal extends to “the non-living.” This is just another layer of difference for McGilchrist to highlight regarding the function of the hemispheres.

The right hemisphere priorities whatever actually is, and what concerns us. It prefers existing things, real scenes and stimuli that can be made sense of in terms of the lived world, whatever it is that has meaning and value for us as human beings. It is more able to assimilate information from the environment, without automatically responding to it, and, possibly as a result, the developing right hemisphere is more sensitive to environmental influences.

At the same time the left hemisphere is more at home dealing with distorted, non-realistic, fantastic – ultimately artificial – images. This may be because they invite analysis by parts, rather than as a whole. But it does appear that they left hemisphere has a positive bias towards whatever is bizarre, meaningless or non-existent, though the data here are particularly hard to interpret because most studies have not sufficiently distinguished confounding elements. (6)

It is worth noting that in the metaphilosophy of both Lonergan and Dewey, analytical pursuits begin as a result of unexpected curiosities, or “bizarre” experiences, which cause us to investigate the nature of some phenomenon more deeply.

Reason versus rationality

Despite the right hemisphere’s overwhelmingly important role in emotion, the popular stereotype that the left hemisphere has a monopoly on reason, like the view that it has a monopoly on language, is mistaken. As always it is a question not of ‘what’, but of ‘in what way’. (7)

Often times science is spoken of as the only rational method we have for making sense of the nature of the world. Ladyman and Ross speak this was when they define science as the set of error filters used to prevent human reasoning from making mistakes. But science is not our exclusive form of reason if for no other reason than there is simply not just and only one kind of reasoning.

In fact reasoning is of different kinds, and though linear, sequential argument is clearly better executed by the left hemisphere, some types of reasoning, including deduction, and some types of mathematical reasoning, are mainly dependent on the right hemisphere. More explicit reasoning is underwritten by the left hemisphere, less explicit reasoning (such as is often involved in problem solving, including scientific and mathematical problem solving) by the right hemisphere. There is a relation between the pleasurable ‘aha!’ phenomenon of insight and the right amygdala, which mediates interactions between emotions and higher frontal cognitive function. In fact an extensive body of research now indicates that insight, whether mathematical or verbal, the sort of problem solving that happens when we are, precisely, not concentrating on it, is associated with activation in the right hemisphere, mainly in the right anterior temporal area, specifically in the right anterior superior temporal gyrus, though where there are high levels of restructuring involved there is also activity in the right prefrontal cortex. Insight is also a perception of the previous incongruity of one’s assumptions, which links it to the right hemisphere’s capacity for detecting an anomaly. (8)

Notes:

(1) McGilchrist, The Master and his Emissary, p. 49.

(2) ibid., p. 50.

(3) ibid., p. 50.

(4) ibid., p. 51.

(5) ibid., p. 54.

(6) ibid., p. 56.

(7) ibid., p. 64.

(8) ibid., p. 65.