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VIRTUALIST REPRESENTATION
ROBERT W. CLOWES
IFL, Faculdade de Ci^
encias Sociais e Humanas,
Universidade Nova de Lisboa,
1069-061 Lisboa, Portugal
robertc@sussex.ac.uk
RON CHRISLEY
Sackler Centre for Conscousness Science,
Centre for Research In Cognitive Science
and
Department of Informatics, University of Sussex,
Brighton BN1 9QJ, UK
ronc@sussex.ac.uk
This paper seeks to identify, clarify, and perhaps rehabilitate the virtual reality metaphor as
applied to the goal of understanding consciousness. Some proponents of the metaphor apply it in
a way that implies a representational view of experience of a particular, extreme form that is
indirect, internal and inactive (what we call \presentational virtualism"). In opposition to this is
an application of the metaphor that eschews representation, instead preferring to view experi-
ence as direct, external and enactive (\enactive virtualism"). This paper seeks to examine some
of the strengths and weaknesses of these virtuality-based positions in order to assist the
development of a related, but independent view of experience: virtualist representationalism.
Like presentational virtualism, this third view is representational, but like enactive virtualism, it
places action centre stage, and does not require, in accounting for the richness of visual
experience, global representational \snapshots" corresponding to the entire visual ¯eld to be
tokened at any one time.
Keywords: Presence; virtual reality; expectations; representation; enactivism; externalism;
internalism; perception; enactive perception.
1. Introduction
It is often the case that work in machine consciousness is heavily in°uenced by
currently prevailing views in cognitive science. This paper seeks to identify, clarify,
and perhaps rehabilitate such a view, one that we call virtualism. Central to this
view, or rather range of views, is the idea that experience, or even mentality in
general, is best understood in terms of the virtual reality metaphor.
1
One of the
1
For early work on this idea see Metzinger [1993] and Revonsuo [1995a,1995b].
International Journal of Machine Consciousness
Vol. 4, No. 2 (2012) 503522
#
.
cWorld Scienti¯c Publishing Company
DOI: 10.1142/S179384301240029X
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curiosities of virtualism is that its proponents sometimes come from di®erent sides of
some of the major contemporary debates on the nature of mind (e.g., internalist/
externalist, realist/anti-realist, representationalist/enactivist). For example, whereas
Noë[2004]andRevonsuo [2006] both embrace the virtual reality metaphor in their
accounts of conscious experience, Noëtakes such a view to imply an anti-repre-
sentationalist (or at least very weakly representationalist) view of mind, while
Revonsuo defends a strongly representationalist theory. This paper seeks to examine
some of the strengths and weaknesses of these positions, not as an end in itself, but as
a way of clarifying what virtualism about mind might mean, in order to assist the
development of a related, but independent view of experience: virtualist repre-
sentationalism. A further goal is to do this in a way that will make this view directly
relevant to (current and, it is hoped, future) work in machine consciousness.
2. Virtualism: For and Against Representation
2.1. The virtuality metaphor in the cognitive sciences
The ideas of virtuality and virtual reality (and the closely related notion of simu-
lation) have blazed a meteoric trajectory in recent theoretical and practical work in
the sciences of the mind. The notion of virtuality has gone in a short time from a
specialized technical concept primarily of interest to Human Computer Interaction
designers to one which has become thanks to popular culture \texts" such as The
Matrix and most recently Avatar a widely referenced cultural trope. Similarly,
within cognitive science, the notions have been given, in a very short time, broad
theoretical scope and now aspire to important explanatory roles in our scienti¯c
understanding of mind and consciousness [see Sanchez-Vives and Slater,2005].
The idea of virtuality gains de¯nition through the creation and consideration of
certain technologies that although they have notable precursors in the history of
technology such as the telescope come into focus with the creation of interactive
digital technologies. Take the idea of telepresence, for instance, which was strange
and new when described by Howard Rheingold back in 1991. In the following pas-
sage, Rheingold describes his experience of telepresence through being linked through
a VR set-up to a robot in the same room as him:
\When the apparatus was switched on,I began to look through the eyes of a
robot.The world looked like the world would look if I was located twelve
feet left of my body,where the robot was located....The strangest moment
was when Dr.Tachi told me to look to my right.There was a guy in a dark
blue suit and light blue painted shoes reclining in a dentist's chair... He
looked like me,and abstractly I understood that he was me,but I know who
me is,and me is here. He,on the other hand was there... It was an out of
the body experience." [Rheingold,1991]
At its most basic, telepresence technology projects presence as if one were
embodied or located di®erently. Technology which alters or displaces presence if not
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exactly everyday is increasingly available in the research labs, art galleries and even
o±ce environments of the world.
2
Telepresence seems to demonstrate that the spa-
tialization of the body can be displaced, stretched and topographically altered by the
use of a mediating interface. Recent experimental work has drawn attention to how
several dimensions of presence can be altered in ways that e®ectively fabricate some
key aspects of out-of-body experiences [Lenggenhager et al.,2007].
3
Perhaps more familiar today, however, are the sorts of virtuality experience where
we are projected into a simulated environment (or world). Through gaming, virtual
reality experiences have become a staple of the leisure pursuits of a sizeable minority
of adults and children throughout the developed world. There are also more \pure"
virtual reality experiences available through attempted total world simulations like
Second Life. In virtual reality proper, we feel we are present not in a translated actual
location (as in telepresence) but a non-actual one which is projected by digital media
technologies. In virtual reality (VR) proper, the space in which we feel embodied and
present is virtual in the sense that our presence is projected into a space that
only exists, or is simulated, within a computer or cloud of computer systems.
