CONFERENCE ABSTRACTS

On this page you will find a pure text listing of all the presentations to be delivered at ASSC6. They are listed in the order of their code, starting with the plenary lectures.

You can easily locate the contribution of any particular author by using your browser's find function. To print the entire document, simply select the text and paste it into any text processing package.

(These abstracts will also be available at the ASSC6 book, delivered at the Welcome Desk of the Science Museum.)

 

PL-01
Aware or unaware? Verbal and Non-Verbal Assessment of Blindsight
Petra Stoerig

Contact:
Petra Stoerig (petra.stoerig@uni-duesseldorf.de)
Institut für Experimentelle Psychologie II Heinrich-Heine-Universität
Universitätsstr. 1
D-40225 Düsseldorf
GERMANY

In human and non-human primates, lesions of the primary visual cortex produce visual field defects. Again in both species, residual detection, localization, and discrimination of visual targets can be demonstrated with
forced-choice paradigms, but only the human patients can be asked whether or not they perceive any of the stimuli they respond to. To learn whether the disscociation between visual awareness and visually guided behaviour that characterizes Blindsight is found in both species, Alan Cowey and I combined a forced-choice localization with a signal detection task in an attempt to non-verbally assess visual awareness. Four hemianopic monkeys and four human subjects, two with absolute defects, one with a relative hemianopia, and one with absolute as well as relative regions of cortical blindnesss were tested. First, 2AFC manual localization of 200ms square-wave grating stimuli was measured as a function of contrast. In addition, the human subjects gave verbal 'seen'-responses which were consistently at 0% in the absolutely blind regions. The second task was similar to the first in that stimuli which could appear in either hemifield were to be localized as before. In addition, on a varying proportion of trials no stimulus appeared, and to indicate these blank trials, a 'no'-area now constantly present above the central startlight was to be touched. Results showed that the human subjects' indicated a blank whenever a localizable stimulus appeared in the absolute defect, but indicated a stimulus on a proportion of trials presented in the relative defects. The non-verbal responses thus matched the verbal ones quite well. As the monkeys only very rarely touched stimuli in their hemianopic field when being given the chance to indicate a blank instead, it seems that monkeys have no conscious vision in the hemianopic field but show blindsight like human patients.

PL-02
On the content of chimpanzee consciousness
Daniel J. Povinelli

Contact:
Daniel J. Povinelli (ceg@louisiana.edu)
Institute of Cognitive Science
University of Louisiana at Lafayette
Rougeou Hall Room 348
241 East Lewis Street Lafayette
Lafayette, LA 70504-3772
USA

In this talk, I describe a theory concerning differences in the nature of the concepts which may populate the minds of chimpanzees and humans. Although the minds of humans and chimpanzees may share many kinds of concepts in common, recent evidence suggests that chimpanzees may be quite limited in their ability to generate concepts of unobservable entities. In particular, I review the evidence concerning their understanding of mental states (e.g., intentions, beliefs, perceptions, desires) and causal phenomena (e.g., gravity, force, weight, physical connection). I conclude that although concepts of these kinds develop early in human development, there is substantial reason to think that chimpanzees do not form them at all. Instead, they appear to be specialized in reasoning about the observable manifestations of such unobservable states and phenomena.

PL-03
Rationality and Reasoning Without Language
José Luis Bermúdez

Contact:
José Luis Bermúdez (jb10@stir.ac.uk)
Department of Philosophy
University of Stirling
Stirling FK9 4LA

Explaining the behavior of non-linguistic creatures in psychological terms requires attributing to them beliefs and desires that in some sense rationalize their actions. Clearly, therefore, we need a notion of rationality that is applicable at the non-linguistic level. The paper suggests that the standard inference-based conception of rationality is inapplicable to non-linguistic creatures. There is no evidence of mastery of logical concepts in the absence of language. The paper describes three different senses in which the behaviour of non-linguistic creatures can be described as rational and explores the consequences for our understanding of non-linguistic creatures.

PL-04
The early development of executive function: A levels of consciousness approach
Philip David Zelazo

Contact:
Philip David Zelazo (Zelazo@psych.utoronto.ca)
Department of Psychology
University of Toronto 100
St. George Street
Toronto, ON M5S 3G3
CANADA

In this talk, I will discuss the Levels of Consciousness (LOC) Model, according to which age-related in the conscious control of behavior depend on age-related increases in self-reflection that permit children to formulate and use increasingly complex systems of action-oriented verbal rules.

PL-05
A dualism of dependent variables
Larry Weiskrantz

Contact:
Larry Weiskrantz (larry.weiskrantz@psy.ox.ac.uk)
University of Oxford
Dept. of Experimental Psychology
South Parks Road
Oxford OX1 3UD
UK

Several examples - taken mainly from neuropsychology - will be given of the insufficiency of on-line measures for concluding that a person or animal is conscious of ongoing events (Astate consciousness@). Off-line confirmation as well as the on-line measure is necessary. In humans this is typically, but not necessarily, a report by the subject; in animals it usually has to be experimentally contrived. Experimental research on the status and the underlying mechanisms of state consciousness is dependent on the conjunction and/or disjunction of the systems underlying both dependent variables. Some fMRI and event-related potential evidence will be discussed in relation to a putative on-line posterior processing system and an anterior commentary system..

PL-06
The end of anonymous phenomenology?
Anthony I. Jack

Contact:
Anthony I. Jack (ajack@light.wustl.edu)
Washington University Campus Box 8225
4525 Scott Avenue
St Louis, Missouri 63110
USA

What is the scientific status of subject reports? Current attitudes in cognitive science are complex, yet the mainstream consensus is clear: Reports can provide interesting, even important, anecdotal evidence. Yet, real experimental 'results' must be established by objective evidence.

In this talk I will discuss some basic philosophical issues and relate them directly to scientific practice. Different views on the methodology for a 'science of consciousness' relate to different philosophical positions on the meaning of mental state terms. My position offers an alternative to Dennett's neo-behaviorism and to the neo-Cartesian views of Searle, Chalmers and Block. Cognitive science can, and should, transform itself into the science of consciousness. It can do so simply by changing its attitude to introspective evidence.

PL-07
Why Are Verbally Expressed Thoughts Conscious?
David M. Rosenthal

Contact:
David M. Rosenthal (drosenth@artsci.wustl.edu)
Clark-Way-Harrison Visiting Professor
Program in Philosophy, Neuroscience, and Psychology
Washington University in St. Louis
(January-June 2002)

Department of Philosophy
Campus Box 1073
One Brookings Drive
Washington University in St. Louis
St. Louis, MO 63130-4899

It's generally recognized that there a close tie between consciousness and speech. One reason is that it seems that all verbally expressed thoughts are conscious. But it's not easy to explain this connection. We can't appeal to speech acts' being deliberate actions that require conscious mental antecedents, since speech acts are seldom deliberate and deliberate action can result from nonconscious antecedents.
A natural explanation does, however, flow from the higher- order-thought (HOT) hypothesis, on which a mental state's being conscious consists in its being accompanied by a seemingly nonin- ferential thought that one is in that state. We recognize, simply by being linguistically competent, that the speech acts of saying that p and saying one thinks that p have the same performance conditions, even though their truth conditions differ. So, when- ever one says that p, one could equally have said one thinks that p. The best explanation is that, whenever one says that p, one actually has the HOT one would express by saying one thinks that p. This also points to an explanation of why one's saying one thinks that p is an exception--why one isn't then conscious of the thought one's speech act expresses, but only the thought one thereby reports.

