Sessions and Events > Concurrent Sessions

Concurrent Session I


Friday June 20, 2:00PM-4:00PM

CS 1.1. Feedback, Control, and Self-Regulation
CS 1.2. Access and Phenomenal Consciousness
CS 1.3. Discriminating Consciousness from Non-Consciousness

CS 1.1. Feedback, Control, and Self-Regulation
The Role of Feedback in Visual Masking, Visual Awareness and Attention

Stephen L. Macknik, Neurosurgery/Neurobiology, Barrow Neurological Institute, USA
Susana Martinez-Conde, Neurobiology, Barrow Neurological Institute, USA

We discuss the role of feedback in visual masking, visual awareness and attention. Our analysis reveals constraints for feedback mechanisms that limit their potential role in visual masking, and in other general brain functions. We propose a feedforward model of visual masking, and provide a hypothesis to explain the role of feedback in visual masking and general visual processing. We review the anatomy and physiology of feedback mechanisms, and propose that the massive ratio of feedback versus feedforward connections in the visual system may be explained solely by the critical need for top-down attentional modulation. Finally, we propose a new set of neurophysiological standards needed to establish whether any given neuron or brain circuit may be the neural substrate of awareness.

  • Keywords: binocular, interocular, dichoptic, monoptic, rivalry, monkey, primate, human, psychophysics,
    ________ _
  • Support: Science Foundation Arizona, Barrow Neurological Foundation, National Science Foundation
  • Corresponding Email:
  • Presentation Website:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Socrates Hall
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Conscious Emotion Regulation Suspenses Genetically Determined Differences in Amygdala Reactivity

Henrik Walter, Department of Psychiatry, University of Bonn, Germany
Dina Schardt, Department of Psychiatry, University of Bonn, Germany
Markus Staudinger, Department of Psychiatry, University of Bonn, Germany
Susanne Erk, Department of Psychiatry, University of Bonn, Germany

It is increasingly recognized that many of our behavioural and psychological dispositions are determined by genetic factors to a considerable extent, ultimately mediated by influencing brain structure and/or function. Due to the complexity of the brain, however, the effects of single genetic factors rarely can be demonstrated on the behavioural level. However, in functional neuroimaging, effects of small genetic variations have repeatedly been shown to result in different reactivity of brain regions in cognitive neuroscience experiments. For example, it has been shown in several independent studies that a polymorphism in the serotonin transporter gene may influence amygdala reactivity to emotional faces or aversive stimuli. In another line of research it has been shown that human subjects are able to downregulate their emotions by conscious emotion regulation strategies thereby downregulating activity in the amygdala. So the questions arises how conscious volition effectuates the genetically determined differences in amygdala reactivity. Is its activity downregulated, but still different for different genotypes? Or does conscious emotion regulation suspenses genetically determined differences? We will show data from an fMRI study investigating 37 female subjects in order to decide between these two alternatives. We found that conscious emotion regulation indeed does suspense genetically determined differences in amygdala reactivity. We will discuss these findings in the light of another fMRI study from our lab demonstrating that conscious emotion regulation also suspences activity in the ventral striatum during expectation of monetary rewards as well as the error prediction signal. We then will discuss implications of our findings for a neurophilosophical theory of volition.

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When Fear is in My Voice but not My Brain: Feedback Effects of Emotional Voice Transformation on Self-Rated Emotion Experience

Rodrigo Segnini, Shimojo Implicit Brain Function Project, ERATO-JST, Japan
Jean-Julien Aucouturier, General Systems Studies, University of Tokyo; JSPS, Japan
Petter Johansson, RCAST, University of Tokyo; JSPS, Japan
Lars Hall, Psychology, Harvard University, USA
Katsumi Watanabe, RCAST, University of Tokyo; ERATO-JST; AIST, Japan

One of the most vexing questions in the history of empirical research on consciousness concerns the relationship between the phenomenology of emotional states and peripheral physiological feedback. Psychologists like James, Festinger, Bem, Schachter and Zajonc have shown great ingenuity in disentangling the influences on emotional states from different potential sources. But an Achilles heel of this type of research has always been the difficulty to conceal the true purpose of the often peculiar manipulations that had to be used (like watching cartoons with a perpetual forced smile from a pencil stuck in your mouth, see Strack, Martin & Stepper 1988), and to conclusively rule out all manifestations of suggestion and demand effects on the results. This is particularly true within the field of voice expressivity, where currently no demand-free technique exists to induce emotionality, and measure the phenomenological and physiological effects of voice feedback.

