THE IMPLICATIONS OF CHANGE AND INATTENTIONAL BLINDNESS FOR UNDERSTAN= DING CONSCIOUSNESS

WHERE EXPERIENCES ARE: = DUALIST, PHYSICALIST, ENACTIVE AND REFLEXIVE ACCOUNTS OF PHENOMENAL CONSCIOUSNESS

Max Velmans, Departmen= t of Psychology, Goldsmiths, University of London, New Cross, London SE14 6NW; email m.velmans@gold.ac.u= k

web address http://www.goldsmiths.ac.uk/departments/psychology/staff/velmans.html<= /o:p>

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Phenomenology and the Cog= nitive Sciences (in press)

Abstract.

Dualists believe that experiences have neither location nor extension, while reductive and ‘non-reductive’ physicalists (biological naturalists) believe t= hat experiences are really in the brain, producing an apparent impasse in curre= nt theories of mind. Enactive and reflexive models of perception try to resolve this impasse with a form of “externalism” that challeng= es the assumption that experiences must either be nowhere or in the brain. However, they are externalist in very different ways. Insofar as they locate experiences anywhere, enactive models locate conscious phenomenology in the dynamic interaction of organisms with the external world, and in some versions, they reduce conscious phenomenology to such interactions, in the hope that this = will resolve the hard problem of consciousness.= The reflexive model accepts that experiences of the world result from dynamic organism-environment interactions, but argues that such interactions are preconscious. While the resulting phenomenal world is a consequence of such interactions, it cannot= be reduced to them. The reflexive model is externalist in its claim that this external phenomenal world, whic= h we normally think of as the “physical world,” is literally outside= the brain. Furthermore, there are= no added conscious experiences of the external world inside the brain. In the present paper I present the= case for the enactive and reflexive alternatives to more classical views and evaluate their consequences. I argue that, in closing the gap between the phenomenal world and what we normally think of as the physical world, the reflexive model resolves one f= acet of the hard problem of consciousness.   Conversely, while enactive m= odels have useful things to say about percept formation and representation, they = fail to address the hard problem of consciousness.

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Keywords: dualism, physicalism, enactive, refl= exive, phenomenology, consciousness, externalism, internalism, reductionism, consciousness, mind, brain, world, perception, Noe, Thomson, Velmans, O’Regan, Myin, projection, space, phenomenal world, Lehar<= /span>

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The problems of consciousness have been extensively discussed in the scientific= and philosophical literature. What is it? What is its function? And how are we = to understand the causal relations between consciousness and brain? In Velmans (2000, 2003a) I have ar= gued that these problems are partly empirical and partly conceptual. Why is the nature of consciousness partly a conceptual problem? We already have innumerable examples of conscious experience in our everyday lives and still puzzle over its nature, so merely having some more experiences, and thinking about them in our habitual ways, won’t advance our understanding of its nature. Dualists and reductionists, for ex= ample, have persistently differing opinions about the nature of consciousness in s= pite of the commonalities of their intersubjectively shared experiences.

The dualist view

The dualist view, which m= any people intuitively adopt, is shown in schematic form in Figure 1 below.

Figure 1. A dualist model of perception

(adapted from Velmans, 2000)

This assumes perception to involve a simple, linear, ca= usal sequence. Viewed from the perspective of an external observer E, light rays travelling from the physical object (the cat as-perceived by E) stimulate t= he subject's eye, activating her optic nerve, occipital lobes, and associated regions of her brain. Neural conditions sufficient for consciousness are formed, and result in a conscio= us experience (of a cat) in the subject’s mind. This model of visual perception is= , of course, highly oversimplified, but for now we are not interested in the details. We are interested on= ly in where external physical objects, brains and experiences are placed.

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It will be clear that there are two fundame= ntal “splits” in this model. Firstly, the contents of consciousness are clearly separated from the material world (the conscious, perceptual&= nbsp; “stuff” in the upper part of the diagram is separated fr= om the material brain and the physical cat in the lower part of the diagram).<= span style=3D'mso-spacerun:yes'> This conforms to Descartes’ = view that stuff of consciousness (res cogitans, a substance that thinks) = is very different to the stuff of which the material world is made (res ext= ensa, a substance that has extension and location in space). Secondly, the perceiving subject is clearly separated from = the perceived object (the subject a= nd her experiences are on the right of the diagram and the perceived object is on = the left of the diagram).

This dualist model of per= ception supports a dualist view of the universe in which the universe is split into= two realms, the material realm and the mental realm (the latter including consciousness, mind, soul and spirit). In interactionist forms of dualism t= hese two realms interface and causally interact somewhere in the human brain.