PL-08
Re-representing consciousness: Dissociations between experience and meta-consciousness
Jonathan W. Schooler

Contact:
Jonathan Schooler (schooler+@pitt.edu)
Department of Psychology
518 Learning Research and Development Center
3939 O'Hara St.
University of Pittsburg
Pittsburgh, PA 15260

A distinction is drawn between conscious experience and the explicit awareness (meta-consciousness) of that experience. Whereas experience is continuous, meta-consciousness is hypothesized to occur only intermittently in response to goal failures, self-reflection, or requests for self-reports. Two types of dissociations follow from the notion that meta-consciousness involves the intermittent re-representation of the contents of consciousness. Temporal dissociations occur when an individual, who previously lacked meta-consciousness about the contents of consciousness, directs meta-consciousness towards those contents. The case of catching one's mind wandering during reading illustrates a temporal dissociation. Once meta-consciousness is triggered, translation dissociations may occur if the re-representation process misrepresents the original experience. Such translation dissociations are particularly likely when one verbally reflects on non-verbal experiences or attempts to takes stock of subtle/ambiguous experiences. This review describes empirical evidence for temporal and translation dissociations and explores their implications for conceptualizing consciousness.

PL-09
Consciousness, Attention, and Reportability
Jesse Prinz

Contact:
Jesse Prinz (jesse@subcortex.com)
SAS Philosophy Programme
University of London
Senate House, Malet Street
London, WC1E 7HU, ENGLAND

Many of our conscious states seem to be reportable. This raises two important questions. Why is there a link between consciousness and reportability? And, Is that link necessary? I defend a neurofunctional theory of consciousness that helps provide answers. (A neurofunctioanl theory is one that explains consciousness by appeal to brain states, but characterizes those states in terms of their functional role, at both local and psychological levels of analysis.) According to the theory, consciousness arises when hierarchically organized sensory systems send afferent signals to working memory systems via dynamic changes in connectivity modulated by selective and ambient attention. Because working memory plays a central role in reportability, conscious states are typically reportable. They are not necessarily reportable, however. I present a principle that distinguishes conditions under which conscious states will be reportable, and I offer an argument for denying the existence of unreportable conscious states that meet those conditions. I also use this analysis to raise two implications for the alleged distinction between access and phenomenal consciousness. First, all phenomenology requires access on the theory I defend. Second, the construct of access can be subdivided into two distinct notions, corresponding to availability to working memory and encoding in working memory. I argue that only the former is essential to consciousness.

PL-10
Artificial Collective Consciousness
Luc Steels

Contact:
Luc Steels (steels@arti.vub.ac.be)
Vrije Universiteit Brussel Artificial Intelligence Laboratory
Pleinlaan 2
1050 Brussels

Sony Computer Science Laboratory - Paris

There has been much speculation on the ability and inability of a robot to be conscious. For some, a conscious robot is a contradiction in terms - even though it may be an interesting source of thought experiments. Others argue that certain aspects of consciousness (such as attention or reflection) are necessary for a very complex autonomous agent engaged in sensori-motor processing, planning or language and that therefore these aspects will progressively appear in robots as they become more complex. In this talk I want to address the issue of collective consciousness. How can there be a sense of conceptual coherence in a population of distributed individuals which, at least at first sight, do not have any direct physical access nor control to each other's internal brain states. Innate archetypes or quantum physics has been invoked to explain this kind of coherence. I will argue however that this need not be the case and show in multi-agent simulations how iterated interactions between adaptive agents may cause the self-organisation of shared concepts and interpretations of reality.

PL-11
Unconscious semantic priming
Pío Tudela

Contact:
Pío Tudela
Department of Psychology
University of Granada
Campus de Cartuja
18001 Granada
SPAIN

The existence of unconscious semantic processing has been a highly debated and theoretically relevant issue both in the realm of attentional as well as perceptual research. In our lab, we have approached this problem using a semantic priming procedure in which awareness of the prime was varied in two different ways. First we employed a backward masking procedure to prevent conscious detection and identification of the prime as measured by both subjective and objective awareness thresholds Second, awareness of the prime was manipulated by changing the distribution of attention over the visual field and by studying the semantic priming produced by parafoveally presented primes. Our results consistently show semantic priming produced by primes of which participants are unaware.

In the first part of my lecture I will present and discuss behavioral data supporting unconscious semantic priming. In the second part, I will present data based on event related potentials (ERPs) suggesting that the scalp signature associated to the priming effect produced by unconscious primes is different, both in time and topography, from the scalp signature associated to the priming effect produced by conscious primes. I will comment our results in the context of present cognitive neuroscience research.

PL-12
Conscious and Unconscious Aspects of Language Structure
Ray Jackendoff

Contact:
Ray Jackendoff (jackendoff@brandeis.edu)
Dept of Psychology
Brandeis University
Waltham, MA 02454
USA

The structure of language includes three major components: Phonological
(sound) structure, syntactic (phrase) structure, and conceptual (meaning) structure. Of these components, the one that appears to correspond most closely to the phenomenology of language is phonological structure: we hear strings of words, both in hearing others speak and in our own linguistic imagery. I will conclude that, with the exception of certain very coarse features, the structure of thought/conceptualization is entirely unconscious. I will show how this relation between language and consciousness accounts for a number of puzzles in philosophy of mind and philosophy of language.

PL-13
Do Small Balls Squeak? Re-evaluating Neonatal Synesthesia
Daphne Maurer

Contact:
Daphne Maurer (maurer@mcmaster.ca)
Dept. of Psychology
McMaster University
Hamilton, Ontario
Canada L8S 2A4

Because newborns share certain brain mechanisms with synesthetes, we have hypothesized that the newborn's senses are undifferentiated and easily confused (Maurer & Maurer, 1988; Maurer & Mondloch, 1996). We will re-evaluate this hypothesis based on recent studies of adult synesthetes (e.g., Smilek & Dixon, 2002; Ramachandran & Hubbard, 2001), of neural mechanisms in the congenitally deaf and blind (e.g., Bavelier & Neville, 2001), and our own data from young children. We tested 30- to 36-month-olds for sensitivity to a correspondence reported by adult synesthetes: the link between higher-pitched sounds and smaller, brighter percepts (e.g., Marks, 1974).
Children were presented with a central auditory stimulus that varied in frequency (with intensity jittered to make it irrelevant) while viewing two bouncing balls that varied in size and/or luminance. They were asked to point to the ball that was making the sound. In Exp. 1 (n=12), children linked the higher-pitched sound with the ball that was smaller and brighter (p <.01). InExperiments 2 and 3, they made the link based only on size (n=12; p <.01) and only on luminance (n=24; p <.01), thereby demonstrating sensitivity even when tested with a link not prevalent in the environment.
Collectively, the evidence suggests that there are natural synesthetic correspondences influencing the development of perception and language.

PL-14
Synesthesia, Qualia and Consciousness
Edward M. Hubbard

Contact:
Edward M. Hubbard (edhubbard@psy.ucsd.edu)
Department of Psychology
University of California, San Diego
9500 Gilman Dr. 0109
La Jolla, CA 92093-0109 USA

People with grapheme-color synesthesia report the novel conscious experience of seeing specific colors when viewing specific letters and numbers. We have previously shown that these synesthetic colors can lead to the pop-out and texture segregation (Ramachandran & Hubbard, 2001). Additionally, we have demonstrated a form of "blindsight" in synesthesia. When subjects are asked to identify stimuli in the periphery, they are significantly better when the stimulus is presented alone, as opposed to when it is flanked with distractors ("crowding"). When presented with crowded graphemes, our synesthetes cannot perceive the grapheme, but do experience colors, saying, "I can't see the middle number but it must be an H because it looks green." Based on this memory association, synestehtes perform significantly better than control subjects in identifying the target grapheme. We now report that synesthetically induced colors are not experienced when stimuli are presented at isoluminance, or at low luminance contrast, even though the inducing grapheme can be readily identified. We systematically varied luminance contrast and obtained subjective ratings on the strength of synesthetic colors. These ratings are consistent over multiple testing sessions, indicating that the effect is not confabulatory in origin. Consistent with their reports of not experiencing synesthetic colors at isoluminance, synesthetes do not perform better than controls on a texture segregation task when graphemes are presented at isoluminance. Collectively these results demonstrate that synesthetes' reports of colors constitute veridical reports of altered conscious states and suggest that the study of synesthesia may provide a novel experimental lever to explore the neural correlates of consciousness.

