CONFERENCE ABSTRACTS

On this page you will find a pure text listing of all the presentations to be delivered at ASSC4. They are listed in the order of their code, starting with the plenary lectures.

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PL-01
"Consciousness, attention and binding"
Anne Treisman

Contact:
Anne Treisman

Princeton University
Department of Psychology
Princeton, NJ 08544-1010
U.S.A.

treisman@princeton.edu

The talk will discuss the relations between binding, attention and consciousness. 
Evidence that attention is required in order to bind features to form integrated 
objects includes the occurrence of illusory conjunctions when attention is 
overloaded or diverted, the binding deficit and the simultanagnosia that 
accompany bilateral parietal damage, the need for focused attention in search for 
unknown conjunctions, and the loss of local statistics on binding when attention 
is globally spread. Behavioral and fMRI studies of visual working memory suggest 
that new mechanisms are recruited when feature bindings must be explicitly 
remembered. According to feature integration theory, temporary "object files" 
are required to individuate and bind particular sets of features through their 
spatial locations. These form the visual substrate of what we consciously 
experience. 
On the other hand there are indications that some implicit 
binding may be registered in the absence of any explicit awareness. Normal 
participants may show priming and learning of long-term conjunctions in 
automatization of visual search and in negative priming; recent studies of a 
Balints patient have shown interference from spatial information about which he 
is at chance in voluntary reports. One very speculative possibility is that 
attention carves out for conscious experience the correct subset of conjunctions 
amid the mass of potential combinations of the features present in the scene, but 
that the latter may indirectly affect either concurrent performance or future 
responses through lingering memory traces, as well as generating occasional 
conscious experiences of illusory bindings. Synchronized firing offers one 
possible neural account of both object files and the implicit priming and 
interference observed when attention is diverted.





PL-02
"Oscillatory synchrony as a signature for the unity of visual experience
in humans."
Catherine Tallon-Baudry

Contact:
Catherine Tallon-Baudry

Mental Processes and Brain Activation Unit
INSERM Unite 280
151 Cours Albert Thomas
69003 Lyon
FRANCE

tallon-baudry@lyon151.inserm.fr

As documented by many imaging studies, the perception of any visual
object involves the activation of distinct, functionally specialized
areas. How does a coherent percept emerge from this distributed network?
We have examined the hypothesis that the neural representation of an
object results from the oscillatory synchronization of the areas
involved in its processing. We have now evidence in the human scalp EEG
for the existence of induced oscillatory activities (e.g., with no fixed
latency relationship with stimulus onset) in the beta (15-20Hz) and
gamma (20-80 Hz) ranges, in different tasks involving the activation of
an object representation. We have studied 1) a feature binding task
(integration of attributes into a coherent object, perceived as a whole)
2) an hidden-object detection task (the subject had to activate the
internal representation of the object searched for in order to pick it
out from the picture) 3) a delayed-matching-to-sample task, in which the
subject had to hold the sample representation active in short-term
memory. In all these experiments, significant enhancements of induced
oscillatory activity were observed, compared to a control stimulus or
condition. In addition, the topography of the oscillations depended on
the experiment, suggesting that they indeed reflected the
synchronization of the areas specifically activated by the task.
The scalp-recorded oscillations are supposed to result from oscillatory
synchronization at a large scale, encompassing several functional areas.
Evidence favoring this hypothesis have been obtained in intra-cranial
recordings in an epileptic patient: in a delayed-matching-to-sample
task, different patterns of within- and between areas synchrony emerged
during stimulus perception, and during its rehearsal in visual
short-term memory. These patterns, involving the lateral occipital
sulcus and the fusiform gyrus, were strongly influenced by the
experimental conditions. It will be examined whether the degree of
synchrony between areas could be a likely correlate of the level of
awareness reached by the object.





PL-03
"Temporal binding and the neural correlates of consciousness"
Andreas K. Engel

Contact:
Andreas K. Engel

Max-Planck-Institut fuer Hirnforschung
60528 Frankfurt
GERMANY

engel@mpih-frankfurt.mpg.de

Theories of binding, previously discussed with respect to perceptual
integration, have recently advanced into the focus of the consciousness
debate. A large body of neuropsychological and physiological evidence
suggests that consciousness - in all of its various forms - has to be
understood as a function of numerous interacting systems. Therefore, one
of the key ingredients of any consciousness theory must be an account of
how multiple component processes can be integrated and how large-scale
coherence can emerge within distributed neural activity patterns.
Furthermore, such a theory must specify mechanisms for the dynamic
selection of subsets of neuronal responses, since only a fraction of all
available information gains access to consciousness. I suggest that both
requirements, cross-systems coherence and dynamic response selection,
can be met by one and the same binding mechanism based on the
synchronization of neuronal discharges. Recent evidence from animal
studies supports this hypothesis, demonstrating that neuronal synchrony
is related to perceptual integration, buildup of coherent
representations, attentional selection, and awareness. These data
suggest that synchronization, particularly if accompanied by fast
oscillations in the gamma-frequency band, may be one of the necessary
conditions for the emergence of conscious mental states.





PL-04
"Neural synchrony and Consciousness: Are we getting somewhere?"
Francisco Varela

Contact:
Francisco Varela

LENA - Neurosciences Cognitives et Imagerie Cérébrale
Hôpital de la Salpètriere
47 Blvd. de l'Hôpital
75651 Paris  cedex 13
FRANCE

fv@ccr.jussieu.fr

The basic idea I will pursue in this presentation is that a cognitive
'self' can be conceived as a transient, dynamical signature of a largely
distributed array of a multiplicity of brain regions and functions.
Phase-locking synchrony appears as the best indicator of such complex
process so far. I will present further support for this view with
results obtained from awake human with multiple implanted electrodes
studied over long periods of time, during the realization of complex
cognitive tasks, and the transition to unconsciousness induced by
anesthesia. The next question is whether such an integrated cognitive
'self ' can, in turn, be relate to consciousness in its strict first
person or phenomenological sense. I will argue this view concerning the
unity of a cognitive subject does better than traditional neural
correlates of consciousness (NCCs) which searches for specific brain
regions or neuronal traits. This is because a constantly re-emerging,
unified cognitive subject provides a natural connection to directly
incorporate first-person data as suggested by the neuro-phenomenological
research project. I will conclude with recent results that encourage
this line of inquiry.





PL-05
"Consciousness Integrated and Differentiated"
Giulio Tononi

Contact:
Giulio Tononi

The Neurosciences Institute
10640 John Jay Hopkins Drive
San Diego, California 92121
U.S.A.

tononi@nsi.edu

A useful way of identifying the neural basis of consciousness is to
consider the kinds of neural processes that could account for its most
fundamental properties. Two fundamental properties of consciousness are
integration or unity, and differentiation or complexity. Integration is
evident in that each conscious state is experienced as a whole and
cannot be subdivided into independent components. Differentiation is
evidenced by our ability to access, in a fraction of a second, any one
out of countless numbers of conscious states. To understand these
properties of consciousness and their neural substrates, a novel theory
is developed that accounts at the same time for the integration and the
differentiation of conscious experience. According to this theory,
encapsulated in the dynamic core hypothesis, consciousness does not
arise as a property of brain cells as such, but rather as a consequence
of dynamic interactions of a continually changing functional cluster of
nerve cells in the thalamus and cerebral cortex. The formulation of this
theory has required the development of new theoretical concepts and
measures, such as those for functional clustering and complexity, and
the construction of large-scale computer models of brain function. A
series of experiments using modern methods of magnetoencephalography has
shown that neural correlates of conscious experience are consistent with
the notion of a dynamic core and involve distributed brain areas which
are different in different individuals.





PL-06
"How the Hippocampus and Prefrontal Cortex can Contribute to the Unity
of Consciousness: A Computational Perspective."
Randall C. O'Reilly

Contact:
Randall C. O'Reilly

Department of Psychology
Muenzinger D251C Campus Box 345
University of Colorado
Boulder, CO 80309-0345
U.S.A.

oreilly@grey.colorado.edu

Using computational neural network models, my colleagues and I have
developed a theoretical framework for understanding the unique
contributions of the hippocampus and prefrontal cortex to learning and
memory. This framework has a number of implications for understanding
the neural basis of the unity of conscious experience. Specifically, we
think the hippocampus contributes to memory by rapidly and automatically
binding together disparate cortical representations into a unitary
representation — this unitary representation can then be recalled
by partial retrieval cues at a later time. Thus, it is the hippocampus
that confers a sense of unity to a particular experience (i.e., an
episodic memory) — otherwise, these experiences would remain just a
jumble of unconnected features and facts (e.g., location, people
present, events that occurred, smells present). However, this
hippocampal contribution is  only evident in retrospective conscious
experience — our memories depend on hippocampal binding, but the
unity of the present does not.
We think the prefrontal cortex is specialized for the ability to rapidly
update and robustly maintain information in an active state (i.e., as
patterns of neural firing). Computationally, this enables a form of
activation-based processing that can be contrasted with the weight-based
processing that the posterior cortex is more suited to perform.
Prefrontally-mediated activation-based processing has two significant
characteristics from a consciousness perspective: (a)
actively-maintained representations provide a strong, dynamic influence
on processing elsewhere in the system, leading to increased unity and
coherence of processing; (b) the contents of activation-based processing
are cognitively (consciously) accessible, whereas the knowledge
underlying weight-based processing is embedded in the weights and is
thus not accessible.
Computational models that motivate and illustrate these ideas will be
presented, and broader role of computational modeling in the study of
consciousness will be discussed.





PL-07
"Consciousness really explained?"
Rodney Cotterill

Contact:
Rodney Cotterill

Department of Physics
Technical University of Denmark
Building 307-309
DK-2800 Lyngby
DENMARK

firodcot@gbar.dtu.dk

While this lecture is being given, the majority of the audience will be
sitting quite motionless, at any instant. Yet everyone will be
consciously attending to the speaker's words. Taken together, these
facts seem to undermine the idea that consciousness is necessarily
related to muscular movement. It will be argued nevertheless that
consciousness does not develop exclusively in the cerebrum's
sensory-processing areas (in conjunction with the thalamus), prior to
signals possibly being dispatched to the motor-planning areas, as
appears to be suggested by Crick and Koch (1995). Instead, it will be
maintained that consciousness can prevail only if those motor-planning
areas have already been activated. The presentation, which is also in
sharp conflict with the multiple-microconsciousnesses idea of Zeki and
Bartels (1999), will bolster the argument for its alternative mechanism
by showing how this could have evolved from a basic design strategy
present even in primitive organisms. And it will review supporting
evidence from psychophysics and from mammalian physiology. By
postulating that consciousness is inextricably tied to (possibly covert)
self-paced probing of the environment, the overt version of which
emerged as a behavioural trait four billion years ago, one can make
mammalian neuroanatomy amenable to dramatically simple rationalisation,
the roles of the cerebrum, thalamus, basal ganglia, cerebellum and
hippocampus all becoming readily understandable. This alternative model
even gives a strong hint as to the neural underpinnings of intelligence.
Above all, the theory produces an attractively transparent explanation
of the unity of conscious experience (Cotterill, 1998). 
Cotterill, R.M.J. (1998). Enchanted Looms - Conscious Networks in Brains
and Computers (Cambridge: Cambridge University Press). ISBN:
0-521-62435-5
Crick, F. & Koch, C. (1995). Are we aware of neural activity in
primary visual cortex? Nature, 375, 121-123.
Zeki, S. & Bartels, A. (1999). Toward a theory of visual
consciousness. Consciousness and Cognition, 8, 225-259.






PL-08
"Fractionating the binding process"
Glyn W. Humphreys

Contact:
Glyn W. Humphreys

The School of Psychology
University of Birmingham
Edgbaston
Birmingham B15 2TT
U.K.