The reductionist v= iew

The problems of assimilating such dualism into a scientific worldview are serio= us (cf Velmans, 2000 ch2). Consequently, it is not surprising that 20^{th
Century philosophy and science tried to naturalise dualism by arguing or
attempting to show that conscious experiences are nothing more than states =
or
functions of the brain. A
reductionist model of visual perception is shown in Figure 2.}

Figure 2. A reductionist model of perception <= /span>

(adapted from Velmans, 2000)

The causal sequence in Figure 2 is the same= as in Figure 1, with one added step. While reductionists generally accept that the subject’s experience of a cat seems to be insubstantial and “in the mind”, they argue that it is really a state or function of the brain. In sho= rt, the reductionist model in Figure 2 tries to resolve the conscious experience—physical world split by eliminating conscious experience or reducing it to something physical that E (the external observer) can in principle observe and measure. But reductionism retains the split (implicit in dualism) between the observer and the observed. The perceived object (on the left = side of the diagram) remains quite separate from the conscious experience of the object (on the right side of the diagram)= .

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This supports a reductionist view of a universe entirely composed of physical material, of which conscious experiences are a tiny part (the bits of human brain identified with those experiences).

Note that in spite of their disagreement about the onto= logy of conscious experiences, dualists and reductionists largely agree about how conscious experiences relate to the brain and physical world. In visual perception, for example,= they would agree that physical input stimuli innervate the optic nerve and visual system, forming preconscious representations of that input in the brain. If that input is attended to, and the necessary and sufficient conditions for consciousness are met, a conscious experience will result along with its ne= ural correlates in the brain. This agreement further highlights the conceptual nature of the dualist versus reductionist debate. If it is agreed that visu= al experiences have neural causal antecedents as well as neural correlates, the empirical discovery of those causes and correlates won’t settle their dispute about whether the experiences are nothing more than th= eir causes and/or correlates.

Note too that dualists and reductionists largely agree about where the external physical world, the br= ain and conscious experiences are placed. In spite of their dispute abou= t what experiences are, they agree (roughly) about where they are. Reductionists, for example, ta= ke it for granted that experiences are really brain states or functions, so they = must be in the brain. Altho= ugh dualists take experiences to be immaterial (and, strictly speaking, without location or extension) they again take it for granted that these must inter= face and interact with the physical world somewhere in the brain. In short, the brain is as close to experiences as one can get—and if experiences ar= e in the brain, they cannot be located in, or part of, the external physical wor= ld. One could describe this view as phenomenological internalism.=

Enactive and re= flexive approaches to consciousness challenge the grounds of the dualist versus reductionist debate by challenging some of these seemingly innocuous assumptions that dualists and reductionists share, namely a) what conscious experiences seem to be like, and b) where conscious experiences are placed in relation to the brain and the physical world.

Enactive accounts of consciousness

There are a family of theories that might broadly be described as enactive, characterised by an emphasis on perception being a sensory-motor skill involving ongoing interaction with the external world, rather than being dependent on an “inner representation” of that world. These theories can be considered in terms of what they say about the= way that perceptual processing works, and in terms of what they say about the ontology of conscious experiences (for example, about the nature of “qualia”). While questions about perceptual functioning and about conscious phenomenology ar= e, in principle, separable, a number of enactive theorists claim them to be connected: according to them, if one understands perceptual functioning in = an enactive way as mastery of a set of sensory-motor skills, one can also understand the nature of conscious experience including its “qualia” in this way—thereby (hopefully) resolving one of= the hard problems of consciousness (see, e.g. O’Regan and Noe, 2001; O= 217;Regan, Myin and Noe, 2005).

At one extreme, theorists sympathetic to the enactive approach argue that a better understanding of h= ow, say, visual perception works, resolves the hard problem of qualia by showing our beliefs about our visual experiences to be entirely false. For example, Dennett (2002) points= out that we commonly think that we experience the visual world in fine detail a= nd colour from the centre of the visual field to the periphery. However, science demonstrates that= this cannot be so, having discovered that peripheral vision has poor acuity and = does not code for colour. According to Dennett, if we can be wrong about colour extending to our visual periphery, we can be wrong about everything to do w= ith our phenomenology, for example, that we experience colour qualia at all. In the same vein, Blackmore (2002) claims “there is no point trying to explain the differences between things that are in consciousness and those that are not because there is no such difference. And it is a waste of time trying to explain the contents of the stream of consciousness because the stream of consciousness does not exist.” (p28)

Other enactive theorists = however, would regard such views as unjustifiably extreme. While some people might have false beliefs about some aspects of their experience that they h= ave not bothered to think about closely, it does not follow that all of = our beliefs about our experiences are or need be wrong—and certainly does= not warrant the claim that conscious qualia do not exist! A moment’s close attention to the qualia of our visual field, for example, is all that is ne= eded to confirm the description of it given by science.   Once one attends to it, it is perfectly obvious that we can discern fine detail at our point of focus but= not at the periphery of vision, and that although colour and detail at the periphery are at best fuzzy, both colour and detail at the focus of attenti= on are clear. In short, lack of = detail and colour of qualia at the periphery of vision has no bearing on the exist= ence of detail and colour of qualia at the focus of vision, and therefore no bea= ring on the existence of qualia as such.[1]