Subjects' embedding in the virtual scene through VR systems is reported to feel more
real insofar as their interface to the virtual world is high-¯delity, i.e., is vivid, and is
responsive to their actions or interactive [Steuer et al.,1995].
4
The concept of presence was largely developed in order to understand how real the
virtual environment feels to the user. The sense of presence here might be de¯ned as
the total sense to a subject of how that subject is located in her environment, how her
embodiment relates to that environment, how the environment is given to her, and
the possible modes of action that the environment makes available. Key related
concepts are the sense of spatialization, the sense of bodily con¯guration (given
perhaps by proprioception and other senses), and the sense of reality of the current
location. Typically, the notion of presence is used to theorize the degree to which a
subject feels herself to be situated in a virtual world. There is, however, no principled
reason that the concept should not be extended to think about the way the subject
feels that her body is organised and situated in the actual world.
The notion of presence is also useful in the analysis of some psychiatric condi-
tions, especially depersonalization disorder (DPD), which might be de¯ned as a
2
The Personal Robotics Group at the MIT media lab have constructed a number of advanced systems that
may populate the business and home environments of the future including the MeBot described at http://
robotic.media.mit.edu/projects/robots/mebot/overview/overview.html. Much discussion of these tech-
nologies can be found in Natural Born Cyborgs [Clark,2003]. An early thought experiment on the philo-
sophical signi¯cance of these technologies for thinking about minds can be found in Dennett's science
¯ction thought experiment Where Am I [Dennett,1978].
3
Thomas Metzinger (in personal communication) maintains that the experiments do not count as actual
out-of-body experiences because these would require not only displaced presence but the subject to see the
world from the position of this displaced presence. Out-of-body experiences and their constituents are
discussed in detail in Metzinger [2009].
4
Our experience of reality is actually, we would contend, a signi¯cantly more complex question than
indicated here, and interactivity and vividness themselves are concepts that are in need of further analysis
even in VR terms, but this goes beyond the scope of this paper.
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pathological condition in which the sense of presence becomes disturbed or atte-
nuated. An early characterization by Acker [1954] describes part of the phenomen-
ology of the disorder as \a subjective feeling of internal and/or external change,
experienced as one of strangeness or unreality".
5
In DPD, conscious experiences are
said to have an as if or, we might say,virtual character which the subject experiences
as the lack of reality of the world or themselves, or perhaps the relationship between
the world and themselves. Discussion of DPD and related psychiatric conditions has
thus helped to ¯ll out the notion of presence to the point that investigations of the
neural mechanisms underlying presence are now underway [Seth et al.,2011]. The
subjective sense of presence may then be becoming accepted as an important con-
stituent of conscious experience, as one of the structural dimensions of consciousness
[Clowes and Seth,2008] or indeed a prenoetic aspect of experience [Gallagher,2005].
Alongside the notion of presence another central idea in VR research is the notion
of an interface. In VR systems, the sense of presence is generally understood to be
conveyed by some technological means an interface. An interface in turn is
understood as technology that conveys a sense of transformed, translated or aug-
mented presence. It can be further conceptualized as an instrument or channel that
conveys information for spatialization, ¯xing of reference frames, or otherwise ¯lling-
out or giving form to a sense of presence. Typically, interfaces are thought of as
extending, displacing, translating, or otherwise altering an existing sense of spatia-
lization and embodiment.
6
The sense of presence in virtual reality research is thus not a unitary notion but
can be analyzed along a number of dimensions. In standard cases, the concept is used
to compare how a virtual reality experience compares to an actual reference case.
Virtual reality research has identi¯ed various dimensions of phenomenal experience
which can be reshaped by technological intervention. The avatar (and interface as a
whole), in that it enables the experience of (virtual) embodiment, can be a laboratory
for the description and recon¯guration of experience a kind of prosthetic arti¯cial
consciousness [Chrisley,2008]. Virtual reality reveals dimensions of experience (often
by accident) when they become disturbed through the construction of some new
projection technology.
Interfaces in standard VR can be viewed as modes of coupling with the (virtual)
environment that transform an already existing sensed-embodiment. To put this
another way, in the original context presence is assumed (perhaps as produced by
unconscious neural mechanisms) and then, through an interactive interface, presence
is \projected" into a virtual world. However, such interfaces could also be viewed as
ways of extending the substrates by and in which presence is constituted. One virtual
reality researcher [Biocca,1997] talks about progressive embodiment: the notion
of more and more dimensions of our sense of how we are present in space being
5
Originally cited in Seth et al. [2011].
6
Extremely interesting work has recently been carried out where VR set-ups have been used to exper-
imentally alter the subject's sense of an integrated spacialization of her body. It seems out-of-body
experiences of a certain order can be induced through virtual reality set-ups. See Lenggenhager et al. [2007].
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progressively stretched out into the virtual realm. The end point of progressive
embodiment would presumably be some full immersion. One (perhaps non-standard)
way of interpreting such progressive embodiment is that the superveniance base
for the establishment of presence is being stretched out beyond the agent, or
the agent's interactions with its proximal environment to include the machinery of
the VR system.
Some cognitive scientists (as we have seen) have recently begun using VR tech-
nology to examine some of the ways that the various aspects of bodily experience and
the sense of presence can be teased apart, using extensions of the rubber hand
experiment to move in the direction of whole-body, out-of-body illusions [Lenggen-
hager et al.,2007]. By opening and extending channels of information that constitute
the sense of presence, such research may not only help in understanding how the
sense of presence might be transformed but also some of the intrinsic mechanisms by
which it is established, some of the dimensions along which it might break down and
ultimately how it is constituted as such.
