Following up on the highly successful experiences of previous ASSC conferences, ASSC4 will again be preceded by a full day of workshops designed to allow researchers and students alike to gain a background in potentially relevant areas that they may know little about.
Each workshop is intended to last approximately three hours. The sizes of workshops will vary between a minimum of 10 to a maximum of around 25 people, thus enabling close interaction between workshop presenters and participants.
For further information about workshops, please contact the workshop coordinator, Patrick Wilken: firstname.lastname@example.org.
To register for one or (maximum) two workshops, please see the registration pages.
|Thursday Morning, June 29th||Thursday Afternoon, June 29th|
|W01: Frith & Rees||W07: Lloyd|
|W02: Reber & Paller||W08: Rensink & Simons|
|W03: Metzinger & Engel||W09: Andrade & Jones|
|W04: Cole, Depraz & Gallagher||W10: Baars, Tononi & Bickle|
|W05: Rosenthal||W11: Keenan|
|W06: Revonsuo||W12: Velmans|
|W01||Chris Frith & Geraint Rees:
On the Use of Brain Imaging to Study the Neural Correlates of Consciousness
In this workshop we will:
|W02||Paul J. Reber & Ken A. Paller:
Neural Correlates of Conscious and Nonconscious Memory
One particularly fruitful way to try to understand the contrast between
conscious and nonconscious processing has been to study dissociations in
Evidence for distinct neural substrates for two types of memory, declarative and nondeclarative, has been principally drawn from a large number of studies of patients with memory disorders due to neurological damage. Measuring the activity of the human brain can provide many clues about the neurophysiological mechanisms responsible for conscious and unconscious memory. In particular, the subjective experience of remembering appears to be closely associated with the ability to recall and recognize facts and events, often termed declarative or explicit memory.
This workshop will consider a rapidly growing body of investigations using ERPs and fMRI to explore brain mechanisms of multiple forms of memory and consciousness. Evidence that patterns of neural activity associated with conscious and nonconscious memory can be differentiated not only reinforces the neuropsychological dissociations but is also helpful for generating and testing new hypotheses about the operation of these types of memory. This work may thus lead to a better understanding of the enigmatic border between conscious and unconscious memory. The application of neuroimaging techniques to the study of memory systems should also serve to illustrate how neuroscientific study of the brain can provide insight into cognitive phenomena that are associated with conscious and nonconscious processing.
|W03||Thomas Metzinger & Andreas Engel:
Constraining Consciousness: Towards a Systematic Catalogue of Explananda
From a methodological point of view, the newly emerged field of
consciousness research has two main characteristics. First, it is currently
in a 'preparadigmatic' stage: There is no single,
comprehensive theory of consciousness in existence, which could function as
a unified background for research or as a shared departure point for
constructive criticism. Second, there is no accepted canon of explananda: We
still don't have a systematic catalogue of what it is that is to be
explained, a clear and rigorous list of research targets, which can be
continuously refined and developed as work progresses. Therefore, the
process of hypothesis generation takes place in a completely unsystematic manner. This workshop
will make a first attempt of tackling the second problem, adopting a
"theory-of-science" stance to the field.
Hour One (Thomas Metzinger):
|W04||Jonathan Cole, Natalie Depraz & Shaun Gallagher:
Unity and Disunity in Bodily Awareness: Phenomenology and Neuroscience
In this workshop we explore how one's body, and especially motor behavior,
shapes conscious experience. To what extent, and in what precise way is
the body present in perceptual experience? Is it possible to have a
non-perceptual present awareness of one's body? To what extent does the
unity of perceptual consciousness depend on the phenomenological
transparency of the body? How does motoric behavior, much of which is not
conscious, affect conscious experience? What is the relationship between
consciousness and gestural movement? We address these issues from several
Outline of workshop:
Consciousness and the Philosophy of Mind
The workshop will provide an background overview of recent and
contemporary philosophical literature about the mind relevant to the
scientific study of consciousness.
There will be three sections, each of about an hour. The first will provide some general background in philosophy of mind. Building on that background, the second section will focus on specific questions about consciousness that have figured prominently in the recent philosophical literature. The third section will survey the major theoretical approaches to consciousness found in that literature and perhaps explore some connections these approaches have with empirical work about consciousness.
I. General Background in Philosophy of Mind
Recent work in the philosophy of mind clusters around four main questions. Two have a distinctively philosophical cast: the meta- physical problem of the relation of mind and body and the epistemo- logical problem of how we know about the minds of others. The other two problems are independent of such traditional philosophical concerns: the question of how to characterize the various types of mental phenomena (what I'll call the "characterization problem") and of how mental phenomena figure in psychological explanation (the "explanation problem").