G.W.HUMPHREYS@Bham.ac.uk

I will present evidence from patients with visual agnosia and
simultanagnosia that suggests that the binding process in vision can be
fractionated into several isolatable processes. First I show that early
processes involved in computing edge collinearity can be preserved in
agnosia, though there can then be poor assignment of edges to shape.
Thus a first stage of binding local elements into edges can be separated
from a process of shape integration. Subsequently I show that binding by
shape can fractionate from the binding of shape to surface detail, in a
simultanagnosic patient. I suggest that shape binding can operate in the
ventral visual system, whilst binding of shape and surface detail
requires linkage through the dorsal visual stream, perhaps modulated by
spatial attention.





PL-09
"Overt and covert face recognition"
Andrew W. Young

Contact:
Andrew W. Young

Departement of Psychology
University of York
Heslington
York
YO10 5DD
U.K.

a.young@psych.york.ac.uk

One of the most intriguing revelations from research into the ways we
perceive the world and access stored information about it is the
finding, repeated across a number of areas, that, in addition to that
which is consciously processed, information is picked up, stored and
retrieved in ways that are variously described as implicit, covert or
unconscious.
This phenomenon has also provoked attention from those interested in
face recognition. It is a matter of common observation that recognition
of a highly familiar face occurs more or less automatically - we cannot
look at a familiar person and decide not to recognise them. Strikingly,
some of these automatic aspects of face recognition seem to be preserved
in cases of prosopagnosia, a severe defect of face recognition caused by
brain injury. Covert recognition of familiar faces in prosopagnosia has
now been demonstrated with a range of physiological and behavioural
measures. Similar effects occur in neurologically normal individuals
when stimuli are presented in such a way as to prevent their being
consciously identified - like prosopagnosic patients, neurologically
normal observers can show discriminative responses to faces they are not
aware of having recognised.
Although such findings are now well-established, their correct
interpretation remains a matter of debate. Contentious issues have
included the relation between overt and covert recognition, the
neurological pathways involved, and attempts to simulate the patterns of
findings with computer models.
I will review these issues, and relate them to potentially important
recent findings which have come from demonstrations that overt
recognition can sometimes be achieved in prosopagnosia and from
investigations of the basis of the Capgras delusion (the delusional
belief that close relatives have been replaced by impostors) and its
relation to prosopagnosia.





PL-10
"The Disunity of Consciousness"
Semir Zeki

Contact:
Semir Zeki

University College London
Wellcome Department of Cognitive Neurology
Gower Street, London WC1E 6BT
U.K.

s.zeki@ucl.ac.uk

The most fundamental function of the visual brain is to acquire
knowledge about the constant, essential properties of the visual world,
in conditions in which the information reaching the brain is never
constant from moment to moment. This requires the brain to undertake
complex operations on the incoming visual signals, discounting all that
is not essential for it to acquire knowledge about the world, selecting
that which is important and subjecting the latter to operations that
make the brain independent of the continually changing and non-essential
information reaching it. One strategy that the brain uses in undertaking
this task is that of functional specialization, through which different
essential features, such as motion and colour, are extracted in
specialized and geographically distinct visual areas lying outside the
primary visual cortex area V1. Our recent psychophysical experiments
show that, just as the processing systems for different attributes of
vision are separate, such as colour, form and motion are perceived at
different times, with colour leading motion by about 80 ms, thus leading
to a perceptual asynchrony in terms of real time. The end-result of the
operations in these individual areas is the acquisition of knowledge.
But knowledge can only be acquired in the conscious state. A conscious
awareness is therefore the corollary of activity in the specialized
visual areas. Recent experiments using imaging and time resolution
methods as well as patients blinded by lesions either in V1 or in more
extensive parts of the visual cortex show that the activity in one or a
small number of visual areas, without involvement of V1, can give rise
to both conscious experience and a crude knowledge about the visual
world. This leads us to the conclusion that consciousness itself may be
modular.
The work of our laboratory is supported by the Wellcome Trust, London.





PL-11
"Action and the Unity of Consciousness"
Susan Hurley

Contact:
Susan Hurley

Department of Philosophy
University of Warwick
Coventry CV4 7AL
U.K.

s.l.hurley@warwick.ac.uk

Can consciousness be only partially unified?  This question cannot be
addressed purely subjectively, in terms of 'what it is like' to be in
conscious states. But how might it be answered in objective terms?
Several neuropyschological examples will be examined and interpreted for
what light they can shed on the possibility of partial unity. I argue
that the possibility of partial unity cannot be settled by appeal to
neuroanatomical isomorphism. However, the cases suggest how certain
assumptions about the relationship of action to consciousness may make
the attribution of partial unity attractive. Questioning these
assumptions leads to a different, two-level approach to the unity of
consciousness and its relation to action, in terms of normative
coherence at the personal level and 'dynamic singularity' at the
subpersonal level.





PL-12
"Consciousness and co-consciousness"
Sydney Shoemaker

Contact:
Sydney Shoemaker

Sage School of Philosophy
Cornell University
218 Goldwin Smith Hall
Ithaca
New York 14853-3201
U.S.A.

ss56@cornell.edu

Let "consciousness atomism" be the view that the factors that go into
making a mental state conscious are independent of those that constitute
unity of consciousness, i.e., make different states co-conscious, and
let "consciousness holism" be the view that denies this. Consciousness
holism affirms, and consciousness atomism denies, that consciousness and
co-consciousness are internally related -- that the factors that
constitute them are inextricably intertwined.
Although seldom articulated, consciousness atomism is frequently taken
for granted. Two current views of consciousness can seem to imply it.
One is the view that a mental state's being conscious is its having
phenomenal character, where this in turn is a matter of having
properties of a certain sort -- "qualia." The other is the view which
says that a state is conscious in virtue of its subject being conscious
of it, where this in turn consists in its being accompanied by a "higher
order thought" which ascribes it to the subject. But a state's having
qualia cannot make a state conscious unless the subject is aware of the
qualia, or at least unless they are introspectively accessible to the
subject (as they are not in a case of blindsight, supposing there are
qualia there at all). And a state's being accompanied by an appropriate
higher-order thought will not make it conscious, and will not make the
subject conscious of it, if both the state and the thought are insulated
from the rest of the subject's mental life. So neither view is
satisfactory unless supplemented with the requirement that the states in
question are integrated with, stand in "access" relationships to, other
states of the subject. And supplementing the views in this way involves
abandoning consciousness atomism, since the integration and access
relationships are an important part of what constitutes the unity of
consciousness. This is one way in which consciousness and unity
consciousness are internally related.
Consciousness and the unity of consciousness are internally related in
another way. Perceptual experiences, which are paradigmatically
conscious, are of things that are either temporally extended (e.g., a
melody, or a spoken sentence) or spatially extended (written sentences,
ordinary physical objects, entire landscapes). Such experiences have
parts corresponding to the temporal or spatial parts of what they
represent, and these must be so related that together they represent
relations between the parts they represent. And this requires that they
be co-conscious. The very existence of such conscious mental states
requires unity of consciousness. But the specification of this sort of
unity of consciousness is precisely a specification of what it takes to
make such states conscious, and more generally what it takes for a
person to perceive spatial and temporal relations between different
things. And this, in turn, involves the considerations that go into
constituting the sort of unity of consciousness considered earlier,
specifically the co-consciousness of perceptual experiences with other
mental states.





PL-13
"Unifying consciousness with explicit knowledge"
Zoltan Dienes

Contact:
Zoltan Dienes

University of Sussex
Brighton BN1 9QG
ENGLAND
U.K.

dienes@biols.susx.ac.uk

In this talk I will establish what it is for something to be implicit or
explicit. The approach to implicit knowledge is taken from Dienes and
Perner (1999), which relates the implicit-explicit distinction to
knowledge representations. What it is for a representation to represent
something implicitly or explicitly is defined and those concepts are
applied to knowledge. Next I will show how maximally explicit knowledge
is naturally associated with consciousness, how some degree of
explicitness is needed for voluntary control and thus how increasing
explicitness is associated with increasing metacognitive abilities. I
will argue that fully explicit knowledge should be associated with a
sense of being part of a unified consciousness, both because of the
explicit representation of the subject of the mental experience and
because explicit knowledge can be represented as knowledge and hence as
coherent (or incoherent) with respect to other knowledge. New evidence
indicating the extent of people's implicit or explicit knowledge in an
implicit learning paradigm will then be presented. This evidence will
indicate people can be consistently correct in dealing with a
context-free grammar while lacking any knowledge that they have
knowledge. The relation of this to unity in consciousness will be
discussed.





PL-14
"Thinking Learning Differently: The Self-Organizing Consciousness (SOC)
Model."
Pierre Perruchet  & Annie Vinter

Contact:
Pierre Perruchet

LEAD
Faculte des Sciences
Universite de Bourgogne
6 Bd. Gabriel
21000 Dijon
FRANCE

perruche@u-bourgogne.fr

In the prevalent conceptions of learning, whether based on symbolic or
connectionist architectures, most if not all of the information
manipulation and computation involved during a training episode takes
place at an unconscious level. The function assigned to consciousness
consists in making the end-product of these computations accessible.
This access is thought of as an epiphenomenon, or at best as allowing
the high-level control of certain operations or actions.
Starting from an alternative, "mentalistic" (e.g. Dulany, 1991; Searle,
1992) view, we propose the hypothesis that the content of phenomenal
consciousness is the very stuff on which unconscious associative
processes operate. This hypothesis explains why conscious percepts and
representations become increasingly isomorphic with the world structure.
Indeed, when ubiquitous principles of associative memory and learning
(such as unit strengthening through repetition, or disappearance in the
absence of reinforcement) are applied to the content of consciousness,
this content self-organizes as a consequence of repeated exposure to a
structured environment. This is simply because associative learning
processes tend to bind together the features of the world that co-occur,
and the features of the world that co-occur have a high chance of
belonging to the same world units. This self-organizing property which,
in the most simple cases, has been demonstrated by means of
computational modeling, may be tentatively generalized to very complex
situations if we admit a few additional, but psychologically plausible,
assumptions. After generalization, this conception accounts for
important phenomena involved in human development and learning, without
the necessity of postulating any sophisticated unconscious learning
system.
Given this view, the unity of consciousness is no longer conceived of
simply as a phenomenon that requires explanation, but instead itself
becomes an explanatory concept. Our proposal is that binding together
the various components of phenomenal experience is a necessary and
sufficient condition for the occurrence of associative learning. Recent
empirical data on the role of attention in learning provide strong
support for this proposal. The unified field of experience resulting
from this integration is certainly of importance in terms of the
immediate adaptive function of any internal representation of the world.
However, when considered within a dynamical perspective, it is itself
the condition for an improvement of the representativity of conscious
contents in subsequent occasions. Although this view is presented here
in connection with cold aspects of cognition, such as visual and
auditory representations, it is worth mentioning that entering the rich
content of phenomenal experience into a causal schema of learning opens
the path for the integration of emotional and motivational aspects of
human life into future developments of this framework.





CS1-1.1
"Subjectivity and the limits of scientific enquiry"
Jordi Fernandez

Contact:
Jordi Fernandez

Brown University
Philosophy Department Box 1918
Providence, RI 02912
USA

Jorge_Fernandez@Brown.edu

In 'The view from nowhere', Thomas Nagel argues for the thesis that no
objective description of the world can be complete. An objective view of
the world, Nagel argues, cannot account for who its subject is and it is
consequently incomplete. The fact to be explained is presumably the fact
that a particular person who is described in the objective view is the
subject of it as well. Given that a scientific picture of the world is
meant to be objective, an important point involved in this discussion is
that subjectivity cannot be scientifically accounted for. I will try to
reconstruct Nagel's argument for the incompatibility of objectivity and
completeness and raise some objections to it. My intention is to show
that Nagel's thesis owes its philosophical significance to an ambiguous
notion of completeness Nagel is working with. I shall distinguish two
plausible senses in which a picture of the world can be said to be
incomplete, that I will call an "epistemic" and "metaphysical" sense. My
suggestion will then be that either Nagel's reasons in support of his
thesis are insufficient (under its metaphysical reading), or the thesis
in question lacks most of the significance it initially seems to posses
(if it is epistemologically read).