PL-15
A Fork in the Road to the Neural Correlate of Consciousness
Ned Block

Contact:
Ned Block (ned.block@nyu.edu)
Department of Philosophy
New York University
Main Bldg, Room 502ª
100 Washington Square East
New York NY 10003

An impressive body of evidence suggests that the neural correlate of visual consciousness is to be found in higher areas in the occipeto-temporal stream of processing, different areas for different kinds of stimuli. But there are circumstances in which these areas are activated, seemingly without consciousness, apparently due to failure of normal processing in parietal areas. One possibility is that visual consciousness has a complex neural correlate involving events in both the occipeto-temporal stream and parietal and maybe frontal areas. Another possibility is that the neural correlate of visual consciousness is entirely confined to the occipeto-temporal stream but that attentional factors centered in the parietal areas are required for the visually conscious states to be accessible and that this access brings in the frontal areas. These two options represent very different strategies in research on what consciousness is in the brain. The paper discusses the pros and cons of both strategies.

CS1-1.1
Disunified Access to a Unified Consciousness?
Tim Bayne

Contact:
Tim Bayne (tbayne@scmp.mq.edu.au)
Department of Philosohpy
Macquarie University
North Ryde
NSW 2109
AUSTRALIA

Many disorders of consciousness have the following structure: the patient is able to report one state of consciousness (S1) in one report modality but not in another report modality, yet they are also able to report another state of consciousness (S2) with the second report modality but not with the former. For example, when exposed to the word "tea-cup" a split-brain patient may say that she saw the word "cup" but not the word "tea". Yet, if asked to produce a left-handed written report of what she saw, the patient may write the word "tea." Similar dissociations in reportability can be found in unilateral neglect, the "hidden observer" in hypnosis, and Marcel's experiments. Most commentators assume that such dissociation in report modality provides evidence for disunity in the phenomenal structure of the subject's consciousness. Such a position seems to rest on the tacit assumption that it is not possible for phenomenally unified states of consciousness to be accessible to distinct report-modalities. I argue that this assumption is unwarranted, and that disunity in access to consciousness doesn't settle the question of disunity in the structure of phenomenal consciousness.

CS1-1.2
Knowing 'where' without knowing 'what': Orienting and spatial localization in the split brain
Diego Fernandez-Duque & Sandra E. Black

Contact:
Diego Fernandez-Duque (diego@rotman-baycrest.on.ca)
Cognitive Neurology, A421
Sunnybrook and Women's College
Health Science Centre
University of Toronto
Toronto, Ontario
CANADA, M4N 3M5

A patient with posterior callosotomy and right mediofrontal stroke was assessed in his ability to recognize and localize objects, as well as in the ability to split attention between and within visual hemifields. When a set of pac-men was briefly displayed in the right visual field, the patient was able to recognize both shape and location. In contrast, when stimuli were displayed in the left visual field, he was unable to report object features either verbally or with his right hand. These data reveal an impaired callosal transfer of object information. In contrast, spatial localization of objects was unimpaired, even in the left visual field. A covert orienting task revealed that attention was split more effectively between visual hemifields than within a given hemifield, a result that suggest a possible role of spatial attention in the localization of unrecognized objects.
FUNDING SUPPORT: This research was supported by a post-doctoral fellowship from the Rotman Research Institute, and by grants to the first author from the Heart and Stroke Foundation of Ontario, and by the Center for Consciousness Studies of the University of Arizona.

CS1-1.3
'K' is for ketamine: an fMRI study of the neural correlates of a ketamine-induced psychotic state on word generation
Cynthia H.Y. Fu, Kathryn Abel, Matthew Allin, Nanda Vythelingum, Sergi Costafreda, Steve C.R. Williams & Philip K. McGuire

Contact:
Cynthia H.Y. Fu (c.fu@iop.kcl.ac.uk)
Section of Neuroimaging
Division of Psychological Medicine
Institute of Psychiatry
King's College London
De Crespigny Park
London SE5 8AF
United Kingdom

Introduction: Phencyclidine (PCP) produces a brief psychotic state in healthy volunteers that is comparable with the symptoms of schizophrenia. A fundamental neurocognitive deficit in schizophrenia is impairments in language processing. Letter verbal fluency is a classical measure of general language abilities in which subjects are required to generate a word in response to letter cues. We sought to examine the neural correlates of an acute psychotic state induced by ketamine (an analogue of PCP) in healthy volunteers as they performed a verbal fluency task. Methods: Eleven healthy male volunteers (mean age 28 years) received either intravenous ketamine or placebo in a double-blind manner, while performing an overt verbal fluency task. FMRI data were acquired at 1.5 T. Results: During the ketamine infusion, subjects developed acute psychotic symptoms. The fMRI data revealed a main effect of ketamine, as compared to placebo, with increased activity in the anterior cingulate, prefrontal and parietal cortices, insula and basal ganglia. During the verbal fluency task, relative to placebo, ketamine was associated with greater activation in the prefrontal cortices and basal ganglia. Discussion: A ketamine-induced psychotic state was associated with increased activity in a distributed set of cortical and subcortical regions and a significant modulation of task-related activation during verbal fluency. The latter interaction implicates a prefrontal-striatal network that normally mediates executive aspects of language function in the pathophysiology of an acute psychotic state.

CS1-1.4
A New Look on Neuropsychological and Psychopathological Syndromes as Derived from a "What" versus "How" Taxonomy of Functions: Its Relevance for Dealing with Consciousness
Paloma Enríquez and Ernst Pöppel

Contact:
Paloma Enríquez (penriquez@psi.uned.es)
Departamento de Psicobiología
UNED
Ciudad Universitaria
28040 Madrid

In the late eighties a new taxonomy for the understanding of neuropsychological deficits was proposed (Pöppel, 1988, 1989). This taxonomy distinguished two broad kinds of brain functions, from which two distinct categories of neuropsychological disturbances (depending on their aetiological origin) were derived: They were referred to as 'what' and 'how' functions.

'What functions' refer to specific located psychological functions. This approach corresponds to the usual cartographic neuropsychological view, grounded on the classical localisationist perspective. By contrast, 'How functions' refer to more dynamic logistical (less or not located) brain functions which support the specific 'what' activity. This critical kind of brain functions has been neglected as a separate functional domain from a more classical perspective on neuropsychology prevailing even today.

The 'What/How' taxonomy, and specifically the focus on the now re-identified 'How functions' suggests a new and conciliate look on several fields usually treated from very distinct perspectives, allowing to conceive challenging new ways towards a possible future integration between them:

1. Direct applications to neuropsychological deficits.

2. New applications to psychopathological syndromes, as for instance those involving dissociative disturbances.

3. Main derivations for dealing with some of the core (and yet unsolved) problems of psychology and neuroscience, as that of consciousness.

CS1-2.1
A new wave of brain imaging evidence fits novel predictions from global workspace theory: The conscious access hypothesis
Bernard J. Baars

Contact:
Bernard J. Baars (baars@nsi.edu / bbaars8788@aol.com)
The Neurosciences Institute
10640 John Jay Hopkins Drive
San Diego 92121, USA.

