Sensation, Perception and Selfhood

We looked in the previous post at how the Buddhist analysis describes the arising of ignorance, the way that we mistake ourselves for a self or subject that has experiences which belong to a ‘me’. In this post I want to go back to the earliest stages of our evolutionary development, namely the way in which our sense of being selves emerged from the role that sensation and perception played in the origin of our species.

One of the key attributes of natural selection was to favour the development of sensitivity at the boundary of the primitive organism. Membranes became increasingly sensitive, better adapted at moving towards the source of energy and better able to repel or avoid those elements of the environment that were potentially harmful. Finer and finer discrimination at their boundaries with the world became a key element in the evolution of lineages of creatures; it is what allowed some creatures to survive and caused others to disappear.

This discriminative ability in turn encouraged an increase in the flexibility of response. For a primitive collection of cells with photo-sensitive components at the surface of its membrane the possible responses are limited- perhaps simply to move the stimulated area towards or away from the source of light. But for more complex creatures there arose the possibility of selective or flexible reaction, selecting some potential positive stimuli over others, or ignoring rather than rejecting other stimuli that were not identified as helpful.

In this way a wider repertoire of responses and reactions emerged to both harmful and to beneficial environmental stimuli, until at some point in evolution there was a shift to non-local and delayed reactivity. More complex nervous systems allowed creatures to relay information from one part of the body to another, and indeed for reactions to be controlled by a central agency. Once we reach mammals we have examples of entities in which reactions occur not at the boundary that creatures have with the world, but in a brain which can monitor and control all signals coming from those boundaries and exercise executive control over what the response should be. Herein lies the origins of mind; animals could be said to have minds when they become capable of storing, recalling and reworking representations of the effects of environmental stimuli on their bodies.

Sensations are unique to the experiencing subject; they are ‘mine’. They are phenomenally immediate. Each is tied to a particular site in the body and each has its own mode. Perceptions can be shared, but sensations are unique and private to the embodied subject. Each is self-characterising; each tells its own story regarding which the subject could never be in doubt. Perceptions can be shared, but sensations are unique. Sensations are located at the spatial boundary between me and not-me, and at the temporal boundary between past and future; one can only have sensations of the present moment. Perceptions on the other hand are amodal and can refer back to the past or forward to the future.

Sensation occurs in the province of the five senses and creates those unique subjective qualities that form our immediate experience. Perceptions are perfective and complete whilst sensations are imperfective, continuing and incomplete. The evolutionary psychologist Nicholas Humphrey outlined this scenario some thirty years ago. In his view all forms of mental activity can be predicated on sensation; introspection is ‘heard’ as the sensation of an inner voice; mental imagery is a memory of visual sensation. Even beliefs, assumptions ideas, and rational thought are brought into mind as an echo of our speech or hearing. Our awareness of our existence is dependent on sensation. I feel, therefore I am.

One key aspect of this process was the maintenance of boundaries with the outside world as molecules encased within the protective sheaf of a semi-permeable membrane formed the first primitive cells. This collection of molecules, a proto-self, was able to control the process of energy and information transfer across its collective surface, thereby separating what was within from what was without. These membranes became the template for the skin that separates you from me and each of us from the world we inhabit.

In this way was created the distinction between inside and outside, between self and other. Of course, the adaptive benefit of this distinction was key to its reproduction. Membranes that could foster the retention of the material that promoted existence, and reject those elements that might endanger it, were more likely to survive and replicate. What enhanced survival was ‘good’, and what threatened it was ‘bad’; an amoeba with the most primitive form of this discriminating technology could favour the one and be averse to the latter.

Somewhere in this evolutionary process there emerged what we would regard as sensation and the distinction or discrimination between good and bad, a positive response to the former and a negative one to the latter. This in turn created a preference for the former and an aversion to the latter, a seeking for the one and an active avoidance of the other. Since what is sought are those elements of the external world that are most ‘like’ the elements inside the membrane, because by definition it is those elements that have been repeatedly allowed to pass through it, a preference for what is most like ‘oneself’ or similar to that self was created.

This gave rise not just to preference and attachment but also potentially to subjectivity, an identification with some aspects of ‘self’ and the world as against others. In this process lie the origins of meaning and intentionality; recognising events at the boundary of the phenotype which are ‘good’, desirable, to be sought after, to be ‘believed’ or invested in.

Inherent in this theory is the notion that sensations are the basis for our first-person view of the world, of our subjective experience. Sensations are laden with affect, with the certain knowledge that they are arising now. In order for sensations to be so self-characterising in respect of their location the organism, argues Humphrey, must be reaching back to create a physical disturbance at the site at which they are felt. This requires a loop to be created in which sensation can inform a response.

In the most primitive organisms this loop returns to the source of the disturbance- the amoeba, for example, moves its body surface toward the energy source. In complex creatures with ganglia, and later brains, it is not the surface area of the body (the area subject to external stimulation) which is subject to the feedback but that part of the ganglia or cerebral cortex which models and controls that specific part of the body.

This shortening of the responsive loop can be seen as a selective adaptation; as the loop becomes shorter the response time is reduced and its adaptive advantage increased. But the loop is not essentially passive, rather the organism is creating the conditions for the sensation by issuing the feedback instructions for it to arise. In this sense sensations, and indeed emotions, are a kind of intentional doing. Sensations and feelings enter consciousness not as something that merely ‘happen’ to us, but as activities that our bodies initiate and that then that loop back on themselves to create our subjective present.

The remarkable aspect of this theory is that it is both a reduction to physical causes whilst maintaining the irreducible nature of first-hand experience. On the physical side sensation and phenomenal consciousness is only experienced by that small group of creatures that have acquired a response mechanism which has become part of a reactivating loop; this loop generates sensations that exist for an extended moment and provide the physical basis for experience. In effect, the sensory responses that the body initiates have a kind of ‘self-resonance’, in Humphrey’s words, ‘that effectively stretches out the present moment’ to create what he calls ‘the thick moment of consciousness.’ This ‘thick moment’ is the basis for our subjective experience of time and what arises in time.

Such an interpretation helps us to understand the concept of the phenomenal ‘now’, the time interval which characterises human sensory and perceptual experience. It makes possible a coherent account of that otherwise mysterious notion of the present moment, something which occurs in the gap between past and future but which as soon as it has been experienced collapses into memory or into nothing. This aspect of time is very different from time as the physical sciences would understand it. It is something we experience, but not something which exists objectively, save as a unit of elapsed time, a few seconds or milliseconds perhaps, that cannot capture the notion of an experienced present.

In this analysis sensation lies at the heart of our relationship with the world, and the path that it takes in our bodies is two-fold. Firstly, it underlies perception, and survival-enhancing perception allows us to navigate a dangerous world and survive within it. Secondly, it is the basis for the primitive self and for the emotions that such a self generates. Such emotions, whether of attraction or aversion, have proved critical in the survival of the human lineage. They need to be powerful and visceral if they are to be effective, but in being such they often overwhelm us and cause us to suffer. However useful they have proved in our evolutionary development, they are no longer fit for purpose.

One of the key aims of the Buddhist ‘skilful means’, and particularly of meditation and mindfulness, is to return the human mind to its origin in sensation and appreciate its qualities, free of the often-troubling emotions and thoughts which so often follow from it.