by Guy Claxton
For example, even blindsight patients can become directly conscious of activity in the blind field if a stimulus suddenly gets brighter or starts to move faster. In another neurological disorder called prosopagnosia, people are specifically unable to recognise faces that they do in fact know well. Show them Princess Diana and they will not know that they know the face, nor be able to put a name to it. But if these patients have previously been shown a picture of Prince Charles – which they have not been able to identify either – the chances of their consciously recognising Diana are increased. Even though Charles did not himself exceed the threshold of consciousness, his picture has been unconsciously recognised, and this is sufficient to send some activation to prime the underlying Diana network. This, added to the activation from Diana’s picture, may be strong enough for the image to reach consciousness.8
But intensity alone cannot account for consciousness. Even very strong stimuli can, with time, be ignored. And there is evidence that some neurons, paradoxically, are more strongly stimulated by subliminal stimuli than by conscious ones. There are cells in the visual area of the brain, for example, that give a more vigorous response to a light that is shone in the eye of a fully anaesthetised animal than one that is wide awake.9
A more crucial condition for consciousness seems to be the persistence of neural activity. Benjamin Libet at the University of California at San Francisco has found, by directly stimulating the part of the brain that is responsible for the sense of touch, that even quite strong stimuli must reverberate in the brain for a minimum period of about half a second before they become conscious, whereas reactions to unconscious processing can occur much faster, and with much briefer stimuli.10 If there is such a minimum time condition for consciousness, then it is possible that people who are asked to move from an unconscious to a conscious mode of responding might show not a smooth increase in their reaction time, but a jump as they move from one mode to the other. Sure enough, the time it takes for people to push a button, as quickly as they can, in response to the onset of a light, is about 200 milliseconds. But if they are asked to slow down their responding by the tiniest possible amount, there is a quantum jump of about half a second, giving total response times of nearly three-quarters of a second. It is as if there is no halfway house: either you are responding instinctively, or you have to wait for consciousness to develop (like a photograph) and then respond.11
There are a number of different reasons why the neural effect of a stimulus might last long enough for consciousness to develop. One, obviously, is the duration of the stimulus event itself. But strong stimuli may become conscious, even if they are objectively too short, simply because intensity causes neural activity to reverberate for a longer time – just as the sound of a well-struck gong hangs in the air. (In this way we can subsume the ‘intensity’ condition under the ‘persistence’ condition.) And such reverberation may come about not just as a result of the strength of a stimulus. Semir Zeki at University College London has proposed, in the case of vision, that two different areas of the visual cortex must be able to ‘sustain a dialogue’ if consciousness is to occur. Francis Crick and Christof Koch at the Salk Institute in California have made a somewhat similar suggestion: that what is required to subserve consciousness is a reverberatory loop linking the thalamus in the midbrain to the neocortex.
A third possibility, and one which ties in with some of the experimental evidence we looked at in Chapter 8, is that it is the involvement of the ‘self’ that extends neural activity to the point of consciousness. We have just seen that asking people to respond self-consciously, rather than instinctively, seems to bump them into a qualitatively different, slower mode of processing. And we have also seen the reverse effect: if people are asked to respond very fast to weak signals – to jump from a careful reliance on the cautious criteria of consciousness to a fast, unchecked way of responding – they give correct answers which consciousness, when it catches up, countermands. From this point of view consciousness may be sui generis self-consciousness.12 We become conscious of stimuli (except when they are in themselves strong or persistent) because they are being referred to a special part of the neural network which corresponds to our self-image, to see if they fit comfortably with the sense of who we are, and with the ongoing life story in which we see ourselves as taking part. This checking process takes time, and thus in itself tends to fulfil the conditions required for neural activity to generate consciousness (though other censoring processes may quickly come into play – as we saw with the phenomenon of ‘perceptual defence’ – if it turns out that the information is judged, on this analysis, to be threatening or uncongenial).13
If a stimulus is either too short or too weak, or does not fit with my model of who I am and what is going on, it can still play its part in determining how the brain is reacting to events, but it will do so covertly rather than explicitly. As John Kihlstrom, one of the leading researchers on the cognitive unconscious, sums it up:
When a link is made between the mental representation of self and the mental representation of some object or event, then the percept, memory or thought enters into consciousness; when this link fails to be made, it does not. Nevertheless, unconscious percepts and memories, images, feelings and the like can still influence ongoing experience, thought and action.. .14
This association between the self and consciousness, and the idea that consciousness demands a time-consuming resonance or reverberation between different circuits of the brain, raises the intriguing possibility that areas of the brain might be getting on with their business at an unconscious level, without bothering to wait for consciousness to develop. A pool of neural activation may split into two, one part resonating with the self, and thus subserving the emergence of conscious awareness, while the other carries on with further processing such as planning a response. This makes sense, particularly if time is short. It may pay you to continue with the preparations for building an extension on to your house at the same time as you are waiting for formal ‘planning permission’ – on the assumption that the permission will be forthcoming in the end. If permission is in the event refused, you can abort the plan before you have started the actual process of construction. Provided you have not physically ‘jumped the gun’, nothing, except the planning time, is lost. If the brain were capable of operating in this dual-track manner, we would have to rethink the function of consciousness. Far from being the instigator of action, the source of orders and decisions, consciousness could, at least under some conditions, simply be receiving notification of what was in fact being decided elsewhere.