Recent findings on inatte= ntional and change blindness are, however, more challenging to our everyday beliefs. Studies of inattenti= onal blindness such as Simons & Chabris (1999), for example, suggest that we= do not see what we do not attend to even when we are directing our gaze at = it. Equally surprising, studies of cha= nge blindness such as Simons & Levin (1998) demonstrate that we do not noti= ce major changes in what we are gazing at unless fast transitions capture our attention, or we happen to be focusing our attention on the precise features that change. Taken together, = such findings provide persuasive demonstrations that what we notice about the perceived world is less complete and detailed than we usually think. The findings also challenge a comm= only held view within psychology about how perception works, namely that we have= a detailed, and complete inner representation of the external world built up = over successive eye saccades out of the degraded information arriving at the retinas. If such a complete representation were updated moment-by-moment, t= hen we should notice changes in the visual field by comparing current input with complete records of the world developed from prior input—but we don’t.

T= he alternative, enactive view suggests that we perceive perhaps 5 to 6 features of the world at any given moment (wherever we gaze) but we are fre= e to pick up any other features, as we need them, by exploring the world (e.g. w= ith eye movements). The reason th= at we think that the visual world is rich in detail and colour is because the wor= ld itself does have this detail and colour, and we see this wherever we look. = We do not need to build up a complete, detailed inner representation of the world because the world itself stores all the relevant information.

If true this would be a g= enuine advance in our understanding of how perception works (that we pick up just = 5 or 6 visual features at each fixation) and about the nature of consequent inner representations of the world (that they are limited to the features that are picked up and are, therefore, not complete). The dynamic interaction between in= ternal information and external information (picked up on a need to know basis) al= so suggests that internal information may sometimes be formatted in a way that= is suited to such ongoing activities, for example as a set of procedures for action, rather than being iconic or propositional. The idea that inner representation= s are at least in part procedural rather than iconic or propositional is a recurr= ing theme in cognitive science (see for example the procedural semantics develo= ped in considerable depth by Miller & Johnson-Laird, 1976). However, the inattentional and change blindness data does not suggest that there are = no inner representations at all (an extreme form of “externalism” sometimes associated with the enactive view, see, e.g. Noe & Thomson, 2004a). Nor does any of this data suggest that there are no “qualia.” On the contrary, there are qualia (associated = with the 5 to 6 features we pick up) wherever we look.

A group of enactive theorists nevertheless = claim that understanding perception in this way allows an explanation of t= he qualia of consciousness in ways that are not open to the more traditional v= iew that these are, in some mysterious fashion, generated by neural activity in= the brain. For example, O’Regan, Myin and Noe (in press?) ask, “What is = it exactly about phenomenal consciousness which makes it seem inaccessible to normal scientific inquiry? What is so special about "feel"?” Their reply is that “Feel is…not "generated" by a neu= ral mechanism at all, rather, it is exercising what the neural mechanism all= ows the organism to do.” The feel of driving a Porsche for e= xample does not reside in any given moment, but rather in the fact that you are currently engaged in exercising the Porsche driving skill. And, “If the f= eel of Porsche driving is constituted by exercising a skill, perhaps the feel of r= ed, the sound of a bell, the smell of a rose also correspond to skills being exercised.” Readers fam= iliar with the consciousness studies literature will recognise that this reductive identification of conscious “feel” with the exercising of a sensory-motor skill is a variant of functionalism, although it locates the relevant functioning in the skilful interaction of organisms with the surrounding world rather than in causal relationships that are exclusively located within the brain. Consequently it may be seen as a variant of the position shown in Fi= gure 2, although it is difficult to represent the exercising of sensory-motor sk= ills in a simple, schematic diagram (I will leave this to the reader as an exercise).

The notion that sensory-motor interaction with the world= may affect aspects of visual perception that have to do with apparent size, sha= pe, location and orientation of objects in space again has classical antecedent= s in psychology, dating back to experiments with inverted retinal images in 1897= by G.M. Stratton, and work with a variety of distorting spectacles by Ivo Kohl= er and others in the 1960s (see Velmans, 2000, ch7). It was also demonstrated,= for example, by the way that the distorted appearance of an Ames room = = [2] only changes once one interacts with it, e.g. by walking around it, or poking the sides of the ro= om with a stick (the appearance is not changed if one is simply told its true dimensions). That said, many would doubt that conscious qualia that cannot = be explored with motor movements (such the appearance of red, the sound of a b= ell or the smell of a rose) are similarly dependent on sensory-motor skills. The nose, for example, has few mot= or options: one can wrinkle it and point it in different directions, but to the best of our knowledge it is its ability to fit appropriately shaped vapour molecules into appropriately shaped receptor sites, not nasal sensory-motor skill, that enables it to discriminate the smell of a rose from the smell of ripe cheese. However, I will = leave the fuller analysis of this more dubious, theoretically overextended aspect= of the enactive view to other commentators in this double issue. I want to foc= us on something more fundamental—on whether sensory motor skill gets one= any closer to explaining the hard problem of conscious “feel.”

