Atas, A., Faivre, N., Timmermans, B., Cleeremans, A., & Kouider, S. (in press). Nonconscious learning from crowded sequences. Psychological Science.
Can people learn complex information without conscious awareness? Implicit learning—learning without awareness of what has been learned—has been the focus of intense investigation over the last 50 years. However, it remains controversial whether complex knowledge can be learned implicitly. In the research reported here, we addressed this challenge by asking participants to differentiate between sequences of symbols they could not perceive consciously. Using an operant-conditioning task, we showed that participants learned to associate distinct sequences of crowded (nondiscriminable) symbols with their respective monetary outcomes (reward or punishment). Overall, our study demonstrates that sensitivity to sequential regularities can arise through the nonconscious temporal integration of perceptual information.
Atas, A., Vermeiren, A., & Cleeremans, A. (2013). Repeating a strongly masked stimulus increases priming and awareness. Consciousness and Cognition, 22, 1422-1430.
Previous studies [Marcel, A. J. (1983). Conscious and unconscious perception: Experiments on visual masking and word recognition. Cognitive Psychology, 15(2), 197–237; Wentura, D., & Frings, C. (2005). Repeated masked category primes interfere with related exemplars: New evidence for negative semantic priming. Journal of Experimental Psychology: Learning, Memory, and Cognition, 31(1), 108–120] suggested that repeatedly presenting a masked stimulus improves priming without increasing perceptual awareness. However, neural the- ories of consciousness predict the opposite: Increasing bottom-up strength in such a par- adigm should also result in increasing availability to awareness. Here, we tested this prediction by manipulating the number of repetitions of a strongly masked digit. Our results do not replicate the dissociation observed in previous studies and are instead sug- gestive that repeating an unconscious and attended masked stimulus enables the progres- sive emergence of perceptual awareness.
Ventura, P., Fernandes, T., Cohen, L., Morais, J., Kolinsky, R., & Dehaene, S. (2013). Literacy acquisition reduces the influence of automatic holistic processing of faces and houses. NeuroScience Letters, 554, 105-109.
Writing was invented too recently to have influenced the human genome. Consequently, reading acqui- sition must rely on partial recycling of pre-existing brain systems. Prior fMRI evidence showed that in literates a left-hemispheric visual region increases its activation to written strings relative to illit- erates and reduces its response to faces. Increasing literacy also leads to a stronger right-hemispheric lateralization for faces. Here, we evaluated whether this reorganization of the brain’s face system has behavioral consequences for the processing of non-linguistic visual stimuli. Three groups of adult illiter- ates, ex-illiterates and literates were tested with the sequential composite face paradigm that evaluates the automaticity with which faces are processed as wholes. Illiterates were consistently more holistic than participants with reading experience in dealing with faces. A second experiment replicated this effect with both faces and houses. Brain reorganization induced by literacy seems to reduce the influence of automatic holistic processing of faces and houses by enabling the use of a more analytic and flexible processing strategy, at least when holistic processing is detrimental to the task.
Chetail, F. & Content, A. What Is the Difference Between OASIS and OPERA? Roughly Five Pixels: Orthographic Structure Biases the Perceived Length of Letter Strings. Psychological Science, 25 (1), 243-249.
A thorough understanding of monosyllabic-word-recognition processes, in contrast with multisyllabic-word processing, has accumulated over the past decades. One fundamental challenge regarding multisyllabic words concerns their parsing into smaller units and the nature of the cues determining the parsing. We propose that the organization of consonant and vowel letters provides powerful cues for parsing, and we present data from a new task showing that a word’s orthographic structure, as determined by the number of vowel-letter clusters, influences estimations of its length. Words were briefly presented on a computer screen, and participants had to estimate word length by drawing a line on the screen with the mouse. In three experiments, participants estimated words comprising fewer orthographic units as shorter than words comprising more units even though the words matched for number of letters. Further results demonstrated that the length bias was driven by orthographic information and not by phonological structure.
Windey, B., Vermeiren, A., Atas, A., & Cleeremans, A. (2014). The graded and dichotomous nature of visual awareness. Philosophical Transactions of the Royal Society B, 369: 20130282
Is our visual experience of the world graded or dichotomous? Opposite pre- theoretical intuitions apply in different cases. For instance, when looking at a scene, one has a distinct sense that our experience has a graded character: one cannot say that there is no experience of contents that fall outside the focus of attention, but one cannot say that there is full awareness of such contents either. By contrast, when performing a visual detection task, our sense of having perceived the stimulus or not exhibits a more dichoto- mous character. Such issues have recently been the object of intense debate because different theoretical frameworks make different predictions about the graded versus dichotomous character of consciousness. Here, we review both relevant empirical findings as well as the associated theories (i.e. local recurrent processing versus global neural workspace theory). Next, we attempt to reconcile such contradictory theories by suggesting that level of processing is an often-ignored but highly relevant dimension through which we can cast a novel look at existing empirical findings. Thus, using a range of different stimuli, tasks and subjective scales, we show that proces- sing low-level, non-semantic content results in graded visual experience, whereas processing high-level semantic content is experienced in a more dichotomous manner. We close by comparing our perspective with existing proposals, focusing in particular on the partial awareness hypothesis.