For this purpose, we have adapted techniques from the field of machine voice synthesis to create a platform that can alter the emotional quality of the participants・ speech in real-time (e.g. in the direction of sadness, fear, happiness, etc.). In our first study, participants were given the task of reading a story out loud while wearing a headset with a microphone. The voice of each participant was then transformed and fed back in his/her headphones with a specific emotional tone. Afterwards, the participants were asked to rate the emotionality of the story and their own experience during the reading. The results show that while participants often fail to notice the manipulation, it can significantly influence their emotional experience, thus demonstrating a feedback effect on emotion from the qualities of voice expression.
At ASSC12 we intend to report on our ongoing studies of emotional voice feedback transformation, both with respect to the current results, and the wider methodological implications of having an unobtrusive non-transparent technique to unravel the complex relationship between emotional expressivity and emotion processing in the voice domain.

Strack, F., Martin, L. L., & Stepper, S. (1988). Inhibiting and facilitating conditions of the human smile: a nonobtrusive test of the facial feedback hypothesis. Journal of personality and social psychology, 54, 768-77.

  • Keywords: emotion, voice feedback, emotional voice transformation
  • Support: JSPS & ERATO-JST
  • Corresponding Email:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Socrates Hall
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Conscious Control of Perceptual States Differs from Spontaneous Control Both in Behavior and in Brain Activity

Eugenio Fernando Rodriguez, Escuela de Psicologia, U. Catolica de Chile, Chile
Paula Lacerna, Escuela de Psicologia, U. Catolica de Chile, Chile

In bistable perception the brain transform ambiguous stimulation into two mutually exclusive percepts, one of which is consciously perceived while the other is suppressed. This selection can occur either spontaneously or by the conscious decision of the viewer. Here we take profit of this fact to search for the neural correlates of the conscious control of mental states. We record electroencephalographic signals of subjects viewing a Stroboscopic Apparent Motion (SAM) ambiguous stimulus, which elicits mutually exclusive perceptions of either vertical or horizontal motion. The task involved two conditions: In the .Spontaneous Condition・ subjects were asked to report by a button press whenever perception spontaneously changed from vertical to horizontal movement or vice versa. In .Voluntary Condition・ the subjects were asked to voluntarily change from one perception to the other and report the change by a button press. A control experiment with unambiguous vertical and horizontal stimuli allowed us to estimate the window for perceptual reversion as 630 +/- 214 ms before button press. The behavioral results show that perceptual switches occur significantly faster during the .voluntary・ than during the .spontaneous・ condition (t test, p < 0.0001). A preliminary analysis of the electroencephalographic results shows: a) that beta and alpha oscillations are both significantly stronger (t test, p < 0.05) in the .spontaneous・ as compared to the .voluntary・ condition. This difference holds during a 300 ms time window preceding the perceptual reversion window. b) that delta and theta oscillations are significantly more synchronous (t test, p < 0.05) in the .voluntary・ as compared to the .spontaneous・ condition during a time window starting 800 ms before perceptual switching and ending abruptly at the time perceptual reversal was resolved. Taken together these result shows that spontaneous control and conscious voluntary control of perceptual states can be differentiated both on behavioral grounds and also on the basis of their electroencephalographic signatures

  • Keywords: voluntary control, bistable perception, mental states, EEG, oscillations
  • Support: Fondecyt 1070846
  • Corresponding Email:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Socrates Hall
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CS 1.2. Access and Phenomenal Consciousness
Phenomenal Consciousness and Accessibility

Tobias Schlicht, Philosophy Department, Ruhr-Universitat Bochum, Germany

Block (2008) argues that phenomenology :overflows; cognitive accessibility, i.e. that we can be conscious of contents without being able to cognitively access them. This claim rests on experiments (Sperling 1960, Landman et al. 2003) in which subjects insist that they consciously perceive a whole array of characters although they can only report (access) a few. When instructed to focus attention on only a few, they can give an accurate partial report. According to Block, subjects are phenomenally (yet not access) conscious of all specific characters. Block・s claim is V unless qualified V not supported by the evidence:
(1) His claim that there can be something it is like for subject S to experience X without S being able to know about it does not accord with his adherence to the .same-order-theory・ stating that being phenomenally conscious of X consists in part in S・s awareness of having the experience.
(2) Just because subject S is access conscious of X on the basis of an attentional act, S need not have been phenomenally (yet not access) conscious of X earlier.
(3) For Block・s conclusion that subjects are phenomenally (yet not access) conscious of each single item to be justified, subjects would have to report not only having a continuing :visual representation of the whole array; (p.17ms), but that with respect to each single item they saw either what letter it is (Sperling) or the shape・s orientation (Landman). But the reports are compatible with the considerably weaker interpretation that subjects are phenomenally conscious of a .generic・ content V a .whole array of characters・, say V being unable to name all characters specifically; only a few details of this percept are .poised・ for use in reasoning or flexible action.
This interpretation accords well with the same-order view and the observations (a) that one and the same content can be either conscious or unconscious (blindsight, split brains etc.); (b) that we can be conscious of X without attending to X, e.g. :gist; perception (Koch, Tsuchiya 2006); and (c) that shifting or focusing attention may even make formerly unconscious contents conscious (Carrasco 2004).