Why should driving a Porsche or any other skill feel = like anything at all? I am not denying that functioning of different kinds in humans often feels like something for humans. However human functioning can often be dissociated from its normal feel. For example, once they are well le= arnt, consciously performed skills can often be performed unconsciously,= = [3] so it does not follow that skilful functioning itself explains the accompanying feel.[4]

If it is a contingent, not a nece= ssary fact that certain kinds of functioning in humans have certain kinds of feel, then switching one’s emphasis away from neural mechanisms as such, to “what neural systems allow an organism to do” gets one no close= r to understanding why that enabling of skill should have a feel at all. Piloting a 747 no doubt, feels like something, to a human pilot and the way that it feels is likely to h= ave something to do with human biology. But why should it feel the same way to an electronic autopilot that replaces the skills exercised by a human being? Or why should it feel like anything to be the control system of a guided missile system? Anyone versed= in the construction of electronic control systems knows that if one builds a system in the right way, it will function just as it is intended to do, = whether it feels like anything to be that system or not. If so, functioning in an electroni= c (or any other) system is logically tangential to whether it is like anything to= be that system, leaving the hard problem of why it happens to feel a certain w= ay in humans untouched [5].

In short, if one helps oneself to the feelings that accompany certain sensory motor acts it might be possible, or not, to extend some of those feelings to aspects of conscious experience th= at are not normally associated with skilful acts, thereby persuading us that t= hese are qualitatively different to how we normally think them to be, as some enactive theorists propose. B= ut this tells us nothing about why skilful acts themselves should feel like anything at all, and consequently fails to address the hard problem of conscious “qualia.”

To sum up, the enactive view differs from standard physicalism and functionalism in that it replaces neural representations in the subject’s brain with sensory-motor interactions between subject and external world that cross the subject—object divi= de, and it is in this sense “externalist”.   However, like physicalists a= nd functionalists, some enactive theorists try to resolve the problem of “qualia” and with it, the conscious experience/physical world split, by reducing conscious experiences to somet= hing that E (the external observer) can in principle observe and measure (to the exercise of sensory-motor skills). To the extent that they try to reduce how things appear from a subject’s first-person perspective to how things appear from E’s third-person perspective they are reductionist. I have given some in= itial reasons to doubt the viability of this enactive alternative to more standard forms of reductionism above—and reductionism has many, additional problems that I do not have space to elaborate on here (cf. Velmans, 2000 chs.3, 4 & 5). Instead, I= want to introduce a more radical proposal: that the dualist and reductionist models of perception shown in Figures 1 and 2 abov= e, should be replaced by the reflexive model of perc= eption shown in Figure 3.

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The Reflexive Model of Perception

Like the enactive view, t= he reflexive model of perception proposes a different analysis of how conscious experience relates to the brain and surrounding world (Velmans, 1990, 2000 ch6). It also accepts that ce= rtain forms of perception arise from a dynamic interaction of observer with obser= ved and that at least some aspects of this interaction have a sensory-motor component. However, unlike so= me supporters of the enactive view, it assumes that such sensory-motor interactions with the world are normally preconscious: these interactions may form part of the causal antecedents to a given experience,= but antecedent causes are not the same as their consequent effects. Consequentl= y, these sensory-motor interactions cannot be ontologically identical to the resulting experiences, and cannot (in this ontological sense) explain their nature (cf. Velmans, 1998, 2000 ch3).

Nor does the reflexive mo= del argue against the existence or importance of internal neural representation= s, although it remains open about the nature of such representations, which ma= y be iconic, procedural or in some other format. Whatever the format, internal repr= esentations are required to support memory, imagery, dreams, and hallucinations (where there is no external stimulus with which to engage in sensory-motor exploration) and once activated, these representations can also be sufficie= nt, proximal causes for very detailed experiences.[6] In short, the reflexive model adopts a largely conventional approach to the causes of perception, while accepting that our knowledge of how perceptual process= ing works is, at present, partial, and needs to be informed in its details by d= ata about change and inattentional blindness (along the lines suggested above) = and by whatever other findings emerge. However, even a full understanding of preconscious causes and correlates, described from a third-pe= rson perspective, won’t tell us all that we need to know about the consequ= ent effects, the qualia of consciousness. = To know about these, we have to ask the subject, and it is only when we have s= uch first-person data that we can construct a complete model of perception. One model of perception that combines (the third-person) information available = to an experimenter with an accurate description of what the subject experience= s is shown in Figure 3.

Figure 3. A reflexive model of perception

(adapted from Velmans, 2000)

In most respects Figure 3= is the same as Figures 1 and 2. As b= efore, there is a cat in the world (perceived by E) that is the initiating stimulus for what S observes, and the proximal neural causes and correlates of what S experiences are, as before, located in S’s brain.[7] The only difference relates to the ontology and location of S’s experience. According to dualists, S’s experience of a cat consists of “stuff that thinks” that is located “nowhere”; according to reductionists, S’s experience of a cat is a state or function of the brain that is located in her brain; according to the reflex= ive model, both of the former models are theoretically rather than empirically driven with the consequence that they systematically misdescribe what S actually experiences. If you = place a cat in front of S and ask her to describe what she experiences, she should tell you that she sees a cat in front of her in the world. This phenomenal cat literally i= s what she experiences, located where it seems to be—and she has no = additional experience of a cat either “nowhere” or “in her br= ain.” According the reflexive model, this added experience is a myth. Applying Occam’s razor gets rid of it.

