One page commentary over the reading attached. The commentary should include some concepts and write whether you agree or disagree, pick a side if you will. An example of a past commentary has been posted and so has the reading.
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Dennett begins by sharing with us an anecdote that seems too good to be true, lions
planning an attack? This was a great first example version of No florid representation without
metarepresentation.(Dennett,pg.12). Florid representations seem to be very common in
everyday life as someone might interpret an ordinary unintelligent thing to have a thought, plan,
or strategy. This was difficult for me to comprehend along with metarepresentation, however an
example I found about drawing something on paper and the person who drew whatever image, is
experiencing a mental metarepresentation. This would be so because whatever is on the paper is
only a representation of what this person is trying to depict. I agree with the idea these
representations stand for, never having heard about these perplexing concepts, I find them
fascinating. They seem to run in circles meaning something can be florid then become
metarepresentational but then it can circle back to only being a florid representation.
This leads to thinking about thinking, meaning small versions of florid representations by
planning ahead with mental representations. Using symbols at first my be a sort of practice for
thinking about thinking and after that no symbols are needed for it all can me a mental
metarepresentation of any scheme, idea, or proposal. All this lead me to think even more about
how we instill this in our minds. For example religion, it is said that one must believe without
seeing but is it really possible to believe without having some sort of mental representation of the
idea of what is God or a God? Let’s say if as a child I was raised to believe in God but never
shown an image of God or ever been told what he looks, could I have imagined God to be a
dragon or a dinosaur? It would have been impossible for me to have thought of God as
something without an image because at such a young age you still need to practice florid
representation then transition it to metarepresentation then later on in this case, it would lead to
some sort of intangible representation.
The author stated minds are composed of tools for thinking(Dennett,pg.21) but is it
possible that we need more than just that, more than just a few pointers on how to use our minds
to their best thinking abilities? What and who is to say that these tools are law and how we use
them is the only way to use them, they are not facts nor ideas just simply objects used by us to
make sense of things. They may not be classified as law but I feel they are necessities in order to
contain ourselves and get rid of useless mind clutter.
BEHAVIORAL AND BRAIN SCIENCES (2001) 24, 9391031
Printed in the United States of America
A sensorimotor account of vision and
J. Kevin ORegan
Laboratoire de Psychologie Expérimentale, Centre National de Recherche
Scientifique, Université René Descartes, 92774 Boulogne Billancourt, France
Department of Philosophy, University of California at Santa Cruz,
Santa Cruz, CA 95064
Abstract: Many current neurophysiological, psychophysical, and psychological approaches to vision rest on the idea that when we see,
the brain produces an internal representation of the world. The activation of this internal representation is assumed to give rise to the
experience of seeing. The problem with this kind of approach is that it leaves unexplained how the existence of such a detailed internal
representation might produce visual consciousness. An alternative proposal is made here. We propose that seeing is a way of acting. It
is a particular way of exploring the environment. Activity in internal representations does not generate the experience of seeing. The outside world serves as its own, external, representation. The experience of seeing occurs when the organism masters what we call the governing laws of sensorimotor contingency. The advantage of this approach is that it provides a natural and principled way of accounting
for visual consciousness, and for the differences in the perceived quality of sensory experience in the different sensory modalities. Several lines of empirical evidence are brought forward in support of the theory, in particular: evidence from experiments in sensorimotor
adaptation, visual filling in, visual stability despite eye movements, change blindness, sensory substitution, and color perception.
Keywords: action; change blindness; consciousness; experience; perception; qualia; sensation; sensorimotor
1.1. The puzzle of visual experience
What is visual experience and where does it occur?
It is generally thought that somewhere in the brain an internal representation of the outside world must be set up
which, when it is activated, gives us the experience that we
all share of the rich, three-dimensional, colorful world. Cortical maps those cortical areas where visual information
seems to be retinotopically organized might appear to be
good candidates for the locus of perception.