CS1-1.2
"On the Search for the Neural Correlate of Consciousness: Some Caveats"
Güven Güzeldere

Contact:
Güven Güzeldere

Duke University
Department of Philosophy &
Center for Cognitive Neuroscience
201 West Duke Building
Durham, NC 27708
USA

guven@aas.duke.edu

I argue that the search for the neural correlate of consciousness (NCC)
may be a misguided research effort.  I argue that if the NCC is
construed on the basis of the non-modularist hypothesis, it is too
general to constitute a genuine research program, and if it is based on
the modularist hypothesis, the debate on how to identify the real NCC
will never successfully get resolved because not only is there no NCC,
in this specific sense, but there cannot be. Regarding the second horn,
my claim is that the only sense in which search for the NCC can
constitute a well-defined research program is committed to a misguided
concept of consciousness. What can make this question meaningful is a
"modular" conceptualization of consciousness such that it can be
isolated in its function and singled out in its anatomical
underpinnings.  This is a misconceptualization, because consciousness is
not dissociable from other mental functions in this way. I argue,
therefore, that there exists no piece of localizable tissue in the brain
the lesioning of which will destroy only consciousness, and leave the
non-conscious organism otherwise indistinguishable in its other mental
functions and behavior, e.g., memory and language.





CS1-1.3
"Redcar Rocks: Strong AI and Panpsychism"
J. M. Bishop

Contact:
J.M. Bishop

Deptartment of Cybernetics
University of Reading
Whiteknights
READING
Berkshire
UK

J.M.Bishop@Reading.ac.uk

The claimed observer relativity of computational states forms the basis
of both Putnams 1988 attack on Functionalism and Searle's 1990 attack on
Computationalism. The argument to be presented herein, being a simple
extension of that originally given by Putnam, is not significantly
original but appears to foil the main criticisms of Putnam and Searle's
approach (see Chalmers et al., 1994), and hence has critical
implications for our understanding of consciousness. In this paper,
instead of seeking to emulate Putnam's claim that, everything implements
every Finite State Automata (FSA), I will simply establish the weaker
result that everything implements the specific FSA [Q], when executing
program (p) on input (x). Then, equating Q(p,x) to an AI program passing
the Turing Test, I will show that conceding the Strong AI thesis for Q
(crediting it with mental states and consciousness) opens the door to a
vicious form of panpsychism whereby all open systems, even rocks and
cups of tea, have conscious experience.






CS1-1.4
"Free will and the readiness potential"
Gilberto Gomes

Contact:
Gilberto Gomes

CPRJ 
R. Lopes Quintas 100-605-I
22460-010 Rio de Janeiro
BRAZIL

ggomes@ax.apc.org.br

The readiness potential precedes voluntary acts by about half a second.
According to Libet, free will does not initiate the neural process that
leads to action but is able to control it. While disagreeing with many
points of his interpretation of results, we should agree that voluntary
acts are nonconsciously initiated. Voluntary acts are felt to have been
determined by a conscious decision. This seems to conflict with the idea
that all physical events are caused by other physical events. However,
choice, decision and action can be considered as part of the natural
world. All we need to assume is a decision system that can represent
actions before their performance and select them according to its
internal state. Free will is not an illusion because free acts are not
caused by external factors.	From the first-person perspective, I am the
cause of my actions. But what am I? According to compatibilism, the free
agent is a brain system capable of choice, decision and action. The
readiness potential will be seen as an expression of it. We should
distinguish the intention to act in the future, the intention to act now
and the irrevocable decision to act now. This causes the action before
we become conscious of it. A distinction is proposed between deliberate
and non-deliberate voluntary acts. A testable prediction is that the RP
should be longer in the case of deliberate actions. Non-deliberate
voluntary acts manifest an intermediate degree of free will, since they
and the possibility of doing otherwise were not consciously considered
before starting their performance.





CS1-2.1
"The role of binding in the brain and of correspondences in theorizing"
P.H. de Vries & G.J. Dalenoort

Contact:
P.H. de Vries

Deptartment of Psychology
University of Groningen
Grote Kruisstraat 2/1
9712 TS Groningen
THE NETHERLANDS

p.h.de.vries@ppsw.rug.nl

At the structural or neural level, binding refers to processes of the
creation of temporary connections between different populations of
neurons. At the functional level these temporary connections provide in
the system an integrated representation of its environment. At the level
of subjective experience the process of binding is likely to be a
necessary condition for the occurrence of a conscious experience. The
fundamental problem in the study of consciousness is then to find the
correspondences between these levels of description. A general
architecture for cognitive brain functioning in terms of a conceptual
network will be presented which is based on these correspondences. The
process of binding is conceived as the effectuation of temporary
connections in a network of cell- assemblies, which allows for the
formation of the concept of, e.g., 'object A at position P'. Binding is
also a necessary mechanism for relating procedural knowledge and
declarative knowledge. The functioning of the network is based on the
selective, context- dependent propagation of excitation loops along
permanent and temporary connections. A computer simulation of the
network will be discussed in relation to new experiments on
object-identification and illusory conjuctions.





CS1-2.2
"Temporal Synchronization: A Possible Mechanism for the Binding Together
of the Conscious Self"
Logan Trujillo

Contact:
Logan Trujillo

Department of Psychology
University of Arizona
Tucson, Arizona, 85721
USA

logant@u.arizona.edu

Current neurobiological approaches to consciousness have proposed that
rudimentary self-consciousness may arise out of the binding together of
neural maps with first-order representational properties to form
second-order mappings. However, the mechanism for such binding, both at
the first- and second-order level, is unclear. It has been suggested
that temporally synchronized oscillatory neural activity may play an
important role in the binding together of cognitive-perceptual events;
an idea for which there is an increasing amount of empirical evidence.
This presentation will address the possibility that synchronous
oscillatory behavior may subserve the binding together of neural
representations associated with the conscious self. It will be proposed
that short- and long-range intramodal synchronies bind together the
neural elements constituting first-order mappings. The binding together
of these maps into the second-order representations underlying
self-consciousness would then be achieved by short- and long-range
intermodal synchronies. This framework has implications for the search
for the neural correlates of consciousness (NCCs) in that such
second-order representations may or may not be localized to particular
cortical regions. In addition, this presentation will explore the
potential usefulness of the temporal synchronization hypothesis towards
understanding the etiology of, and providing a means of clinical
assessment for, psychological dissociative disorders where the conscious
self is fragmented in a maladaptive manner.





CS1-2.3
"The temporal binding problem: what it is and how it might be solved"
David M. Eagleman & Terrence J. Sejnowski

Contact:
David M. Eagleman

Computational Neurobiology Lab
The Salk Institute
10010 N. Torrey Pines Rd.
La Jolla, CA  92037
USA

eagleman@salk.edu

While it is clear that different features of stimuli are processed in
different areas of the brain, it is underappreciated that information is
processed in these areas at widely varying times.  Yet somehow
perception retains very exact temporal information about outside events. 
This leaves us with the surprising result that physiologically-measured
latency differences do not generally translate into perceptual time
differences.  This is what we define as the temporal binding problem. 
In other words, how do the widely varying stimulus-evoked latencies in
the neural tissue become temporally aligned to yield the coherence of
perception?  Concentrating on the visual system, we employ physiological
and psychophysical data to argue that the features of awareness
necessitate a window of delay and postdiction, the act of
retrospectively attributing an interpretation to events in the past.  We
demonstrate that postdiction is the only framework that provides a
unified explanation for many psychophysical phenomenon.





CS1-2.4
"Cortical MEG activity dissociates coherence and meaning"
Marina Pavlova, Werner Lutzenberger, Alexander  Sokolov & Niels
Birbaumer 

Contact:
Marina Pavlova

Institute of Medical Psychology and Neurobiology
MEG-Centre
Otfried-Müller-Str. 47
72076 Tübingen
GERMANY

marina.pavlova@uni-tuebingen.de

Although current research views the high-frequency cortical oscillations
as subserving binding mechanisms for processing of coherent stimuli
(Bertrand and Tallon-Baudry, 1999; Singer, 1999), it remains unclear
whether brain responses in the gamma frequency range vary with stimulus
coherence by itself or also with a meaningful representation of a
coherent structure. By manipulating task demands, we have demonstrated
that only an attended pattern of visual motion leads to an increase in
gamma MEG activity (Sokolov et al., 1999). Most recently, however, we
showed that when a task requires attention to both a coherent stimulus
and a similar incoherent noise, only coherent patterns elicit
enhancements in the gamma response. Furthermore, it appears that the
early MEG gamma response (80-100 ms) over the primary visual cortex
exhibits a sensitivity to the stimulus coherence regardless of
perceptual awareness, while later consecutive enhancements over parietal
and temporal areas reflect the meaningful representation of a coherent
structure from motion. Such evidence helps to clarify the ongoing debate
about the neural correlates of consciousness (Crick and Koch, 1998;
Logothetis, 1998; Singer, in press).





CS1-3.1
"Perceptual Filling-in of Darkness"
Michael E. Rudd

Contact:
Michael E. Rudd

University of Washington
Department of Psychology
Box 351525
Seattle, WA  98195-1525
USA

mrudd@u.washington.edu

A growing body of evidence suggests that the visual brain computes
surface color in a multistage process that includes 1) an early neural
encoding of color contrast at the locations of borders between regions
of homogeneous luminance within the retinal image and 2) a subsequent
filling-in of the colors belonging to regions lying within or between
the borders. I will present a computational model of brightness
(achromatic color) based on this type of multistage neural algorithm.
The model differs significantly from earlier filling-in models by
emphasizing the importance of the filling-in of darkness signals, as
opposed to lightness signals. The behavior of the model will be
illustrated by showing how it accounts quantitatively for the magnitudes
of darkness induction effects exerted by regions of high luminance
within the visual scene on the brightness of a test region of lower
luminance, as measured by a psychophysical brightness matching technique
(Rudd & Arrington, ARVO, 2000).





CS1-3.2
"Priming the kinetics of pointing movements: Online-control by barely
visible isoluminant color stimuli"
Thomas Schmidt

Contact:
Thomas Schmidt

University of Goettingen
Institute of Psychology
Gosslerstr. 14
37073 Goettingen
GERMANY

tschmid8@uni-goettingen.de

Two-visual-systems theory (Milner & Goodale, 1995) states that color
processing is generally separated from motor control in the primate
brain. In order to use color information in a motor task, one would have
to rely on color as consciously experienced, which would be very
difficult if stimuli are efficiently masked. Here, a motor priming
paradigm (Vorberg, Mattler, Heinecke, Schmidt, & Schwarzbach, in
prep.) was used where participants were required to make a speeded
pointing response toward the one of two target stimuli having a
prespecified color. Targets were preceded by primes at the same
positions having the same (consistent) or reversed (inconsistent) colors
as the targets. Due to masking by the targets, discriminability of
primes was uniformly low independent of prime-target delay. In spite of
this, pointing movements started off in the direction specified by prime
rather than target color, with a time course closely locked to prime
onset. When the target arrived, this movement was either maintained when
primes and targets were consistent or had to be reversed when they were
inconsistent, with a time course now locked to target onset. These
results strongly suggest a direct dynamic link between color processing
and response control.