Reasons that we might have for considering interfaces as theoretical tools for
understanding the constitution of presence derive in part from wanting to see the way
that presence is constituted as deriving from connections with the actual world. On
this view, interfaces merely extend or replace our standard worldly couplings [Clark,
2003]. However, if we instead see interfaces as playing an essential role in the con-
stitution of presence the door is opened to another conception of virtual represen-
tations, one in which the (phenomenally experienced) world itself is taken as a sort of
brain simulation.
2.2. Presentational virtualism
Antti Revonsuo was one of the ¯rst in the philosophy of mind/cognitive neuro-
sciences to extensively discuss virtuality as a metaphor for, or model for, under-
standing consciousness more broadly as a sort of virtual projection of presence
[Revonsuo,2006]. Revonsuo's book draws on the ideas of \presence" and \full
immersion" discussed above and these, he argues, are key in conferring a sense of
what he calls being-in-the-world, a sort of intended con°ation of a technical (Hei-
deggerian) and more existential notion. Here, we outline some of the basic features of
such a position, labelling it \presentational virtualism".
The weight of Revonsuo's argument comes from considering virtual reality tech-
nologies in the context of dreaming. He points out that our biologically endowed
\virtual reality" interfaces can operate in the absence of normal environmental
coupling, i.e., in dreams. As in the case of technological VR, dream experience is best
understood, it is claimed, as the experience of a non-actual, virtual world. Revonsuo
says that in dreams we typically project bodily and worldly presence, yet the systems
projecting this presence, at least in dreams, are entirely internal to the brain; although
we might add it is a brain which is embedded in and connected to the body in multiple
ways [see Cosmelli and Thompson,2007, for further discussion of this point].
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In normal representational con¯gurations, our sense of presence might be
explained in terms of closely coupled interactions with the world beyond the body.
(Indeed we shall discuss below Noë's important work that seeks to develop just this
point). But in dreams, our sense of presence assuming we have such can only
be explained by the \projections" of the brain. In essence, Revonsuo is arguing that,
as presence can be experienced in the absence of dynamic world coupling, such
coupling cannot be necessary for (the experience of) presence. His conclusion is that
being-in-the-world, and the experience of presence even in normal con¯gurations, is
virtual.
7
2.2.1. Virtuality as indirect perception
From his review of virtual reality research and research on dreaming Revonsuo
argued for what he calls a world simulation model of consciousness. He writes:
\[I]n world simulation,the brain creates for us only virtual presence or
telepresence in the surrounding world,but we ourselves,and our con-
sciousness never in actual fact escape the con¯nes of the brain."
[Revonsuo,2006,p.109]
We term this family of positions presentational virtualism because they advocate
that not only does sensory experience involve virtual objects which may or may
not correspond to actual, non-virtual objects (representation) but their involve-
ment proceeds via the subject's awareness of them (presentation):
\In perception and dream experience,I ¯nd virtual objects that are
directly present for me." [Revonsuo,2006, p. 121]
In its unelaborated form, presentational virtualism faces several traditional pro-
blems. First, the position is internalist to an extent that appears to put us radically
out of touch with the world, in familiar ways. For those acquainted with the history
of the philosophy of perception, it is hard to resist seeing this kind of virtualism as an
old, discredited theory of perception the indirect theory in modern technological
guise. On this picture, virtualism is advocating that: (1) when we are dreaming there
is no further reality beyond the virtual, dreamed reality for our experiences to be of,
so they are of the virtual objects, properties, etc., that constitute that virtual world;
and therefore, in the same way, (2) when we are not dreaming, our experiences are
not of a further, external world to which we have no access, but are again of virtual
objects, properties, etc., that constitute a virtual world (those created by the neural
\interface", which is the same, after all as the \interface" in operation during
dreaming) that we merely take to be an actual world. (Some anti-realist variations on
this view go on to question the very coherence of this notion of an \actual" (nou-
menal) world beyond the world we experience, although this threatens to undermine
7
Clark [2004] excavates some of the ways in which dream presence is experientially con¯gured, and how
this is rather di®erent from normal sense of presence. Further analysis of dream presence might o®er some
interesting ways to disagree with Revonsuo; but we shall not pursue them here.
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the very distinction which de¯nes the position in the ¯rst place.) One problem, then,
is that the implied (or assumed) lack of access to the actual, external world invites
perennial problems of scepticism and solipsism.
Partly in response to these worries, Revonsuo has developed a more sophisticated
version of presentational virtualism. Although he still lays claim to the virtual reality
metaphor, he backs o® from the most problematic aspects of presentationalism. For
example:
\[P]erception via a representative mechanism is not as indirect as the
skeptic tries to lead us to believe,for we do not in everyday perception
distinguish between the (virtual)objects in our awareness and the (physical)
objects in the external world.The phenomenal world and its virtual objects
are wholly transparent,and in our everyday perception the nature of
the external world is certainly not somehow indirectly and e®ortfully
inferred from them." [Revonsuo,2006, p. 123]
By way of explanation of this more sophisticated presentational virtualism,
Revonsuo appeals to an analogy between internal and external representation:
\J.R.Smythies has often compared the way our brain comes to know the
world through representative mechanisms to the way we use external
representative mechanisms,such as television,to gain knowledge of
external states of a®airs in the world.When we watch a live broadcast of
a football game on color TV,we actually see the game, not a complex
arrangement of patterns of luminous phosphor on the TV screen on the
basis of which we would have to e®ortfully infer what is going on in
the game.The screen is,as a vehicle of analog pictorial representation,
perfectly transparent for our perception.The states of the screen
reveal the remote events for us.They are a perceptual window to the
world,not a veil cast between us and the real-world events.In a similar
vein,phenomenal representations in consciousness of the transparent
surrogates that constitute the world simulation in the brain reveal
the world for us rather than hide it,and by virtue of them we may say
that we have knowledge of the external world." [Revonsuo,2006,
pp. 123124]
Insofar as Revonsuo is claiming that perception puts us in direct epistemic contact
with the world, he is certainly giving up the most problematic component of pre-
sentational virtualism. But it is hard to square this sophisticated view with the
position as explicated by Revonsuo when not attempting to rebut these criticisms.