Consciousness may help mobilize and integrate brain functions that are otherwise separate and independent. Evidence for this 'conscious access hypothesis' was described almost two decades ago, in a framework called global workspace theory (Baars, 1988, 2002). Recent neuroimaging evidence from different laboratories using different methods to compare conscious vs. unconscious sensory input, appears to support the hypothesis (e.g. Dehaene et al, 2001). The methods include visual backward masking, inattentional blindness, change blindness, neglect, extinction, sleep-waking, repetition priming, etc. Versions of the hypothesis are now supported by philosophers like Daniel Dennett and Ned Block, and by some cognitive and neuroscientists.

If consciousness implies global access in the brain it may be needed for any process that is not completely predictable. It therefore has implications for perception, learning, working memory, voluntary control, attention, and self systems in the brain. Gamma synchrony in the thalamocortical complex may facilitate conscious access.

Baars, B.J. (1988) A cognitive theory of consciousness. Cambridge University
Press. Also at www.nsi.edu/users/baars.

Baars, B.J. (2002) The conscious access hypothesis: Origins and recent
evidence. Trends in Cognitive Sciences, Jan., 6 (1). Also at
www.nsi.edu/users/baars.

Dehaene, S. et al (2001) Cerebral mechanisms of word masking and unconscious
repetition priming. Nature Neuroscience, 4, 752-758.

CS1-2.2
What IDA says about conscious and unconscious language processing and verbal reports
Stan Franklin

Contact:
Stan Franklin (franklin@memphis.edu)
Computer Science
University of Memphis
Memphis, TN, 38152
USA

A conceptual and computational model of consciousness provides its answers to questions of the relationship between consciousness and verbal report, of the role of verbal reports in the scientific study of consciousness, and of the characteristics of conscious and unconsciousness processing of language. In the IDA model, a complex software agent based on Baars¹ global workspace theory, incoming language is processed unconsciously by the perception module prior to selected derived meanings coming to consciousness. Computational mechanisms for both perception and consciousness, and their interaction, will be described, providing hypotheses about the characteristics of unconscious vs. conscious processing. There is currently no provision for verbal reports in the model. However, adding it conceptually or computationally would present no difficulty. Existing mechanisms within the model will suffice. Consciousness would work perfectly well with or without verbal report. IDA¹s understanding and generation of language, while real, is rudimentary by human standards due to her narrow domain. As a result, the model should prove useful as an extreme case in the study of the relationship between consciousness and language. Researchers can see what relations hold even in a relatively primitive system.

CS1-2.3
Searching for a unified science of consciousness
Antti Revonsuo

Contact:
Antti Revonsuo (revonsuo@utu.fi)
Department of Philosophy, Center for Cognitive Neuroscience
University of Turku
FIN-20014 Turku
FINLAND

If the diverse studies on consciousness are supposed to develop into coherent science, then we should expect a unified research program to emerge at some point. The unified research program should define a set of widely shared background assumptions that guide both empirical and theoretical research, and it should give a clear and empirically plausible answer to the philosophical questions concerning the place of consciousness in nature (Revonsuo 2000). My suggestion for the core assumptions of a unified research program is Biological Realism or treating consciousness as a biological phenomenon. This basic assumption implies that the explanation of consciousness should be done within a biological framework. Recent advances in the philosophy of neuroscience indicate that to explain a particular biological phenomenon involves tracing the different dimensions in a causal-mechanical network surrounding the phenomenon. This biological explanatory framework greatly clarifies what it really means to "explain" consciousness: it turns out that the explanation of consciousness consists of several different dimensions of explanation, and different sorts of questions and evidence are relevant for illuminating each of these explanatory dimensions. The biological framework also illuminates in a new way the nature of the central research problems in consciousness studies (e.g. the neural correlates of consciousness [Revonsuo 2001], the binding problem [Revonsuo 1999]), and could eventually lead to a unified research program on consciousness.
References
Revonsuo A (1999) Binding and the phenomenal unity of consciousness. Consciousness and Cognition 8(2), 173-185.
Revonsuo A (2000) Prospects for a scientific research program on consciousness. In: Metzinger T (Ed.) Neural Correlates of Consciousness, 57-75. Cambridge, MA: MIT Press.
Revonsuo A (2001) Can functional brain imaging discover consciousness in the brain? Journal of Consciousness Studies 8 (3): 3-23.

CS1-2.4
Consciousness and Revolution
William Seager

Contact:
William Seager (seager@utsc.utoronto.ca)
Division of Humanities
Univ. of Toronto at Scarborough
Scarborough, Ontario, Canadaa
M1C 1A4

Consciousness presents a special, probably unique, challenge to the scientific world view. Many maintain nonetheless that a way will be found to smoothly integrate the phenomena of consciousness into science. Others insist that there is simply no way to integrate consciousness into a scientific vision of the world, either because of intrinsic human limitations or because consciousness involves some aspect of reality that goes beyond what science can investigate.

A third group of thinkers seeks a way to explain consciousness within science, while recognising that current science makes no explanatory contact with it. Such a viewpoint assumes that explicating consciousness will require a revolution in science. In some ways this is the most radical position on consciousness, since it is the only one that explicitly undercuts current science. Yet it has been espoused, with more or less enthusiasm or reluctance, by a distinguished and diverse group of thinkers, including Roger Penrose, John Searle, Thomas Nagel and Noam Chomsky.

This paper aims to examine the grounds adduced for an impending scientific revolution forced by the very possibility of a science of consciousness. Are there common arguments converging on the conclusion that only a scientific revolution would permit an explication of consciousness? Or is there merely a disparate set of intuitions at work here, ultimately only restating the fundamentally mysterious nature of consciousness?

CS1-3.1
The language of conscious thought
Antoni Gomila

Contact:
Antoni Gomila (tonigomila@teleline.es)
Dep. Psychology
Univ. Balearic Islands
07071 Palma de Mallorca (Spain)

There is a growing consensus in Cognitive Science in establishing a dual view of cognition; one that distinguishes between either implicit and explicit processes, or automatic and controlled, or associative and rule-based. There are plenty of varieties of this view, which was much encouraged by the success of the notion of modularity.
I want to explore to what extent this dual view of cognition coincides with the distinction between unconscious and conscious processes, and to what extent language acquisition can be thought of as the key developmental process in giving rise to the duality of processes. My contention is that the difference between these two sorts of processes is representational, rejecting the view that what makes a mental state conscious is different from what characterizes it functionally.
I will present, first, a range of dual theories of basic processes (attention, perception, memory, learning, reasoning); second, I will show that neither of the pairs of opposite processes can be seen as exclussive and exhaustive, since in development, what is implicit can become explicit, what is controlled can become automatic (through practice), what is associative can become rule-based, and viceversa. Third, I will content that the main reasons for the existence of a language of thought hold only for linguistic minds, thus finding a representational difference between both kinds of processes; and fourth, that linguistic development correlates with development of the executive function, which typically involves awareness.

CS1-3.2
Structured Representations and Systematic Revision in Conscious Mental Processes
Joe Lau

Contact:
Joe Lau (jyflau@hku.hk)
Department of Philosophy
The University of Hong Kong
Pokfulam Road
Hong Kong

Fodor and Pylyshyn have famously argued that the systematicity of cognition is best explained by postulating structured, mental representations. Many connectionists disagree, and they believe that connectionist networks can exhibit systematicity without invoking structured representations. In this paper I present a new version of the systematicity argument. It is suggested that representations involved in conscious mental processes are subject to systematic manipulation and revision. For example, part of the phenomenology of formulating linguistic intentions and action plans is that they have components that can be modified and replaced easily. This can be readily explained if the representations involved in such processes are indeed classically structured representations. A connectionist alternative might involve representational schemes using for example RAAM, simple recurrent nets, or holographic reduced representations. However, I shall argue that there are various difficulties and inadequacies in employing such schemes to explain systematic revision in a non-classical manner.

