Length effect during word and pseudo-word reading. an event-related fMRI study

This event-related fMRI study has assessed the cerebral activations obtained during the reading of words and of pseudo-words of varying length (one, two and three syllables). Eight right-handed volunteers were examined. A pseudo-randomized fMRI paradigm with six types of stimuli was applied and the SPM'99 software was used for data processing. The number of cerebral regions involved in reading increased with the stimulus length, both for words and for pseudo-words. This concerned not only regions related to sensory-motor aspects of reading but also regions related to more "central" language processes. Independently of the length, the reading of words and of pseudo-words activated the same regions, an observation consistent with the connectionist models for reading. Considering the length of the stimuli, we obtained significant differences, in terms of cerebral regions, only between polysyllabic words and pseudo-words, not between monosyllabic words and pseudo-words. These results are in line with the connectionist view of reading, especially with the multi-trace connectionist model of Ans et al (3).