That is, how can the sophisticated view just quoted, according to which the \virtual
objects are wholly transparent" be reconciled with the direct awareness of virtual
objects asserted in the quotations just above it? The sophisticated view that avoids
the criticisms is in direct opposition to Revonsuo's own statement of \the philoso-
phical theory of perception that underlies the world-simulation metaphor", which
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includes the claim:
\...perception is realized not by any immediate or direct contact with the
external world,but indirectly via a surrogate of the external object in
consciousness,directly experienced." [p. 121]
One way of resolving this tension is to reject as uncharitable our interpretation of
Revonsuo's sophisticated presentational virtualism, and in particular of his use of the
term \transparent" when expounding that position. Elsewhere, at least, Revonsuo
does not use \transparent" in a naïve, literal way (in which transparent things are
not seen), but in a technical way that follows to some extent Metzinger's [1995,2000]
usage. On Revonsuo's usage, the transparency of a representation consists not in it
being unexperienced, but rather in it not being experienced as a representation.
Instead, representations are experienced as being the world itself (pp. 105106). On
this reading, then, transparency can be understood to be, ironically, a kind of hyper-
opacity: not only is it the case that it is representations, and not the world they
represent, that are directly phenomenally present to us; but we do not even experi-
ence these intermediaries as intermediaries.
But now the pendulum swings the other way: how can this be squared with the
sophisticated view into which Revonsuo was forced? How can it be squared with his
discussion of Smythies' analogy, in which Revonsuo says \we actually see the game,
not a complex arrangement of patterns of luminous phosphor" (emphasis shifted)?
8
Perhaps as a way of responding to this tension, Revonsuo states:
\...neither the phenomenal level as a whole nor any of its parts are
somehow ‘perceived'themselves.That is,they do not serve as objects of
perception in anything like the manner that external physical objects do.
The phenomenal level incarnates the ultimate realizer and presence of
perceptual experience,not the object of some further perceptual process or
the modulator of some further state which could still be regarded as
perceptual."[p. 129]
But this seems to undermine the central feature of the virtual reality metaphor.
To see why, it may be helpful to be more explicit about how the metaphor proceeds in
this case. In normal perception, according to Revonsuo, we perceive objects in the
external world by virtue of the \presence" to us of unperceived, virtual objects that
8
In a sense, Metzinger might have an easier time than Revonsuo in accommodating Smythies' analogy.
Metzinger conceives transparency as being \a special form of inner darkness" [Metzinger,2004, p. 331]
which means that the representational vehicle properties are unavailable to the agent itself. All that is
available in fact are the content properties. So for Metzinger, the analogy would indeed involve asserting
that we do not see \a complex arrangement of patterns of luminous phosphor" (vehicle). But for reasons we
elaborate below, this seems incorrect: seeing the patterns of phosphor is rather a requirement for seeing the
game. Furthermore, Metzinger's account here forces him to reject the other part of Smythies' analogy (at
least as conceived by Revonsuo): for Metzinger, we are not actually seeing the game itself, but rather a
phenomenal content that corresponds to the game.
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(happen?) to correspond with those external objects. The neural processes that
constitute the world-simulation containing these virtual objects are themselves
objects which, normally, are neither perceived by us nor present to us. But now it is
unclear how the VR metaphor is meant to proceed, since each way of drawing the
analogy seems to highlight more di®erences than similarities. Consider a VR con-
¯guration in which the virtual objects presented to the subject are caused by and
correspond to the actual, real objects in the subject's environment. This is meant to
be analogous to the case of normal veridical perception. In such a situation, the
mapping underlying the VR metaphor would be:
VR technology use (Source) Normal perception (Target)
Real objects (perceived) Real objects (perceived)
Virtual objects (perceived) Phenomenal objects (\present", not perceived)
Phenomenal objects by virtue of which
we perceive the above (\present", not
perceived)
??
VR headset/display (perceived) ??
Computer hardware underlying world-simu-
lation (not \present", not perceived)
Neutral hardware underlying world simulation
(not \present", not
perceived)
The key components of the sophisticated presentationalist view are crucially
disanalogous with what is going on in the use of virtual reality technology. When we
use such technology, we exercise the very same perceptual processes when we are
wearing the VR gear as when we are not. In particular, it is only by being able to
perceive the VR gear that a subject can be made aware of (and thus, presumably,
perceive) the virtual world it makes available; a subject that cannot see the headgear
and its display will not be able to see the virtual world it makes available. So the
core feature of Revonsuo's sophisticated position the distinction between being
transparently present and being the object of perception is not captured by the
metaphor.