  • Keywords: phenomenal consciousness, access consciousness, attention
  • Corresponding Email:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Locke Hall
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The Phenomenal-Concept Gap

Benjamin Daniel Young, Philosophy and Cognitive Science, City University of New York Graduate Center, USA

The Phenomenal-concept approach is a recent attempt to surmount a particular obstacle faced by mind-body physicalism in reducing qualitative mental states to brain states. The epistemological explanatory gap, as this obstacle has been labeled, is said to block the reducing of the qualitative character of experience to physical mechanisms (Levine, 1983, 1993). Phenomenal-concept theorists have argued that we can overcome that apparent obstacle if we construe the concepts we have for qualitative properties, as such, not as ordinary descriptive concepts, which can occur in the absence of their referents, but rather as phenomenal concepts, which represent these states by eliciting some of the experience, thereby requiring that the experience itself be part of the concept.
Central to the phenomenal-concept approach is the Experience Thesis, which holds that to posses such a concept one must have the relevant qualitative experience (Stoljar, 2005). The experience thesis is particularly evident in exemplar theories (Papineau, 2006; Block, 2002, 2006), which claim that the phenomenal concept is partially constituted by the having of an exemplar qualitative experience.
But in requiring the having of experiences as the primary necessary condition for the acquisition and possession of the relevant phenomenal concepts, exemplar theories undermine the plausible constraints of publicity and stability. Publicity holds that we interpersonally share identical concepts. Stability requires that intrapersonal conceptual types be stably generated from multiple tokens of a finite experiential base. The paper focuses upon exemplar theories, because they so clearly fail to conform to these constraints, but the same can be demonstrated for recognitional (Loar, 1997; Tye, 2003), demonstrative (Chalmers 2003, 2006), and quotational-indexical theories (Balog, 2006; Papineau, 2002).
Current phenomenal-concept theories therefore fail as theories of concepts, and so cannot resolve the explanatory gap. Accordingly, I offer an alternative approach, which denies interpersonal publicity but maintains intrapersonal stability. My theory retains the Experience Thesis, but argues that the possession and content of phenomenal experiences is physically determined by the sensory state, its context, and a theory of object persistence through changes of features (Feldman 2003, 2007; Feldman & Tremoulet, 2006; Tremoulet & Feldman, 2006). In addition to providing an adequate treatment of concepts, my theory of physical qualitative states accounts for why the explanatory gap seems intuitive.

  • Keywords: Phenomenal-concept, Qualitative Consciousness, Explanatory Gap, Experience Thesis,
    ______ ___Physicalism, Concepts, Publicity, Stability
  • Corresponding Email:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Locke Hall
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The Ability to Report is Neither Sufficient nor Necessary for the Occurrence of Conscious Experience

David Cannon Drake, Philosophy, National Chengchi University, Taiwan

A subject・s reports, verbal or otherwise, are a vital part of most investigations into the nature of conscious experience. I see this as unfortunate, but acceptable considering issues of practicality and the fact that we have yet to determine the neural correlates of consciousness. What I find unacceptable is the claim made by some researchers that the ability to report is a necessary condition for consciousness, some even going so far as to suggest that consciousness arises out of this report-giving ability. I will argue that the ability to provide a report is neither sufficient nor necessary for conscious experience. At best, reports are a kind of raw data that are generally useful in ascertaining the presence and nature of conscious experiences in a given subject, but we are not justified in assuming that it is always sufficient evidence or that it is a requirement. To support my argument I will draw upon several examples from the research literature. Evidence for the insufficiency argument can be found in various cases wherein seemingly normal experience-reporting speech is produced in what appears to be a verifiably unconscious state. As for the argument against necessity, split-brain patients (people who have had their corpus callosum severed) have shed light on the possibility that consciousness might be separable in a single human being: by some interpretations, there are (always or sometimes) two separate streams of consciousness in these patients, corresponding to their left and right hemispheres, with the right hemisphere being severely limited in its ability to provide (or contribute to) reports. If such an interpretation is sound, it raises the possibility that, in principle, any human brain could, at times, have two or more separate streams of consciousness occurring at the same time, some of which may be dissociated from the brain・s ability to produce a report. Such a possibility is troublesome from a research perspective, but if the possibility exists then it should be investigated. I will also discuss pain asymbolia, potential cases of non-reportable conscious experience and how we might identify them, and issues relating to infants, fetuses, animals, and neuroethics.