CS1-3.3
"Can Synesthesia be explained by 40Hz Oscillations?"
Lucy Troup

Contact:
Lucy J. Troup

Department of Psychology
University of the West of England, St Matthias Campus
Oldbury Court Road, Fishponds,
Bristol. BS16 2JP
UK

lucy.troup@uwe.ac.uk

Synesthesia has been explained as a break down of modularity in
perceptual processes. What is unclear is the nature of the processes
that elicit synesthetic experiences. Interestingly research in
developmental psychology suggests that neonates are in fact synesthetes
and modularity of perceptual processing evolves over time. In the last
10 years there has been a great deal of research implicating 40hz
oscillations as a possible mechanism for perceptual processing. It has
more controversially been implicated as a possible mechanism for visual
binding. Computer modeling work has suggested that 40hz oscillations are
mediated by feedback connections in artificial oscillatory neural
networks. Interestingly there is research that suggests that visual
system in the neonate is far from fully developed. In fact it is not
until the neonate is a year old that its feedback pathways in the brain
begin to develop. Is it possible that this, coupled with the notion that
cognitive processing, namely perceptual processing, is in fact explained
by 40hz oscillations, could be a possible mechanism for synesthesia? Is
it that synesthetes have some kind of dysfunctional or inappropriate
feedback pathways causing synchrony of 40hz oscillations in
inappropriate "perceptual modules"?





CS1-3.4
"Digit-Colour Synaesthesia: An Investigation of Extraordinary Conscious
Experiences"
Daniel Smilek, Mike J. Dixon, Cera Cudahy & Philip M. Merikle

Contact:
Daniel Smilek

Department of Psychology
University of Waterloo
Waterloo, Ontario
N2L 3G1
CANADA

dsmilek@watarts.uwaterloo.ca

Digit-colour synaesthesia occurs when a black digit elicits a conscious
experience of a highly specific colour (a photism). It has been
suggested that photisms differ from imagery in their consistency, their
automaticity and their reliance on externally presented stimuli for
elicitation. We tested C, a digit-colour synaesthete, to evaluate these
claims. The consistency of C's photism colours for each digit (0-9) was
evaluated by having her name the colour of each digit. C named the same
colour for each digit over 10 repetitions.  To assess the automaticity
of C's photims, digits were displayed in colours congruent or
incongruent with her photism colours. C's colour naming reaction times
were significantly slower for incongruent trials than congruent trials.
Finally, to evaluate whether an external stimulus was necessary to
elicit C's photisms, C was shown arithmetic problems (e.g., 5+2)
followed by a colour patch that she had to name. Naming times were
slower when colours were incongruent with C's photisms for the answer to
problems than when the colour patches were congruent. We conclude that
the photisms experienced by C are consistent, automatic and can be
induced simply by activating the concept of a digit in the absence of an
external stimulus.





CS1-4.1
"When are we conscious? Some thoughts on a seemingly uncontentious
topic"
Rimas Cuplinskas

Contact:
Rimas Cuplinskas

Philosophisches Seminar
University of Bonn
Am Hof 1
D-53113 Bonn
GERMANY

cuplinskas@uni-bonn.de

Precisely what scientists from the different fields studying the human
mind mean by the term "consciousness" is less clear than it may seem.
Although philosophers are in general agreement that being conscious
involves a subject being in a phenomenal state, such states are strictly
speaking not directly accessible from a third-person perspective. For
this reason the empirical sciences have had to work with other
operational definitions according to which one might infer whether or
not a subject is conscious of a given stimulus. Bernard Baars (1997), in
attempting to define more clearly the differences between our concepts
of consciousness, attention, perception and working memory, has
suggested "accurate reportability" as an operational definition for
consciousness. However, if we posit the existence of a short-term
sensory buffer for visual and acoustic stimuli, the contents of which
may if necessary be consciously reviewed, then it would both be true
that (i) one was not conscious of a given stimulus at the time of
perceiving it, and that (ii) one is nevertheless able to accurately
report on it when cued within the buffer's decay period. Recent findings
concerning so-called "change blindness" as well as Ned Block's
distinction between phenomenal and access consciousness will also be
reviewed within this context.





CS1-4.2
"The Categorical Fluency Effect: Nondeclarative Memory in Visual
Category Learning "
Paul J. Reber

Contact:
Paul J. Reber

Department of Psychology
Northwestern University
2029 Sheridan Road
Evanston, IL 60201
USA

preber@nwu.edu

Nondeclarative memory affects behavior without conscious retrieval of
specific facts and events.  One mechanism by which nondeclarative memory
has been shown to affect processing is by affording perceptual fluency
for previously presented stimuli (priming).  The role of fluency in
complex cognitive processing such as categorization has not been
explored.  Four experiments are reviewed that examine the neural basis
of a visual category learning task that is supported by nondeclarative
memory.  These results suggest that fluency for categorical stimuli
plays an important role in categorization.  The hypothesis is advanced
that learning a new visual category results in a change in early visual
processing that leads to increased fluency for subsequent processing of
categorical stimuli.  This fluency effect is contrasted with the neural
correlates of similar declarative memory tasks such as recognition or
categorization supported by a conscious, explicit strategy.  The
patterns of activity in the visual system are shown to consistently
distinguish between the operation of nonconscious, nondeclarative memory
and conscious, declarative memory.  This contrast suggests that fluency
supports more complex cognition than simple repetition priming effects
and is distinct from the mechanisms support conscious memory retrieval.





CS1-4.3
"Conscious and nonconscious memory across saccadic eye movements"
Karl Verfaillie, Peter De Graef & Veerle Gysen

Contact:
Karl Verfaillie

Department of Psychology
University of Leuven
Tiensestraat 102
3000 Leuven
BELGIUM

Karl.Verfaillie@psy.kuleuven.ac.be

In a transsaccadic integration paradigm, observers make a saccadic eye
movement to a visually presented target object and they have to detect
object changes that occur during their saccade. Because of saccadic
suppression, the transient that normally accompanies such a change is
not perceptible and change detection is only possible by the integration
of presaccadic and postsaccadic information. We previously observed that
object displacements are very hard to detect while depth rotations of
the object are readily noted, suggesting that transsaccadic memory for
object position is inaccurate whereas memory for depth orientation is
good. However, it has been suggested that, in contrast to what our
findings suggest, transsaccadic coding of object position is in fact
accurate, but the information is unavailable to conscious perception,
because the visual system assumes the world remains stable. Deubel et
al. (Vision Research, 1996) demonstrated that, by briefly blanking the
saccade target during and just after the saccade, the default assumption
of a stable visual world is invalidated and saccade- contingent
displacements are relatively easy to detect. We report a series of
experiments in which we use this blanking technique to unravel the
nature of conscious and nonconscious transsaccadic memory.





CS1-4.4
"Electrophysiological measures of conscious and nonconscious memory"
Ken Paller

Contact:
Ken Paller

Northwestern University

paller@howard.psych.nwu.edu

In contemporary memory research, the subjective experience of
remembering a fact or event, conscious recollection, has frequently been
dissociated from a variety of other forms of memory that tend to occur
without any recollective experience. In particular, patterns of memory
impairment in patients with amnesia suggest that memory for facts and
episodes depends on a process of neocortical consolidation that is not
required for other types of memory such as perceptual priming.
Electrophysiological and hemodynamic measures of brain activity can
provide additional insights into the processes responsible for
remembering. In this presentation I will describe distinct brain
potentials that have been specifically associated with recollection and
priming. These electrophysiological results add to the growing body of
evidence supporting neurobiological conceptualizations of the
distinction between recollection and priming. Moreover, these results
hold promise for measuring and conceptualizing the brain events
responsible for the conscious experience of remembering.





CS2-1.1
"Does consciousness achieve binding? "
Max Velmans

Contact:
Max Velmans

Department of Psychology
Goldsmiths
University of London
UK

psa01mv@gold.ac.uk

In 1980, the dualist, John Eccles proposed that the "self-conscious
mind" selects, attends to and integrates information displayed on the
neocortex. Adopting a form of functionalism, Baars (1997) makes the
related claim that consciousness carries out system-wide integration and
dissemination of information, forms new links between unconscious
processors, and so on. In this paper, I suggest that these claims are
false, whether they are couched in dualist or functionalist terms.
Neural binding is likely to be  a necessary condition for having an
integrated conscious experience.  However conscious experience does not
carry out neural binding, nor does it disseminate information throughout
the brain.  Such claims confound correlation and causation with
ontological identity, and they confuse the relation of conscious
phenomenology to the information processing that supports it. Neural
binding and information dissemination are both achieved non-consciously.





CS2-1.2
"A Mentalistic View of Conscious Unity and Dissociation"
Donelson E. Dulany

Contact:
Donelson E. Dulany

Department of Psychology 
University of Illinois, Urbana-Champaign
603 East Daniel Street
Champaign, IL 61820
USA

ddulany@s.psych.uiuc.edu

Mentalism is a metatheory of mind that specifies roles for conscious
states and nonconscious mental operations in a way that can provide
constraints for theories of a range of phenomena (Dulany, 1997).  On
this view, symbols are mental contents carried exclusively by conscious
states, a function that gives consciousness the adaptive significance of
coping with a world beyond ourselves.  Mental activity consists
exclusively of mental episodes in which conscious mental states and
contents are transformed by nonconscious mental operations, operations
that are brain processes interrelating those conscious states and
contents. Contents come in literal and identity codes that can be focal
or non-focal, and remembrance and inference operations can yield higher
order states of consciousness and a sense of agency. Dissociations occur
within consciousness, when mental operations fail, not between
consciousness and an unconscious. They can occur (a) between different
forms of mental episodes, the evocative ("implicit") and the
deliberative ("explicit"), (b) between literal and identity codes of
awareness, (c) between first- order and higher-order consciousness, and
(d) between conscious contents and a sense of agency (possession).  The
view is applied to several phenomena, ranging from imperfect unity in
normality to more dramatic dissociations with brain pathology.





CS2-1.3
"Integration, Phenomenal Unity, and Self-consciousness"
Robert Van Gulick

Contact:
Robert Van Gulick

Philosophy/Cognitive Science
541HL
Syracuse University
Syracuse, New York 13244-1170
USA

RNVANGUL@syr.edu

The problem of unification and binding occurs in many forms: 
* some of which apply only to phenomenal processes, 
* some only to nonphenomenal processes and 
* others of which apply to both. 
Diverse versions of the problem focus on different types of integration
or coherence including : temporal (at a time), cross-temporal, causal,
dynamic, representational, intentional, experiential, intra-modal,
cross-modal, and intuitional (in the Kantian sense of intuitions as the
forms of sensible awareness)  The general space of problems provides an
opportunity for exploring detailed relationships between consciousness
and its nonconscious correlates or substrates.  What sorts of
correspondences, isomorphisms and dependencies can one articulate
between the types of unity and coherence that apply respectively at the
conscious (phenomenal) level and nonconscious levels?  Are such
correspondences explanatory?  In particular, might they help us
understand how phenomenal consciousness could arise from or be wholly
constituted by nonconscious process?  That is, can understanding
cross-level relations between the types of unity and coherence
significantly help us close "the explanatory gap" and reduce the
residual mystery that surrounds the so called "hard problem".  The
answer is yes, as long as one does not set an unjustifiably high
standard of what counts as an explanatory correspondence. The notion of
self-consciousness, if understood in a sufficiently broad and general
way, may provide one useful bridge to link the diverse types of unity
that apply at different levels.





CS2-1.4
"Binding by synchrony and the transparency of consciousness"
Markus Werning

Contact:
Markus Werning

Department of Philosophy
Free University of Berlin
Am Schiessberg 6
D-61449 Steinbach
GERMANY

markus.werning@berlin.de

Being conscious of something - say, a red apple - does not only imply
having a representation of a red apple, but also implies that it is for
the subject as if she were in a world with a red apple. This feature of
consciousness is called transparency because the subject seems to access
the object represented without prior accession of any intermediate
representational state such as a mental sentence or image. Transparency
can only be explained if the subject mistakes the representation of an
object for the object represented. I define a neuronal algebra N which
accounts for the empirically rather well confirmed hypotheses that there
are collections of property-indicative neurons and that properties
indicated by different collections are bound into a representation of an
object by synchronous activation. Algebra N turns out to be isomorphic
to a further algebra W that comprises worldly objects, properties and
facts. Because N and W are isomorphic, they are indistinguishable for
certain systems. To explain the transparency of consciousness, we have
to assume that the brain is such a system: It mistakes the neuronal
states of its own for objects, properties and facts of a possible world.