One might question one part of the disanalogy outlined above: why say that
virtual objects are perceived in the VR technology case? Why not instead say that
they are, as in the case of normal perception, present but not perceived? The reason is
that it is only phenomenal representations (whether vehicles or contents), and not
virtual objects created in a computer program, that can be present in the appropriate
way. This presence is meant to be what is unique about consciousness. Presence is
here meant to be understood as the \self-presentation" of \intrinsically conscious"
objects. Surely the virtual objects of computer simulations in today's VR systems are
not present in this sense. Presumably, on Revonsuo's account, when we perceive
the virtual objects in a VR simulation, we do so by virtue of having phenomenal
representations of them. Of course, these phenomenal representations may very well
be present in Revonsuo's sense. But that just underlines the fact that the virtual
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objects themselves are not present. Further, to try to use these phenomenal rep-
resentations to explain the phenomenal representations present in normal perception
would be vacuously circular.
This latter problem is likely not speci¯c to Revonsuo's position, but rather a result
of a weakness in the virtual reality metaphor itself: namely, its elision of an important
di®erence between normal and VR-mediated experience. Speci¯cally, the virtualist's
application of the metaphor relies on ignoring the fact that VR technology, unlike the
human sensory system, is always used by a pre-existing, sensory-endowed subject. No
matter how \hi-¯" a VR system is, it is essential to its very identity as a VR system
that it is external to us, that it is a piece of technology which we, as pre-existing
experiencing subjects, can choose to use, and choose to stop using. VR technology
parasitizes the pre-existing, biologically endowed (in our case) sensory capacities of
an autonomous subject to create an experience of a virtual world, a world whose
virtuality is de¯ned relative to the actuality of the world made available by the pre-
existing sensory system.
9
Because of this, there can be no straightforward meta-
phorical understanding of what it is to be an experiencing subject in terms of use of
VR technology, since such use already crucially involves the presence of an experi-
encing subject. Of course, all metaphors ask us to ignore some features of the source
when creating some isomorphism with the target. But the virtualist is asking us to
simultaneously employ the VR metaphor and ignore an essential,ineliminable fea-
ture of the source (the use of VR technology by a pre-existing subject) while doing so.
For this reason the metaphor (at least in its presentational virtualist form) fails in its
attempt to portray a coherent, alternative conception of mind and experience.
Finally, it seems to us that presentational virtualism assumes what we call
occurrent representational isomorphism: for each aspect of the content of experience
at a given time, there is an occurrently tokened, causally active representation that
carries that content. A representation is a phenomenal representation, contributing to
the content of current experience, only if it is occurrent, present, currently tokened.
This position has all (or at least most) of the familiar drawbacks that O'Regan and
Noë[2001], Brooks [1991], and other researchers have identi¯ed: on this view, per-
ception becomes a representational bottleneck, one that is: (a) computationally
expensive to create, maintain and employ; (b) in many ways believed to be at odds
with neurophysiological reality; and (c) unnecessary to get the job done anyway.
Despite these problems, we remain optimistic that there is something of value to
the notion of virtualism it just needs to be teased apart from the strangling
strands of indirectness, internalism, and incoherence.
9
This is not to rule out a priori the possibility of non-biological, technological modi¯cations to our
experience that do not involve, as does VR technology, a subject using such technology. For example, this is
the kind of situation one might presume brains-in-vats to be in. But it would ispo facto not be VR
technology as we understand it now, and so could not sustain a VR-metaphorical understanding of
experience. Nor would it be of any use as a metaphor in its own right one might as well propose the
\brain/body metaphor" for understanding experience.
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2.3. Enactive virtualism
One objection to virtualism, then, is that it is really just a re-expression of the
traditional idea of representation in technologically novel clothes. If it is just a
reworking of standard representational positions then it is subject to all of the same
familiar objections. In what follows, we shall try to show this is not the case by
arguing that virtualism, understood in a way continuous with, but distinct from, the
notion as employed by the presentational virtualist, gives us an important vantage
point on understanding how the content of perception is generated and how the
relationship of our representational architecture to the environment should be
understood. In ¯lling out this case, we now turn to Alva Noë's much discussed
rethinking of representation.
2.3.1. Moderate enactive virtualism
In giving an account of perceptual content, Noëargues for a view of perception and
(indirectly) representation that might be called virtualist.
Noë's position here is best understood by looking at a couple of examples he uses
to explain his approach to perception and what he calls the problem of perceptual
presence. First: \Consider, as an example, a perceptual experience such as that you
might enjoy if you were to hold a bottle in your hands with eyes closed. You have a
sense of the presence of a whole bottle, even though you only make contact with the
bottle at a few isolated points. Can we explain how your experience in this way
outstrips what is actually given, or must we concede that your sense of the bottle as a
whole is a kind of confabulation?" [Noë,2004,p.60]
Noë's second example asks us to imagine sitting behind a picket fence and in so
doing notice that although, strictly speaking, we imagine we are seeing a whole cat,
we are (in a sense) not. Or as Noëputs it \You have a sense of the presence of a cat
even though, strictly speaking, you only see those parts of the cat that show through
the fence. How is it that we can in this way enjoy a perceptual experience as of the
whole cat?" [Noë,2004,p.60]
Noë's answer to this question, which he calls \the problem of perceptual presence"
is in terms of what he calls, appropriately enough, perceptual presence. One way of
expressing the problem is to ask: why do we experience the world as made up whole
objects when our sensory contact with those objects is at best partial?