CS1-3.3
Is there any good introspective argument for the language of thought ?
Edouard Machery

Contact :
Edouard Machery (edouardmachery@hotmail.com)
Université de Paris-Sorbonne, philosophy dpt
80-82, rue de la Roquette
Bâtiment D
75011 Paris
France

The language of thought hypothesis (LOTH) claims that thoughts are complex mental representations (MRs) compounded out of simpler MRs (concepts) in a syntactic way. Now the conscious inner speech seems to corroborate partly this thesis. The introspective argument draws on that point (Carruthers, 1996):
1/ The introspection suggests that our conscious thoughts tokens are subvocalized natural language sentences.
2/ Barring any cogent objection, we are entitled to trust the outcome of introspection.
3/ There are no cogent objections.
4/ Hence, conscious thoughts are subvocalized natural language sentences.
5/ Hence, LOTH is at least true of the conscious thought, though it does not require any mentalese.
This paper claims that at least when the truth of LOTH is in question, the introspection cannot be justifiably trusted : hence the crucial premise 2/ is wanting. Our objection consists of two theses:
A/ LOTH concerns the vehicles of our thoughts.
B/ We don't have any introspective access to the properties of the vehicles of our thoughts.
This paper argues for both theses and responds to a possible argument against B/ :
/ The forms of inner speech sentences causally drive the reasoning.
/ We have an introspective access to these forms.
/ Only properties of the vehicles of our MRs are causally efficient.

CS1-3.4
Compositionality and Introspection
Markus Werning

Contact:
Markus Werning (markus.werning@uni-erfurt.de)
Erfurt University
P.O.Box 900221
99105 Erfurt
Germany

The opinions that introspective thoughts are possible and that thought is semantically compositional, the paper argues, can only be reconciled if we assume that introspective thoughts are formed in a language that combines symbolic elements from expressible sub-symbolic elements.

Since an introspective thought reports another thought, it should be understood analogous to the report of a sentence by another sentence, i.e., as quotation. There are two options to analyze quotation. The first option postulates the rule: If p is a well-formed symbol of the language, then 'p' is a well-formed symbol of the language and the meaning of 'p' is p. This option, it is shown, violates the principle that the meaning of a syntactically complex symbol is determined by the meanings of its syntactic parts and the syntactic rule by which the parts are combined. The second option treats quotations as concatenations from a finite set of sub-symbolic elements. This option is consistent with compositionality, but requires that sub-symbolic elements are expressible in the language.

Unlike formal languages and Mentalese, natural languages do build symbolic elements, i.e., morphemes, from expressible sub-symbolic elements, i.e., phonemes. It is concluded that introspective thoughts necessarily are formed in (imagined) natural (i.e. phonetic) language.

CS1-4.1
A Home for Wayward HOTs
Jared Blank

Contact:
Jared Blank (jaredblank@mindspring.com)
769 Greenwich Street
New York, New York 10014

I intend to defend the Higher Order Thought (HOT) theory of consciousness, advocated by Rosenthal, from its most damaging criticism: the Wayward HOTs Objection. A principle explanatory virtue of the HOT theory is that it analyzes consciousness in terms of a semantic relation between HOTs and their targets. A mental state is conscious, according to the theory, when one is in a higher order state the content of which is just that one is in the target state. The character of the conscious experience, though, is determined by the representational content of the HOT even when the HOT is wayward or misrepresents the target state. Given wayward HOTs power to determine one's conscious experience, the explanatory relevance of the relation between HOTs and their targets has been questioned; if HOTs determine the character of conscious experience when they misrepresent their target states then the general explanatory function of the target states seems to be rendered impotent. Though I show how Rosenthal's response to this criticism is inadequate, certain aspects of it prove to be instructive: I demonstrate how they point the way towards a proper understanding of the relation between HOTs and their targets and so to a resolution of this criticism.

CS1-4.2
Self-Ascription and Co-Consciousness: A Neo-Kantian view
Alan Thomas

Contact:
Alan Thomas (alanthomas@clara.co.uk)
Department of Philosophy
University of Kent at Canterbury
Canterbury, Kent, CT2 7NF
United Kingdom

This paper explains our capacity to self-ascribe our mental states and the unity of consciousness expressed by the exercise of such a capacity. Shoemaker has argued that a functionalistically describable subject "self-tokens" its first-order beliefs, via reliably functioning cognitive mechanisms, so as to meet a defensible co-consciousness requirement. This paper develops a rival view (more radically Kantian). Kant offers a tri-partite account of consciousness: an adverbial theory of first order consciousness, an account of the necessity of self-ascription, and an account of self-consciousness as clearly distinct from the other two phenomena. The perspectival character of first order conscious experience is the basis of a capacity to self-ascribe conscious mental states that shows, but does not say, the unity of the conscious mental life of that subject. This avoids an important problem for higher order theories of consciousness: the fact that our conscious mental lives are unified is shown by the exercise of a capacity for self-ascription that can be deployed by a subject who does not possess the concepts of a self, or of mental kinds. Thus, an account can be given of the unity of the self that avoids crediting a conscious subject with a concept of itself that makes the account circular. Overall, the paper serves to undermine the idea that a mental state is conscious if it is in some way "targeted" by an inner analogue of the intentionality of those states that are directed "outwards".

CS1-4.3
Wine, Words, and What It's Like
Josh Weisberg

Contact:
Josh Weisberg (jwsleep@aol.com)
236 Dekalb Ave.
Brooklyn, NY
11205

In the course of learning the art of wine tasting, one acquires a variety of new words for picking out subtle variations in the taste of wine. Words like "flinty" "tannic" and "peppery" are taught to the novice, who then learns to categorize wines appropriately. Arguably, learning these words, and the mental concepts that they express, actually influences what it is like to consciously experience the rich gustatory sensations of the wine. Prior to acquiring the concepts, the wine tastes one way; afterwards, the experience is different.
David M. Rosenthal (1997, forthcoming) has argued that wine tasting, and related cases, provide a degree of support for the "higher-order-thought" (HOT) hypothesis of mental state consciousness. In this presentation, I will explore this claim, and consider if there are viable competing explanations of the cases. I will also investigate the close connection between consciousness and the learning of words and concepts, from the perspective of the HOT theory.
REFERENCES
Rosenthal, David M. (1997) "Apperception, Sensation, and Dissociability," Mind and Language 12, 2 (June): 206-223.
Rosenthal, David M. (forthcoming) "Explaining Consciousness," in Philosophy of Mind: Classical and Contemporary Readings, ed. David J. Chalmers, New York: Oxford University Press, 2002.