Cortical maps undoubtedly exist, and they contain information about the visual world. But the presence of these
maps and the retinotopic nature of their organization cannot in itself explain the metric quality of visual phenomenology. Nor can it explain why activation of cortical maps
should produce visual experience. Something extra would
appear to be needed in order to make excitation in cortical
maps provide, in addition, the subjective impression of seeing.
A number of proposals have come forth in recent years
to suggest how this might come about. For example, it has
been suggested, from work with blindsight patients, that
consciousness in vision may derive from a commentary
system situated somewhere in the fronto-limbic complex
(taken to include the prefrontal cortex, insula and claustrum; cf. Weiskrantz 1997, p. 226). Crick and Koch (1990),
© 2001 Cambridge University Press
Kevin ORegan moved to Paris in 1975 after studying
theoretical physics in England, to work in experimental
psychology at the Centre National de Recherche Scientifique. After his Ph.D. on eye movements in reading he
showed the existence of an optimal position for the eye
to fixate in words. His interest in the problem of the perceived stability of the visual world led him to question
established notions of the nature of visual perception,
and to recently discover, with collaborators, the phenomenon of change blindness. His current work involves exploring the empirical consequences of the new
approach to vision.
Alva Noë is a philosopher at the University of California, Santa Cruz. He received a Ph.D. in philosophy from
Harvard University and a B. Phil. from Oxford University, and he has been a Research Associate of the Center for Cognitive Studies at Tufts University. He has
published articles on topics in the philosophy of perception, philosophy of mind, and other areas, including
a previous Behavioral and Brain Sciences target article
on perceptual completion. He is currently at work on a
book on the relation between perception and action,
and he is a co-editor of Vision and Mind: Selected Readings in the Philosophy of Perception (MIT Press, forthcoming).
ORegan & Noë: A sensorimotor account of vision and visual consciousness
Llinas and Ribary (1993), Singer (1993), and Singer and
Gray (1995) suggest that consciousness might be correlated
with particular states of the brain involving coherent oscillations in the 4070 Hz range, which would serve to bind
together the percepts pertaining to a particular conscious
moment.1 Penrose (1994) and Hameroff (1994) suggest
that the locus of consciousness might be a quantum process
in neurons microtubules. Edelman (1989) holds that reentrant signaling between cortical maps might give rise to
consciousness. A variety of other possibilities that might
constitute the neural correlate of consciousness has been
compiled by Chalmers (1996b).
A problem with proposals of this kind is that they do little to elucidate the mystery of visual consciousness (as
pointed out by, for example, Chalmers 1996b). For even if
one particular mechanism for example, coherent oscillations in a particular brain area were proven to correlate
perfectly with behavioral measures of consciousness, the
problem of consciousness would simply be pushed back
into a deeper hiding place: the question would now become, why and how should coherent oscillations ever generate consciousness? After all, coherent oscillations are observed in many other branches of science, where they do
not generate consciousness. And even if consciousness is assumed to arise from some new, previously unknown mechanism, such as quantum-gravity processes in tubules, the
puzzle still remains as to what exactly it is about tubules that
allows them to generate consciousness, when other physical mechanisms do not.
1.2. What are sensory modalities?
In addition to the problem of the origin of experience discussed in the preceding paragraphs, there is the problem of
differences in the felt quality of visual experience. Why is
the experience of red more like the experience of pink than
it is like that of black? And, more generally, why is seeing
red very different from hearing a sound or smelling a smell?
It is tempting to think that seeing red is like seeing pink
because the neural stimulation going on when we see something red is similar to that underlying our perception of pink:
almost the same ratios of long, medium and short wavelength photoreceptors will be stimulated by red and pink.
But note that though this seems reasonable, it does not suffice: there is no a priori reason why similar neural processes
should generate similar percepts.2 If neural activity is just
an arbitrary code, then an explanation is needed for the particular sensory experience that will be associated with each
element of the code. Why, for example, should more intense neural activity provoke more intense experiences?