  • Keywords: consciousness, language, report, commentary, sufficient, necessary, evidence, conditions, basis,
    _________ split-brain, corpus callosum, pain asymbolia, zombie, animal consciousness
  • Corresponding Email:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Locke Hall
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Quantifying the Limits of Introspection

Jerome Sackur, Departement d'Etudes Cognitives, Ecole Normale Superieure, France
Guido Corallo, Integrative Neuroscience Laboratory, University of Buenos Aires, Argentina
Mariano Sigman, Integrative Neuroscience Laboratory, University of Buenos Aires, Argentina
Stanislas Dehaene, Chaire de Psychologie Cognitive, College de France, France

Ever since Wundt, the introspective method and the study of mental chronometry have followed distinct paths. While introspection has led to the flourishing field of meta-cognitive studies, chronometric studies have been most useful in dissecting elementary cognitive processes. However, mental chronometry largely left aside the link between cognitive processes and conscious experience. To address this issue, we designed a new methodology: :quantified introspection; (QI). We engaged participants in a standard response time (RT) experiment, but after each trial we also asked them to give a quantitative subjective estimate of the time it took them to respond (introspective RT). This enabled us to study the relation between objective times and introspective estimates, and thus to determine, amongst the processes contributing to response time, which are accessible to introspection and which are opaque. In a series of experiments we demonstrate that IRT can be a sensitive measure, tightly correlated with objective RT in a single-task context. In stark contrast, however, in a psychological refractory period task, the objective processing delay resulting from interference with a second concurrent task is totally absent from introspective estimates. Those results suggest that our subjective introspection of time spent on a task tightly correlates with the period of availability of central processing resources. It thus appears that there might be some stringent limits on what parameters of a task are consciously available. If one follows the classical distinction between early effortless parallel processing and late effortful central processing, our studies suggest that subjects are mostly sensitive to factors that affect central processing stages. In follow-up experiments, we extend the methodology to other parameters of cognitive tasks: the sense of effort, ease of access and confidence. We believe that quantified introspection may be a new and important tool in the study of conscious and non-conscious cognitive processing. The robustness of our results suggests that quantified introspection provides a powerful methodology to map the contents of conscious experience within what we currently understand of participants・ cognitive architecture.

  • Keywords: introspection, conscious access, cognitive architecture
  • Corresponding Email:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Locke Hall
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CS 1.3. Discriminating Consciousness from Non-Consciousness
Weak Signal or No Signal? How Imaging and Firing Rate Signals Missed a Robust Functional Circuit for Brightness Perception

Chou Po Hung, Institute of Neuroscience, National Yang Ming University, Taiwan
Benjamin M. Ramsden, Department of Neurobiology and Anatomy, School of Medicine, West Virginia University,
____________________ _USA
Anna Wang Roe, Department of Psychology, Vanderbilt University, USA

Understanding the neuronal codes underlying perception and cognition is a fundamental challenge in neuroscience. Population codes based on imaging and neuronal firing rates have been shown to contain extraordinarily rich information about visual representations. However, in response to the Cornsweet edge-induced illusory brightness stimulus (a weaker stimulus input), we have detected only weak modulations in firing rate (Hung et al 2001, 2002; Roe et al 2005), typically much weaker than the firing rate modulation in response to perceptually-comparable real luminance modulation. In contrast to firing rate changes, we measured robust three-fold increases in the coincidence of neuronal spike times recorded from pairs of neurons. This change in spike coincidence was cell- and condition-specific and suggests a functional circuit which may underlie the phenomenon of edge-induced brightness perception (Hung et al. 2007).