In short, the reflexive model’s externalism applies to the phenomenology of some experiences. Unlike the exter= nalism of enactive theory, which applies to the antecedent causes or vehicles of g= iven experiences, the central claim of the reflexive model is that insofar as experiences are anywhere, they are roughly where they seem to be. For example, a pain in the foot really is in the foot, and this perceived print= on this page really is out here on this page. Nor is a pain in the foot accompanied by some additional experience of pain in the brai= n, or is this perceived print accompanied by some additional experience of<= /i> print in the brain. In terms of ph= enomenology, this perceived print, and my experience of this print are one and= the same.= [8]

It should be easy to gras= p the essence of this. The external objects that we experience seem to be out there in the world, not in our he= ad or brain—and classical “mental” sensations such as itches= and pains seem to be clearly located on the surface of our skin. But this immediately presents us with the problem of perceptual projection: g= iven that the proximal neural causes and correlates of what we experience are= in the head or brain, how can we explain the fact that various sensations a= nd experiences seem to be beyond the brain?

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P= erceptual projection

It is impo= rtant to be clear about what is meant by “perceptual projection” in o= rder to convey its role in the reflexive model. Crucially, perceptual projection refers to an empirically observable effect, for example, to t= he fact that this print seems to be out here on this page and not in your brain. In short, perceptual projection is an effect that requires explanation; perceptual projection is= not itself an explanation. We kno= w that preconscious processes within the brain produce consciously experienced eve= nts, which may be subjectively located and extended in the phenomenal space beyo= nd the brain, but we don’t really know how this is done. We also know th= at this effect is subjective, psychological and viewable only from a first-per= son perspective. Nothing physical is projected from the brain. Although we don’t have a full understanding of how perceptual projection works, there is a large experime= ntal literature about the information that is used by the brain to model distance and location. There are also = many ways to demonstrate perceptual projection in action, for example in hallucinations, phantom limbs, stereoscopic pictures, holograms, and virtual realities. I have discussed t= his literature elsewhere, along with some potentially useful models (holography= and virtual reality) in Velmans (1990, 2000); but for our present purposes we do not need to examine the details. &nbs= p; We simply need to note that the evidence for perceptual projection is all around us. In spite of the fact that the proximal neural causes and correlates of conscious experiences are inside our brains, our experienced phenomenal bodies and worlds appear to be outside our brains.

How phenomenal space relates to real space=

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No one doubts that physic= al bodies can have real extension and location in space. Dualists and reductionists neverth= eless find it hard to accept that experiences can have a real, as opposed to a ‘seeming’ extension and location. They do not doubt, for example, th= at a foot has a real extension and location in space, but, for them, a pain in t= he foot can’t really be in the foot, as they are committed to the view t= hat it is either nowhere or in the brain. In sum, location in phenomenal space = is not location in real space.

According to the reflexiv= e model however, this ignores the fact that, in everyday life, we take the phenomen= al world to be the physical world. It also ignores the pivotal role of phenomenal space in forming our very understanding of space, and with it, o= ur understanding of location and extension in measured or “real” space.

What we normally think of= as the “physical foot” for example is actually the phenomenal foot<= /i> (the foot as seen, felt and so on). That does not stop us from pointing to it, measuring its location and extension and so on. If so, at least some phenomenal objects can be measured. While a pain in the foot mig= ht not be measurable with the same precision, few would doubt that we could specify its rough location and extension (and differentiate it for example = from a pain in the back).

What we normally think of= as “space” also refers, at least in the initial instance, to the phenomenal space that we experience through which we appear to move. Our intuitive understanding of spatial location and extension, for example, der= ives in the first instance from the way objects and events appear to be arranged relative to each other in phenomenal space (closer, further, behind, in fro= nt, left, right, bigger, smaller and so on). We are also accustomed to making s= ize and distance estimates based on such appearances. This print for example appears to be out here in front of my face, and THIS PRINT appears to be bi= gger than this print. However, we recognise that these ordinal judgments are only rough and ready ones, so wh= en we wish to establish “real” location, distance, size or some ot= her spatial attribute, we usually resort to some form of measurement that quantifies the dimensions of interest using an arbitrary but agreed metric (feet, metres etc), relative to some agreed frame of reference (for example= a Cartesian frame of reference with an agreed zero point from which measureme= nt begins). The correspondence, or lack of correspondence, between phenomenal space and measured space is assessed in the same way (e.g. by comparing distance judgments with distance measurements) in psychology experiments. For example, I can estimate the distanc= e of this phenomenal print from my nose, but I can also place one end of a measu= ring tape on the tip of my nose (point zero) and the other end on this print to determine its real distance.[9]