CS1-4.4
The Self-Consciousness of Consciousness: Conceptual Convergence and Clues to an Ontology
Kenneth Williford

Contact:
Kenneth W. Williford (kwillifo@zeus.ia.net)
Department of Philosophy
The University of Iowa
269 EPB
Iowa City, IA 52242 USA

The claim that all consciousness is self-consciousness is typically met with a number of important objections. Doesn't the claim lead to an infinite regress? Doesn't it seem phenomenologically inaccurate: surely we can think of objects other than ourselves? What about infants and animals lacking a "self-concept"? What about long-distance truck driving? What about unconscious mental processing? The present paper seeks to obviate some of and accommodate the rest of these objections by recovering, clarifying (both phenomenologically and conceptually), and defending a version of the thesis that has largely been forgotten, viz., that all consciousness is implicit, marginal, tacit, or non-positional consciousness of itself. The thesis, articulated notably by Sartre, Merleau-Ponty, and Gurwitsch, has more recently been defended by David Woodruff Smith and Tomis Kapitan. I distinguish the thesis from its relatives, so-called "higher-order thoughts" theories of consciousness, and note some of its advantages. In particular, I argue that a proper understanding of the thesis leads to the following: 1) A unification of many apparently disparate descriptions of consciousness found in theorists as different as Douglas Hofstadter, Antonio Damasio, et al. 2) A clarification of the often misunderstood relation between the constant, implicit reflexivity of consciousness and the sporadic, explicit reflectivity manifest in thoughts that employ a robust concept of the self. 3) A unification of phenomenological work on consciousness with work inspired by the logic of self-reference (e.g., Hofstadter,Perlis, Bojadziev), along with an articulation of a phenomenological method that stresses the importance of the formal features of consciousness as opposed to its overly emphasized qualitative ones. 4) An indication of vital clues to the solution of several outstanding problems in the theory of consciousness: qualia, the semantic determinacy of thought!, the unity of consciousness, the capacity for reflection, volitional causation, and the hard problem itself.

CS2-1.1
Neuromagnetic correlates of perceptual convergence in primary visual cortex
John-Dylan Haynes, Gerhard Roth, Michael Stadler & Hans-Jochen Heinze

Contact:
John-Dylan Haynes (haynes@www.h-w-k.de)
c/o Abteilung fuer Neuropsychologie
Universitaet Bremen
Grazer Str. 6
28334 Bremen / Germany

Among the various experimental paradigms that can be interpreted within the framework of neural correlates of consciousness one has unjustly received little attention:
"Perceptual convergence" refers to experiments designed to track at which stage visual processing of stimuli that are physically different but are perceived to be identical converges. This is complementary to the "perceptual divergence" approach as in multistable perception where a single stimulus can lead to alternation between several interpretations. Here we demonstrate that perceptual convergence for low level features such as contrast may occur as early as primary visual cortex using a combination of EEG and MEG with source localisation. Stimuli with the same physical contrast but very different perceived contrasts due to lateral masking elicit very different responses in primary visual cortex. However stimuli that are psychophysically adjusted to match but have very different physical contrasts evoke highly similar responses in V1, especially at a later feedback stage of processing. This is discussed in the light of recent evidence that primary visual cortex may play a
larger role in direct conscious representation of low level visual features than previously thought.

CS2-1.2
Two Modes of Conscious Visual Perception: Cerebral Sites & Cortical Mechanisms
Shaul Hochstein & Merav Ahissar

Contact:
Shaul Hochstein (shaul@vms.huji.ac.il)
Institute of Life Sciences
Neural Computation Center
Hebrew University
Jerusalem, Israel 91904

We report a new view, dividing conscious perception into two modes: rapid "vision at a glance" and slower "vision with scrutiny". The dichotomy encompasses a wide variety of phenomena, including our ability to perceive complex images even when these are presented at very rapid rates (RSVP) but a surprising inability to note seemingly large changes in flashed pictures (change blindness). We attributes rapid conscious vision with spread attention to the large receptive fields of high-level cortical areas, where neurons respond to complex images but generalize over precise object location, orientation, size, lighting or particular details that originally formed the recognized category. In contrast, slower perception with focused attention is seen as a conscious return to lower cortical levels following reverse-hierarchy feedback connections to the ultimate sources of higher level activation, recovering detailed information available in the specialized receptive fields
found there. Indeed, the characteristics of these perceptual modes match those of higher and lower areas, respectively. This dual correspondence is especially apparent in the two modes of visual search: Spread- attention feature search ("what" without "where") derives not from low-level cortical areas as previously assumed, but from higher-level position-insensitive receptive fields. On the other hand, scanning-attention difficult or conjunction search derives from explicit perception's return to low-level position-encoding receptive fields. We present additional perceptual phenomena, backed by physiological data, in support of this novel Reverse Hierarchy Theory. Thus, conscious perception begins at post-hierarchical processing high cortical levels where complex images are perceived with spread attention, and later dips back down in reverse hierarchy fashion to focus attention on specific details represented in low cortical level receptive fields.

CS2-1.3
Change Detection, Visual Representation, and Consciousness
Douglas B. Meehan

Contact:
Douglas B. Meehan (dbmeehan@yahoo.com)
CUNY Graduate Center, Philosophy Program
365 Fifth Ave.
New York, NY 10016-4309

Change blindness experiments show that subjects are often unaware of significant changes in visual scenes. This suggests that we don't see in as much detail as we believe we do. Kevin O'Regan and Alva Noë (forthcoming) conclude that visual perception doesn't involve detailed picture-like representations, giving an alternative explanation of visual experience in terms of our implicit knowledge of correlations between visual stimulation and eye-movement.

This rejection of visual representations assumes, however,
that if they did occur, we would have exhaustive access to them. But we don't have exhaustive access to our perceptual states, as unconscious perception shows. Further, there is evidence that we can detect changes in visual scenes even when we cannot report doing so (Fernandez-Duque and Thornton, 2000).

These considerations suggest, I argue, that we can best
explain change blindness not by supposing that there are no visual representations but by recognizing that we sometimes aren't conscious of them. That, in turn, is best explained in terms of a higher-order theory of consciousness (e.g., Rosenthal, 1997). Finally, I explain the nature of the representations involved in visual experience with Sellars' (1956) view that families of mental properties are
homomorphic to families of visible stimulus properties.

Fernandez-Duque and Thornton (2000). Change detection
without awareness: Do explicit reports underestimate the representation of change in the visual system. Visual Cognition, 7, 324-344.
O'Regan, Kevin and Noë, Alva (forthcoming). A Sensorimotor Account of Vision and Visual Consciousness. Behavioral and Brain Sciences, 24(5).
Rosenthal, David M. (1997). A Theory of Consciousness. In N. Block, O. Flanagan, G. Güzeldere (Eds.). The Nature of Consciousness. Cambridge: MIT Press.
Sellars, Wilfrid (1956). Empiricism and the Philosophy of Mind. In Science, Perception and Reality. Atascadero: Ridgeview, 1963.

CS2-1.4
Evidence for a non-continuous transition between conscious and unconscious processing of visual stimuli
Claire Sergent & Stanislas Dehaene

Contact:
Claire SERGENT (clairesergent@yahoo.com)
4, place du General Leclerc
91401 ORSAY
FRANCE

If two targets are to be identified among distractors displayed in rapid sequence, correct identification of the 1st target hinders identification of the 2nd. This phenomenon is called the Attentional Blink. We used in this phenomenon to investigate the nature of the transition between unconscious and conscious processing of visual stimuli.

We asked participants to evaluate the visibility degree of the 2nd target on a continuous scale. There were two main conditions : a condition in which identification of the 1st target was required ("dual task") which produced an attentional blink on the 2nd target, and a condition in which no identification of the 1st target was required ("single task") producing no impairment on the 2nd target. In both conditions, the target was absent in half of the trials.

During the attentional blink (dual task), participants used the continuous scale in a bimodal way : they mainly used the higher or the lower visibility degrees and hardly ever used intermediate visibility. A multiple regression on this pattern of response revealed that it was a combination of the patterns obtained when the 2nd target was absent and when it was present and easily detected (single task).

These results suggest that, during the attentional blink, the 2nd target is either perfectly identified or not detected at all. Thus, unconscious processing obtained by manipulation of attention would be better discribed as an alternative to the conscious processing than as an impoverishment of the conscious processing.

