The time course of visual influences in letter recognition.
Sylvain Madec, Kévin Le Goff, Stéphanie K Riès, Thierry Legou, Guillaume Rousselet, Pierre Courrieu, F-Xavier Alario, Jonathan Grainger, Arnaud Rey
Author Information
Sylvain Madec: Laboratoire de Psychologie Cognitive-CNRS, Aix-Marseille Université, 3, place Victor Hugo-Case D, 13331, Marseille Cedex 03, France.
Kévin Le Goff: Laboratoire de Psychologie Cognitive-CNRS, Aix-Marseille Université, 3, place Victor Hugo-Case D, 13331, Marseille Cedex 03, France.
Stéphanie K Riès: Department of Psychology, Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.
Thierry Legou: Laboratoire Parole et Langage, CNRS & Aix-Marseille University, Aix-en-Provence, France.
Guillaume Rousselet: Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
Pierre Courrieu: Laboratoire de Psychologie Cognitive-CNRS, Aix-Marseille Université, 3, place Victor Hugo-Case D, 13331, Marseille Cedex 03, France.
F-Xavier Alario: Laboratoire de Psychologie Cognitive-CNRS, Aix-Marseille Université, 3, place Victor Hugo-Case D, 13331, Marseille Cedex 03, France.
Jonathan Grainger: Laboratoire de Psychologie Cognitive-CNRS, Aix-Marseille Université, 3, place Victor Hugo-Case D, 13331, Marseille Cedex 03, France.
Arnaud Rey: Laboratoire de Psychologie Cognitive-CNRS, Aix-Marseille Université, 3, place Victor Hugo-Case D, 13331, Marseille Cedex 03, France. arnaud.rey@univ-amu.fr.
This study builds on a specific characteristic of letters of the Roman alphabet-namely, that each letter name is associated with two visual formats, corresponding to their uppercase and lowercase versions. Participants had to read aloud the names of single letters, and event-related potentials (ERPs) for six pairs of visually dissimilar upper- and lowercase letters were recorded. Assuming that the end product of processing is the same for upper- and lowercase letters sharing the same vocal response, ERPs were compared backward, starting from the onset of articulatory responses, and the first significant divergence was observed 120 ms before response onset. Given that naming responses were produced at around 414 ms, on average, these results suggest that letter processing is influenced by visual information until 294 ms after stimulus onset. This therefore provides new empirical evidence regarding the time course and interactive nature of visual letter perception processes.