All four problems are crucial for understanding current philosophical discussions of consciousness. (1) The mind-body problem has led to questions about whether conscious qualitative properties outstrip physical reality (Frank Jackson's "Knowledge Argument") and David Chalmers's "Hard Problem" about how conscious qualitative states can occur in physical systems. (2) The other-minds problem raises issues about the special, privileged access we seem to have to our own conscious states. (3) The characterization problem points to the question of whether the various kinds of mental state can occur without being conscious and, if so, in virtue of what conscious states differ from states that are not conscious. It also raises issues, highlighted by Ned Block and others, about whether there are distinct, independent properties we refer to under the heading of consciousness. (4) The explanation problem, finally, raises Joseph Levine's question about whether an explanatory gap separates physical processes from qualitative consciousness, as well as the question whether consciousness has any distinctive function.
II. Philosophical Questions about ConsciousnessBuilding on this background, the workshop will focus on discussion in the recent philosophical literature of four clusters of questions specifically about consciousness.
Recent discussions of consciousness in the philosophical literature fall into two main groups: those which represent consciousness as an intrinsic property of mental states and those which represent it as a relation conscious states bear to something else.
Intrinsicalist views describe consciousness by way of a relatively small circle of interdefined notions, such as subjectivity, perspective, point of view, and the like. So these views do not lend themselves to giving an informative, scientific account of consciousness with empirically testable consequences. Thomas Nagel's view, on which the subjective, perspectival character of conscious mental phenomena precludes any objective account of their nature, is usefully seen as an example of this kind of approach. (This is different from Colin McGinn's view that limitations on our mental nature itself preclude our developing or even understanding any informative account of consciousness.)
Relational models, by contrast, readily lend themselves to empirically testable predictions and explanations. The standard example of such a model is the "Inner Sense" view, on which a mental state's being conscious consists in one's sensing it. A second relational model discussed in the recent philosophical literature is Daniel Dennett's Multiple Drafts Model, on which consciousness is the continually revised result of many interacting subpersonal processes. A third version is the higher-order-thought hypothesis, on which a state's being conscious consists in one's having a non-conscious, noninferential thought that one is in that state.
These three models will be discussed, possibly in connection with such topics of current empirical research as metacognition, confabulatory introspective reports, blindsight and other dissociative disorders, confabulatory introspective reports, and the causal efficacy of conscious, voluntary decision. (Because our concern will be with how to characterize consciousness, we will not address questions about the neural correlates of consciousness.)
David Rosenthal - City University of New York
Binding and the Unity of Consciousness
The binding problem appears in different forms in neuroscience,
cognitive science and consciousness research. In this workshop we will
clarify how these formulations differ from each other and what the
relation between the binding problem and the classical problem of the
unity of consciousness is. Some of the formulations of the binding
problem make no mention of consciousness, whereas others are directly
related to aspects of phenomenal experience. Certain formulations are
closely connected to the currently fashionable search for the neural
correlates of consciousness. We will review the latest theories and
discoveries that concern the binding problem, including the views of
some of the plenary speakers in the conference (e.g. Engel, Treisman,
Zeki). Many of the issues discussed in the workshop can be found in the
Special Issue on Binding and Consciousness, Consciousness and Cognition
8 (2), June 1999, which is recommended reading. This workshop is meant
to function as a useful introduction to some of the central issues in
the rest of the conference.
Antti Revonsuo - University of Turku
Unity, Association, and Dissociation of Temporal Consciousness in Recurrent Neural Networks
The unity of consciousness over time is one of the fundamental issues of
classical phenomenology. Husserl, for example, devoted much of his
Phenomenology of Internal Time Consciousness to an analysis of the
structure of the experienced now, which he noted contained within it a
retention of the past and anticipation of the future. This fundamental
aspect of consciousness studies is only indirectly treated in cognitive
science, in the study of working memory and prospective memory. This workshop
will explore topics in the underlying neural architecture of the unity of
temporal consciousness. Issues to be addressed include the following:
Workshop participants will receive complete specifications of the models discussed, and access to a public domain modeling software environment that readily permits construction of recurrent network models, and includes a built-in utility for cluster analysis and principle components analysis. Since I will have the models with me in a laptop, there will be time during and after the workshop to conduct new experiments as well.
Dan Lloyd - Trinity College
|W08||Ron Rensink & Dan Simons:
Change Detection, Attention, and the Contents of Awareness
This workshop will examine recent evidence from the study of change
blindness: the surprising finding that people fail to notice large
changes to natural scenes. Such findings are particularly striking in
the face of metacognition about change detection. People feel that they
would detect such changes despite the fact that they rarely do. Such
impressions are founded on the intuitive belief that we represent the
details of our visual world. Yet, recent evidence that people fail to
notice large changes to images of natural scenes across eye movements,
blank screens, movie cuts, and real world occlusion events suggests that
we may not.