And what exactly is the mapping function: is it linear, logarithmic, or a power function? And why is it one of these
rather than another? Even these questions leave open the
more fundamental question of how a neural code could
ever give rise to experience at all.
Not very much scientific investigation has addressed this
kind of question. Most scientists seem satisfied with some
variant of Müllers (1838) classic concept of specific nerve
energy. Müllers idea, in its modern form,3 amounts to the
claim that what determines the particularly visual aspect of
visual sensations is the fact that these sensations are transmitted by specific nerve pathways (namely, those originating in the retina and not in the cochlea) that project to particular cerebral regions (essentially, cortical area V1). It is
BEHAVIORAL AND BRAIN SCIENCES (2001) 24:5
certainly true that retinal influx comes together in relatively
circumscribed areas of the brain, and that this may provide
an architectural advantage in the neural implementation of
the calculations necessary to generate visual-type sensations. But what is it about these pathways that generates the
different sensations? Surely the choice of a particular subset of neurons or particular cortical regions cannot, in itself,
explain why we attribute visual rather than auditory qualities to this influx. We could suppose that the neurons
involved are of a different kind, with, say, different neurotransmitters, but then why and how do different neurotransmitters give rise to different experiences? We could
say that the type of calculation done in the different cortical areas is different, but then we must ask, how could calculations ever give rise to experience? The hard work is left
undone. Much still needs to be explained.
1.3. An alternative approach: The sensorimotor
The present paper seeks to overcome the difficulties described above by adopting a different approach to the problem of visual experience. Instead of assuming that vision
consists in the creation of an internal representation of the
outside world whose activation somehow generates visual
experience, we propose to treat vision as an exploratory activity. We then examine what this activity actually consists
in. The central idea of our new approach is that vision is a
mode of exploration of the world that is mediated by knowledge of what we call sensorimotor contingencies. We show
that problems about the nature of visual consciousness, the
qualitative character of visual experience, and the difference between vision and other sensory modalities, can now,
from the new standpoint, all be approached in a natural
way, without appealing to mysterious or arcane explanatory
2. The structure of vision
As stated above, we propose that vision is a mode of exploration of the world that is mediated by knowledge, on the
part of the perceiver, of what we call sensorimotor contingencies. We now explore this claim in detail.
2.1. Sensorimotor contingencies induced
by the visual apparatus
Imagine a team of engineers operating a remote-controlled
underwater vessel exploring the remains of the Titanic, and
imagine a villainous aquatic monster that has interfered
with the control cable by mixing up the connections to and
from the underwater cameras, sonar equipment, robot arms,
actuators, and sensors. What appears on the many screens,
lights, and dials, no longer makes any sense, and the actuators no longer have their usual functions. What can the engineers do to save the situation? By observing the structure
of the changes on the control panel that occur when they
press various buttons and levers, the engineers should be
able to deduce which buttons control which kind of motion
of the vehicle, and which lights correspond to information
deriving from the sensors mounted outside the vessel,
which indicators correspond to sensors on the vessels tentacles, and so on.
ORegan & Noë: A sensorimotor account of vision and visual consciousness
There is an analogy to be drawn between this example
and the situation faced by the brain. From the point of view
of the brain, there is nothing that in itself differentiates nervous influx coming from retinal, haptic, proprioceptive, olfactory, and other senses, and there is nothing to discriminate motor neurons that are connected to extraocular
muscles, skeletal muscles, or any other structures. Even if
the size, the shape, the firing patterns, or the places where
the neurons are localized in the cortex differ, this does not
in itself confer them with any particular visual, olfactory,
motor or other perceptual quality.
On the other hand, what does differentiate vision from,
say, audition or touch, is the structure of the rules governing the sensory changes produced by various motor actions,
that is, what we call the sensorimotor contingencies governing visual exploration. Because the sensorimotor contingencies within different sensory domains (vision, audition,
smell, etc.) are subject to different (in)variance properties,
the structure of the rules that govern perception in these
different modalities will be different in each modality.