Such comparisons allow on= e to give a broad specification of how well phenomenal space corresponds to or m= aps onto measured space. According to the reflexive model, phenomenal space provides a natural representation, shaped by evolution, of the distance and location of objects viewed from the perspective of the embodied observer, w= hich models real distance and location quite well at close distances, where accu= racy is important for effective interaction with the world. My estimate that this page is about 0.5 metres from my nose, for example, is not far off. However, phenomenal appearances and our consequent distance judgments quickly lose accuracy as distances increase. For example, the dome of the night sky provides the outer boundary of the phenomenal world, but gives a completely misleading representation of dista= nces in stellar space.[10]

Note that, although we ca= n use measuring instruments to correct unaided judgments of apparent distance, si= ze and so on, measuring tapes and related instruments themselves appear to us = as phenomenal objects, and measurement operations appear to us as operations that we are carrying out on phenomenal objects in phenomenal space. In short, even our understanding of “real” or measured location is underpinned by our experience of phenomenal location. And crucially, whether I make dist= ance judgments about this perceived print and judge it to be around 0.5 metres in front of my face, or measure it to find that it is only 0.42 metres, does not alter the phenomenon that I am judging or measuring. The distance of the print that I am judging or measuring is the distance of this perceived print out here on this page, and not the distance of some other ‘experience of print’ in my brain.

Why this matters

These observations about = the spatially extended nature of the experienced phenomenal world fit in with common sense and common experience and they will come as no surprise to tho= se versed in European phenomenology. They also have many theoretical antecedents, for example in the work= of Berkeley, Kant, and Whitehead, the neutral monism of James, Mach, and Russell, and the scientific writings of Köhler and Pribram. However, the view that experienced phenomena which seem to be outside the brain really are outside the brain is fiercely resisted by both dualists and reductionists, who are committed to the view that experiences must either be nowhere or in the bra= in, and therefore separate from what we normally think of as “the external world”. Enacti= ve theorists are similarly eager to distance themselves from a claim about conscious phenomenology that is supposedly so ‘unscientific.’ N= oe & Thomson (2004b) for example make it clear that they do not defend externalism about experience (as they have different views on this matter). And they wish to def= end themselves against the charge made by Jack & Prinz (2004) that “In the hands of Noe & Thomson, externalism becomes an eccentric doctrine t= hat locates consciousness outside the organism. To our minds, this is the kind = of philosophical manoeuvring that prevents scientists from taking philosophers seriously. Rather than clarif= ying concepts, it obfuscates by conflating relational conditions on representati= on individuation with claims about their literal location” (p55) In their defence, Noe & Thomson (2004b) stress that “It is not our = view that consciousness is outside the head, but rather that some of the causal substrates of consciousness might be.” (p93)

Yet, according to the ref= lexive model, it is precisely in the confused, unempirical, and doctrinal nature of some philosophical and so-called scientific thinking on this issue that a m= ajor source of the hard problem of consciousness is to be found. To understand h= ow conscious experience relates to the brain and physical world, one must first describe the phenomenology of that experience accurately. If conscio= us phenomenology is systematically misdescribed, its relation to the brain and physical world cannot be understood. The empirical fact of the matter appea= rs to be that preconscious processing in the embodied brain interacting with t= he world results in the three-dimensional, external phenomenal world that we experience. In everyday life, it is precisely this 3D phenomenal world that= we see, hear, touch, taste and smell around our bodies that we think of as = the physical world, although we recognise that this experienced physical world only models in a rough and ready way the subtler world described by modern physics (in quantum mechanics, relativity theory, etc.). If so, there never was an explanatory gap between what we normally think of as the physi= cal world, and conscious experience. This phenomenal physical world is part of conscious experienc= e, not apart from it.

It should be apparent tha= t this observation, if true, would alter the nature of the “hard problemR= 21; of consciousness, although, in isolation, it can be no more than a first st= ep on the way to a theory. There= is more than one thing to understand, for example the relation of conscious qu= alia to their neural correlates, the relation of the phenomenal physical world to the world described by modern physics, the causal efficacy and function of consciousness, and so on.   I do not have space to present a more detailed theory here, although I have d= one so elsewhere (see, for example, Velmans, 1990, 2000, chs. 6 to 12, 2003). I will, however, try to make it clear why this first step is crucial.

Is the brain in the wo= rld or the world in the brain?

Readers familiar with the= problem of conscious ‘location’ will recognise that the force of my suggestion that some experiences have both a spatial location and extension outside the head hangs on whether the appearance-reality distinction= can be applied to conscious phenomenology.&nbs= p; Are experiences really where they seem to be or not?