CS2-2.1
"When 'I think' doesn't accompany my thoughts"
Frédérique de Vignemont

Contact:
Frédérique de Vignemont

CREA
1, rue Descartes
75005 PARIS
FRANCE

devigne@poly.polytechnique.fr, vignemo@club-internet.fr,
vignemo@u.arizona.edu

In this paper, I intend to develop on conceptual and empirical grounds
the distinction between two kinds of underlying mechanisms of
consciousness unity, that is, the notion of access, and the notion of
self-attribution. And none of these mechanisms is infallible, not even
self-attribution, contrary to Shoemaker's claim of immunity to error
through misidentification relative to the first-person. Usually,
split-brain phenomenon is considered as the paradigmatic trouble of
consciousness unity. Many accounts emphasize the notion of access (to
controlateral hemisphere, to consciousness, to verbalization and so on).
Unity of consciousness implies having access to one's own mental states.
But it is not sufficient, as it appears in some schizophrenic symptoms.
In thought insertion, the patient believes that someone has put an alien
thought in his mind. He has access to it, but there is still a problem
of unity, because of the defective monitoring of the cause of the
thought. Unity depends on the acknowledgment of ownership, and so, on
sense of agency. So, we have to distinguish two senses of consciousness
unity. In the weak sense, the sufficient condition is to have conscious
access to mental states. In the strong sense, we need to attribute to
the same subject the available states.





CS2-2.2
"States of consciousness in schizophrenia : a metacognitive approach to
semantic memory"
Elisabeth Bacon & Jean-Marie Danion

Contact:
Elisabeth Bacon

INSERM Unit 405, Psychiatric clinic,
University Hospital, BP 426,
F-67091 STRASBOURG Cedex,
FRANCE

bacon@alsace.u-strasbg.fr

Recent studies suggest that schizophrenia is a disease affecting states
of consciousness. The present study aimed at investigating metamemory,
i.e. knowledge about ones own memory capabilities, in patients with
schizophrenia. The accuracy of Confidence Level (CL) in the correctness
of recall answers and the predictability of Feeling Of Knowing (FOK)
towards recognition were measured using a task of general information
questions assessing semantic memory. Nineteen outpatients were paired
with 19 control subjects with respect with age, sex and education.
Patients with schizophrenia exhibited an impaired semantic memory. CL
ratings and CL and FOK accuracy were not significantly different in the
schizophrenic and comparison groups. However, FOK ratings were
significantly reduced in patients, and discordant FOK ratings for
correct answers were observed more frequently among schizophrenics.
These results indicate that FOK judgments are impaired in patients with
schizophrenia. They provide support for the hypothesis that the
impairment of semantic performance observed in schizophrenia is due to a
defect of access to appropriate knowledge and confirm that schizophrenia
is characterized by an impaired conscious awareness of ones own
knowledge.





CS2-2.3
"Attribution of action in schizophrenic patients"
Chloe Farrer , Nicolas Franck, Nicolas Georgieff & Marc Jeannerod

Contact:
Chloe Farrer

Institute of Cognitive Sciences
67 Bd Pinel
69675 Bron cedex
France

cfarrer@fil.ion.ucl.ac.uk, farrer@isc.cnrs.fr

One class of schizophrenic symptoms the so-called positive symptoms are
suggestive of an alteration of the awareness of ones own action and of
the recognition of actions performed by others. One-hypothesis
postulates that self consciousness relies on discrimination between
central representations activated from within and those activated by
external agents. A first experiment by Daprati et al (1997) has shown
that schizophrenic patients tend to overattribute to themselves actions
produced by others. In order to analyse more precisely the influence of
the perceptive information on this agency judgement we realised another
experiment where the parameters of the visual information were
controlled using an electronic device, which allowed modifying the
apparent direction and/or velocity of the movement actually performed,
by the subject. 29 normal and 29 schizophrenic subjects performed a
manual motor task and an agency judgement about this task. We determined
angular and temporal threshold values for which subjects were no longer
to distinguish the movements they executed from those they saw. The
results showed greater thresholds values and significant more
self-attribution responses for the patients compared to controls. We
explained those results by a deficit at the level of the consciousness
of action. Compared to controls schizophrenic subjects have more
difficulties in recognising their own actions.





CS2-2.4
"Binding in Dreams"
Antti Revonsuo

Contact:
Antti Revonsuo

Department of Philosophy
Center for Cognitive Neuroscience 
University of Turku
FIN-20014 Turku
FINLAND

antti.revonsuo@utu.fi

Dreaming provides us with a unique view to the way phenomenal
representation -- consciousness -- is organized in the brain. Dream
images often contain deviations and peculiarities that in dream research
are referred to by the term "bizarreness". Bizarreness (e.g.
incongruity, discontinuity) can be reconceptualized as referring to
aberrations in the binding of phenomenal dream images coherently
together. Incongruous dream images have features or appear in contexts
inconsistent with waking perception. Discontinuity in dreams manifests
failures of binding across time: successive dream images do not retain
or properly update phenomenal representations, which leads to sudden
appearance, disappearance or transformation of dream elements. Studies
of bizarreness could therefore provide us with detailed descriptions of
how the binding of phenomenal representations succeeds or fails during
dreaming, possibly illuminating the mechanisms that work beneath the
surface of phenomenal organization. I present a study on the bizarreness
of human characters in dreams, especially designed to chart the failures
of different types of binding. The results show that in dreams certain
types of aberrations in binding are much more common than others.
Information contributed by single modules tends to be coherent, but the
global integration of phenomenal features contributed by non-modular or
a number of different modular processing systems tends to be
incoherently combined when binding the phenomenal dream world together.





CS2-3.1
"Experience is not something we feel but something we do: a principled
way of explaining sensory phenomenology, with Change Blindness and other
empirical consequences"
J. Kevin O'Regan & Alva Noë

Contact:
J. Kevin O'Regan

Laboratoire de Psychologie Expérimentale
Institut de Psychologie
Centre Universitaire de Boulogne
71, avenue Edouard Vaillant
92774 Boulogne-Billancourt Cedex
FRANCE

oregan@ext.jussieu.fr

Any theory of experience which postulates that brain mechanisms generate
"raw feel" encounters the impassable "explanatory gap" separating
physics from phenomenology.
A way around the problem is to postulate that experience is not
something we feel, but something we do: a kind of give-and-take with the
environment, analogous to the "feel" of driving a car. One consequence
of such a "sensorimotor" theory of experience is that it provides a way
of explaining the differences between seeing, hearing, touch, etc.,
which is more principled and has more explanatory power than
Müller's notion of "specific nerve energy" or its modern
counterpart, the notion of sensory pathways or cortical areas. The
feasibility of sensory substitution is an empirically verifiable
implication of this approach.
As applied to visual perception, a consequence of the sensorimotor
approach is the idea that seeing does not consist in the creation of a
"re-"presentation of the world inside the brain, but rather in knowledge
that the outside world is immediately accessible through a flick of the
eye or of attention, like an "outside memory". The
world-as-an-outside-memory idea has empirically verifiable consequences
in the phenomenon of Change Blindness, among others.






CS2-3.2
"Unintended cognitive processing in briefly attended locations"
Maria Stone & Roger W. Remington

Contact:
Maria Stone

MS262-4, NASA-Ames Research Center
Moffett Field, CA 94035
USA

mstone@mail.arc.nasa.gov

Previous experiments by Remington, Folk & McLean, using spatial
cueing paradigm, have demonstrated that involuntary shifts of attention
lead to processing of nontarget stimulus identity when the goals of the
observer do not include such identity processing.  Current experiments
using the same paradigm examined limits on such unintended processing
with cognitive operations that are more complex (Experiment 1) and less
related to the observer's task (Experiment 2).  In Experiment 1, we
examine whether or not subjects carry out unintended same/different
comparison of briefly attended nontarget stimuli, and in Experiment 2 we
examine whether or not bilingual  Russian-English subjects process
letter identity of briefly attended nontarget letters in Russian when
asked to respond to identities of English target letters.  The results
have implications for the more general question of when voluntary
control over cognitive operations fails and when it is possible.





CS2-3.3
"Capacity limitations in the detection and identification of change in
visual arrays"
Patrick Wilken & Jason B. Mattingley

Contact:
Patrick Wilken 

Department of Psychology
University of Melbourne
MELBOURNE  VIC 3010
AUSTRALIA

p.wilken@pgrad.unimelb.edu.au

Observers typically have trouble reporting salient changes between two
visual displays if these are presented in alternating sequence, with a
blank interval of short duration interposed between them. This
phenomenon, commonly known as 'change blindness' (CB), suggests that the
visual system maintains a relatively sparse representation of the world.
Work in a number of research areas -- transsaccadic memory,
visual-tracking, and visual short-term memory -- suggests that visual
processing capacity is limited in many tasks to approximately 4-6 items.
Here we report on an experiment in which observers were asked to detect
and identify change in an array of coloured forms. In separate blocks of
trials subjects were asked to detect and identify either a colour change
(e.g. 'red' to 'blue') or a form change (e.g. 'L' to 'T') to one of the
items in the array. False alarm rates were estimated from responses to
those 50% of trials in which no change occurred. As expected the
probability of detecting or identifying change in the form condition was
much poorer than that in the colour condition. However, a simple lawful
relationship was found to exist between the detection and identification
of change in both conditions. Our results are inconsistent with a model
in which limitations in the identification and detection of change are
the result of a single underlying process, operating on a limited number
of coherent objects held in a high-level working memory store. Instead,
we suggest that detection and identification of change are separate
processes, that share a common informational bottleneck.





CS2-3.4
"Representing change with and without awareness: imaging studies"
Diego Fernandez-Duque, Giordana Grossi, Ian M. Thornton & Helen
Neville

Contact:
Diego Fernandez-Duque

Rotman Research Institute
Baycrest Centre for Geriatric Care
3560 Bathurst Street
Toronto, ON, M6A 1E6
CANADA

diego@rotman-baycrest.on.ca 

Observers are often unaware of changes in their visual environment until
attention is drawn to the location of change. Focused attention mediates
change perception by giving objects coherence across space and time. To
study the relation between focused attention and aware/unaware
perception of change, we recorded Event Related Potentials from subjects
performing a change blindness task. A complex scene was repeatedly
presented for 500 ms, separated by a 300 ms blank mask. After several
cycles, a change was introduced in the scene. Original and modified
versions alternated until the change was reported (unaware change,
unattended location of change). During the subsequent 30 to 40 flickers,
subjects attended to the location of change and reported when the change
was removed (aware change, attended location of change). Next, subjects
looked for a second change in the same scene, usually absent (no change,
unattended location of original change). Finally, subjects focused
attention at the location of the original change to report its
re-occurrence (no change, attended location of change). Preliminary
analysis indicates activation differences, both as a function of
attention (attended versus unattended location) and level of awareness
(aware versus unaware). We plan to further explore these effects using
functional magnetic resonance imaging.





CS2-4.1
"Priming capabilities of 'attention masked' words and pictures: ERP
studies on the attentional blink"
Michael Niedeggen & Petra Stoerig

Contact:
Michael Niedeggen

Institute of Physiological Psychology II
Heinrich-Heine University of Duesseldorf
Universitaetsstr.1
D-40225 Duesseldorf
GERMANY

michael.niedeggen@uni-duesseldorf.de

The 'attentional blink' relies on the rapid serial visual presentation
(RSVP, ~10 items/s) of stimuli, in which two relevant targets are
embedded: When the first target is detected, explicit processing of the
second target (probe) is suppressed if it is presented 200-400ms later.
To learn whether these 'attention masked' items (Exp.1: words, Exp.2:
pictures, each n=16) affect the processing of test words presented
following the RSVP, we studied covert recognition by presenting either
the masked probe or a new stimulus. To examine semantical priming, we
presented test words related or unrelated to the probes (Exp.3, n=12).
Processing of the test word was monitored by recording event-related
brain potentials (ERPs). The absence of explicit probe recognition
reflected in a diminished P3 amplitude, probably indicating a mismatch
in episodic memory. Nevertheless, repeated stimuli are treated
differently from new items which generated a more negative-going ERP
waveform. A comparable reduction of ERP negativity was obtained for
semantically related in contrast to unrelated test words (Exp.3). In
sum, our results indicate that lexical meaning of 'attention masked'
items seems to be encountered, but not upgraded in episodic memory.