Remarkably, with respect to temporal coding, we also observed a border-to-surface shift in the temporal coincidence of spike times consistent with perceptual filling-in. The observed shift was absent when borders were absent and could be reversed with relocation of the stimulus border, indicating that the direction of information flow is highly dependent on stimulus conditions. Furthermore, this effect was area-specific and was seen predominantly in 17V18, and not 17V17, interactions. These results demonstrate a border-to-surface mechanism at early stages of visual processing and emphasize the importance of interareal circuitry in vision.

Hung CP, Ramsden BM, Roe AW (2007) A functional circuitry for edge-induced brightness perception. Nature Neuroscience 10(9): 1185V1190.

Roe AW, Lu HD, Hung CP (2005) Cortical processing of a brightness illusion. PNAS USA 102(10): 3869V3874.

Hung CP, Ramsden BM, Roe AW (2002) Weakly-Modulated Spike Trains: Significance, Precision, and Correction for Sample Size. J Neurophysiol. 87: 2542V2554.

Hung CP, Ramsden BM, Chen LM, Roe AW (2001) Building Surfaces from Borders in Areas 17 and 18 of the Cat. Vision Res. 41 (10V11): 1389V1407.

  • Keywords: vision, perception, binding, neurophysiology, synchrony, neuronal coding
  • Support: US NIH grants EY-11744, NEI 5T32 EY-07115 and 5T32 DA-07290, the Whitehall Foundation,
    ____ ___ Packard Foundation, Yale Brown-Coxe Postdoctoral Fellowship, Taiwan MOE 5 Year Aim for the
    _____ __ Top University Plan, and Taiwan MOE/NSC Outstanding Scholar Fellowship
  • Corresponding Email:
  • Presentation Website:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Plato Hall
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Bridging the Gap? A Neurophilosophical Assessment of :Mind Reading; Technology

Stephan Schleim, Psychiatry/Medical Psychology, University Clinics Bonn, Germany

Neuroscientists have been able to predict subjective experiences with a high accuracy from brain imaging data recently. Using multivariate pattern analysis or algorithms of machine learning, they could infer perceived visual objects as well as hidden intentions, to name just a few examples. These successes have led some researchers to refer to the new methods as :brain interpretation; or :mind reading; technology.

These results are immediately relevant to questions of philosophy of mind and consciousness. Considering classical essays discussing the :hard problem of consciousness; (Chalmers, 1995) or the :explanatory gap; (Levine, 1983), it remains controversial whether subjective experience can be explained by investigating their underlying mechanisms. Thus, the new findings raise several questions that should be analyzed from an empirically informed philosophical perspective.

First, a conceptual analysis of the notion of :mind reading; yields a set of constraints that allow to assess how close these methods really get to a subject・s experience. Is it really warranted to speak about :mind reading; or is it better understood as a metaphor V at least for the time being? Are there experiences that are easier to predict (e.g. from the visual domain) than others? Which are the main factors limiting the empirical progress to develop a :universal mind reading machine;?

Second, the idea of :mind reading; technology addresses arguments concerning the externalism of mental content as well as the possibility of psychophysical laws, which have a long tradition in philosophy of mind. For example, if mental content can be individuated by investigating a subject・s brain, then Putnam・s Twin Earth thought experiment (1973, 1975) appears to be refuted on empirical grounds; and if brain researchers can predict subjective experiences reliably from their data, Davidson・s Anomalism of the Mental (1980) appears to be wrong.

Considering both, the empirical and philosophical issues concerning :mind reading;, I will present my conceptual scheme which implies answers to these questions. The conclusion of my talk will be that the empirical findings have to be taken seriously from the philosophical point of view but that there is still more research to be done in order to :bridge the gap;.

  • Keywords: Mind Reading, Brain Reading, Neurophilosophy, Consciousness
  • Support: Volkswagen Foundation
  • Corresponding Email:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Plato Hall
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Three Different Continuous Awareness Scales Predict Performance in a Visual Identification Task and Support the View that Consciousness Is a Gradual Phenomenon

Kristian Sandberg, Research Unit, Hammel Neurorehabilitation and Research Center, Aarhus University Hospital,
_________________ Denmark
Bert Timmermans, Cognitive Science Research Unit, Universite Libre de Bruxelles, Belgium
Axel Cleeremans, Cognitive Science Research Unit, Universite Libre de Bruxelles, Belgium
Morten Overgaard, Hammel Neurorehabilitation and Research Center, Aarhus University Hospital, Denmark

We examined three measures of awareness both using dichotomous and continuous scales, in order to test their correlation with subject performance in a visual identification task. Geometric figures were presented for a number of milliseconds ranging from 16 to 192, followed by a mask. On each trial, subjects had to identify the presented figure and use one of three awareness scales, either in a dichotomous or a continuous (4-point) response format. 12 subjects used the PAS (Overgaard et al, 2006) to rate the clarity of their perceptual experience, 12 subjects rated their confidence (Dienes & Scott, 2005) in having identified the figure correctly, and 12 subjects reported how much they would wager (post-decision) (Persaud, McLeod & Cowey, 2007) that they had identified the figure correctly. All continuous measures were transformed to 4-point scales in order to make results comparable.