Although various thinkers have noticed the apparent spatial location and extension of some experiences, and have tried to fit t= his into a general theory of mind (see above), few workers in modern consciousn= ess studies have noted the potential consequences of this for an understanding = of consciousness. Of those that have, some have tried to dismiss the significa= nce of spatially extended phenomenology with the argument that, if the neural causes of experience are in the brain, the experiences themselves must be t= here too. However, this presuppose= s the truth of a local model of causation that has long been abandoned by physics (which accepts that electricity inside a wire can cause a magnetic field outside the wire, that planets exert a gravitational pull on each other at great distances, that there are non-local effects = in quantum mechanics, and so on).

Of more interest are a nu= mber of thinkers who take the apparent, spatially extended nature of much of experi= ence very seriously, but nevertheless argue that such experiences are really bra= in states that are by definition in the brain. As it turns out, their attempt to assimilate 3D phenomenology into a form of “biological naturalismR= 21; is highly instructive.

In the modern era, John S= earle was one of the first to address this problem. As he noted,

"Common sense tells = us that our pains are located in physical space within our bodies, that for example= , a pain in the foot is literally in the physical space of the foot. But we now know that is false. The brain forms a body image, and pains like all bodily sensations, are parts of the body image. The pain in the foot is literally = in the physical space in the brain." (Searle 1992, p63)

However, Searle does not wish to dismiss conscious phenomenology. Indeed, later in the same book, he concludes that =

"...consciousness consists in the appearances themselves. Where appearance is concerned we cannot make the appearance-reality distinction because the appearance is the reality." (Searle 1992, p121).

This illustrates the acute problem that apparent spatial location poses for biological naturalism: If biological naturalism is true, experiences are states of the brain, which are necessarily in the brain. However, if “the appearance = is the reality”, and the pain appears to be in the foot, then it really is in the foot. Either biological naturalism is true, or the appearance is the reality. One can’t have both.

Has science discovered th= at (despite appearances) pains are really in the brain as Searle suggests? It = is true of course that science has discovered representations of the bo= dy in the brain, for example, a tactile mapping of the body surface distributed over the somatosensory cortex (SSC). However, no scientist has observed act= ual body sensations to be in the brain, and no scientist ever will, for the sim= ple reason that, viewed from an external observer's perspective, the body as experienced by the subject cannot be observed (one cannot directly obse= rve another person’s experience). Science has nevertheless investigated the relationship of the body image (in SSC) to tactile experiences. Penfield & Rassmussen (1950), for example, exposed areas of cortex preparatory to surgical removal of cortical lesions responsible for focal epilepsy. To avoid surgical damage to areas essential to normal functioning, they explored the functions of these areas by lightly stimulat= ing them with a microelectrode and noting the subject's consequent experiences.= As expected, stimulation of the somatosensory cortex produced reports of tacti= le experiences. However, these feelings of numbness, tingling and so on were subjectively located in different regions of the body, not in the brain<= /i>. In sum, science has discovered that neural excitation of somatosensory cort= ex causes tactile sensations, which are subjectively located in different regions of = the body. This effect is precisely the “perceptual projection” that= the reflexive model describes.

In recent years the spati= ally extended nature of visual experience has once more become a topical issue. = For example, Pribram (1971, 2004), one of the first scientists to address this problem, has continued to develop his earlier theories of holographic representation in the brain; Revonsuo (1995) developed the suggestion that = the phenomenal world is a form of virtual reality (see also Velmans, 1993); and Lehar (2003) in a recent BBS target article has attempted to develop= a mathematical model of how objects appear as they move in phenomenal space (as opposed to how they really are as they move in phenomenal space). As these, and other scientists (such as Gray, 2004) have pointed out, the 3D nature of the phen= omenal world is likely to have important consequences for neuroscience, for the obvious reason that the brain has to be organised in a way that supports su= ch spatially extended experiences.

However, these theorists = remain divided on the issue of whether some experiences are really outside the brain. Pribram (2004) takes t= he view that they are, and outlines a broad theory of perception that he explicitly links to the reflexive model developed in Velmans (2000). Revonsuo, Lehar and Gray adopt a f= orm of biological naturalism, arguing for example that the entire 3D phenomenal wo= rld, stretching to the horizon and the dome of the sky, is a form of virtual rea= lity that is literally inside the brain.

Paradigm crunch

Lehar (2003), however, po= ints out that if the phenomenal world is inside the brain, the real skull must be outside the phenomenal world (the former and the latter are logically equivalent). Let me be clear:= if one accepts that

a)&n= bsp;     The phenomenal world appears to have spatial extens= ion to the perceived horizon and dome of the sky.

b)&n= bsp;     The phenomenal world is really inside the brain.

It follows that

c)&n= bsp;     The real skull (as opposed to the phenomenal skull)= is beyond the perceived horizon and dome of the sky.