CS2-4.2
"Effects of Color in Implicit Memory"
Andre Melzer & Werner Wippich

Contact:
Andre Melzer

University of Trier
Fb-1 Psychology
Universitaetsring 15
D-54286 Trier
GERMANY

melzer@cogpsy.uni-trier.de

In two sets of experiments we investigated (a) the effects of study-task
and object-color association manipulations on implicit memory for
color-to-object identity bindings, and (b) whether the representations
underlying task performance are semantic or perceptual in nature. In
contrast to the study phase, test items were presented without color
information. In the implicit color-choice test, priming of color was
shown when the target colors were chosen more frequently for old items
than for new items. In the first set of experiments, priming was
observed even when participants disregarded the color information in the
color-pictures study condition. However, when color information had been
presented on separate cards during encoding, priming depended on whether
the study task required attention to both the object identity and its
specific color. We conclude that the amount of focal attention needed
for color-to-object identity bindings to be reflected in an implicit
memory test depends on the spatial integration of the color and the
object identity during encoding. As to the second major issue, results
were inconclusive: While there was evidence for a semantic basis
underlying task performance in one experiment, results of a second
experiment suggested that mental representations may also be perceptual
in nature.





CS2-4.3
"Distinguishing conscious from non-conscious discrimination: Exploring
functional analogs of blindsight in normals using visuo-motor responses
to masked targets"
Mark C. Price, Elisabeth Norman & Simon C. Duff

Contact:
Mark C. Price

Cognitive Section
Institutt for Samfunnspsykologi
Psychology Faculty
University of Bergen
Christiesgt. 12, 5015, Bergen
NORWAY

mark.price@psych.uib.no

"Blindsight" patients with lesions in primary visual cortex have
impaired phenomenal experience of visual stimuli, but may still make
above-chance forced-choice discriminations to such stimuli, e.g. by
pointing to their location. We report attempts to model blindsight in
brain-intact subjects by using masking paradigms (borrowed from research
on non-conscious perception) to present visual targets subliminally.
These studies reveal potential pitfalls with both introspective and
behavioural/operational measures of consciousness, raising doubt over
some previous claims to have modeled blindsight in normals. For example,
although subjects may declaratively indicate (by key pressing) the
location of peri-liminal masked targets more accurately than they can
distinguish between their presence or absence, this seems to be a
consciously mediated advantage rather than the "blindsight-like" effect
previously claimed by some studies. Further studies investigate whether
masking paradigms can be used to obtain functional analogs of blindsight
in normals when subjects attempt to guess the location of masked visual
targets using finger pointing (visuo-motor) responses. Our studies are
based on converging behavioural controls for consciousness that exploit
qualitative differences between conscious and non-conscious processing,
and which may be of relevance to future studies which attempt to map the
contents of visual consciousness in patients.





CS2-4.4
"A neural correlate of visual awareness: exploring the N265 component"
Ville Ojanen, Maria Wilenius-Emet & Antti Revonsuo

Contact:
Ville Ojanen

Centre for Cognitive Neuroscience
University of Turku
FIN-20014 Turku
FINLAND

viloja@utu.fi

In a recent EEG study by Wilenius-Emet and Revonsuo (in preparation)
visual awareness was examined during an object detection task where the
target stimuli were briefly flashed between forward- and backward masks.
A prominent negative ERP-component that correlated with conscious
perception was observed at around 265 ms after target stimulus onset.
This "N265" component was elicited by all consciously perceived stimuli
(i.e. objects and scrambled objects presented at stimulus durations at
or above the recognition threshold) but not by any stimuli that could
not be consciously perceived (i.e. similar stimuli presented at stimulus
durations below the recognition threshold). Thus, the N265 component
seems to reflect the neural correlates of visual awareness and binding.
The present EEG study is a modification of the previous study by
Wilenius-Emet & Revonsuo and the MEG study by Vanni et al. (1996).
The aim was to further examine the N265 component and its correlation to
visual awareness. The original experiment was modified to see whether
the N265 component primarily reflects the conscious detection of
stimulus brightness changes during the stimulation sequence (the target
stimulus had higher luminance than the forward and backward mask) or the
sequential presentation of three stimuli (mask-stimulus-mask). The
experiment was modified respectively by prolonging the stimulus duration
and by excluding either the forward or the backward mask or both from
the sequence. The results discussed in the talk show how these
manipulations modulate the generation, latency and amplitude of the N265
component. This in turn reveals whether the component is the "vertex
negative component" earlier identified and studied by Jeffreys (1989)
and how exactly this ERP-component is related to visual binding and
awareness.





CS3-1.1
"Memes and the malign user illusion"
Susan Blackmore

Contact:
Susan Blackmore

Department of Psychology
St Matthias College
University of the West of England,
Bristol BS16 2JP
UK



Many authors have suggested that the apparent unity of consciousness is
an illusion. Parfit contrasts ego theorists with bundle theorists, who
believe that underlying the apparent continuity of self is only a series
or bundle of experiences. Dennett, having rejected the audience in the
Cartesian Theatre, suggests that the self is a benign user illusion. If
we accept this, we must ask (1) How is the illusion constructed? (2) Why
is it constructed, and (3) Is it really benign? Possible answers come
from evolutionary, cognitive and social explanations. I shall argue that
none of these is valid, for the illusion does not benefit either us or
our genes, it benefits our memes. I shall explain the basic principles
of memetics, pointing out sources of confusion over definitions and
false analogies with genes, and stressing the importance of
understanding memes as replicators. I shall explain how and why memes
group together into co-adapted meme complexes, one of which is the self.
This memeplex is constructed by the memes for their own propagation, not
for our benefit. Indeed it is arguably the root of all human suffering.
I conclude that both scientifically, and for living our lives, the
illusion is malign.





CS3-1.2
"Unity of Consciousness: What It Is and Where It Occurs"
Andrew Brook

Contact:
Andrew Brook

Institute of Interdisciplinary Studies
Carleton University
Ottawa, Ontario, K1S 5B6
CANADA

abrook@ccs.carleton.ca

Unity of consciousness is our capacity to be conscious of a number of
items all at once, in what could be called a single conscious act. Such
unity is found in at least three 'places': consciousness of the world in
general, consciousness of self in general, and paying focal attention to
aspects of either. In all three, unified consciousness has both a
synchronic and a diachronic dimension. That is to say, consciousness is
unified both at a given moment and over time. Unified consciousness can
break down by splitting (into two unified centres of consciousness, as
in brain bisection operations) and by shattering (as in some severe
schizophrenias and dysexecutive disorder). Studying it in its breakdown
conditions is a good way to throw light on it. In this paper, we will
delineate the unity of consciousness, explore some situations in which
it breaks down, and relate it to some other mental unities.





CS3-1.3
"The Appearance of Unity: A Higher-Order Interpretation of the Unity of
Consciousness"
Josh Weisberg

Contact:
Josh Weisberg

The Graduate School and University Center of The City University of New
York
Department of Philosophy, 7th floor
365 5th Ave. New York, NY 10016
USA

jwsleep@aol.com

Recent work in neuroscience and psychology has put pressure on the
traditional philosophical idea of the unity of consciousness. Studies of
split-brain and hemineglect subjects, as well as results from various
priming and confabulation experiments, challenge the vision of unbroken
subjective experience.  Yet from the first-person point-of-view, things
seem unified.  Can this appearance of unity be accounted for in a
physicalist theory of consciousness, or must we reject and eliminate the
very notion of the unity of consciousness? In this paper, I will
investigate the possibility that "higher-order" theories of
consciousness can provide an explication of the appearance of unity,
while respecting the relevant neuroscientific and psychological results. 
I will focus on David M. Rosenthal's higher-order-thought hypothesis
(1986, 1997), which holds that higher-order thought determines what it
is like for us to be conscious of our mental states.  But higher-order
thought can also have the effect of "cleaning up" the appearance of
target states.  We may represent things as unbroken and unified at the
target level, when in fact they are not that way.  The appearance of
unity derives from the manner in which higher-order thought interprets
lower-order states.  I will evaluate the success of this proposal,
focusing in particular on the idea that there may be an
appearance/reality distinction within consciousness itself.

REFERENCES
Rosenthal, D. M.  (1986).  "Two Concepts of Consciousness." 
Philosophical Studies 49, 329-359.
Rosenthal, D. M.  (1997). "A Theory of Consciousness."  in Block, N.,
Flanagan, O., and Guzeldere, G.,(eds.), The Nature of Consciousness:
Philosophical Debates, Cambridge, MA: MIT Press, 729-753.




CS3-2.1
"The continuity of self in collectivism and individualism"
William P. Banks, Kris Y. Yi, Angela V. Lumanau & Nancy Chen

Contact:
William P. Banks

Department of Psychoilogy
Pomona College
Claremont, CA 91711
USA

Wbanks@pomona.edu

One important factor in the unity of consciousness is the self, which
provides a resource for continuity, a reference for memories, and a
coherent interpretation of reality.  Cultural factors are essential to
the construction of the self.  The dimension of individualism and
collectivism emerges as a universal classification of societies, and
this is explicity a dimension that concerns the structure of the self.
We found that individualistic respondents (American college students)
and collectivistic respondents (college-age Japanese citizens) had,
surprisingly, almost identical degrees of the self-reference effect in
memory (the finding that a list of random trait adjectives, when judged
as applicable to one's self, are easier to remember and recall than a
list of the same adjectives learned using other methods).  We also
compared the two groups in the fundamental attribution error.  We found
the typical error for the individualistic participants, but a great
reluctance by the collectivistic participants to make any attribution at
all.  Finally, we showed that a state of "war" (an intercollegiate game)
causes American team members to become more collectivistic and to have
simpler out-group stereotypes, and more complex and positive in-group
attributions, than a non-war state.  Implications for continuity and
self cross-culturally will be discussed.





CS3-2.2
"Alien Voices: An Event-Related fMRI Study of Overt Verbal
Self-Monitoring"
Cynthia H.Y. Fu, Edson Amaro Jr, Mick Brammer, Farooq Ahmad, Chris
Andrew, Steve C.R. Williams, Nanda Vythelingum & Philip K. McGuire

Contact:
Cynthia H.Y. Fu

Division of Psychological Medicine
Institute of Psychiatry
de Crespigny Park
London  SE5 8AF
UK

c.fu@iop.kcl.ac.uk

Introduction
A fundamental aspect of consciousness is the awareness of one's own
thoughts, which requires monitoring of self-generated cognitive
activity.  The neural correlates of verbal self-monitoring have been
investigated using positron emission tomography (PET)  (McGuire et al.,
1996).  Functional magnetic resonance imaging (fMRI) has an advantage of
greater temporal and spatial resolution than PET, but it has a
disadvantage of the production of scanner noise during image
acquisition.  We have therefore employed an event-related fMRI design
and scanner acquisition sequence to overcome this confound.
Method  
FMR images were acquired on a 1.5 Tesla GE Signa System.  Seven healthy
dextral male subjects read aloud adjectives and heard their voice which
were either: (i) undistorted; (ii) pitch distorted; (iii) replaced by an
"alien voice"; (iv) replaced by a distorted "alien voice". 
Results
The fMRI data revealed common areas of cerebral activations in an
extensive network which includes the basal ganglia, insula, and inferior
frontal, superior temporal, cingulate and cerebellar cortices. 
Conclusions
Modified event-related sequences provide a means of avoiding the effects
of scanner noise during fMRI.  Verbal self-monitoring involves a network
of areas implicated in the generation and perception of speech. 