We will review the conclusions that can be drawn from change blindness and from related phenomena. Specifically, we consider what these phenomena can tell us about the structure and accessibility of our representations. In so doing, we will also examine recent evidence that change blindness may simply indicate our lack of awareness of the representations we do have. In other words, non-conscious, implicit representations of the details of scenes may at least partially underlie our experience of a stable, continuous visual world. We will also discuss how the techniques used to study change detection may help to determine the role of attention and effort in the formation of both conscious and non-conscious representations. At the end of the workshop, we will consider how the mechanisms underlying change blindness and change detection work together to provide a continuous, stable impression of our visual world.
The workshop will be segmented roughly as follows:
Hour 1: Intentional detection of change
|W09||Jackie Andrade & Gareth Jones:
Anaesthesia as a tool for exploring consciousness
Imagine having drugs with which, simply by varying the dose, you could
produce alterations in consciousness ranging from mild cognitive impairment
to temporary coma. Such drugs could open up a whole range of exciting
possibilities for consciousness research, and they already exist in the
form of commonly used general anaesthetic agents. This workshop will review
the current literature on cognition during anaesthesia and discuss its
implications for our understanding of consciousness. It will discuss some
of the practical problems with using anaesthetics as a research tool and
suggest some methodological solutions. It will be divided into three
sections, each of which will review the current literature and discuss
avenues for future research:
1. Learning during general anaesthesia
2. Measuring depth of anaesthesia
3. The effects of impaired consciousness on cognition
|W10||Bernard Baars, Giulio Tononi & John Bickle:
Criteria for consciousness in the brain: Methodological implications of recent developments in cognitive neuroscience
When can scientists infer that some brain activity underlies conscious
experience? This workshop reviews 7 sets of studies that make claims
about consciousness in the brain. Each set appears to support at least
one criterion for consciousness: most use the widely used operational
index of accurate reportability of conscious events; some refer to the
distinctive neuroanatomy, neurochemistry, and neuroelectrical activity
of waking consciousness; some to the cortical properties of conscious
contents when compared to matched unconscious events; to local causal
evocation of conscious events; to correspondences between reported
conscious experiences and brain events in timing, topography, and
connectivity; to plausible relations to other known features of
conscious processes, such as limited capacity and a wide range of
contents; and finally, a few studies aim to establish discriminative
validity, to separate the brain basis of consciousness from related
constructs like selective attention, working memory, executive control
and sensory knowledge. Taken together these studies set a very high
threshold for the identification of brain events underlying
Hour 1. Current operational definitions and waking consciousness
Introduction. An historic PET scan obtained by Paulesu and colleagues (Paulesu, Frith & Frackowiak, 1993, shown in Baddeley, 1993) shows regions of high metabolic activity in the left hemisphere speech areas of a subject engaged in silent mental rehearsal. But it is not obvious from the PET scan which "hot spots" involve conscious events. This article helps to exemplify the kinds of questions and answers one can raise about the brain basis of conscious experience.
Current operational definitions. Accurate reportability of a wide range of stimuli is widely taken to be the most natural observable index of conscious sensory experiences. A remarkable study by Cowey & Stoerig (1995) made use of a commentary response to test whether macaques with cortical blindness lose the phenomenal visual qualia like color and motion, which humans report losing with similar brain damage. This approach may provide an equivalent to the reportability criterion in humans.
Properties of the conscious waking state. Waking consciousness has a distinctive anatomical, neuroelectrical, and neurochemical signature, separate from unconscious or low-conscious states. Consciousness during REM sleep resembles waking consciousness in many respects. Slow-wave sleep shares similarities with some comas, high-dose general anesthesia, and epileptic states of absence.
Much evidence supports the idea that conscious contents such as perceptual experiences or inner speech, require waking consciousness. This commonsense idea has been challenged by the finding that people woken up from slow-wave sleep may report mental activity, though different from typical REM dream reports (Foulkes, 1996; Cavallero et al, 1990).
Hour Two: Experiments contrasting conscious and unconscious brain events.
Studies showing differences between conscious and unconscious contents in the awake brain. These studies treat consciousness of a given content as an experimental variable. For example, binocular rivalry allows similar content to be presented to two eyes, though only one eye will be conscious. The brain responses to the conscious and unconscious input can therefore be compared. As Crick (1996) has written, "Binocular rivalry is a phenomenon of importance in its own right; but its real importance is that it may shed light on the baffling problem of visual awareness, a visual form of consciousness."
Local causal evocation of specific conscious contents. Local stimulation of isolated retina does not lead to conscious experiences. But local stimulation of visual cortex does lead to conscious phosphenes, which have recently been used as a prosthesis for the blind. Very local stimulation of visual neurons in area MT have also been shown to change the perception of visual events in the macaque (Newsome, 1993). Conversely, interference with normal cortical processes also blocks ordinary conscious visual contents.