A first law distinguishing visual percepts from perception
in other modalities is the fact that when the eyes rotate, the
sensory stimulation on the retina shifts and distorts in a very
particular way, determined by the size of the eye movement, the spherical shape of the retina, and the nature of
the ocular optics. In particular, as the eye moves, contours
shift and the curvature of lines changes. For example, as
shown in Figure 1, if you are looking at the midpoint of a
horizontal line, the line will trace out a great arc on the inside of your eyeball. If you now switch your fixation point
upwards, the curvature of the line will change; represented
on a flattened-out retina, the line would now be curved. In
general, straight lines on the retina distort dramatically
as the eyes move, somewhat like an image in a distorting
Similarly, because of the difference in sampling density
of the retinal photoreceptors in central and in peripheral vision, the distribution of information sensed by the retina
changes drastically, but in a lawful way, as the eye moves.
When the line is looked at directly, the cortical representation of the straight line is fat in the middle and tapers off to
the ends. But when the eye moves off the line, the cortical representation peters out into a meager, banana-like
shape, and the information about color is radically undersampled, as shown in the bottom right hand panel of Figure 1. Another law that characterizes the sensorimotor contingencies that are particular to visual percepts is the fact
that the flow pattern on the retina is an expanding flow
when the body moves forwards, and contracting when the
body moves backwards. Visual percepts also share the fact
that when the eyes close during blinks, the stimulation
changes drastically, becoming uniform (i.e., the retinal image goes blank).
In contrast to all these typically visual sensorimotor contingencies, auditory sensorimotor contingencies have a different structure They are not, for example, affected by eye
movements or blinks. They are affected in special ways by
head movements: rotations of the head generally change
the temporal asynchrony between left and right ears. Movement of the head in the direction of the sound source
mainly affects the amplitude but not the frequency of the
We therefore suggest that a crucial fact about vision is
that visual exploration obeys certain laws of sensorimotor
Figure 1. Top: The eye fixates the middle of a straight line and
then moves to a point above the line. The retinal stimulation
moves from a great arc on the equator of the eye to a different,
smaller great arc. Bottom left: Flattened out retina showing great
arc corresponding to equator (straight line) and off-equator great
arc (curved line). Triangles symbolize color-sensitive cone photoreceptors, discs represent rod photoreceptors. Size of photoreceptors increases with eccentricity from the center of the retina.
Bottom right: Cortical activation corresponding to stimulation by
the two lines, showing how activation corresponding to a directly
fixated straight line (large central oblong packet tapering off towards its ends) distorts into a thinner, banana shaped region, sampled mainly by rods, when the eye moves upwards. As explained
in Section 2.2, if the eye moves along the straight line instead of
upwards, there would be virtually no change at all in the cortical
representation. This would be true even if the cortical representation were completely scrambled. This is the idea underlying the
theory that shape in the world can be sensed by the laws obeyed
by sensorimotor contingencies.
contingency. These laws are determined by the fact that the
exploration is being done by the visual apparatus.
In summary: the sensorimotor contingencies discussed
in this section are related to the visual apparatus and to the
way three-dimensional objects present themselves to the
visual apparatus. These sensorimotor contingencies are distinctive of the visual sense modality, and differ from the
sensorimotor contingencies associated with other senses.
2.2. Sensorimotor contingencies determined
by visual attributes
Real objects have properties such as size, shape, texture,
and color, and they can be positioned in the three-dimensional world at different distances and angles with respect
to an observer. Visual exploration provides ways of sampling
BEHAVIORAL AND BRAIN SCIENCES (2001) 24:5
ORegan & Noë: A sensorimotor account of vision and visual consciousness
these properties which differs from sampling via other
senses. What characterizes the visual mode of sampling object properties are such facts as that …
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