CS3-2.3
"Mental states of oneself and others are distinctly implemented in the
human brain."
K. Vogeley, P. Bussfeld, A. Newen, S. Herrmann, F. Happé, P.
Falkai, J. Shah & K. Zilles

Contact:
Kai Vogeley

Department of Psychiatry
University of Bonn
Sigmund-Freud-Str. 25
D-53105 Bonn
GERMANY

vogeley@uni-bonn.de

The capacity for the meta-representation of one´s own mental
states is a human cognitive capacity, closely related to theory of mind
(TOM) paradigms in which mental states of others have to be modeled.
However, it was unknown, whether the meta-representation of mental
states of others and of oneself are differentially implemented in the
brain. To empirically address this issue, a fMRI study was performed,
employing a well-characterised "theory of mind" (TOM) paradigm, that was
extended to include self perspectivity stimuli in a two-factorial
design. Short stories with subsequent questions were presented to 8
right-handed normal male test persons in five different conditions
(control condition, TOM- SELF-, TOM+ SELF-, TOM+ SELF+. TOM- SELF+).
Activation associated with theory of mind-capacity was located in the
anterior cingulate gyrus, as shown in previous studies (Fletcher et al.,
Cognition 57, 109-128, 1995). Activation associated with self
perspectivity was mainly located in the right temporoparietal region,
closely related to the body image region in the right parietal lobe.
These results provide data on the cerebral implementation of a partial
feature of human self-consciousness and suggest, that self perspectivity
is involving the body axis as center of the ego-centered experiential
space.





CS3-3.1
"Stability phase transition in binocular rivalry"
Yoshi Tamori & Ken Mogi

Contact:
Yoshi Tamori

Human Information System Laboratories
Kanazawa Institute of Technology
3-1, Yatsukaho, Matto
Ishikawa 924-0838
JAPAN

yo@his.kanazawa-it.ac.jp

In binocular vision, there are two possible phases. Stable phase, when
we get a stable visual image in our visual awareness, and unstable
phase, when the percept we get changes with time. The latter phase is
best studied in the binocular rivalry paradigm. By using partially
low-path filtered (blurred) images of human face and natural objects, we
studied the factors which contribute to the above transition between
stable and unstable phases. Specifically, two images which have been
low-path filtered in alternating patchy regions were presented
binocularly. Under a certain range of parameters (e.g. cut-off frequency
used in blurring and the size of the blurred patchy regions), the
subject was able to see a stable and overall clear image. In this case,
the brain has successfully picked up alternating "sharp" regions and
constructed an overall sharp and stable image. Our analysis suggests
that in order to have a stable percept, the overall structural coherence
as well as a certain level of correlation between the binocularly
presented images are necessary. When there is structural coherence but
the correlation is low, the resulting percept becomes unstable. We
discuss the factors contributing to the stability of visual awareness.





CS3-3.2
"Evidence for multistability in visual perception of pigeons"
J.-D. Haynes, G. Vetter & S. Pfaff

Contact:
John-Dylan Haynes

Institute for Psychology and Cognition Research
University of Bremen
Grazer Str. 4
28359 Bremen
GERMANY

haynes@uni-bremen.de

Perceptual multistability refers to cases where perception alternates
between two or more interpretations of an unchanging sensory stimulus.
We performed experiments with pigeons (Columba Livia) in order to seek
for evidence for perceptual reversals. In a first experiment we trained
8 pigeons to discriminate horizontal and vertical apparent motion
stimuli and then presented a multistable motion display. In 5 cases
their behavior showed alternations similar to those known from human
experiments. In a second experiment we varied the aspect ratio of the
display in order to support the hypothesis of a percept-driven nature of
the switching behavior. The pecking rates and mean phase durations
varied as predicted: The animals responded significantly longer to the
pecking key associated with the biased stimulus. Also the animals that
did not reverse in experiment 1 now showed reversals. This is the first
evidence of visual multistability in animals confronted with classical
ambiguous figures. The data are evaluated and discussed in terms of
classical models, such as satiation/adaptation, top-down processes and
stochastic processes. Our results support a stochastic mechanism but
with slightly different parameters than known from humans and from
animal studies on binocular rivalry.





CS3-3.3
"What is salient in binocular rivalry"
Fumihiko Taya & Ken Mogi

Contact:
Ken Mogi

Sony Computer Science Laboratories
Takanawa Muse Bldg.
3-14-13, Higashigotanda
Shinagawa-ku, Tokyo, 141-0022
JAPAN

kenmogi@csl.sony.co.jp

We studied what stimulus features count as salient in binocular rivalry.
The stimuli were moving circles in a homogeneous background. There was a
variable phase difference between the circles moving in the images
presented to the right and left eyes. Under this condition, both circles
were visible most of the time, indicating that the ocular dominance
pattern is modulated in the spatio-temporal domain in such away that
salient features (moving circles) were visible most of the time.
Comparing this result with the control experiment where the circles were
stationary, we conclude that motion is very effective in determining the
ocular dominance pattern in binocular rivalry, suggesting a predominance
of the dorsal visual pathway. A further experiment involving interactive
computer graphics indicate that attention in general is dissociated from
the process which correlates with the ocular dominance pattern in
binocular rivalry. We thus arrive at a model of binocular rivalry
involving three phenomenological layers. What we see in binocular
rivalry is largely determined by the interaction between "pointers" and
qualia, where the pointers represent salient features. Attention has
only an indirect effect on visual awareness  through its amplification
of a particular pointer element.





CS3-4.1
"Attentional guidance based on a preattentive analysis of emotional
expression"
John D. Eastwood, Daniel Smilek & Philip M. Merikle

Contact:
John D. Eastwood

Department of Psychology
University of Waterloo
Waterloo, Ontario
N2L 3G1
CANADA

jdeastwo@watarts.uwaterloo.ca

To evaluate whether the focus of attention can be guided on the basis of
a preattentive analysis of the emotion expressed in a face, participants
searched displays of schematic faces for the location of a unique face
expressing either a positive or negative emotion. On each trial the
unique face was embedded among 6, 10, 14, or 18 distractor faces
expressing a neutral emotion. The slopes of the search functions for
locating the negative face were shallower than the slopes of the search
functions for locating the positive face. However, when the faces were
inverted to reduce holistic face perception, yet maintain feature
differences, the slopes of the search functions for locating positive
and negative faces did not differ. Taken together, the results suggest
that emotion can be perceived outside the focus of attention and that
focal attention can be guided on the basis of a preattentive analysis of
the emotion expressed in a face.





CS3-4.2
"Can emotions be dissociated from cognition?"
Susanne Erk & Henrik Walter

Contact:
Susanne Erk

Department of Psychiatry
University of Ulm
Leimgrubenweg 12-14
89075 Ulm
GERMANY

susanne.erk@medizin.uni-ulm.de

The development of neuroimaging techniques has considerably contributed
to recent progress in research on mental functions and emotions.
Functional neuroimaging studies focus on localizing emotions to
structures as amygdala, orbitofrontal cortex, basal ganglia,
hypothalamus or brainstem. Several studies have tried to correlate
specific emotions with specific activation patterns in these structures
but the results have been more or less inconclusive. Apart from
methodological problems we think that the reason is that most studies
have tried to isolate pure emotions. But whether emotions can be
isolated from cognitive processes at all naturally hinges on the
question of what emotions really are - a question for which a rather
huge number of answers exists. We propose a new concept of emotions
which is based on computational models as well as neuromodulatory
concepts of emotions. Emotions should be understood as modulators of
behavior and cognition - the "how" of information processing. This
approach has considerable implications for the role of emotions in
constructing a theory of consciousness as well as for functional
neuroimaging studies of emotions. We will present some of our own data
using fMRI as an example for the plausibility of this approach.





CS3-4.3
"Unconscious Emotions - Black Holes in the Cartesian Theatre?"
Christoph Jaeger & Anne Bartsch

Contact:
Christoph Jaeger

Universität Leipzig
Institut für Philosophie
Burgstr. 21
04109 Leipzig
GERMANY

cjaeger@uni-leipzig.de

In this paper we shall ask how recent psychological research on
repression bears upon philosophical models of the self. Specifically, we
shall discuss the consequences for the view that self-conscious subjects
enjoy epistemically privileged access to their current thoughts and
sensations. Although it is generally conceded that a tolerable
formulation of this old "Cartesian" claim requires refinements and
provisos, many philosophers (e.g. D. Davidson, S. Shoemaker) still hold
that there is at least the following asymmetry: for a vast number of
mental properties it holds that their ascriptions to others must rely on
behavioral evidence, whereas self-ascriptions thereof need not rest on
any such basis. However, recent psychological findings on emotional
self-deception and repression (D.A. Weinberger, G.E. Schwartz, M.N.
Davidson, K.W. Davidson, M. Mendolia,) seem to jeopardize even moderate
versions of such tenets, according to which people are at least
acquainted with their non-propositional, sensory mental states in a
direct, non-inferential way, and corresponding reports enjoy a special
first-person authority. Emotions seem to be paradigm examples of such
states. But if, as current psychological investigations suggest, even
emotions can be systematically ignored or misinterpreted, it seems that
one of the last bastions of special access is ruined. In our talk,
however, we shall argue that this conclusion is unwarranted. Relating
the issue of repression to neurological theories of emotional
information processing (LeDoux, Damasio), we shall argue, firstly, that
there is a primary, subcortical level of emotion that cannot, by causal
necessity, become conscious, and therefore can neither be a target of
repression nor a realm of the mind where privileged access claims make
sense. Repression must involve a representational level of potentially
conscious emotion. Following Damasio, we shall, secondly, introduce a
distinction between emotions and feelings, the latter being construed as
experienced emotions. The advocate of privileged access can argue that
emotional repression does not threaten his claim with regard to
feelings, since they do have phenomenal content for their subjects.
Thirdly, and perhaps most importantly, it will be shown that the very
concept of repression only makes sense on the assumption that privileged
access to (potentially conscious) emotions exists.





CS4-1.1
"Sensory Qualities, Concsiousness, and Perception"
David M. Rosenthal

Contact:
David M. Rosenthal

Ph.D. Program in Philosophy
CUNY Graduate Center
365 Fifth Avenue
New York, NY  10016-4309
USA

dro@ruccs.rutgers.edu

For a mental state to count as a sensation of any sort, it must have
qualitative properties.  But there is a popular notion that a state's
having qualitative properties means that there is something that it's
like to be in that state--something that it's like _for the subject_. 
And, since there is something it's like for one to be in a state that
isn't conscious, all sensations must, on this view, be conscious. One of
my aims here will be to undermine this conception of what sensations
are, which I believe is unfounded theoretically and unsupported by any
reliable commonsense intuition.  I'll argue that clarity about just what
properties are essential to a state's being a sensation leaves no doubt
that states can have those properties without being conscious.  I'll
then briefly sketch the higher-order-thought model of consciousness I've
developed elsewhere, and argue that, contrary to what some critics have
claimed, this model does justice to what's involved in there being
something it's like for one to have conscious sensations.  I'll conclude
with an account of the qualitative properties of sensations which both
fits with and sustains the earlier arguments.





CS4-1.2
"Constrained inversions of sensations"
Erik Myin

Contact:
Erik Myin

AI Lab (WE Arti) & Wijsbegeerte (LW EMEP)
Vrije Universiteit Brussel
Pleinlaan 2
B-1050 Brussel
BELGIUM

emyin@vub.ac.be

Inverted sensation arguments such as the inverted spectrum thought
experiment are often criticised for relying on an unconstrained notion
of 'qualia'. In reply to this criticism, 'qualia-free' arguments for
inversion have been proposed, in which only physical changes happen:
inversions in the world (e.g. the replacement of surface colors by their
complements) and a rewiring of pheripheral input cables to more central
areas in the nervous system. I show why such constrained inversion
arguments won't work. The first problem is that the world lacks the
symmetry to invert physical properties in the way required. The second
problems concerns 'rewiring'. Empirical evidence indicates that the
necessary rewirings are either impossible, or would not result in an
inversion of sensations. This is illustrated by detailed examples
involving both lightness and hue inversion. I propose the deeper reason
for the failure of constrained inversion arguments lies in the fact that
sensations are not properties of brain states, but spread into the world
and the body.