Doyen, S., Klein, O., Simons, D.J., & Cleeremans, A. (in press). On the other side of the mirror: Priming in cognitive and social psychology. Social Cognition.
Over the past several years, two largely separate traditions have collided, leading to controversy over claims about priming. We describe and contrast the main accounts of priming effects in cognitive and social psychology, focusing especially on the role of awareness. In so doing, we consider one of the core points of contention, claims about the effects of subliminal priming. Whereas cognitive psychologists often are interested in exploring how priming operates with and without awareness, social psychologists more commonly assume subliminality in order to bolster claims about the automaticity of priming. We discuss the criteria necessary to claim that a stimulus was processed entirely without awareness, noting the challenges in meeting those criteria. Finally, we identify three sources of conflict between the fields: awareness, replicability, and the nature of the underlying processes. We close by proposing resolutions for each of them.
Cleeremans, A. (in press). Connecting conscious and unconscious processing. Cognitive Science.
Consciousness remains a mystery — “a phenomenon that people don’t know how to think about —yet” (Dennett, 1991, p. 21). Here, I consider how the connectionist perspective on information processing may help us progress towards the goal of understanding the computational principles through which conscious and unconscious processing differ. I begin by delineating the conceptual challenges associated with classical approaches to cognition insofar as understanding unconscious information processing is concerned, and to highlight several contrasting computational principles that are constitutive of the connectionist approach. This leads me to suggest that conscious and unconscious processing are fundamentally connected, that is, rooted in the very same computational principles. I further develop a perspective according to which the brain continuously and unconsciously learns to redescribe its own activity itself based on on constant interaction with itself, with the world, and with other minds. The outcome of such interactions is the emergence of internal models that are metacognitive in nature and that function so as it make it possible for an agent to develop a (limited, implicit, practical) understanding of itself. In this light, plasticity and learning are constitutive of what makes us conscious, for it is in virtue of our own experiences with ourselves and with other people that our mental life acquires its subjective character. The connectionist framework continues to be uniquely positioned in the Cognitive Sciences to address the challenge of identifying what one could call the “computational correlates of consciousness” (Mathis & Mozer, 1996) because it makes it possible to focus on the mechanisms through which information processing takes place.
Chetail, F., Drabs, V. & Content, A. The role of consonant/vowel organization in perceptual discrimination. Journal of Experimental Psychology: Learning, Memory and Cognition, 2014 Apr 21. [Epub ahead of print], doi: 10.1037/a0036166.
According to a recent hypothesis, the CV pattern (i.e., the arrangement of consonant and vowel letters) constrains the mental representation of letter strings, with each vowel or vowel cluster being the core of a unit.
Six experiments with the same/different task were conducted to test whether this structure is extracted prelexically. In the mismatching trials, the targets were pseudowords built by the transposition of 2 adjacent letters from base words. In one condition, the pseudowords had the same number of vowel clusters as the base word, whereas in another condition, the transposition modified the number of vowel clusters (e.g., poirver: 2 vowel clusters vs. povirer: 3 vowel clusters, from POIVRER: 2 vowel clusters). In Experiment 1, pseudowords with a different number of vowel clusters were more quickly processed than pseudowords preserving the CV structure of their base word. Experiment 2 further showed that this effect was not due to changes in syllabic structure. In Experiment 3, the pattern of results was also replicated when the category (consonant or vowel) of the transposed letters was strictly equated between conditions. Experiments 4 and 5 confirmed that the effects were not attributable to lexical processing, to differences in letter identity, or to the position of transpositions. The results suggest that the orthographic representation of letter strings is influenced by the CV pattern at an early, prelexical processing stage.
Kolinsky, R., Morais, J., Cohen, L., Dehaene-Lambertz, G. & Dehaene, S. (2014). L’influence de l’apprentissage du langage écrit sur les aires du langage/The impact of literacy on the language brain areas. Revue de Neuropsychologie, 6, 173-181.
L’acquisition de la lecture et de l’écriture, ou littératie,constitue vraisemblablement l’un des plus puissants instruments de transformation cognitive et cérébrale que nous acquérons au cours de notre vie. Dans cette revue, nous discutons du fait que, en plus de permettre l’acquisition de nouvelles connaissances (par l’intermédiaire de la lecture) et le stockage extérieur de l’information (via les notes manuscrites, les livres, les ordinateurs, etc.), la littéeatie entraîne trois grands types de changements dans les circuits cérébraux du langage. Nous illustrons le fait que l’apprentissage de l’écrit mène non seulement à une activation des aires du langage parlé par l’écrit, mais aussi à des modifications du traitement du langage parlé lui-même, et ce par deux mécanismes. En effet, la littératie améliore le codage phonologique (dans le planum temporale) et conduit, dans certaines situations d’écoute, à une activation « top-down » des représentations orthographiques (dans le cortex occipito-temporal gauche). En outre, l’acquisition de la littératie s’accompagne de changements anatomiques, notamment dans la connectivité intra- et inter-hémisphérique. Pour finir, nous discutons des implications théoriques et pratiques de ces découvertes pour les neuropsychologues.