Another study by Ben Libet has demonstrated that this bifurcation of the mind does occur.15 He asked people to hold out a hand and, whenever they felt like it, to flex one of their fingers. While they were doing this simple task, he recorded three points in time. Firstly, by virtue of electrodes attached to the person’s head, he was able to pinpoint the moment at which the precursors of the action were discernible in the brain’s patterns of electrical activity (the EEG). Secondly, Libet asked people to indicate, by registering the position of a spot on a rotating clock in front of them, the moment at which they were first aware of the intention to make the movement. And finally, by recording activity in the muscles of the finger, he was able to note when the physical movement itself began. He found that the voluntary action began to develop in the brain about 350 milliseconds – a third of a second – before the appearance of the conscious intention, which occurred, in turn, some 200 milliseconds before the start of the action itself. These results indicate clearly that it is the unconscious brain which decides what to do, and when; and that what we experience as an intention is merely a post hoc confirmation of what has already been set in motion. Consciousness receives a kind of corollary ‘despatch note’, and then presents this as if it were the original order.
‘Will’, or even ‘free will’, on this evidence, seems to belong to the brain, rather than to consciousness. But this does not mean that con
sciousness is left without any function at all. If conscious awareness is associated with the process of checking a situation for concealed threats to self, it may also be instrumental in inhibiting actions and experiences that are adjudged to be risky, rather than in routine instigation and construction. The detection of some irregularity or threat, real or imagined, may result in a veto that can block the execution of the evolving plan before the ‘point of no return’. As psychologist Richard Gregory has speculated, it may be that we – that is, consciousness – do not have ‘free will’, but we do have ‘free won’t’.
This brings us to the question: what is consciousness for? We are most conscious of those things which might threaten us (except when the feeling of threat is so great, so threatening in itself, that the very experience is inhibited, as in hysterical blindness, traumatic amnesia or psychopathological forms of repression). Where the brain’s initial unconscious diagnosis declares the situation to be safe and familiar, there is no need to dwell on it – no need to refer it to the self for further tests. The flow of activation moves on too quickly for the persistence condition for consciousness to be met. But where there is some initial doubt, then the flow of activation is arrested and the predicament is allowed to resonate with the priorities and checks of the self, so that further data may be collected, or a wider pool of associations activated. If this results in the ‘all clear’, action can proceed unhindered. If a threat is uncovered, then censorship and self-control can save the day. Consciousness is for selfprotection.
From this perspective, conscious awareness emerges as fundamentally quizzical and questing. We become conscious of that which is being actively probed for its significance. As many cognitive scientists have recently argued, focused, conscious awareness, the spotlight of the mind, is primarily associated with states of disruption or emergency, and with the activities of investigation, detection and resolution that follow.16 Some segment of the world poses a puzzle, and high levels of activation concentrate in the corresponding areas of the neural network, so that the nature of the predicament – ‘What is it, out there (or in here)?’ – can be discerned more fully, and an appropriate response discovered. In an emergency, or a state of utter absorption, the proportion of the brain’s (limited) resources that are appropriated by this enquiry may be so great that other competing activities are temporarily shut down – we freeze, we stop breathing. Consciousness, it has been suggested, originally made its evolutionary appearance in the context of this focused, arrested response to threat or uncertainty.
This view of the mind is very different from the commonsense one, which sees consciousness as the executive boardroom of the mind, and as the theatre in which ‘reality’ is displayed. Specifically, the evidence seems to suggest two rather radical conclusions. First, common sense tells us that consciousness is what we can trust: that the world is as it appears to be. But brain research indicates that consciousness manifests not what is certain, but what is in question. Focused consciousness is associated with those aspects of the mind’s activity which are currently being treated as problematic. Whatever occupies the centre of conscious attention is there precisely because its meaning, its significance, its interpretation, is in doubt. Through dwelling on something we may be led to a richer, ‘truer’ understanding of it, but that is the result of being conscious, not the prerequisite.
The second conclusion is that consciousness per se does not actually do anything. Consciousness accompanies, and is therefore symptomatic of, a particular mode of operation of the brain-mind as a whole: one in which ongoing action is arrested, careful attention to the probable source of the interruption is being paid, all the sub-systems are listening carefully for new information, priorities are being revised, and new plans being laid. These are the circumstances under which the brain-mind ‘generates’ conscious awareness. The intense pooling and resonating of activation creates the conditions in which consciousness appears. Consciousness accompanies a very particular and very useful mode of mind, though it does not itself possess any executive responsibility. Although I earlier suggested that we, qua consciousness, may possess ‘free won’t’, even this formulation credits consciousness with power that it does pot intrinsically possess; for the process of vetoing action or editing experience is itself carried out by the brain. Even the ‘self’ turns out to be just one sub-system among many within the overall neural economy of the brain – the system that defines what is to count as ‘threat’ or ‘desire’, and which examines experience through these filters.