CS4-1.3
"Capturing Qualia:  Higher-order Concepts and Connectionism"
Bryon Cunningham

Contact:
Bryon Cunningham

Department of Philosophy
Emory University
Bowden Hall, 214
561 S. Kilgo Circle 
Atlanta, GA 30322
USA

bcunn03@emory.edu

Antireductionist philosophers have argued for higher-order
classifications of qualia that locate consciousness outside the scope of
conventional scientific explanations, viz., by classifying qualia as
intrinsic, basic, or subjective properties, antireductionists
distinguish qualia from extrinsic, complex, and objective properties,
and thereby distinguish conscious mental states from the possible
explananda of functionalist or physicalist explanations.  In this paper
I argue that, in important respects, qualia are intrinsic, basic, and
subjective properties of conscious mental states, and that, contrary to
popular opinion, this higher-order classification is compatible with
qualia reduction.  This is shown by taking a closer look at the putative
higher-order properties of qualia and comparing them to the higher-order
properties characteristic of connectionist models of cognitive
processes. It is my contention that the higher-order properties
characteristic of connectionist networks approximate (in intertheoretic
terms) the putative higher-order properties of qualia sufficiently well
to conclude that qualia reductionism can accommodate: (1) claims that
qualia are intrinsic, basic, and subjective properties; and (2) the
motivating intuitions for those claims generated by inverted, absent,
and alien qualia thought experiments.  In this way I argue that
(approximate versions of) the putative higher-order classifications of
qualia not only fail to defeat qualia reduction but, ironically, turn
out to support it.





CS4-1.4
"Continuity and Consciousness"
William S. Robinson 

Contact:
William S. Robinson

Department of Philosophy and Religious Studies
402 Catt Hall
Iowa State University
Ames, IA  50011-1306
USA

wsrob@iastate.edu

It seems that many experiences exhibit continuity, e.g., foghorn sounds
are spread out in time without interspersed silences, and ice cubes of
the kind that Sellars called "homogeneously pink" are pink throughout,
pink without gaps in the color expanse. A realist about continuity holds
that apparently continuous spread of qualities of external things is
possible because there actually is strictly continuous spread of
phenomenal qualities in consciousness. The first part of the present
paper defends realism about continuity against a highly developed
critique by Austen Clark. Key distinctions here are between conditions
on causes of appearances and conditions on appearances themselves, and
between continuity of phenomenal qualities (or 'regionality' as
contrasted with punctate character), and continuity of changes of
phenomenal qualities. An implication of the first part is that
continuity is a kind of unity (of phenomenal qualities with time and in
some cases with both time and space). The second part of the paper
articulates the nature of this unity, and investigates how it, and its
causes, are similar and different to other kinds of unities, and their
causes. This part of the paper thus clarifies the range of phenomena
that a theory of causes of consciousness must explain.





CS4-2.1
"The Dimensions of Conscious Experience: A Quantitative Analysis"
Steven Lehar

Contact:
Steven Lehar

Schepens Eye Research Institute
14 Crooked Lane
Manchester MA, 01944
USA 


slehar@cns.bu.edu

There are many fundamental   properties of visual experience  that are
difficult to  account for, not only in  terms of contemporary theories
of   neural  representation,  but even   in  more  general   terms  of
computational theory.    In   the  first   place  vision  is   vividly
three-dimensional,  consisting of   solid volumes,  bounded by colored
surfaces, embedded  in a spatial void.   Every point  on every visible
surface produces  a distinct experience  of  color.  The perception of
transparency,  and the experience of  empty space between the observer
and a  visible surface, demonstrate that  multiple depth values can be
experienced in every direction in visual space. Furthermore, perceived
objects  are observed  to   translate  and rotate coherently   through
perceived space    while maintaining their  structural   integrity and
recognized identity, even  through perspective and elastic distortion.
These   properties  of   perception have    been  so   problematic for
contemporary  theories    of neurocomputation  that    they have  been
essentially ignored.   I  propose a perceptual  modeling  approach, as
opposed to a neural modeling  approach, i.e.  to model the  subjective
experience of   vision   in  quantitative   terms,  rather  than   the
neurophysiological  mechanism  by which that experience  is subserved.
This approach leads to new insights into  the nature of the perceptual
transformation, and the informational content of conscious experience.





CS4-2.2
"Is Language Structure Accessible to Consciousness?"
Maxim I. Stamenov

Contact:
Maxim I. Stamenov

Institute of the Bulgarian Language
Bulgarian Academy of Sciences
Shipchenski Prokhod St. 52, bl. 17
1113 Sofia
BULGARIA

maxstam@bas.bg

One of the great puzzles in cognitive sciences is the problem about the
way of accessibility and representability of cognitive structure within
and outside consciousness. Here the views expressed by different authors
diverge radically. Searle (1992) made the point that for some mental
content to be considered as such, it MUST be in principle accessible to
consciousness. Those 'contents' which are in principle inaccessible to
consciousness actually do not belong to the province of the mental but
are just 'brute neurophysiological facts'. Chomsky (1965, 1993, 1995),
on the other hand, in many publications repeatedly pointed out that
language structure is in principle inaccessible to consciousness.
Chomsky's argumentation possesses some specific features based on the
methodology of the study of language. His points are sometimes not well
appreciated outside linguistics. The aim of this paper will be to
elucidate with appropriate examples why Chomsky found possible to
maintain such an 'extravagant' position regarding the relationship
between language and consciousness.





CS4-2.3
"On the unitary representation of the visual world: global criterion
constraints in local visual awareness"
Andrei Gorea & Dov Sagi

Contact:
Andrei Gorea

Laboratoire de Psychologie Expérimentale
CNRS & René Descartes University
71 Ave. Edouard Vaillant
92774 Boulogne-Billancourt, Cedex
FRANCE

gorea@psycho.univ-paris5.fr

Perceptual studies make a clear distinction between sensitivity and
decision-criterion. The former is taken to characterise the processing
efficiency of the underlying sensory system and it increases with
stimulus strength. The latter is regarded as the manifestation of a
subjective operation whereby individuals decide on (as opposed to react
reflexively to) the occurrence of an event based on factors such as
expectation and pay-off, in addition to its intensity. To do so,
individuals need to have some knowledge of the internal response
distribution evoked by this event. In a natural, multi-stimulus
environment, observers must handle many such independent distributions
in order to optimise their decision criteria. Here we show that they
cannot do so. Instead observers adjust each criterion in relation to the
internal distributions generated by the concurrent stimuli. The
consequence of this global constraint is that less visible events are
reported less frequently in the presence of more visible ones, whereas
the latter are reported more frequently in the presence of the former.
The specifics of this behaviour are in quantitative agreement with
predictions based on the notion that observers represent a
multi-stimulus environment as a unitary internal distribution to which
each stimulus contributes proportionally to its probability of
occurrence. This "unity" of the internal representation of the external
world may underlie, or be tantamount to the unity of the (visual) world
as experienced. It may account at least in part for a number of
intriguing perceptual phenomena such as blindsight, hemineglect and
extinction.





CS4-2.4
"The tri-partite system of consciousness"
Benny Shanon

Contact:
Benny Shanon

Department of Psychology
The Hebrew University
Mount Scopus
Jerusalem
ISREAL

msshanon@mscc.huji.ac.il

On the basis of a review of the literature coupled with a
phenomenological analysis, it is proposed that consciousness be regarded
as a unified system comprising of three states. The first, and
fundamental, state is one of ill-defined, undifferentiated qualities;
the second, which is the pivotal one, is that of well-defined,
articulated patterns of expression and behavior; the third is a
second-order state taking the patterns of the second state as objects
for manipulation and reflection. These three states are encountered in
all different facets of the system of consciousness: subjective
experience, the self, meaning and time. For instance, in the case of
subjective experience, the three states are manifested in the phenomena
of sentience, internal mentation and reflective meta-cognition,
respectively. It appears that there are regular relationships between
the three states so that together they define one coherent and
internally structured system. Furthermore, a dynamic perspective may be
taken whereby the system is viewed in terms of the functional mappings
between the states. These mappings may be regarded as "the acts of
consciousness". Among them are internalization, differentiation,
objectivization and world-building. The discussion is grounded in a
pragmatic approach by which the basic capability of the human cognitive
system is being-in- and acting-in-the-world. It is proposed that the
systematic study of the acts of consciousness defines a new paradigm of
psychological investigation. Theoretically, this paradigm conceptualizes
psychology as the study of  human experience; methodologically, it is
based on systematic phenomenology.





CS4-3.1
"The mechanism of action of hallucinogenic drugs"
Hans Flohr

Contact:
Hans Flohr

Brain Research Institute
University of Bremen
P.O. Box 33 04 40
28334 Bremen
GERMANY

flohr@uni-bremen.de

Hallucinogenic drugs cause altered states of consciousness,
characterized by sensory illusions, hallucinations, disorganized thought
and bizarre ego-disorders. According to their site of action one can
distinguish three groups of hallucinogens:
(1.) partial serotonin agonists, like LSD and mescaline,
(2.) anticholinergic drugs, like scopolamine and atropine,
(3.) non-competitive NMDA antagonists, like phencyclidine and ketamine.
In spite of their different targets the psychedelic symptoms caused by
the different hallucinogens are remarkably similar. Here we propose a
hypothesis on the mechanism of action of psychedelic drugs that (1.)
leads to a realization hypothesis for altered states of consciousness
and (2.) can explain this similarity:

(1.) Hallucinogenic effects are due to a common mechanism of action
distal from the primary target. The ultimate target relevant for the
occurence of altered states of consciousness is the formation of
large-scale neuronal assemblies which is made possible by the cortical
NMDA synapse.

(2.) All hallucinogenic drugs directly or indirectly inhibit the NMDA
receptor and thereby the induction of activity-dependent, rapid plastic
processes controlled by this receptor.

This hypothesis is in line with previous hypotheses on the key role of
the NMDA synapse in the realization of conscious states (Flohr 1991,
1995a, b). According to these hypotheses the NMDA synapse implements the
binding mechanism that the brain uses to produce large-scale neuronal
assemblies which instantiate higher-order representations. Abnormal
states of consciousness are produced, iff this binding mechanism is
disturbed and deformed higher-order representations are generated.

Flohr, H. (1991) Theory and Psychology 1, 245-262
Flohr, H. (1995a) Neuropsychologia 33, 1169-1180
Flohr, H. (1995b) Behav.Brain Res. 71, 157-161






CS4-3.2
"Interaction between precuneus and dorsolateral prefrontal cortex may
play a unitary role in consciousness - A principal component analysis of
rCBF"
Troels W. Kjaer & Hans C. Lou

Contact:
Troels W Kjaer

The John F. Kennedy Institute
Gl. Landevej 7
DK-2600 Glostrup
DENMARK

neurology@dadlnet.dk

A fundamental principle in the neural organization in all mammals is a
division into two major moieties, a posterior for perception and an
anterior for action. The dichotomy is present in the spinal cord, in the
diencephalon and extends upwards into the cerebral cortex, where the
regions posterior to the central sulcus are dedicated to perception, and
those in front to action. The perception-action-cycle suggested by
Fuster (1995), implies that consciousness of goal directed action is a
function of interaction between polymodal cortices in the perceptory and
executory domains. It is hypothesized that if neural activity here
exceed some threshold in intensity and / or time consciousness occurs.
We hypothesize that this axis has a mere general role in consciousness
independent of action. To test this hypothesis we analyzed H2O15-PET
data on regional cerebral blood flow from 42 PET scans of 7 yoga
practitioners during attentive