Repetition enhancement and perceptual processing of visual word form

Frontiers in Human Neuroscience

Karine eLebreton¹  Francis eEustache¹  Nicolas eVillain¹  Brigitte eLandeau¹  Gaël eChételat¹  Vicente eIbanez⁴  François eLazeyras⁵  Mohamed L. eSeghier⁷ 

[1] Centre Hospitalier Universitaire, U1077;Ecole Pratique des Hautes Etudes, UMR-S1077;INSERM, U1077;Psychiatric Neuroimaging Unit, Division of Neuropsychiatry, University Hospitals of Geneva;University Hospitals of Geneva;Université de Caen Basse-Normandie, UMR-S1077;Wellcome Trust Centre for Neuroimaging, Institute of Neurology, UCL;

关键词: fMRI;    priming;    repetition suppression;    Visual Processing;    repetition enhancement;    word priming;   

DOI  :  10.3389/fnhum.2012.00206

来源: DOAJ

【 摘 要 】

The current study investigated the cerebral basis of word perceptual repetition priming with fMRI during a letter detection task that manipulated the familiarity of perceptual word form and the number of repetitions. Some neuroimaging studies have reported increases, instead of decreases, in brain activations (called repetition enhancement) associated with repetition priming of unfamiliar stimuli which have been interpreted as the creation of new perceptual representations for unfamiliar items. According to this interpretation, several repetitions of unfamiliar items would then be necessary for the repetition priming to occur, a hypothesis not explicitly tested in prior studies. In the present study, using a letter detection task on briefly flashed words, we explored the effect of familiarity on brain response for word visual perceptual priming using both words with usual (i.e. familiar) and unusual (i.e. unfamiliar) font, presented up to four times for stimuli with unusual font. This allows potential changes in the brain responses for unfamiliar items to be assessed over several repetitions, i.e. repetition enhancement to suppression. Our results reveal significant increases of activity in the bilateral occipital areas related to repetition of words in both familiar and unfamiliar conditions. Our findings support the sharpening hypothesis, showing a lack of cerebral economy with repetition when the task requires the processing of all word features, whatever the familiarity of the material, and emphasize the influence of the nature of stimuli processing on its neuronal manifestation.

【 授权许可】

Unknown