One way of interpreting Noëis to take him to be claiming that when we perceive
an object, we are only really (occurrently) sensorially in touch with a small part
of what we perceive or see, but nevertheless the whole object is perceptually (but
virtually) present to us. This occurrent perceptual in-touchness happens when we
exercise (in action) our mastery of the patterns of sensorimotor dependence. Through
this action, we make sense of those sensations and form (actualize) perceptual con-
tent. However, this is not an interpretation of the virtualist position that Noëfavors
for he instead claims that the content of experience is \virtual all the way in". [Noë,
2004, p. 134]
Virtualist Representation 513
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He later explains, saying \We cannot factor experience into an occurrent and a
merely virtual or potential part. Experience is fractal, in this sense. At any level of
analysis, it always presents a structured ¯eld that extends outward to a periphery,
with elements that are out of view." [Noë,2004, p. 135]
But this is problematic: If we are not to factor at least the subpersonal components
of experience into occurrent and virtual or potential parts, how are we to explain
what proponents of the two factors use them to explain? Or to put it another way:
How is sensory contact actualized in such a way that perceptual experience is
generated?
This actualization process happens, in all versions of Noë's theory, through acting.
Put slightly di®erently, and in the terminology that Noëfavors, perceptual content is
given through occurrent deployment of our mastery of sensorimotor dependencies
(originally contingencies [O'Regan and Noë, 2001]); that is, very roughly, the way
that sensory information follows or frustrates our expectations that arises out of our
mastery of sensorimotor °ow. Perceptual presence on this analysis arises because of
the mastery of dependencies we acquire as we move around and interact with objects.
Perceptual presence for Noëis to be explained, like perceptual content itself, from our
mastery of the laws of sensorimotor dependence.
Perceptual content arises through this ongoing contact and is virtual in the sense
of the relevant information not being inside but accessible to the agent, its character
again deriving from the agent's mastery of sensorimotor dependencies.
10
For Noë,
perception is actional or enactive but is also in a certain sense projected. What we
experience is not what is simply given in our occurrent sensorimotor contact but what
is somehow generated in that contact. Perceptual content is generated because we are
constantly in touch with the world. However, this still leaves somewhat mysterious
how the process of composition of perceptual content actually happens.
Noë's thinking is in part motivated by his response to research into change
blindness [Simons and Rensink,2005] and inattentional blindness [Mack,2003;
Simons and Chabris,1999] and especially the theoretical response to this work that
argues that the perceptual world is a grand illusion [Blackmore,2002;O'Regan,
2002]. As O'Regan put this idea:
\Despite the poor quality of the visual apparatus,we have the subjective
impression of great richness and ‘presence'of the visual world.But this
richness and presence are actually an illusion." [O'Regan,1992, p. 484]
Here \visual world" means the world as visually experienced, or the visual
experience of the world as a world (we generalize this to all modalities of sensory
10
Despite some key similarities between Noë's approach and our own, there are several aspects of Noë's
theory that we do not fully endorse; some of these will become clear in what follows, many will not.
However this article is not really conceived as a full-blooded critique of Noë's ideas, but rather an attempt
to use his notion of virtuality as a backdrop against which to contrast our own. Developing a full, detailed
account of how the theory of virtual representation implied here di®ers from (yet endorses parts of) Noë's
account is future work.
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experience by using the term \perceptual world" in a similar way). On the Grand
Illusion view, the richness of the perceptual world is apparent rather than real, and
we are incorrect in believing that our perceptual access to the world is of the rich and
detailed type that we take it to be.
11
Noëargues that the Grand Illusion account is
misguided and hinges on a \snapshot" representationalist conception of perception
which regards us as having an experience with a certain degree of richness only if we
have occurrent elaborated internal representations which themselves have that
degree of richness (although he does not put the point in precisely those terms). He
proposes an alternative picture (that we here call enactive virtualism), claiming: \to
experience detail virtually, you don't need to have all the detail in your head. All you
need is quick and easy access to the relevant detail when you need it" [Noë,2004,
p. 50]. On Noë's account, we do not need to build a detailed internal model of the
world because the world is always there to lean upon and is considered \its own best
model" [Brooks,1990].
Noë's favored account thus presents an alternative picture where there is no
illusion. The detail is still present but virtually. Noëpartially explicates this idea in
the following way:
\We have the impression that the world is represented in full detail in
consciousness because,wherever we look,we encounter detail.All the
detail is present,but it is only present virtually, for example,in the way
that a web site's content is present on your desktop." [Noë,2004, pp.
4950]
For Noë, our perceptual systems are virtual but realizing in the sense that they
pull in content on a need-to-know basis, leaning on environmental resources that are
ever-present. Noëcites Minsky with approval to the e®ect that: \We have the sense of
actuality when every question asked of visual systems is answered so swiftly that it
seems as though those answers were already there." [Minsky,1985, p. 257]
12
How-
ever, this wording creates a problem for Noë's view, in suggesting that there is an
implicit quali¯er that has been dropped o® the end: \it seems as though those
answers were already there, even though they weren't". This has the result of giving
credence to a (quali¯ed) Grand Illusion view: experience seems to be such that the
\answers are already there", but they are not they are only virtually there. So, in
an important sense, and against Noë's claims to the contrary, according to his own
account experience is not what it seems.
2.3.2. Radical enactive virtualism
The other option for Noëwould be to retract the preceding statement, and insist on a
more radical notion of virtualism. On this view, it is the states of the world themselves
that contribute to and partly constitute the richness of experience. The fact that the
11
Or, as Noëwrites: \To propose that the presence and richness of the visual world is an illusion."
12
Cited in Noë[2004], p. 50.
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book is red, together with the ability to fetch this information, constitute having an
experience of the book being red, even if that information is not actually retrieved.
Unlike the moderate view discussed above, this radical virtualism would permit Noë
to dispel the Grand Illusion: true, there is no richly detailed representation of the
world, but this does not imply that experience is not richly detailed the rich detail
of the actual world itself (and the mere capacity to access it) explains and makes true
the way experience seems richly detailed.