Results were twofold. First, dichotomous measures suggested a large degree of above chance performance without awareness, while continuous scales did not, or to a much lesser degree. Second, we found no significant systematic differences between the three measures of awareness. For all three measures, increased performance accuracy was followed by increased awareness, with performance accuracy increasing more steeply than awareness. Both awareness ratings and accuracy can be expressed as sigmoid functions of stimulus duration. Differences in tangents of each awareness function and its corresponding accuracy function was examined in order to determine whether conscious experience is best viewed as dichotomous or gradual in the context of the present experiment. Our analyses support the latter view. Differences in adjustments along the x-axis were also analysed in order to find support for subliminal processing. So far, data suggest that awareness indeed does lag performance slightly.

Dienes, Z., & Scott, R. (2005). Measuring unconscious knowledge: Distinguishing structural knowledge and judgment knowledge. Psychological Research, 69, 338-351.

Overgaard, M., Rote, J., Mouridsen, K. & Ramsoy, T.Z. (2006): Is conscious perception gradual or dichotomous? A comparison of report methodologies during a visual task, Consciousness and Cognition, 15, 700-708.

Persaud, N., McLeod, P. & Cowey, A. (2007). Post-decision wagering objectively measures awareness. Nature Neuroscience, 10 (2), 257-261.

  • Keywords: visual identification, masking, awareness scale, dichotomy of consciousness, subliminal perception
  • Support: The MindBridge project is co-funded by the European Commission under the Sixth Framework
    ___ ____ Programme, Contract No. 043457
  • Corresponding Email:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Plato Hall
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Mapping the Transition from Unconscious to Conscious Knowledge

Ryan Bradley Scott, Department of Psychology, University of Sussex, UK
Zoltan Dienes, Department of Psychology, University of Sussex, UK

In various implicit learning paradigms, initial unconscious knowledge can precede the emergence of conscious knowledge (e.g. Fu, Fu, & Dienes, in press). Adopting higher order thought theory and exploiting subjective measures of consciousness we examine this transition in an artificial grammar learning (AGL) paradigm. In the standard AGL task participants are initially exposed to strings of letters, which unbeknown to them conform to a complex set of grammar rules. Subsequently participants are informed of the rules and required to distinguish the grammaticality of each of a new set of test strings. Participants reliably distinguish grammaticality while apparently unaware that they are able to do so.

Simple claims that the knowledge is conscious or unconscious ignore the range of experiences and mental states involved in AGL decisions. Thus, we employed a range of subjective reports to tease apart the unconscious and conscious states of knowledge which support those accurate responses. Participants rated the familiarity of each test string, reported their confidence in each grammaticality judgment, and indicated the perceived basis for each decision e.g. random choice, intuition, familiarity, rules, or recollection. Participants classified the test strings twice, enabling us to map the transition between the reported bases for judgments and examine how the relationship between confidence, familiarity, and the decision bases changed over time. Responses revealed both unconscious and conscious knowledge from the outset but with a clear transition between them.

Differences in the subjective familiarity of test strings accounted for almost all the grammaticality knowledge. Familiarity could initially influence responses without awareness, predicting grammaticality judgments that were reportedly selected at random. Over time participants realised that their choices reflected differences in feelings of intuition and subsequently familiarity, but often continued to lack confidence in their judgments indicating the absence of meta-knowledge that these feelings distinguish grammaticality. Meta-knowledge supporting confidence, and hence conscious judgment knowledge, was shown to emerge through a process of calibration, as the assessed reliability of knowledge relating to the distribution of familiarity increased. We argue that in general higher order thoughts may arise through converting objective probability estimates into subjective probabilities.

  • Keywords: unconscious knowledge, artificial grammar learning, higher order thought theory, HOT, AGL,
    __ _ _ ___ subjective measures
  • Corresponding Email:
  • Presentation: Talk, Friday June 20, 2:00PM-4:00PM at Plato Hall
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