The idea that the brain, unsupervised by the conscious intellect, does smart things on its own, and that consciousness per se does not carry out any cognitive function, can be discomfiting, because it seems to leave ‘us’ at times with nothing to do. Yet this disconcerting feeling of redundancy may be the price we have to pay if we wish greater access to the slow ways of knowing. Certainly there are many neuroscientists who firmly believe that the physical brain is all we need to account for human intelligence. One of the clearest spokespeople for this point of view is the self-styled ‘neuro-philosopher’ Patricia Churchland, who has written:
The cardinal principle for the [neuroscientist] is that . . . there is no little person in the brain who ‘sees’ an inner television screen, ‘hears’ an inner voice . . . weighs reasons, decides actions and so forth. There are just neurons and their connections. When a person sees, it is because neurons, individually blind and individually stupid neurons, are collectively orchestrated in the appropriate manner . . . In a relaxed mood we still understand perceiving, thinking, control and so forth, on the model of a self – a clever self – that does the perceiving, thinking and controlling. It takes effort to remember that the cleverness of the brain is explained not by the cleverness of a self but by the functioning of the neuronal machine that is the brain . . . In one’s own case, of course, it seems quite shocking that one’s cleverness should be the outcome of well-orchestrated stupidity.17
Perhaps any discomfort that these ideas cause is merely a product of having identified ourselves too closely with the habits and values of d-mode, and that all that is required to dispel the unease is an expansion of this shrunken definition of intelligence to reincorporate the brain.
CHAPTER 11
Paying Attention
One day a man of the people said to Zen master Ikkyu: ‘Master, will you please write for me some maxims of the highest wisdom?’ Ikkyu immediately took his brush and wrote the word ‘Attention’. ‘Is that all?’ asked the man. ‘Will you not add something more?’ Ikkyu then wrote twice running ‘Attention. Attention’. ‘Well,’ remarked the man rather irritably, ‘I really don’t see much depth or subtlety in what you have just written.’ Then Ikkyu wrote the same word three times running: ‘Attention. Attention. Attention’. Half-angered, the man demanded: ‘What does that word “Attention” mean anyway?’ And Ikkyu answered gently: ‘Attention means attention.’
Philip Kapleau Roshi
In d-mode, perception is diagnostic. Its role is to sample the information that is arriving through the senses until it can recognise, categorise and label what is ‘out there’ – a ‘traffic jam’, a ‘politician’ – or ‘in here’ – ‘sadness’, a ‘headache’. Once perception has come up with its diagnoses, its job is done, and interest shifts downstream to what can be inferred, and done, about the situation thus described. If the snap diagnosis is accurate and adequate, thought builds on a firm foundation. But there is always a risk that such a skimpy approach to perception may neglect information that does not, on first sight, seem to be significant, but which, had attention been less precipitate, might have revealed its relevance and its worth. D-mode determines the way in which attention is to be deployed, and it is not always the best way. If we get stuck in d-mode’s particular way of attending, we may prematurely and unwittingly discard just what we need. Sometimes a slower, more meticulous approach to perception can lead to a richer mental image of what is happening, and hence to a better way of knowing. If
we are to know as well as we can, we sometimes need to switch from the high-speed scanning of d-mode into a contemplative perceptual stance in which the world is allowed to speak more fully for itself. This chapter explores four different ways of paying attention, or ‘slow seeing’: detection, focusing on inner states, poetic sensibility, and mindfulness.
The habit of attending closely and patiently to the evidence, even – sometimes especially – to tiny, insignificant-looking shreds of evidence, is characteristic of skilled practitioners of a variety of arts, crafts and professions, prototypically the hunter. From a bent twig, a feather or a piece of dried excrement the expert hunter can recreate an animal, its age and state of health; and he does so in an apparently leisurely fashion in which these scraps of information are allowed to resonate, largely unconsciously, with his mental stock of lore and experience. You can’t rush a tracker. Each detail, slowly attended to, is allowed to form a nucleus, an epicentre in the brain, around which associations and connotations gradually accrete and meld, if they will, into a rich, coherent picture of the animal and its passage. As Carlo Ginzburg, author of a fascinating essay on ‘Clues’, has surmised, the hunter squatting on the ground, studying the spoor of his quarry, may be engaged in the oldest act in the intellectual history of the human race.1 Many other feats of vernacular connoisseurship – telling an ailing horse by the condition of its hocks, an impending storm by a change in the wind, a run of salmon by a scarcely perceptible ripple on the river, a hostile intent by a subtle narrowing of the eyes – are of the same kind. Each is an act of high intelligence, bringing to bear on the present a complex body of past knowledge, and accomplished by the eye, with little if any assistance from deliberate thought.