One thing that is interesting here is that radical virtualism seems to play the other
way from varieties of virtualism we have previously looked at in that the virtual now
needs to be actualized in the world beyond the brain and the potential for interaction
with such. Noë's notion of virtuality can be interpreted as one where the world
beyond the brain (and body) is playing an ongoing role as part of the supervenience
basis of (virtual?) reality projection.
13
This is a fresh and bold move, to be sure, but comes at the cost of considerable
implausibility. At least in the form that we have explicated above, radical virtualism
would imply that a change in the detail of the visually accessible world before a
subject would constitute a corresponding change in visual experience even if that
detail was not visually accessed. The upshot is that radical virtualism fails to explain
and allow for such phenomena as change blindness [Rensink et al.,1997], phenomena
that were, ironically, used by Noëto critique the representationalist view.
2.4. Taking stock
We have examined two broad varieties of applying the virtual reality metaphor to
understand experience: one fervently representationalist, one just as fervently anti-
representationalist; one paradigmatically internalist, the other externalist in the
extreme. Each version encounters problems (that in at least one case recursively
fracture it into sub-varieties that themselves face problems, etc.).
Metaphors are important in scienti¯c and philosophical model building.
14
But
given the above discussion we must ask, how useful, ultimately, is the virtual reality
metaphor? It is easily misused, such as when it is suggested that we are \imprisoned
in the brain". However, we believe that the metaphor, suitably modi¯ed, provides
real purchase in understanding some of the ways in which situated agents like us
experience our presence in the world. It o®ers new possibilities for developing a
re¯ned analysis of that sense of presence and even how having sense of presence itself
might be explained in large part through agent-environment coupling. At a theor-
etical level then, can we reconstruct the virtuality metaphor such that its felicities are
preserved and some of its more paradoxical implications overcome?
13
Whether the particular story that Noëfavors here can be made to work is a controversial matter. Clark
(2009) for example argues that it cannot.
14
See Lako® and Johnson [1999].
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3. Virtual Representationalism and Expectational
Theories of Experience
We think that it is possible to o®er a new notion of virtualist representation that,
because of its distinctive character, presents interesting ways forward on a variety of
problems, but for the purpose of this article we will focus solely on the problem of
giving a coherent account of visual phenomenology. To this end, the discussion in Sec
2.3 can serve as our guide. Suppose, like the enactivist, one wishes to avoid these
tenets of presentational virtualism:
(1) Indirectness: fundamentally, the subject is not experiencing the world, but
rather is directly aware only of (representational) intermediaries.
(2) Occurrent representational isomorphism: for each aspect of the content of
experience at a given time, there is an occurrently tokened, causally active
representation that carries that content.
Why would one want to avoid these? To recap the discussion from Sec. 2.2:
.Position (1) famously leads to skepticism, and, pace Revonsuo, gets intentionality
wrong (our perceptions, thoughts, talk, concerns, etc., end up being about our
representations of the world, not the world itself ).
.Position (2) has the familiar drawback of making visual experience a represen-
tational bottleneck, one that is computationally expensive, neurophysiologically
dubious, and unnecessary.
On the other hand, suppose also that one does not want to end up where the
enactive virtualist ends up: only able to avoid the Grand Illusion at the price of an
implausible radical externalism. That is, suppose one wants to avoid both:
(1) The Grand Illusion: It seems to us as if our sensory experience is richly detailed
(our visual ¯eld is coloured to the periphery, etc.), but it is not.
(2) Radical externalism: States of the world, even those to which one does not
currently have causal access, directly constitute the content of current percep-
tual experience.
We are not claiming to have here refuted these four positions. Rather, we are
proposing that the notion of virtuality (albeit of a di®erent kind still than the var-
ieties of virtuality we have seen so far) may be used to construct a position that allows
those who wish to avoid these \pitfalls" to do so. We call this position virtual
representationalism.
Virtual representationalism is more easily explicated in the context of a partic-
ular instance of it, the expectational theory of experiential content [Chrisley and
Parthemore,2007]. At the heart of the expectational theory is the notion of a (sub-
personal) expectation. These take the form of answers to questions of the form: \If I
were to move this way, what input would I receive?" Such answers are intrinsically
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tied to the actions referred to in their characteristic question, and are contentful in
that they can be true or false. According to the expectational theory, the content of (a
non-conceptual subset of) a subject's sensory experience is identical to the sum of
these expectations, spatially structured by the actions that characterize them. Fur-
ther, a distinction can be made between expectations that are active (explicitly
tokened, as in: \I am engaging in this action, so this is what I expect to happen next")
and those that are merely dispositional or counterfactual (involving actions that are
not currently being taken).
One way of visualizing (and implementing) such a set of sub-personal expectations
is by way of a feed-forward arti¯cial neural network that instantiates a forward
model, a mapping from the current state and a given action to (predicted/expected)
input that results from that action [see, e.g., Chrisley,1990]. Each of these (state,
action, and predicted input) are represented as occurrent activity patterns across a
set of units in the network. The mapping as a whole is realized in a set of connection
weights between these and other, \hidden", units. At any given time, one state
representation and one action representation are active, activating one predicted
input representation. In models of visual experience based on this theory (sketched in
Chrisley and Parthemore [2007]), the occurrent predicted input would be a small,
fovea-like subset of the entire visual ¯eld.
A striking feature, then, of the expectational theory is that it places virtuality
center stage. According to the theory, the content of (visual, say) experience (or some
subset of it) is determined not by the content of actual, occurent representations, but
by the contents of non-actual, counterfactual, virtual representations all those
representations of predicted inputs arrayed spatially
15
according to the spatial
relations of the actions (look up and to the left, look up and slightly less to the left,
etc.) that would cause the tokening of those representations of predicted inputs were
those action representations to actually be input to the network/forward model.