Studies showing explicit neuronal correspondence between brain events and reported experiences. Crick and Koch (1995) have argued that area V1 does not explicitly represent visually conscious information, because its neurons do not respond to visual features that are lost from consciousness when V1 is lesioned. This suggests a more general criterion. Studies by Logothetis and coworkers illustrate this kind of evidence.
Hour Three: A set of criteria for brain proposals.
The five kinds of studies cited above can provide criteria to be met by any adequate theory of the brain basis of consciousness. Two more can be added.
Studies showing plausible relations to other known features of conscious processes. Any candidate brain basis for consciousness should be consistent with other well-established features, like limited moment-to-moment conscious capacity and a wide range of potential conscious contents. (Baars, 1988, 1997, 1999; Searle, 1994).
Discriminative validity.The brain basis for consciousness must be distinct from related constructs like selective attention, working memory, sensory knowledge and executive control.
|W11||Julian Paul Keenan:
Repetitive Transcranial Magnetic Stimulation:
Implications for Research on Consciousness
Philosophical issues, including topics of consciousness, are now
routinely addressed employing functional neuroimaging. Techniques now
widely available including functional Magnetic Resonance Imaging (fMRI)
and Positron Emission Tomography (PET) are providing fundamental answers
to questions relating to consciousness. However, reliance on these
techniques is problematic as the data provided by such methods reveals
only correlation information, which is further complicated by the
indirect measure of neuronal activity via blood oxygenation and the
reliance on control tasks. Repetitive Transcranial Magnetic Stimulation
(rTMS) provides a non-invasive method for establishing causal and
necessary components within cortical networks. When combined with
traditional functional methods such as fMRI and PET, questions as to the
direct nature of cognition and consciousness can be addressed. The use
of this technique is not limited, and the adaptation of rTMS employing
numerous methodolog ies allows for a flexible and specific test of
A description of the cortical process of self-awareness is far from complete, though networks for cognitive processes that are related (e.g., Theory of Mind) are beginning to be elucidated. The integration of rTMS with traditional neuroimaging methods addressing the cortical correlates of self-awareness provides a background in which researchers interested in consciousness may develop an understanding of rTMS. This workshop will therefore provide an introduction into the methodologies of rTMS within the context of examining higher-order cognitive processes with a specific emphasis on self-directed awareness.
The topics as follows:
The participants of the workshop should expect to leave the workshop with an firm and thorough introduction as to the methodologies of rTMS. Further, the participant will be in a position to implement his or her own questions of consciousness within the rTMS environment. Therefore the goals of the workshop are to a) Provide an introduction to those unfamiliar with rTMS, b) Demonstrate that rTMS can be a powerful tool in tests of hypotheses related to higher-order consciousness, c) Provide information and practical information regarding the integration of rTMS with fMRI and PET, d) Evaluate the shortcomings of the technique, and e) Provide enough information to the participant so that he or she can independently evaluate the validity of rTMS for use with his or her own research. This workshop is intended for persons with an interest in neuroimaging, and no previous experience with functional techniques is assumed.
Julian Paul Keenan - Harvard Medical School
Four ways of understanding consciousness: conceptual blocks in dualism, physicalism, functionalism and reflexive monism
There is not one consciousness/brain problem, but many. These
can be roughly divided into four groups, focused on the following
Similarly, it seems obvious that consciousness has a function. Indeed, according to evolutionary theory consciousness must have a function otherwise it would not have evolved to be so central in our lives. There have been many proposals in the scientific literature about what that function might be. Common suggestions are that consciousness is necessary to deal with novelty or complexity, to provide feedback, to enable memory and learning, to enable language and problem solving, to enable imaginal short and long-term planning in advance of carrying out acts in the real world, and so on. However these proposals face a central dilemma: Once one can specify how such functions work in information processing terms, one no longer seems to need consciousness to explain the working of the system which embodies that processing. One can envisage the same processes operating in mechanical or electrical systems unaccompanied by any subjective conscious experiences. So - what, if anything, does subjective experience add to effective functioning? Questions 1 to 4 also interconnect. If one is not clear about what consciousness is, how can one find its neural substrates in the brain? Nor can questions about causal efficacy be dissociated from questions about function. If consciousness has no causal influence on neuronal activity, it is not easy to see what its function in the brain's activity could be.
This workshop summarises the strengths and weaknesses of current attempts to deal with these problems within dualism, physicalism, and functionalism. Given the overall focus of the conference on information integration, we will give particular attention to the proposal that consciousness carries out the functions of a "global workspace" concerned with information integration and dissemination (a form of psychofunctionalism). The workshop will also introduce reflexive monism, an alternative approach to such problems, developed in depth in Understanding Consciousness(Routledge, 2000).
Max Velmans - University of London