CS2-2.1
Consciousness, Inner Speech & Language
Garry Briscoe

Contact:
Garry Briscoe (briscoe@uwosh.edu)
Computer Science Department
University of Wisconsin Oshkosh
800 Algoma Blvd.,
Oshkosh, Wisconsin, 54901, USA

While some contend that language is important for higher states of consciousness, this presentation proposes that it is not language per se that is essential, but rather inner speech, our ability to converse with ourselves.

The traditional view of language holds that external speech sounds are processed within Wernicke's area in the left posterior temporal cortex, where composite words are recognized. This model further proposes that language signals then travel to Broca's area in the left inferior frontal lobe where expressive language is encoded into articulatory form. Recently, however, this view of language has come under challenge as researchers, using mainly imaging techniques, have noted language tasks that seem to involve cortical regions outside of those associated with the classical models.

A new neural model of cortical processing will be outlined in which streams of neural activations enter the system at primary sensory areas, and proceed through association and frontal areas. These flows are multiply recurrent, and so represent a highly dynamic system. The majority of flows are concerned with unconscious bodily behaviors, and involve the learning of perceptual (nameless) concepts that link external sensory inputs with corresponding learned motor behaviors; in other words, learned skills.

The language component of the proposed model extends that of the classical theory, suggesting that multiple areas of the cortex are involved in the processing of language. For example, it is now known that flows along the superior temporal cortex are involved in speech recognition. The model proposes that the function of the temporal cortex is that of a differentiation device, allowing sounds to be recognized as particular words. Recurrently linked self-organizing maps allow just such an interpretation.

The model proposes that incoming auditory inputs are divided into essentially two streams (as is supported by recent experimental results), one stream traveling along the superior temporal lobe, and the second traveling through the insular region to the frontal lobe. It is this second flow that forms the major component of inner speech. Recurrent linkages from Broca's area back to Wernicke's area allow for the generation of internally-generated pseudo-sound sequences that form inner speech. In other words, a part of the cortex (Broca's area) that is adjacent to motor areas responsible for expressive speech, is able to generate internal speech that travels directly to auditory input areas rather than travel through the external medium of the environment. A similar proposal for the visual modality allows for inner signing.
The presentation will describe primary consciousness as resulting from neural flows not involved with inner speech. This form of consciousness is shared by other animals, and involves being awake and alert, and being able to link sensory inputs with connected motor outputs.

Inner speech, however, forms a major part of the experience of consciousness for humans, and this additional component of consciousness is termed secondary consciousness. Inner speech allows us to bifurcate the world into multifaceted concepts, and provides a mechanism for direct inner awareness. Without inner speech, conscious experience is greatly reduced, and several neurological deficits (such as blindsight) will be used to illustrate this point.

CS2-2.2
The Statistical Brain: Reply to Marcus' The Algebraic Mind
Francisco Calvo Garzón

Contact:
Francisco Calvo Garzón (fjcalvo@um.es)
Departamento de Filosofía
Edificio Luis Vives
Universidad de Murcia
E-30100 Murcia (Spain)

Gary Marcus (The Algebraic Mind, Cambridge, Mass.: MIT Press, 2001) distinguishes two separate ontologies in the connectionist realm: implementational connectionism and eliminative connectionism. The former accounts for cognitive phenomena by positing sets of explicit rules that serve the purpose of symbolic manipulation. The latter, in terms of computational abilities which are the result of an associative memory. Marcus argues that the connectionist models which preserve their computational equivalency with respect to classical ones are those that implement classical rules. In this notice, I shall offer a three-fold reply to Marcus: First, (i) I shall argue that he does not provide a robust criterion to decide when a network implements a rule. Second, (ii) I'll argue that his proposal to implement recursive combinations by means of encodings where tokens that belong to the same representational type are identical lacks biological plausibility. And finally, (iii)
I'll argue that even if points (i) and (ii) were wrong, the neural substrate may impose limitations on the mechanisms that permit the system carry out the appropriate computations. These limitations may tip the balance in favour of a (biologically plausible) Hebbian arquitecture. I shall conclude that Marcus fails in his attempt to override eliminative connectionism.

CS2-2.3
Automaticity of Semantic Processing on a Sentence Level
Dana Ganor & Joseph Tzelgov

Contact:
Dana Ganor (danaga@bgumail.bgu.ac.il)
Dept. of Behavioral Sciences
Ben Gurion University of the Negev
Beer Sheva, Israel 84105

Tzelgov's (1997) definition of automatic processing as being processing that takes place although it is not part of a task requirement, was used as a basis for investigating automaticity of semantic processing on a sentence level. In the first series of studies the effect of type of experimental task on the conditions under which the automatic process would take place was investigated. Will automatic processing occur only when the experimental task triggers it? To study automatic semantic processing, the type of experimental task was varied from one which involves a process similar to semantic processing (i.e., syntactic processing), to one that involves a linguistic process on a lexical level, and to one that involves a non-linguistic process (i.e., font judgment). Under all three tasks evidence was found for automatic semantic processing. The second series of studies examined whether automatic semantic processing took place when sentences were not well formed
(i.e., containing grammatical errors or presented in a scrambled order). It was found that subjects extracted meaning from sentences that were poorly constructed even though they were not asked to do so. The results suggest that semantic processing of sentences occurs automatically, regardless of experimental task and the quality of presented material.

CS2-2.4
Time and space in phoneme perception.
Kei Omata & Ken Mogi

Contact:
Ken Mogi (kenmogi@csl.sony.co.jp)
Takanawa Muse Bldg.
3-14-13, Higashigotanda
Shinagawa-ku, Tokyo, 141-0022 Japan

Phoneme perception is an important step in language cognition. The McGurk effect (McGurk & MacDonald 1976), where a simultaneous presentation of incompatible visual and auditory stimuli leads to a misperception of phonemes, demonstrates that audiovisual integration plays an essential role in phoneme perception. Here, we report a series of psychophysical experiments aimed at elucidating the spatio-temporal constraints involved in the integration process. Using modern technologies, incompatible visual and auditory stimuli were presented with various timing and localization conditions. Presentation of the visual and auditory stimuli in the right egocentric field resulted in a stronger McGurk type effect, possibly related to the left hemisphere dominance of language processing. The effect of the proximity of audio and visual stimuli also exhibited a marked lateral asymmetry. Taking into account the results on the effect of timing in experiments of our own and others (e.g. Munhall et al.1996), we construct a model of the spatio-temporal ?streamlining? involved in the integration process. Our model puts phoneme perception within the context of the more general neural mechanisms of multimodal integration, with a particular emphasis on the relation to the egocentric spatio-temporal perception, such as body image

CS2-3.1
Reflective consciousness and intentionality
Lisa Bortolotti

Contact:
Lisa Bortolotti (lisab@coombs.anu.edu.au)
Philosophy Program RSSS
Coombs Building ANU
ACT 0200 Canberra
AUSTRALIA

According to Davidson, one can be a believer only if one has the concept of 'belief' and is able to recognise oneself and others as believers. These requirements are often tied to the presence of reflective consciousness and linguistic abilities. In the literature on animal cognition there is scepticism about non-human animals (even primates and dolphins) being reflectively conscious and viewing themselves and others as intentional systems. Thus, Davidson's view seems to imply that non-human animals cannot entertain beliefs. In Rational Animals (1982) and The Emergence of Thought (1997), he explicitly denies that non-human animals and human infants can be believers. I find this consequence of Davidson's requirements on belief possession implausible and I suggest an alternative view. Suppose we construe a minimal account of belief, where beliefs are simply mental states with content that are formed on the basis of some evidence, can be revised on the basis of some other evidence and can be acted upon. Then perceptual consciousness, but not reflective consciousness, seems to be necessary for a creature to be a believer.The requirements for rational believers, instead, require the capacity of the creature to critically examine her own mental states, evaluate evidence and aim at consistency and coherence. This is the kind of cognitive achievement that seems precluded to most non-human animals.My suggestion has one clear advantage over Davidson's. It allows us to see continuity between human and non-human animal cognition and to describe non-human animals as intentional systems when they categorise, learn and communicate.