These representations are virtual, but they are not presentationally virtual, in
the sense of Sec. 2.2. Most obviously, \occurrent representational isomorphism" is
explicitly rejected. But so also is indirectness. Although the subject's experience is
characterized in terms of these representations, there is no suggestion here that the
subject's experience is of or about them, or that the subject is even aware of these
representations at all. The representations are about the world, as are the experiences
they characterize.
15
Talk of the contents being \arrayed spatially" should not be understood literally on this view, there
are no \pictures in the brain" (nor anyone to look at them even if there were). As stated in Chrisley and
Parthemore [2007], \Talk of a sensation Sbeing spatially located at Lis metaphorical shorthand; what is
thereby referred to is a content C an abstract object with no location that presents the world as
being S-like at L." (p. 51). On the other hand, it may be very useful, when trying to grasp or communicate a
particular spatially structured visual content, for a theorist to depict it by creating a conventional, publicly
observable image (static, or dynamic such as those in VR systems) whose spatial arrangement of visual
features is isomorphic with the (abstract) spatial structure of that content. This is a key notion of (at least
one sort of ) synthetic phenomenology [Chrisley,2009;Gamez,2008].
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Although enactive virtualism also rejects presentational virtualism, virtual
representationalism does so in a way which avoids the enactivist's dilemma of
choosing between the Grand Illusion and a mysterious, even occult, conception of
experience tracking the (unseen, occluded, distal) world by incorporating it into the
experience itself. By making experience not directly dependent on what is actually out
there, but rather on what one (sub-personally) expects to be out there, virtual
representationalism opens up the right sort of gap between the way the world seems to
us, and the way it actually is. Change the external world in such a way that the visual
system receives no information concerning the change, and virtual representational-
ism gives the right result: no change in experience (because no change, ceteris paribus,
in expectations). So the implausibility of radical enactive virtualism is avoided. But
the Grand Illusion view is also avoided, which was the reason for bringing in radical
enactivist virtualism in the ¯rst place. Even though our visual systems are, for
example, only receiving color information about a small, foveal subset of the visual
¯eld at any given time, this does not imply that the way visual experience seems
(colored to the periphery) is incorrect. It would imply that, perhaps, if we assumed
that the content of visual experience at a given time is determined by the information
our visual systems are receiving at that time. But virtual representationalism denies
this. The content of visual experience is determined by the content of (the virtual
representations that constitute) sub-personal expectations; these are not the product
of current input, but are rather the joint upshot of: (1) an interleaved history of action
and resulting input; and (2) endogenous dynamical processes that modify, extend,
and \¯ll-in" these sets of expectations. So it is open to the virtual representationalist
to deny the Grand Illusion by con¯rming that visual experience is as it seems
colored to the periphery because a color-sighted subject (or rather, the sub-per-
sonal visual system which partly constitutes such a subject) possesses a spatially
structured set of expectations about what color information would be received were
they to ¯x their gaze on parts of the world at which they are not currently gazing.
There are other notable di®erences between virtual representationalism in general
(and the expectational theory in particular), and Noë's enactive virtualism.
.According to the expectational theory, not only do (representational) expectations
concerning sensorimotor dependencies, rather than the dependencies themselves,
most proximally determine experiential content; it is also that these expectations
are sub-personal. For Noë, by contrast, the relevant knowledge is conceptual, and
therefore presumably personal.
.The expectational theory does not require mastery for experience: it is possible for
an expectational model to assert, contra Noë, that a set of expectations may be
radically wrong and yet still ¯x the content of experience (although it is also
possible to construct an expectational model that denies this and agrees with Noë).
.The expectational theory does not in any sense require the exercise of knowledge or
expectations in order for them to play a role in determining the content of
experience (indeed, this can be seen as the de¯ning feature of the theory). A
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fortiori, it does not metaphysically require action for occurrent experience (even if
action is a practical requirement for the acquisition of the sensorimotor expec-
tations which determine the content of experience).
.Expectational models can be constructed that align with Noë's notion of virtuality
\all the way in", in that the content of the entire visual ¯eld, even the currently
foveated region, is determined not by the current input, but by the current
expectations of what input would be received were the agent to move in such a way
that its gaze were ¯xed on that location. However, one can also construct expec-
tational models that pull back from this, allowing current input, rather than
expectations, to play a dominant role in determining the content of the foveal
portion of the visual ¯eld, while at the same time employing expectations to
determine the content of the parafoveal region in the manner described above.
4. The Strengths of Virtualist Representation
To summarize, we have explored three positions that might fairly be called virtualist
in some sense. One, presentational virtualism holds that that the content of our
experiences is virtual and perception is, in an important sense, similar to hallucina-
tion because it is ultimately internal perceptual vehicles that we perceive rather than
the external worldly objects they represent. In contrast, enactive representationalism
sees us as being in deep contact with the world, but at the \price" of conceiving of our
representational systems as partly composed by the world. We have seen that the
former trades on di±culties with the metaphor of virtuality itself while the latter
tends to commit us to problematic views: either the Grand Illusion or the idea that
external world contributes to perceptual content independently of our sensory con-
tact with it. We have sketched a third view which, we believe, avoids the weaknesses
of the other two views.
Acknowledgments
Robert Clowes would like to gratefully acknowledge a Portuguese Science Foun-
dation Grant/BPD/70440/2010 that supported the writing of this paper.
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