Matthieu Dubois

My research activity is essentially focused on visual multi-element processing in dyslexia and it's impact on visual word recognition. This topic is investigated in single and multiple-case neuropsychological studies, using various experimental and psychophysical methodologies, and mathematical modelling. More generally speaking, I'm particularly interested in the investigation of the visual front-end of reading, as well as the interactions between vision and reading acquisition.

Finally, I have also developed special interest for methodological and statistical peculiarities of the single case approach in neuropsychology. This has lead to the development of a package (named Singlecase) for the R software environment for statistical computing and graphics. The package deals with the single-case methodology in neuropsychology. Currently, the package includes statistical methods developed by John Crawford and collaborators. They are all designed to test the difference between a patient and a control group of small sample size.

Articles in peer-reviewed journals

- Dubois, M., Lafaye de Micheaux, P., Noël, M.P., and Valdois, S. (2007). Pre-orthographical constraints on visual word recognition: Evidence from a case-study of developmental surface dyslexia. Cognitive Neuropsychology, 24(6), 623–660.

- Mermillod, M., Auxiette, C., Chambres, P., Dubois, M., Derost, P., Galland, F., et al. (2008). L’apport de la psychologie et des neurosciences cognitives dans l’exploration des substrats anatomiques et fonctionnels impliqués dans le syndrome de Gilles de la Tourette [The contribution of psychology and cognitive neuroscience to the exploration of anatomical and functional substrata implicated in the Gilles de la Tourette’s syndrome]. Annales Médico-Psychologiques, 166(5), 398–402.

- Prado, C., Dubois, M., and Valdois, S. (2007). The eye movements of dyslexic children during reading and visual search: Impact of the visual attention span. Vision Research, 47(19), 2521–2530.

Work in progress

- Dubois, M., Kyllingsbæk, S., Prado, C., Peiffer, E., Lassus, D., and Valdois, S. (in revision). Fractionating the multi-element processing deficit in developmental dyslexia: Evidence from two case studies.

- Dubois, M., Kyllingsbæk, S., Mermillod, M, Alleysson, D, and Valdois, S. (in preparation). Multi-element processing deficit in dyslexia: Investigating not letter-like elements.

- Mermillod, M., Alleysson, D., Dubois, M., Musca, S. C., Barra, J., Atzeni, T., et al. (submitted). Does a biologically inspired model of computer vision with drastic dimensional reduction could yield to better performance than direct pixel coding for a neural network classifier?

Doctoral thesis

- Dubois, M. (2008). Pre-orthographical constraints in reading and multi-element processing in dyslexia: Evidence from single case studies and data modelling. Unpublished doctoral dissertation, Catholic University of Louvain, Cognition and Development Lab, Louvain-la-Neuve, Belgium. Available from http://edoc.bib.ucl.ac.be:81/ETD-db/collection/available/BelnUcetd-02072008-161701/

Chapters and Professional journals

- Dubois, M. (2002). L’approche cognitive en rééducation : étude de cas approfondie d’un patient dyslexique-dysorthographique developpemental de surface. Cahiers de la Société Belge de Logopèdes Universitaires, 12, 6-15.

- Dubois, M. (2004). Diagnostic et rééducation d’un déficit des représentations orthographiques en contexte développemental : le cas MT. In M.A. Schelstraete & M.P. Noël (Eds.), Approches psycholinguistique et neuropsychologique des troubles du langage oral, du langage écrit et du calcul chez l’enfant. Fernelmont: Editions Modulaires Européennes. 

Software

Dubois, M. (2008). Singlecase: A package for single case statistics in neuropsychology. Available from http://www.code.ucl.ac.be/MatthieuDubois/R_code.html (Software: R Package, singlecase, version 0.1)

- Dubois, M., and Noël, M.P. (2004). Developmental surface dyslexia and visual span: a case study. Poster presented at the 6th British Dyslexia Association (BDA) International Conference: Warwick, UK; 27th –30th of March.

- Dubois, M. (2005). Visual span and the Viewing Position Effect in word recognition: Case study and simulation. Poster presented at the 6th Colloque des Jeunes Chercheurs en Sciences Cognitives (CJCSC): Bordeaux, France; 2th –4th of May.

- Musca, S. C., Barra, J., Dubois, M., Palluel-Germain, R., Atzeni, T., and Mermillod, M. (2006). From correlated noise in reaction times to intentional content: disentangling explicit from implicit learning. Poster presented at the Tenth Annual Meeting of the Association for the Scientific Study of Consciousness (ASSC 10), Oxford, UK, 23th –26th of June.

- Musca, S.C., Atzeni, T., Dubois, M., Barra, J., Palluel-Germain, R., and Mermillod, M. (2006). Evidencing implicit learning in amnesic patients in serial reaction time tasks: A method based on the fractal dimension of background noise in reaction times. Poster presented at the 2nd meeting of the European Societies for Neuropsychology (ESN). Toulouse, France, 18th –20th of October.

- Dubois, M. (2006). Multi-element array processing as a constraint to visual word recognition: A case study and ideal-observer modeling. Poster presented at the 2nd meeting of the European Societies for Neuropsychology (ESN). Toulouse, France, 18th –20th of October.

- Dubois, M., Prado, C., Valdois, S., and Kyllingsbæk, S. (2007). Fractionating the multi-element visual processing deficit in developmental dyslexia. Poster submitted to the 15th European Societies for Cognitive Psychology (ESCoP) Conference. Marseille, France, 29th of August–1st of September.

- Dubois, M., Prado, C, Kyllingsbæk, S. and Valdois, S. (2008). Fractionating the multi-element visual processing deficit in developmental dyslexia: Evidence from multiple-case studies. Oral Communication presented at the 7th British Dyslexia Association (BDA) International Conference: Harrogate, UK; 27th –29th of March.

- Mermillod, M., Aleysson, D., Dubois, M., Musca, S.C., Barra, J., Atzeni, T., Palluel, R., and Marendaz, C. (2008). Does a biologically inspired model of computer vision with drastic dimensional reduction could yield to to better performance than direct pixel coding for a neural network classifier? Oral Communication accepted at the 11th Neural Computation and Psychology Workshop (NCPW11): Oxford, UK: 16th –18th of July.

- Dubois, M., Kyllingsbæk, S., and Valdois, S. (2008). Multi-element processing in developmental dyslexia: evidence from single case studies and data modelling. Poster accepted at the 1st Meeting of the federation of the European Societies of Neuropsychology (ESN): Edinburg, UK: 2–5 of September. 

 - Søren Kyllingsbæk. Center for Visual Cognition, Copenhagen, Denmark.

The Center for Visual Cognition has developed a computational model of the attentional involvement in (multi-) object recognition [Bundesen, C. (1990). A Theory of Visual Attention. Psychological Review, 97(4), 523-547.]. This model was widely used to study attentional fonctions in brain damaged patients, by fitting individual performance on adequate psychophysical paradigms. The collaboration aimed at using this model as a framework to analyse the multi-element deficit observed in dyslexic children.

- Pierre Lafaye de Micheaux. Grenoble Institute of Neuroscience, France

Most of my research was done trough single-case studies and individual data fitting. The collaboration aimed at introducing in single-case studies individual measurement error estimates and hypothesis testing derived from bootstrapping methods.