CS2-3.2
Content and Infant Consciousness
Sarah E. Clegg

Contact:
Sarah Eleanor Clegg (pip00sec@sheffield.ac.uk)
Department of Philosophy
University of Sheffield, Western Bank
Sheffield, S10 2TN
United Kingdom

In recent years representational theories of phenomenal consciousness have grown in both popularity and number. Among these theories are the much discussed higher-order thought (HOT) theories which state that a mental state is conscious just in case it is, or is disposed to be, targeted by a higher-order thought about itself. One of the most common objections levelled against such theories (e.g. Dretske 1995) is that they exclude infants and autistic individuals. In this paper I argue that the objection can be answered, but that doing so depends on both the account of content and on the version of HOT theory adopted. In particular, I outline how adopting a teleosemantic theory of intentional content will allow *dispositional* higher-order thought theories to escape from this objection. Such an account of intentional content, allows us to show that an infant's experiences are phenomenally conscious in virtue of their function. I argue that, given a normal developmen
t, the function of the infant's perceptual experiences is to feed into higher-order thoughts about themselves regardless of whether the relevant higher-order systems are in place. In the same way, I shall argue that autistic people will also be phenomenally conscious according to Dispositional HOT theory.

CS2-3.3
Language and Theory-of-Mind Development: 4-Year-Old Spanish Children's Linguistic Abilities in the Understanding of False Belief.
Belén Pascual, Jaime Nubiola, Gerardo Aguado & María Sotillo

Contact:
Belén Pascual (mpasmel@alumni.unav.es)
Dept. Educación
Universidad de Navarra
E-31080 Pamplona

The main period of theory-of-mind development, the ability to seeing oneself and others in terms of mental states (beliefs, desires, intentions, imagination, emotions, and so on), is also the major period of language acquisition, from 2- to 5-year-olds. Studies of thought and language in child development are usually focused on two fields: 1) the capacity of children to represent false-beliefs, and 2) their linguistic abilities that provide the representational format needed to understand false-belief, including the contributions of syntax and semantics.

The present study explores the relationship between natural language production and the classic false-belief task performance in a sample of twenty-five children between 3;11 and 4;2-year-old. The natural language, transcribed and analyzed using CHAT codes and CLAN programs provided by the CHILDES Project (MacWhinney, 1995), was assessed according to four focal components: mean length of utterance (MLU), syntactic complexity, grammatical form of sentences with mental verbs and the frequency of their occurrence. Findings are consistent with the claim that language is fundamental to theory-of-mind development (Astington & Jenkins, 1999; Segal, 1998; de Villiers, 2000; Zelazo, 1999).

CS2-4.1
RATIONALITY AND ACCESS CONSCIOUSNESS
Matteo Mameli

Contact:
Matteo Mameli (g.mameli@lse.ac.uk)
London School of Economics
Dept. of Philosophy, Logic and Scientific Method
Houghton Street, London WC2A 2AE
United Kingdom

Is access consciousness necessary for (theoretical or practical) rationality? Does one need to be able to register one's own mental states in order to be rational? Does rationality require the ability to represent to oneself the contents of one's own thoughts? Does it require the ability to report to others the contents of one's own thoughts? The answers to these questions depend on what one means by 'rationality'. I argue that there are at least two distinct theoretical roles that 'rationality' plays in discussions about the correctness of thought and behaviour. That is, there are at least two distinct concepts of rationality. If one is thinking about rationality in terms of one of these two concepts, then it can be shown that access consciousness and reportability are not required for rational thought and behaviour, and that, in some cases and for some tasks, one can be more rational by not having access consciousness or by not using it. In contrast, if one is thinking about rationality in terms of the other concept, then access consciousness becomes an essential feature of rationality, and reportability (in case this is distinct from access consciousness) becomes a tool for being more rational.

CS2-4.2
Why are some verbal-like thoughts amenable to consciousness?
Benny Shanon

Contact:
Benny SHANON (b.shanon@mscc.huji.ac.il)
Department of Psychology
The Hebrew University
Mount Scopus
Jerusalem, Israel

The relationship between consciousness, thought processes and language is examined on the basis of the analysis of thought sequences, that is - trains of verbal-like expressions that spontaneously pass through people's heads. A large corpus of such sequences was collected and subject to various structural analyses. In this presentation, I consider the possible functional advantages of the conscious experience of thought sequences. I propose that such an experience affords mentation with a quality of rawness analogous to that associated with perception. This entails three functional benefits. First, rawness allows for non-fixedness in terms of prior codification, and thus affords fluidity in the progression of thinking and hence potential cognitive novelty. Second, rawness provides a medium that makes the thinking process akin to action in the real world. In this fashion, consciousness may be viewed as affording a virtual reality in which cognitive agents may act when concrete
action in the real world is not feasible. Third, verbal-like articulation results in objectivization that provides compartmentalization of thought and serves as the basis for further reflection. While the present discussion is based primarily on the analysis of verbal-like expressions, it is pointed out that analogous patterns are encountered in other domains of cognitive activity. Together, these suggest a new perspective by which the function of consciousness may be considered.

CS2-4.3
Access consciousness and its phenomenal properties
Finn Spicer

Contact:
Finn Spicer (finn.spicer@kcl.ac.uk)
13 Herbert Crescent
London
SW1X OHB

This paper offers a model of how we have authoritative access to consciously held propositional attitudes-an account of what access-consciousness consists in. The account is in terms of an ability one has to token a first-order thought at will (an 'entertaining' of a content), and then (by inner demonstrative) form a demonstrative concept which types propositional attitudes according to content (Fregean sense). The ability to entertain a thought at will is described as a product of the language faculty, and is close to what is known as 'inner speech'. Like inner speech, an entertaining of a content has phenomenal-conscious properties; hence this account offers an explanation of why certain phenomenal properties attach to access- consciousness propositional attitudes.

CS3-1.1
Impaired implicit cognition following frontal brain injury
Lynne Barker & Jackie Andrade

Contact:
Jackie Andrade (j.andrade@shef.ac.uk)

Dept of Psychology
University of Sheffield
Western Bank
Sheffield S10 2TP, UK

Frontal brain injury is associated with deficits in conscious cognition such as planning, sustained attention, decision making. Marked changes in personality, emotional lability and social behaviour are also seen. Theoretical accounts that emphasise disorders of controlled attention and goal-directed behaviour give little insight into these more socially-mediated aspects of the disorder. We hypothesised that deficits in implicit cognition may contribute to behavioural changes manifested after frontal damage. We tested 15 people with frontal brain injury on a battery of tests including the WAIS, WMS and BADS, the latter giving measures of executive function. We compared their performance with that of 14 age- and IQ-matched controls on two tests of implicit cognition: a serial reaction time task (SRTT) and an implicit memory task that measured the mere exposure effect as an increase in preference for previously presented non-words. The control group showed significant learning on the SRTT (p < .001) and a mere exposure effect (p < .03). Frontal patients showed no evidence of learning on the SRTT and no effect of exposure to the non-words (p > .10). We will discuss the relationship between these impairments in implicit cognition and patients' problems with social behaviour and explicit cognition.

CS3-1.2
Evidence for unconscious learning during anaesthesia
Catherine Ha