Although Lehar accepts th= is conclusion, he admits that this consequence of biological naturalism is “incredible”. In = my view, this casts an entirely different light on the so-called ‘scientific’ status of biological naturalism and the so-called ‘unscientific’ claims of the reflexive model. Put your hands on your head. Is that the real s= kull that you feel, located more or less where it seems to be? If that makes sen= se, the reflexive model makes sense. Or is that just a phenomenal skull inside = your brain, with your real skull beyond the dome of the sky? If the latter seems absurd, biolog= ical naturalism is absurd. Choose for yourself.[11]

&n= bsp;

References

Blackmore, S.J. (2002) There is no s= tream of consciousness. Journal of Consciousness Studies, 9 (5-6), 17-28.

Dennett, D (2002) How could I= be wrong? How wrong could I be? Journal of Consciousness Studies, 9 (5-= 6), 13-16.

Gray, J. (2004) Consciousness: Creeping = Up On The Hard Problem. Oxford: Oxfo= rd University Press.

Jack, A.I. and Prinz, J.J= . (2004) Searching for a scientific experience. Journal of Consciousness Studies, 11= (1), 51-55.

Lehar, S. (2003) Gestalt isomorph= ism and the primacy of subjective conscious experience: A gestalt bubble model.= Behavioral & Brain Sciences 26(4), 375-444.

Miller, G. and Johnson-La= ird, P. (1976) Language and Perception. Cambridge: Cambridge Universi= ty Press.

Noe, A. and Thomson, E. (2004a)= Are there neural correlates of consciousness? Journal of Consciousness Studies 11(1), 3-28.

Noe, A. and Thomson, E. (2004b) Sorting out the neural basis of consciousness. Journal of Consciousness Studies, 11(1), 87-98.

O’Regan, J. K., Myin, E. and Noe, A. Towards an analytic phenomenology: the concepts of “bodiliness”= and “grabbiness.” In A. Carsetti (Ed.) Proceedings of the International Colloquium : "Seeing and Thinking. Reflections on Kanizs= a's Studies in Visual Cognition". Univ. Tor Vergata, = Rome, June 8-9, 2001. Kl= uwer (in press).

Penfield, W. and Rassmussen, T.B. (1950) The Cerebral Cortex of Man, Princeton: Princeton University Press.

Pribram, K.H. (1971) Languages of the brain: experimental paradoxes and principles in neuropsychology. New York: Brandon House.

Pribram, K. (2004) Consciousness reassessed= . Mind and Matter, 2(1), 7-35.

Revonsuo, A. (1995) Consciousness, dreams, = and virtual realities. Philosophical Psychology, 8(1): 35= -58.

Searle, J. (1992) The Rediscovery of the Mind, Cambridge, Mass: MIT Press.

Simons, D.J. and Chabris, C. (1999) Gorillas in Our Midst: Sustained Inattentional Blindness for Dynamic Events. Perception, 28(9), 1059-1074.

Simons D.J and Levin = D.T., (1998) Failure to d= etect changes to people in a real-world interaction" Psychonomic Bulletin= and Review, 5, 644 – 649.

Velmans, M. (1990) Consciousness, brain, an= d the physical world. Philosophical Psych= ology, 3, 77-99.

Velmans, M.(1993) A Reflexive Science of consciousness. In Experimental and Theoretical Studies of Consciousness. CIBA Foundation Symposium 174. Wiley, = Chichester, pp 81-99.

Velmans, M. (1998) Goodbye to reductionism.= In S.Hameroff, A.Kaszniak & A.Scott (eds) Towards a Science of Consciousness II: The Second Tucson Discussions and Debates. M= IT Press, pp 45-52.

Velmans, M. (2000) Understanding Consciousness, London: Routledge/Psychology Press.

Velmans, M. (2001). Heterophenomenology ver= sus critical phenomenology: a dialogue with Dan Dennett. Online at http://cogprints.ecs.soton.ac.uk/archive/00001795/index.html

Velmans, M. (2003a) How Could Conscious Experiences Affect Brains? Exeter: Imprint Academic.

Velmans, M (2003b) Is the= brain in the world, or the world in the brain? Behavioral and Brain Sciences, 26(4): 427-429.

=

&nb= sp;

The dualist view

Figure 1. A dualist model of perception

(adapted from Velmans, 2000)

<= o:p>

The reductionist v= iew

Figure 2. A reductionist model of perception <= /span>

(adapted from Velmans, 2000)

<= o:p>

This supports a reductionist view of a universe entirely composed of physical material, of which conscious experiences are a tiny part (the bits of human brain identified with those experiences).

Enactive accounts of consciousness

Figure 3. A reflexive model of perception

(adapted from Velmans, 2000)

<= o:p>

P= erceptual projection

How phenomenal space relates to real space=

Why this matters

&n= bsp;

Lehar, S. (2003) Gestalt isomorph= ism and the primacy of subjective conscious experience: A gestalt bubble model.= Behavioral & Brain Sciences 26(4), 375-444.

Noe, A. and Thomson, E. (2004a)= Are there neural correlates of consciousness? Journal of Consciousness Studies 11(1), 3-28.

Noe, A. and Thomson, E. (2004b) Sorting out the neural basis of consciousness. Journal of Consciousness Studies, 11(1), 87-98.

&nb= sp;